Doc PR3/IOP CLIVAR SSG-14, 19-22 April 2006 1. Panel or Working Group: CLIVAR/GOOS Indian Ocean Panel The Panel was established in 2004 and has met on three occasions: February 2004 (Joint with AAMP) in Pune India, March 2005 in Hobart Australia and March 2006 in Honolulu USA. The primary goal was to prepare a regional implementation plan for sustained observations relevant to climate. The implementation plan is published now (WCRP Informal Report No. 5/2006 and GOOS Report no. 152) and can be downloaded from http://eprints.soton.ac.uk/19645/. The Panel’s success is reflected in increasing investment in the observing system from several countries. The Panel’s activities (e.g. meetings) are supported jointly by IOC-Perth Office and WCRP, a cost-sharing arrangement that is expected to continue. 2. 2.1 Contributions to CLIVAR’s 4 major themes: ENSO and other modes of tropical variability: The Panel has identified the interaction between ENSO and the Indian Ocean zonal dipole mode (IOD) as a key research issue. Plans and initial steps were taken to establish an observing system that will allow us to understand the role of Indian Ocean circulation and structure in the IOD-monsoon–ENSO interaction. Understanding upper ocean dynamics is a critical factor in identifying the instability of the IOD mode. We have started the implementation of a basin scale mooring array and a multi-platform observing system to provide data to support this research. JAMSTEC (Japan) will maintain three TRITON moorings and an ADCP near the equator at 90-95°E. NOAA (USA) will maintain ATLAS moorings at 1.5°N, 0°, and 1.5°S along 80.5°E and at 0°, 90°E and an ADCP near 0°, 80°E . DoD (India) will maintain three moorings on the equator at 77°, 83° and 93°E. The Panel reviewed the progress of the INSTANT experiment which aims at designing a monitoring array for mass, heat and salt transports in the Indonesian Throughflow. Data from the first 18 months have been collected and additional 18 months are expected after the final recovery in December 2006. The data will be used to determine cost-effective proxy methods for long term monitoring. The mapping accuracy for seasonal to interannual temperature and salinity fields using the fully implemented Argo profile data was demonstrated by observing system simulations. Advice on the regional implementation of Argo to observe seasonal to interannual variation was provided to the International Argo Science Team. The Panel critically reviewed the Indian Ocean XBT network and identified the lines that have highest priority for implementation. The network was enhanced to improve observation of oceanic structure related to Indonesian Throughflow and inflow to the western boundary cross equatorial currents. The Panel has reviewed recent progress and identified some of the important scientific advances including: o Results of the IOD-ENSO forecast experiments using GFDL coupled model and SINTEX-F model presented at IOP-3 by Gabriel Vecchi and Yukio Masumoto and a communication from Roxana Wajsowicz on the NASA/GMAO and NCEP/EMC coupled systems show that past o o o o IOD events in the models demonstrate a possible predictability with a lead time of about six months, although there is a significant influence of the predictability barrier during winter and spring seasons. There are three places in the Indian Ocean where the thermocline is shallow enough to allow for significant dynamical feedback to SST. They are the upwelling regions off Somalia and Sumatra/Java and the ridge in the thermocline near 5-10°S. These places are important because slowly evolving features like Rossby and Kelvin waves and major currents can alter SST and interact with the atmosphere. There are a number of studies now that point toward the important (and often subtle) impacts of Indian Ocean SST on climate on a global scale. Model results suggest that the development of ENSO is influenced by Indian Ocean SST. The idea is that Indian Ocean SST does not cause ENSO but influences how it evolves. Annamalai showed that cool SST off Sumatra hastens and enhances the onset of El Nino. Tim Li (IPRC) and co-authors showed that warming in the western equatorial Indian Ocean hastens the end of El Nino and the transition to La Nina. The years of the 20th century when El Nino and positive IOD occurred together or separately (and when La Nina and negative IOD occurred together or separately) were identified using the Hadley SST data as an index of upwelling in the Pacific cold tongue and the Java/Sumatra zone (Meyers, 2006). One result shows that IOD acting alone has as large an impact on rainfall in southeastern Australia as ENSO alone or ENSO coupled to IOD. The southwest tropical Indian Ocean is emerging as an important region for climate variability with potential predictability because of the thermocline ridge in 10-15°S. Large ocean Rossby waves in response to ENSO and/or IOD propagate into the region and induce SST anomalies associated locally with precipitation and tropical cyclone activity (Xie et al. 2002). The transit time for these ocean waves across the basin is about one year, a delay that gives rise to enhanced predictability in the region (Luo et al. 2005). Annamalai (2006) has identified the response in the atmosphere and how it interacts with Pacific SST patterns to affect climate as far away as North America. 2.2 Monsoons: Recognizing that intraseasonal variations are the building blocks of monsoons, the Panel has identified understanding the heat budget of the upper ocean, particularly the mixed layer, at intraseasonal time scales as a critical area of research. How does the fast upper ocean heat budget depend on ocean dynamics, if at all? Continuous time series are required for this research and it is one of the key reasons for establishing a basin-scale mooring array with upper ocean temperature, salinity and current measurements. The meteorological measurements at the moorings will also be extremely valuable to data assimilation issues concerned with weather forecasting and reanalysis efforts. At present there are few such measurements in the Indian Ocean and this lack of information prevents accurate initial condition determination of weather forecasts and limits reanalysis efforts. The Panel coordinated the planning of two research vessel based process studies on ocean-atmosphere interaction in intraseasonal variability—MISMO in the eastern Indian Ocean and VASCO/CIRENE in the western Indian Ocean. The Panel has reviewed recent progress and identified important scientific advances including o The Indian Ocean ocean-atmosphere exhibits energetic intraseasonal SST variability. In particular, there is substantial sub-seasonal SST variability - O(1-2°C) - in the southwestern Indian Ocean thermocline ridge. Strong Ekman pumping raises the thermocline close to the surface (Harrison and Vecchi 2001, Duvel et al 2004, Duvel and Vialard 2006, Saji et al 2006) and affects SST. Vecchi argued that model experiments suggest 3-D oceanic processes and active oceanatmosphere coupling occur during the events. The response in the atmosphere may influence large-scale intraseasonal variability beyond the Indian Ocean. Decadal variability and the thermohaline circulation: 2.3 The Panel reviewed what is currently known about decadal and multidecadal variation of the Indian Ocean in the implementation-report. All of the available MBT, XBT and hydrographic temperature profiles for the Indian Ocean during the 20 th century were assembled and a new, high quality, flagged data set called the Indian Ocean Thermal Archive (IOTA) is available for research applications. A newly developed surface heat flux dataset by the Objective Analyzed airsea Fluxes (OAFlux) project is available. The product integrates satellite observations with surface moorings, ship reports, and atmospheric model reanalyzed surface meteorology. An urgent need for the future is to establish in situ flux reference sites to collect calibration data for satellite-estimates of the fluxes. A key research issue is the role of subduction and mode-water formation in meridional circulation variability, and the interaction of subduction and modewater formation with other modes of Indian Ocean variability. The integrated, multi-platform observing system will provide data to describe and understand the cross equatorial and shallow overturning cells, their associated subduction and upwelling regions and the role of these features in the monsoons. Ultimately we need to understand to what extent the monsoons are a coupled oceanatmosphere phenomenon and how the ocean plays a role in long term variation. The Panel has reviewed recent progress and identified important scientific advances including A preliminary analysis of the linear subsurface temperature trend in using IOTA in the tropics from 1960 to 2000 shows warming of the surface layer and cooling in the depth range of the thermocline, i.e. increased stratification. Analysis of the subtropical and sub-antarctic region shows a warming trend extending to considerable depth, >500m. A preliminary analysis of OA-flux and other products pre-dating the satellite period found that the amount of the net heat gain received by the tropical Indian Ocean has been reducing due to a large increase of oceanic latent heat loss. Surprisingly, surface heat fluxes alone cannot explain the warming trend observed in much of the tropical Indian Ocean surface layer. Anthropogenic climate change: Summary of contribution to annual workshop(s) 2.4 3. 4. 5. The IOP implementation plan was presented at the AAMP meeting held at the Irvine PanMonsoon workshop. Contributions to the additional theme of the ocean’s role in climate (where not covered under the 4 themes) See 2.1, 2.2, 2.3 Highlights of contributions to wider areas of climate science, including modelling, observational and synthesis studies: The Panel is very active in the Indian Ocean GOOS Regional Alliance (IOGOOS) To promote regional interest in development of the ocean-climate observing system. To develop links to interests in the impact of climate on coastal environments and ecosystems. To develop links to management of terrestrial climate impact on nations around the Indian Ocean. The Panel is building links to the Indian Ocean Tsunami Warning and Mitigation System (IOTWS) To identify and use potential synergies e.g. ship time. To promoting the concept of a multi-hazard warning system, including tsunami and other weather-related threats. To insure the IOTWS tide-gauges serve the dual purpose of short term and long term climate applications. New activities being planned: (see proposed new terms of reference) 6. 6.1 Modelling activities, including activities related to regional assessment of global model outputs: 6.2 6.3 6.4 Enhanced interaction with AAMP and VACS Continue observing system simulation experiments Synthesis activities: Contribution to the CLIVAR-GODAE global intercomparison Coordinated field programmes and other observational activities: Ongoing coordination and enhancement of the basin scale mooring array. MISMO and CIRENE process studies directed toward ocean atmosphere interaction at the intraseasonal time scale in late 2006/2007 Workshops etc: The Panel is helping to plan the Workshop on Sustained Indian Ocean Biogeochemical and Ecological Research (SIBER) to be held in October 2006. Links to applications: 6.5 The Panel will develop links with applications research at IRI to better understand how sustained ocean-observations contribute to managing and mitigating the societal impacts of climate. 6.6 7. 8. 9. 10. Cross Panel and Working Group Links: Coordination with AAMP and VACS Participation in OOPC Cross WCRP/COPES links Data management activities: Integration of data management activity at major facilities in India (INCOIS) and Hawaii (APDRC) to provide a comprehensive, single access-site for ocean-climate data. INCOIS Argo data Centre Joint PMEL/JAMSTEC near real time mooring data center Post-WOCE Upper Ocean Thermal Data Assembly Center for ongoing quality control of XBT data. Review of appropriateness of ToRs Other: The case for continuing the CLIVAR/GOOS Indian Ocean Panel as a body in CLIVAR like the other Basin-Panels is presented in an accompanying letter addressed to the Panel’s three sponsors, IOGOOS, CLIVAR and IOC-Perth Office. The proposed new terms of reference are: The need for high-quality ocean observations is shared by research (CLIVAR) and ocean applications and services (GOOS) and there is a shared conviction that, together, the ocean community should endeavour to establish the basis for a comprehensive ocean observation network and oversee the staged implementation of a sustainable ocean observing system for the Indian Ocean. It is therefore agreed that a Panel will be established and supported by CLIVAR and GOOS (through Indian Ocean GOOS and the Perth Office of the IOC) with the following Terms of Reference. 1. Provide scientific and technical oversight for implementation of a sustained ocean observing system for the Indian Ocean following the plans in WCRP Informal Report No. 5/2006 and GOOS Report no. 152, in particular with regard to: Promotion and implementation of the basin-scale mooring array, working in closer collaboration with GEOSS, JCOMM and other bodies. Testing, planning and coordination of an integrated, multi-platform approach to the observing system in collaboration with GODAE, GSOP and other bodies. Establishing links to coastal applications through the IOGOOS Regional Alliance. Encouraging new participants in the observing system by demonstrating usefulness of the implementation already accomplished. Identifying and utilizing synergies with the Indian Ocean Tsunami Warning and Mitigation System, in particular with regard to advocating a multi-hazard approach that integrates tsunami warning with other weather related threats. 2. Coordinate and plan research on the role of the Indian Ocean in the climate system in collaboration with other CLIVAR Panels and OOPC with a focus on describing, understanding, modeling and predicting intraseasonal, monsoonal, interannual and decadal oceanic processes and their relationship to climate impacts on all the surrounding continents. 3. Liaise with biogeochemical and ecological research programs and identify opportunities to understand the relationships between climate- and biogeochemical research. 4. In collaboration with IRI and local experts in each region of interest, identify the societal impacts of climate and oceanic variation that require Indian Ocean observations as a foundation for management and amelioration. 5. Rotate up to 30% of the Panel membership each year in order to acquire the skills needed to address the evolving development of the observing system. 6. Advise the CLIVAR SSG on Indian Ocean climate research and report to GOOS through the IOC Perth Office. 11. Issues for the SSG: We see a need to nominate a Panel Co-chair, and after deliberation propose Dr Yukio Masumoto of the University of Tokyo and the Frontier Research Center for Global Change (FRCGC). Dr Masumoto is an internationally recognized climate scientist and ocean-modeler. He will also represent a major Japanese process study of air sea interaction in monsoon intraseasonal variations of the eastern Indian Ocean (MISMO). He has been a Panel member since it was established. FRCGC is a major partner in establishing the basin-scale mooring array. The present Chair, Dr Gary Meyers, requests to step down in mid-2007. At that time a new Co-chair will be nominated to work with Dr Masumoto. Dr Meyers will remain engaged with the Panel as a past Chair. We also see a need to reconstitute the Panel with new expertise and broader representation of the international community. The following members have offered to rotate off the Panel at the end of 2006: Safri Burhanuddin, Peter Hacker, Robert Molcard, Satish Shetye, Bronte Tilbrook, and Peter Webster. We are grateful for the unique contributions these members have made to the Panel’s activities. It is likely that the Panel ―alumni‖ will also remain engaged with the Panel because some of their work is still in progress. The nominations for new members are: Dr VSN Murty: Deputy Director of the Indian National Institute of Oceanography and an expert in Indian Ocean oceanography. Dr Weidong Yu: Deputy Director for Marine Science and Numerical Modeling at the First Institute of Oceanography (China) and leader of the Chinese study of western Pacific/eastern Indian Ocean heat pool. Dr Tony Lee: an expert in Indian Ocean modeling, including advanced methods of ocean data assimilation and observing system simulations. Dr Gabe Vecchi: an expert in Indian Ocean modelling of intraseasonal variation, and application to observing system simulation. Dr Jerome Vialard: Leader of the French process study of air-sea interaction in monsoon intraseasonal variations of the western Indian Ocean. TBA: an Indonesian scientist TBA: a link to carbon and biogeochemistry observing systems Annex A Proforma for CLIVAR Panel and Working Group requests for SSG approval for meetings Requests should be made through D/ICPO (email@example.com), against the following headings: 1. Panel or Working Group: CLIVAR/GOOS Indian Ocean Panel 2. Title of meeting or workshop: Fourth meeting of the Panel 3. Proposed venue: Africa or western Indian Ocean 4. Proposed dates: Early April 2007 5. Proposed attendees, including likely number: panel members plus 3-5 invited experts. About 20 participants in total. 6. Rationale, motivation and justification, including: relevance to 4 CLIVAR themes and any cross-panel/working group links and interactions involved: Implementation of the Indian Ocean observing system is happening quite fast now. There are tactical issues such as coordinating the use of ships for maintenance and enhancement of the mooring array. There also are strategic issues such as an agreed plan on how to role out the array over the next five years. We make good progress on the observing system when we sit at the table face to face. If we let more than a year go by we loose momentum. Also, IOP is serving the needs of the Indian Ocean GOOS Regional Alliance. IOP plays a big role in the annual IOGOOS meeting. Our concerns in linking to IOGOOS are considerably broader than just climate research in that we are making links to coastal and societal issues. I see these issues gaining pace in coming years. Again letting more than a year go by will just slow the developments down. Invited experts at his meeting will be VACS members from Africa. 7. Specific objectives: a. Maintenance and enhancement of the basin scale mooring array. b. Review initial results of the MISMO and CIRENE process studies of MJO. c. Review research on the role of the Indian Ocean (including subtropical regions) in climate variation of tropical and southern Africa. 8. Anticipated outcomes: Meeting report 9. Format: Round table 10. Science Organising Committee (if relevant) 11. Local Organising Committee (if relevant) 12. Proposed funding sources and anticipated funding requested from WCRP: More than half the funding will be provided by IOC Perth Office, as in past meetings.