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					                  Nils Gunnar Kvamstø and Tore Furevik &LFHURQH 5/2000
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The new model was developed as part of a joint project between the Department of
Geophysics, University of Bergen and the Nansen Environmental and Remote Sensing Center
(NERSC). In RegClim, the model will be used to study the role of the North Atlantic, the
Nordic seas, and the Arctic Ocean in the development of regional climate. The results from
the preliminary tests are now being validated. The findings will be used to calibrate the model
before more advanced model experiments take place.


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To achieve a realistic long-term simulation of global climate variability or future climate
change, a realistic description of all of the components in the climate system is needed. In
coupled models, the various components are modeled separately, but at a specified time they
exchange data with each other in the same way the atmosphere and the ocean exchange
energy and water. Typically a general circulation model of the atmosphere will be coupled
with a comparable model of the oceans, which also includes a description of sea ice and its
concomitant processes. Both models must be three-dimensional, that is, they must calculate
the change over time of the physical variables such as temperature and wind/current both
horizontally and vertically. In some coupled models, sea ice is also treated as a separate
module. Land processes, such as vegetation and urbanization, must also be included.
Traditionally these processes have been integrated in the atmospheric component, but in more
recent and advanced models they have also been modeled as separate modules. In particular,
it appears that changes in vegetation can play a significant role in the climate system. For very



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                  Nils Gunnar Kvamstø and Tore Furevik &LFHURQH 5/2000
                     1HZ PRGHO SURYLGHV PRUH UHDOLVWLF FOLPDWH GDWD



long simulations, processes in terrestrial and marine biosystems—as well as changes in
continental glacial systems—are included.
        Coupled models are primarily used to increase our understanding of the natural
climate variations, i.e., variations with a typical time frame of a couple of years to ten or
maybe one hundred years. But these models are also useful for calculating future climate
scenarios, providing seasonal forecasts for up to two years in advance, and reconstructing the
climate of historical periods.


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From the time the first simple numerical weather forecasting models were tried out in the
1950s up to the models of today, there has been an enormous development in the complexity
of the models. The most important reason for this is the technological progress that has
resulted in a formidable increase in the available power and storage capacity of computers.
Moreover, large-scale measuring programs, both land-based and satellite-based, have been
established that provide researchers with data and knowledge to improve many of the
processes that are included in the models. It is primarily research and development on weather
forecasting models over the last 20–30 years that has made it possible to create realistic global
climate models.
         As is well known, the coupled simulations of scenarios of change in our climate have
provided the basis for the statements of Intergovernmental Panel on Climate Change (IPCC)
regarding future climate development. Behind every coupled simulation lies a comprehensive
test and validation study of the models. In an article in the international journal 6FLHQFH (16
June 2000), Harmut Grassl points out that the models should ideally be able to provide a
realistic picture of today’s climate and climate variability, simulate historical periods with a
unique climate, and indicate a transition between two different climate regimes. While many
models handle today’s climate rather well, there are greater problems with simulating
historical climates. One reason for this is that we possess much less information about the
state of the atmosphere and ocean in earlier times, thus making it very difficult—if not
impossible—to set up a model experiment with accurate initial conditions.


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Comprehensive evaluation programs, such as “The Coupled Model Intercomparison
Programme (CMIP)” (http://www-pcmdi.llnl.gov/cmip/cmiphome.html), have given the
IPCC a more solid foundation for evaluating the quality of the models. Given the CMIP
results, Grassl believes that the models should be ascribed more credibility now than before.
This is because the latest generation of coupled models have, among other things, a higher
resolution than before, and therefore provide a fairly realistic representation of the natural
variability in the climate system. One example is the El Ninõ phenomenon in the Pacific
Ocean, which even a few years ago was not satisfactorily modeled. But even with more
realistic models, Grassl does not believe that the uncertainty estimates for future climate
development will be significantly less in the coming IPCC report than in the previous.
Certainly the various models show similar results—for example, that the global climate is
becoming warmer, moister, and will have increased precipitation. But they differ considerably



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                   Nils Gunnar Kvamstø and Tore Furevik &LFHURQH 5/2000
                      1HZ PRGHO SURYLGHV PRUH UHDOLVWLF FOLPDWH GDWD



when it comes to the magnitude and distribution of the increase. Grassl maintains that the
uncertainty estimates cannot be further reduced before we know more about the feedback
effects of water vapor and clouds. Progress here requires new, more, and better observations
and more realistic parameterization of the hydrological cycle. These shortcomings aside, it is
equally clear that current models provide a realistic representation of the global climate and
that they are increasingly able to provide a foundation for (and input in to) decision making –
that is, they are used with increasing confidence by politicians in their efforts to design
climate policy measures.
          Higher resolution, that is, a shorter distance between grid points in the models, is one
of the main reasons that the models have become more realistic. Higher resolution provides
the opportunity to describe the climate in more detail. But even the highest resolution
currently used by the major climate centers to run coupled models with does not provide
enough detail to describe the climate in such a small area as Scandinavia and its surrounding
ocean areas. At the same time, the processes in these areas are crucial to the amount of water
that sinks down here and thus to the transport of heat to the Scandinavian regions. (See
Furevik and Grønås, &LFHURQH 4/99.) To describe details in the regional climate, downscaling
must increase the richness of detail from the global simulations. As mentioned in earlier
articles in &LFHURQH, such downscaling is achieved in RegClim’s global climate models either
dynamically (Haugen and Bjørge, 2/99) or statistically (Benestad 2/99). The first article
showed results from dynamic downscaling, where a regional atmospheric model with high
resolution used results from a global model (Max Planck in Hamburg) as input data for the
lateral boundaries, and for temperatures at the sea surface. This work has provided a much
more detailed description of the climate variables in the area covered by the model. A
disadvantage of this method is that there is only one-way communication between the models.
That is, information goes from the global model to the regional, but not vice versa. Thus the
high regional resolution will not be able to improve the global model.


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An alternative method to the dynamic downscaling is to use variable resolution in a global
climate model. In this way, a global model can be used while simultaneously selecting a focus
area with relatively high resolution. The surrounding areas will then have a gradually lower
resolution. At the Department of Geophysics, University of Bergen and at NERSC, we have
coupled a global atmospheric model and a global oceanic model which can both use a
variable horizontal resolution. One advantage with this kind of system is that there is a two-
way communication between the focus area and the rest of the global model domain. At the
same time, it is possible to study the effect that an interactive ocean with a detailed structure
has on the regional climate. Our model configuration is called the %HUJHQ &OLPDWH 0RGHO
(BCM). This model combines the atmospheric model ARPEGE/IFS, which has been
developed jointly by Meteo France and the European Centre for Medium Range Forecasts
(ECMWF), and the oceanic model MICOM, which was developed at Florida State University,
Miami. The oceanic model has been developed further and improved at NERSC, and a
module for sea ice is built into the model system. To couple the oceanic and sea-ice models,
we have used a coupling program called OASIS. OASIS was developed at CERFACS,
Toulouse and has been used in many other coupled models. The main functions of OASIS are


                                                3
                   Nils Gunnar Kvamstø and Tore Furevik &LFHURQH 5/2000
                      1HZ PRGHO SURYLGHV PRUH UHDOLVWLF FOLPDWH GDWD



to: 1) synchronize the simulation so that the fastest model component waits until the slower
component has reached the specified time interval when the models are to exchange data, 2)
read the fields for the variables that are to be exchanged between the models and
interpolate/adjust the fields of the recipient’s grid structure, and 3) handle any flux corrections
or apply known climatology to selected areas. Flux corrections are artificial calibrations made
to ensure that the simulated climate does not become unrealistic. The variables that are
exchanged in the BCM are described in Table 1.

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 Surface temperature        Ocean model             Atmospheric model        Exact
 Sea-ice cover              Ocean model             Atmospheric model        Exact
 Albedo (reflection)        Ocean model             Atmospheric model        Exact
 Solar radiation            Atmospheric model       Ocean model              Exact and weighted
 Other radiation            Atmospheric model       Ocean model              Exact and weighted
 Rain                       Atmospheric model       Ocean model              Exact
 Snow                       Atmospheric model       Ocean model              Exact
 Evaporation                Atmospheric model       Ocean model              Exact
 Run-off                    Atmospheric model       Ocean model              Exact
 Easterly wind stress       Atmospheric model       Ocean model              Gaussian
 Northerly wind stress      Atmospheric model       Ocean model              Gaussian
 Albedo                     Atmospheric model                                Used for weighting
 Surface temperature        Atmospheric model                                Used for weighting
 DQ/DT                      Atmospheric model                                Used for weighting




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To evaluate BCM, we made two test runs of today’s climate, one 20-year run and one 50-year
run. Here we tested the model set up with a relatively coarse and almost uniform resolution in
both components (5.6o in the atmosphere and 3o in the ocean). The initial values for the
atmosphere are based on current analyzed observations from ECMWF. The initial values for
the ocean model are based on a 50-year spin-up period with climatological forcing data from
the National Center for Environmental Prediction (NCEP). We are currently working on
validating the second run. Results from the first run are presented in a technical report from
RegClim (Furevik et al., RegClim General Technical Report No. 4/2000). Based on this run,
we will first show the simulated mean sea level pressure in the summer and winter, compared
with comparable fields from NCEP, i.e., analyses based on measured data (Figure 1). We see
that we recreate the large-scale global climate system with low pressure in the tropics, high


                                                4
                                                                                              Nils Gunnar Kvamstø and Tore Furevik &LFHURQH 5/2000
                                                                                                 1HZ PRGHO SURYLGHV PRUH UHDOLVWLF FOLPDWH GDWD



pressure in the sub-tropics (about 30o N and 30o S), and low pressure in the subpolar regions
(about 60o N and 60o S). But generally the low-pressure and high-pressure readings are too
weak. Thus we do not get a powerful enough wind system. One result of this is that the ocean
currents are too weak, resulting in too little heat transported to the north. Together this
provides a small drift in the climate away from a realistic climate, which is common in
climate models with poor resolution.

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                                                                                                                                                                                                                                                                                                                                                                                                                                                                              1017.5 2



                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    2.5
                                                                                                                                                                                           1020                                                                        02
                                                                                                                                                                                                                                                                                  7.5




                                                                                                                                                                                                                                                                                                                                       1002.51000 005                                                                 101          2.5




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    12
                                                                                                                                                                101 101
                                                                                                                                                                                                                                                                                         1015




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   10
                        .5                                                                                   1010                                                                                                      10 10                                                .5                                                                                                                                                 102
                                                                                                                                                                                                                                                                                      20




                   1012                                                                                                                                                             10                                                                                                                                           10         10071
                                                                                                                                                                                                                                                                                                                                                .5
                                                                                                                                                                                                                                                                                       .5




                                                                                                                                                                                                                         12 10                                               05




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  101

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                100
                  1015.5




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  10
                                                                                                                                                                                                                                                                              100




                                                                                                                                                                                                                                                                                                                                                                                                                                                103
                                                                                                   .5 5                   7.5                                                          22                                                                                                                                           12                                                     10
                  1017                                                                 1012                        101                                                                    .5                               .5                                           10




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     05
                                                                                                                                                                                                         20




  o                                                                                                                                                                                                                                              o                                                                                     .5
                                                                                                                                                                                                                                                                                                            0




                                                                                                       1                                                                                                                                                                                                                                                                                          17
40 N                                                                                                                                                                                                                       1015                40 N                                                                                                                                                                                                          10 .5




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      0
                                                                                                    10                                                                                                                                                                                                                            1015                                                                                                                                            10
                                                                                                                                                                                                                                                                                                           102

                                                                                                                                                                                                                                                                                                                 102




                                                                                                                                                                                                                                                                                                                               1017                                                                                                                         1027




                                                                                                                                                                                                                                                                                                                                                                                                                                                   0
                                                                                                                                                                                                     10




                                 0                                                                                                                                                                                                                                                                                                  .5                                                                .5                             10
                              102 .5
                                                               1015 2.5                                                                          10
                                                                                                                                                     20         1017.5                                                                                                                                                                                                                                                                  2                      25
                                                                                                                                                                                                                                                                                                                                                                                                                                                                     22
                                                                                                                                                                                                                                                                                                                                                                                                                                                                        .5          15
                                                                                                                                                                                                                                                                                                                                                                                                                                  1017.5 0
                                                                                                                                                                                                                                                                                                                  0




                             1017                                                                                                                               15   1010                                                                                                                                                                1020                                                                                                                     10
                                                                101                                     1010                                                 10                                                 1012.5                                             1015           1017.5
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 1015
                             1010                    1007.5                                                                    1007.5 1012.5                                                   1007.5                                                                1012.5                                                           1015
                                                                                                                                                                                                                                                                                                                                          1017.5                                                                        101
                                                                                         1005                                                                                                                                                                                                                                                                                                                               5
               1005                                             1002.5                                                                                                 05                                                                                                                                                                  1012.5                                                                              .5                                                    1010
     o
                                                                                                                                      10
                                                                                                                                         02                        10                                     1002.5                                       o
                                                                                                                                                                                                                                                                                                                                                                                         1010                             1012
 0                                                                                    10                                                    .5                                                                                                     0
                  100                                                                         00
                                                                                                                                                                                                                                                                                                                           101




                         0                                                                                                                                                                                                                                            10                                                                                           1015
                                                                          7.5




                                                                                                                                                                                                                                                                    10 .5
                                                                                                                                                                                                                                                                                                                                          1012.5
                                                                                                                                                                                                                                                                                                                                           1010




                                                                                                                                                                                                                                                                                                                                                                                                                       10       1007
                                                                                                                   10




                                                                                                                                                                                                                                                                             15
                                                                                                                                                                                                                                                                                                                                2.5




                                                                                                                                                                                                                                                                       2                                                                                                                                                  15          .5
                                                                                                                                                                                                                                                                                                                                                                                         1017.5
                                                                       99




                                                                                                                                                                                                                                                                   101    10                                                                                                                       .5
                                                                                                                    00




                                                                                                                                                                                           10
                                                                                                                                                       0




                                                                                                                                                                                                                                                                                                                                                                                              1012                                 1010
                                                                                                                                                                                                                                                                                                                                                                                                                                1012
                                                                                                                                                    100




                                                                                                                                                                                               00             997.5
                                                                                                                                                                                                                                                                                                                                                    10




                                                                                                                                                                                                                                                                                                                                                                                                                                     .5
  o                                                                                                                                                                                                                                              o                                 1020                                                                                                                     1017.5
                                                                                                                                                                                                                                                                                                                                                        15




40 S                                                       1000                                                                                                                                                                                40 S                            1017.5                                                                                                              1012.5        1015                        1012.5
                                                                                                                                        997.5                                                                                                                                        1015                    1010                                                                                                     1010
                             997.5
                                                                                                               992                                                                                         997.5                                                     1012.5
                                                                                                                                                                                                                                                                       1010                 07.5                                                                                          1002.5 1007.5
                                                                                                                                                                                                                                                                                                                                                                                                      1005                        1002.5 1007.505
                                  992.5                        995                                           990 .5
                                                                                                                                            995
                                                                                                                                                                                        992.5                  995
                                                                                                                                                                                                                                                                             0   1002.5 10 1005            997.51000                                                                                     995 992.5 997.5
                                                                                                                                                                                                                                                                                                                                                                                                                         1000                  10
                                990 987.5                                                                          987.
                                                                                                                 985 5
                                                                                                                                                                                      990 987.5                                                                     997.5100                    995
                                                                                                                                                                                                                                                                                                      992.5
                                                                                                                                                                                                                                                                                                                                                                                               990
                                                                                                                                                                                                                                                                                                                                                                                                 987.5                                   990      995
                                    985
                                     982.5                                                                                                                                                 985                                                                 992.5             990                                                                                                                        987.5
                                                                                                                       982.5




                                                                                                                                                                                                            98                                                                      987.5                                                                                                  990                                     990 99
                                                                                                                                                                                                                 2.5                                                                                                                                                                        997.5 992.5 995                         997.5 2.5
                                                                                                                                                                                                                                                                                                                                                                                          1002.5




                                                                                                                                                                                                                                                               987.5                                                                                                                               1000                    1002.5
                                                                                                                                                                                                                                                                          990
                                                                                                                                                                                                                                                                                                                                                                                                       5




  o                                                                                                                                                                                        985                                                     o                                        992.5




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         99
                                                                                                                                                                                                                                                                                                                                                                                                   100




80 S                                                                                                                                                                                                                                           80 S                                                                                                                                                               1005




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             5
                                                                                                                                                                                                                                                                                                                                                                                                                             1002.5
                                                                                                                           98




                                                 982.5                                                                                                                                          985                                                          995                      997.5       995
                                                                                                                               5




 180oW                                  120oW                             60oW                                             0o                               60oE                               120oE                              180oW            180 W   o                   o
                                                                                                                                                                                                                                                                                         120 W     o
                                                                                                                                                                                                                                                                                                                                60 W                                                 0   o                   o
                                                                                                                                                                                                                                                                                                                                                                                                                             60 E  o
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  120 E                            180oW




         The changes in sea temperatures are shown in Figure 2. We see that we do not get
any dramatic changes, but because of the insufficient wind velocities, the tropics are warmed
up. Too little heat is transported with the ocean currents to the north, and less heat is released
into the atmosphere.

)LJXUH  7KH PDQ VXUIDFH WHPSHUDWXUH LQ WKH RFHDQ PRGHO IRU WKH ILUVW \HDU RI
WKH FRXSOLQJ  DQG WKH ODVW \HDU 

 o                                                                                                       BCM run 4: Annual mean sea surface temperature in 1997                                                                                    o                                                                                                               BCM run 4: Annual mean sea surface temperature in 2016
90 N                                                                                                                                                                                                                                           90 N
  o                                                                                                                                                                                                                                              o
80 N                                                                                                                                                                                                                                           80 N
                                                                                                                                           4 2                 0                                                                                                                                                                                                                                  4             20                               0
                                                                                         0                                          6                                                                                                                          0         2                                                       0                                                                                                              4 2                                                     20
                         2 0                                                                                                                                                 4
                                                                                                                                                                             6             2                                    0                                                   86
                                                                                                                                          8




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        4




                                                                                                                                                                                                                                       4
                                                                                                                                                                                                                                                                                                                                               6




                     4
                                                                                                                                                                                                                                                                        10




                                                                                                                                                                                           8                                                                            12                                                        210               8                                                                 6 28
                                                                                                                                                                                                                                                                                                                                                                                                                      10 1
         6                                                                42                                                                    10                16
                                                                                                                                                                  18                                10                                                                                                                                                                                                                 1 4           18                                 6 108 1
                                                                                                                                                             242




                                                                                                                                                                  22                                                                                                     14                                                      124
                                                                                                                                                                                                                                                                                                                                   1                                                                                                                                       12
                                                                                                                                                                                                                                                                                                                                                                                                                                  16




                             8                                            8
                                                                                                                                                               0




                                                                                                                                                                                                                                                                                                                                                                                                                                  20 2                                            4 16
                                                                                                                                                             11




               10 12                                             6         10 14 12 18                                                                           26                                                                                                      16                                           4                        16           18                                                                                          24
 o                                                                                  16                                                                                                                         12 16                               o                              18                                                                                                                                                   6
40 N            14               16                                                                                                                                                                           14 20                            40 N                                                                                                         20                                                                                                                    20                   18
                                                                                                                                                                                                                                                                                                                                                                                                                                                            22
                                                                                                                                                          24




                                                                                                                                                                                                                                                                                                                 26




                                  18                                                                                                                                                                              18                                                               20                                     24              22
                                                      22




                                                                                                                                                                                                                                                                                                                                                                                                                                              28




                                                                                                                                                                                                                    22
                                                     20




                                                                                                                                                                                                              24
                                                                                                               20




                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        24




                                                                                                                                                                                                                 26                                                    22
                                                                                                   24




                                               24 6            28 28                                           22                                                                                                                                                                                                                                                                   26 0               24
                                                                                                                                                                                                                                                                                                                                                                                                                  2




                                                2                                                                                                                                                     28                                                                                                                                                                              3
                                                                                                                                                                                                                                                                                                                                                                                                             28 2




                                                                                                                                                                                                                                                                                                                                                                                                                                       28




                                                                                                             26                                     28                                                                                                       24                                                            28
             28                                                                                                                                                                                                                                                                                                                                                                                                                                                                   26
                                                                                                                                                                                                                                                                                                      28




                                                  26                                                            28                                                                                                                                     o
 0o                                                                                                                                                                                                                                                          26                                                                                                                                                                                         28
                                                                                                                                                                                                                                                                                                                          30




                                                                24                                                                                                                                                                                 0
                                                                                                                                                            28




                                                                                28                                                                                                                                                                                                                          28
                                                                                                                                                                                                                                                                                                                                                                                    28




                                                                                                              26           24
                                                                     20




                                                                                                                                                                                                                 28
                                                                            22




             28
                                                                                                                                         22




                                                                                                                                                                                                                                                                                                                                                                                                                                                                         30




              26                                                                                                                                            26                        24                                     26                                                                                                                                                                                                        26
                24                                                                                                                                                                                                                                                                                                                                          26                                                                                                             28                          26
                                                                                                                                         18




                                 22                                                                                                                                                             22                                                                                           26                                          2
                                                                                                                               20
                                                                            181




          20                                                                                                                                                            20                                                      20                               24                                                                   22 4                                                                                     24                                                              2422
                                                                                                                                                                                                                  18




            18                                                                                                                                                                                                                                   o             22
40oS
                                                                                6




           16                                                                14                                                                        18
                                                                                                                                                        16
                                                                                                                                                        14                                                                   16                40 S                                                                                     20                                                                                    22
          14                                                                 12                                                                          12
                                                                                                                                                          10                                                                  14                              20
                                                                                                                                                                                                                                                              18                                                                       18                                                                                       20
                                                                                                                                                                                                                                                                                                                                                                                                                               18
         12                                                                  10                                                                            8
                                                                                                                                                           64                                                                  12                                                                                                      16                                                                                      16
          10                                                                   8                                                                                                                                                10                           16
                                                                                                                                                                                                                                                              14                                                                        14                                                                                      14
                                                                                                                                                                                                                                                                                                                                                                                                                                12
            8
           64                                                                  64
                                                                                 2
                                                                                                                                                             2                                                                  68                            12
                                                                                                                                                                                                                                                             10                                                                          12                                                                                    108
              2                                                              0                                                                           0                                                                       4                             8                                                                         10
                                                                                                                                                                                                                                                                                                                                          8                                                                                  46                                                                         8
         0                                                                                                                                                                                                                    0 2                            6                                                                                                                                                                                                                                     46
                                                                                                                                                                                                                                                                 4                                                                    46                               2                                                 0                          2                                                   2
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               0
                                                                                                                                                                                                                                                           0




80oS                                                                                                                                                                                                                                           80oS                                               2                                                0
                                                                                                                                                                                                                                                                                                                                                                                                                                        0
90oS                                                                                                                                                                                                                                           90oS o
         o                                       o                              o                                               o                                  o                                  o                                    o     180 W                                      120oW                                   60oW                                             0o                                       60 E     o
                                                                                                                                                                                                                                                                                                                                                                                                                                                                  120oE                                180oW




                                                                                                                                                                                                                                               5
                  Nils Gunnar Kvamstø and Tore Furevik &LFHURQH 5/2000
                     1HZ PRGHO SURYLGHV PRUH UHDOLVWLF FOLPDWH GDWD



         The two test runs show that the model concept works and that the model modules
appear to communicate as expected. The runs show that it is important to properly close the
hydrological cycle (water budget) since rapid “loss” of fresh water will have a large impact on
the surface salinity of the ocean, which can have dramatic effects on freezing and submersion
of water masses. Because of different model grids in the atmosphere and the ocean, and thus
slightly different placement of the coasts in the two model components, we have had some
problems with eliciting an accurate description of the water budget.


3ODQQHG UXQV
The experiments have shown us that a 5.6o resolution in the atmosphere is not enough to
result in a sufficient low-pressure zone, and thus strong enough wind fields. As mentioned
above, the sea receives too little energy, slowing down the ocean currents. In the next runs we
will therefore double the resolution in the atmosphere as well as improve the oceanic
resolution. We can also mention that several simulations with a variable grid resolution are in
the planning stages. Simulations of this type have not been carried out before, and there is
thus a high degree of interest attached to the results from the simulations with variable grid
resolutions.




                                              6