SPAWksp_Barth by xiuliliaofz

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									Deep Convective Clouds and Chemistry (DC3)
             Field Experiment

                  Principal Investigators:
           Mary Barth (NCAR), Bill Brune (PSU),
        Chris Cantrell(NCAR), Steve Rutledge (CSU)

Steering Committee:
       Ken Pickering     Jim Crawford        Laura Pan
       Andrew Heymsfield Don Lenschow        Owen Cooper
       Andy Weinheimer   Paul Krehbiel       Jeff Stith
       Alan Fried
                       DC3:
Characterize the effects of continental, midlatitude
      deep convection on the transport and
   transformation of ozone and its precursors

•   Processing in the convection,
•   Processing in the anvil
•   Processing in the convective outflow 12-48 hours
    later
•   Contrast different types of convection and different
    emission regions



          http://utls.tiimes.ucar.edu/Science/dc3.shmtl
       Ancillary Objectives of DC3

• Halogen Chemistry in the UTLS

• Determine mass fluxes of air and trace gases into
  and out of the storm,

• Cloud electrification and lightning discharge
  processes

• Effects of deep convection on UT water vapor

• Convective processing of aerosols and their impact
  on water and ice particles

       http://utls.tiimes.ucar.edu/Science/dc3.shmtl
A Storm Penetrating Aircraft (SPA) can help reach
               these objectives:


•   Processing of trace gases in the convection,
•   Processing in the anvil (mid to lower regions)


3. Cloud electrification and lightning discharge
   processes
4. Effects of deep convection on UT water vapor
5. Convective processing of aerosols and their impact
   on water and ice particles
Importance of Production of NOx by Lightning




                              Barth et al., 2006, submitted to JGR
Cross Section of CO




                  CO used as a
                  tracer of boundary
                  layer air




        ppbv




               Barth et al., 2006, submitted to JGR
Soluble Species and Their Fate in Deep
             Convection
                               Total CH2O mixing ratios
                               = gas + cloud water +
                               rain + ice + snow + hail




                       Barth et al., 2006, submitted to JGR
                                     CH2O (gas)
                                          CO      O3
Transects across
     Anvil

                                     H2O2 (gas)


                                           CO     O3




                                     HNO3 (gas)



Disagreement among
models, but no
observations available


Barth et al., 2007, in preparation
    Priority Instruments on a SPA to Understand
       Convective Processing of Constituents

•   NO
    150 lbs., 10 pptv detection limit, and 0.5-sec time response
    (courtesy of Andy Weinheimer, NCAR)

•   CO


•   Soluble Species:
    Formaldehyde, Hydrogen Peroxide, Nitric Acid
Ozone in the UT/LS region is important for climate
change and for affecting the UV radiation reaching the
Earth’s surface.
Deep convection alters the composition of the UT/LS
region.
Important precursors of O3 are NOx, HOx, and the HOx
precursors.
      Previous Studies of Convection and
                  Chemistry

• Comprehensive cloud and
  lightning with a fair amount of
  chemistry information
   – STERAO, EULINOX, ELCHEM,
     TROCCINOX, SCOUT


• Comprehensive chemistry
  with little cloud and lightning
  information
   – INTEX, TRACE-P
                Goals of DC3
1. To quantify the impact of continental, midlatitude
    convective storm dynamics, multiphase chemistry,
    lightning, and physics on the transport of chemical
    constituents to the upper troposphere,
                      Goals of DC3
2. To determine the role of anvil dynamics, multiphase
    chemistry, microphysics, radiation, and electrification on
    the chemical composition of convective outflow,
                               Goals of DC3
3. To determine the effects of convectively-perturbed air masses on
    ozone and its related chemistry in the midlatitude upper troposphere
    and lower stratosphere 12-48 hours after the near convection region
    is sampled,

                                CO at z = 10.6 km
                                00 Z 15 June 1985


                                06 Z 15 June 1985
Modeling study showing
convectively-transported CO
advection downwind of active
convection. From Park et al.
(2004)
                                12 Z 15 June 1985
                      Goals of DC3
4. To contrast the influence of different surface emission
    rates on the composition of convective outflow.



  NOx emissions                    Isoprene emissions
                  Ancillary Goals of DC3
•   To determine partitioning of reactive halogen and reservoir species in
    the UTLS

•   To determine the mass fluxes of air and trace gases into and out of
    the storm, including entrainment (determine fraction of boundary layer
    air that reaches LS, UT; determine fraction entrained; determine what
    part of the boundary layer is ingested by the storm; determine quantity
    of stratospheric ozone entrained into anvil)

•   To improve our understanding of cloud electrification and lightning
    discharge processes

•   To investigate the role of deep convection in contributing to the UT
    water vapor and in the transport of water vapor into the lowermost
    stratosphere

•   To connect aerosol and cloud droplet and ice particle number
    concentrations with convection characteristics and trace gas convective
    processing
               Facilities:
• High altitude aircraft: HIAPER
• Low altitude aircraft: NASA DC-8 or C-130
• Ground based dual Doppler and
  polarimetric radars
• Lightning mapping arrays
• Others
  – Ground precipitation network
  – Discussion of other aircraft (A-10, DOE G-1)
                                            Annual Average Precipitation
          Setting:
• Summer 2009
  – 6 week period
  – start and stop times are still being
    determined

• Northeast Colorado and Central
  Oklahoma and Northern Alabama
  – Sufficient ground-based facilities
  – Likelihood of convection occurring in
    one of the three places is good
  – Contrast different environments (long
    -lived, shear storms vs airmass
    storms; high cloud bases vs low
    cloud bases; low chemical emissions
    vs higher emissions)
                                               JJA
                                            Lightning
                    Northeastern Colorado
•   Facilities:
     – CHILL and PAWNEE radars in place
     – Need portable LMA installed

•   Chemistry:
     – Agricultural emissions
     – Denver emissions likely to
       be sampled
•   Convection:
     – Variety of single, multi and
       super cell convection
     – Lightning peaks in July




                                      Figure from Brenda Dolan (CSU)
         Oklahoma                                    2-D



                                                     3-D



•   Facilities:
     – LMA in place
     – Have both Doppler and
       polarimetric radars


•   Chemistry:                         •   Convection:
     – Urban emissions from Oklahoma       – large storms dominate in May and
       City                                  June (tornado season)
     – Agricultural emissions nearby       – air mass storms dominate in July
     – Isoprene emissions in eastern         and August
       Oklahoma                            – Lightning peaks in late June
                 Northern Alabama

• Facilities:
   – LMA in place
   – Have radars, ozone lidar,
     ozonesondes
• Chemistry:
   – High biogenic emissions
• Convection:
   – Shear-induced convection
     in May; airmass
     thunderstorms during June,
     July, August
   – Peak lightning in July
                                  Radar ranges and
                                    LMA location
 Recommendations from Recent Workshop

• Prefer to sample isolated convection for
  analyzing convective processing of chemical
  species
• Base aircraft near Oklahoma City
  – Central location; can easily fly to NE CO or N.AL;
    longer endurance because of lower elevation (than
    JeffCo)
• Preliminary studies of forecasting convective
  plume downwind
• Need to address specific issues
                 Working Groups

1) Climatology (O. Cooper)
2) Forecasting Convection and Downwind Plumes
   (M. Weisman)
3) Airborne Platforms (A. Fried)
4) Ground-based Platforms (D. MacGorman, S. Rutledge)
5) Flight Plans to address Science Goals (D. McKenna)
6) Satellite Data Contribution (L. Pan)
7) Linking Models and Observations (K. Pickering)
8) Education and Outreach (D. Rogers, S. Rutledge)
                      Timeline

• Working Groups address specific issues (now –
  Sept)
• PIs and steering committee incorporate
  information into Science Plan and Experimental
  Design Overviews
  – Decisions on specific issues
• Draft of documents by Oct/Nov
• Submit proposal to NSF/OFAP by Jan 2007

								
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