Summary of NASA EOS SAFARI 2000 Workshop

 

Summary of NASA EOS SAFARI 2000 Workshop

 

Bob Swap (Swapper@virginia.edu), Tim Suttles (tim.suttles@gsfc.nasa.gov), Michael King, Harold Annegarn, Bob Cook, Jim Drummond, Bill Emanuel, John Gille, Peter Hobbs, Chris Justice, Luanne Otter, Stuart Piketh, Steve Platnick, Jeff Privette, Lorraine Remer, Gary Shelton, and Hank Shugart

Overview

The Southern African Regional Science Initiative, SAFARI 2000, presents an opportunity to study global change issues on a regional scale in a comprehensive fashion. A level of excitement exists at the prospect of coordinating and leveraging off of existing inter-agency and international research activities in Southern Africa to successfully conduct SAFARI 2000. As part of the progression in the coordination and planning of this regional science initiative, North American and Southern African scientists came together to participate in the NASA EOS SAFARI 2000 workshop held during May 12-14, 1999 at the National Center for Atmospheric Research, in Boulder Colorado.

The Purpose of the Workshop was to review the SAFARI 2000 science plan; identify specific measurement needs and critical gaps in that plan; define and coordinate aircraft platforms and activities; plan and coordinate US contributions to the SAFARI 2000 Implementation Meeting in Gaborone, Botswana, during July 26-30, 1999. Participants in the workshop numbered approximately 60 and were affiliated with various universities and national government agencies.

The Boulder Workshop was conducted over 2 1/2 days. Day 1 was devoted to a review of the evolving plans for the science initiative, the status and progress of funded and planned investigations, and keynote presentation on each of the core elements of the Science Plan. These reviews and presentations set the stage for activities on Day 2, which included Discipline Breakout Groups to address the strategy for core element activities and potential gaps and Airborne/Surface Measurement Breakout Groups to address the measurement requirements and capabilities. On the final day of the workshop, Implementation Breakout Groups met to define approaches for coordinating and integrating activities of the science steering committee, the airborne operations teams, and the ground-based measurement teams. Reports were presented on the breakout group deliberations and other discussions were held on coordination between US and in-region research activities; identification of potential collaborative partnerships; data policy and principles; and Memorandum of Understanding, Letter Agreements, and International Protocol needs. The final session concluded with writing assignments to key participants with the objective of converting the workshop results into a U.S. Implementation Plan for SAFARI 2000.

The vision of SAFARI 2000 was presented with the breadth of that vision having followed, in part, from the remaining unanswered questions from SAFARI 92. Those questions focus on: total emissions and magnitude of different emission sources; varying emission estimates and the validation of these estimates; temporal, spatial, chemical and optical characteristics of the regional atmosphere as related to these emissions; and impacts of these emissions on biogeochemistry, radiative forcing, air quality and rain production. The concept of a SAFARI 2000 Core Experiment to address many of these unanswered questions was presented (Figure 1). The Core Experiment aims to study aerosol and trace gas emissions, their transports and transformations, their deposition and their impacts in Southern African as determined by ground-based, and in-situ and remotely sensed airborne measurement campaigns. The SAFARI 2000 Core Experiment is comprised of the following core elements: Terrestrial Ecology; Land Cover and Land Use Change; Aerosols; Trace Gases; Clouds and Radiation; and Modeling. Research and EOS validation activities associated with each of the core elements were discussed by the discipline specific breakout groups.

There was some concern in the breakout groups, given the workshop attendees present at Boulder, about being able to address some of the objectives of the Science Plan to a sufficient level. The breakout groups identified the need to involve a broader community of scientists to discuss ways to achieve some of the objectives of the Science Plan. In particular, the groups identified the need to strengthen the modeling activities (e.g. interdisciplinary modeling, integrated modeling, transport modeling, and ecological modeling). Such issues should be addressed at the upcoming workshop in Gaborone.

A proposed Management Structure for US participation was presented and couched within the existing SAFARI 2000 management structure. This will be developed for review at the Gaborone workshop. Guidelines for participation in SAFARI 2000 were also presented. The need for interactions and negotiations between US and regional scientists to be facilitated by the regional and US SAFARI 2000 secretariats was also stressed. Adherence to established international protocols regarding Memorandums of Understanding, overflight permissions and mutually agreeable shipping procedures were also discussed. The US international agreements are to be worked by the NASA Office of External Relations and facilitated by the regional SAFARI 2000 secretariat.

Discipline Breakout Groups

Three discipline breakout groups, Land-Modeling And Data, Aerosol – Clouds and Radiation, and Trace Gases, were given the charge to evaluate the core experiment concept and to identify research areas deemed important and not yet sufficiently addressed by SAFARI 2000. These breakout groups discussed existing data sets, funded projects and proposed projects related to SAFARI 2000. The workshop participants generally reached consensus regarding the broad science goals, the core elements and associated activities, and the idea of a core experiment associated with SAFARI 2000, but it was concluded that questions remain concerning informational and personnel gaps in the initiative. The workshop participants stressed the importance for getting cooperation between measurements and modeling groups. While many of the research activities were viewed as relatively straightforward in terms of the development of a research strategy, others that were perceived as having high science benefit required more discussion and input from researchers with a different complement of expertise than was present at the workshop.

There was general consensus on several cross cutting needs:

  1. need for an interdisciplinary modeling component examining interactions over several time and space scales;

  2. need for modest resources to support the integrating modeling activities associated with SAFARI 2000; and

  3. need to further strengthen research components that link surface emission processes of aerosols and trace gases to the atmospheric chemistry and transport of free troposphere via the planetary boundary layer.

Specific activities requiring additional attention and strengthening include:

  1. flux tower measurements of trace gases (CO2, O3 and reactive nitrogen species) and aerosols at both the Mongu and Skukuza micrometeorological tower sites;

  2. deposition studies, especially those studies focusing on the dry deposition of aerosols; and

  3. atmospheric profiling of the boundary layer and troposphere via balloon studies, acoustic sounders and additional rawinsondes.

A number of proposals are currently under development to address some of these needs. The most likely funding sources appear to be the NASA Research and Analysis Program and the National Science Foundation. The South African Weather Bureau agreed to construct a proposal to submit to national, regional and international funding agencies for the procurement of additional rawinsondes to augment daily ascents performed routinely by regional meteorological services.

The Land/Modeling Breakout Group stressed the need for in-region field observations during the initial phase of the growing season. Flux tower and aerosol and trace gas deposition data, especially for carbon, nitrogen and sulfur for incorporation into site specific and regional models was stressed as a programmatic need. Involvement of the vegetation canopy lidar instrument team in SAFARI 2000 was highly desirable for the determination of canopy structure and fuel load. The need for climate data records, AVHRR archived data and hydrological data in terms of soil moisture and rainfall was also articulated. The involvement of the Tropical Rainfall Measurement Mission (TRMM) and their data products in SAFARI 2000 was seen as highly desirable. The possibility of using the gauged Vaal River catchment and the South African Weather Bureau’s (SAWB) overlapping radar network to validate the TRMM products for the southern African sub-continent was identified has a possible project that could produce a significant test of our understanding of the hydrological cycle. There is a possible modeling comparison exercise that would make use of a benchmark data set collected along the Kalahari Transect that could provide an important regional-scale test of the current site of dynamic global vegetation models. A clearly defined source of funding to support the necessary integrative and interdisciplinary modeling exercises required by SAFARI 2000 is needed. Data issues focused on the use of the Oak Ridge National Laboratory Distributed Active Archive Center (ORNL DAAC) on the US side and a regional mirror data site, most likely to be located in Botswana to handle and disperse the data collected in SAFARI 2000. It is planned that the establishment of a mirror data center with meta-data links established by regional participants will be clarified at the Gaborone meeting.

The Aerosol-Cloud and Radiation Breakout Group discussed objectives centered around the physical and chemical characterization of aerosols and their radiative effects, linking aerosol characteristics to fire sources, and cloud-aerosol interaction in maritime clouds. The implementation strategy required to address those objectives was viewed as straightforward. In terms of objectives focusing on the evolution of physical, chemical and optical properties of aerosols, biogenic aerosol, and cloud-aerosol interaction in continental clouds, the implementation strategy is not yet clear, but discussion has commenced. Similarly linking aerosol and cloud studies to ecological modeling, requires further attention. This group also requested additional ancillary data in the form of rawinsondes and dropsondes as well as access to data sets from the NASA Data Assimilation Office (DAO) and the SAWB. Input from transport models is also required for mission planning and post –intensive data analyses. A suggestion was made that those researchers who have the expertise to tie aerosol transports and deposition to ecological modeling provide the leadership necessary to address this goal of SAFARI 2000.

The Trace Gases Breakout Group was able to make significant advancement in meeting the charges given to them during the workshop. Through their extensive discussions and deliberations, they were able to produce a number of recommendations to the SAFARI 2000 steering committee. Chief among them were the following:

  1. strong need for compilation and maximum utilization of existing databases that include a variety of forms of printed material, CD publications and electronically stored data;

  2. the formation of a measurement-modeling liaison working group to aid in the designing of in-situ flight plans and sampling strategies;

  3. need to measure dew composition and precipitation concentration to address issue of dry and wet aerosol sinks;

  4. the study of frequency and intensity of lightning as a measurement of opportunity to aid in determining the production of NOx;

  5. need for inter-comparison of airborne and spaceborne systems;

  6. enhancement of existing meteorological infrastructure within the region – augmentation of upper air sondes and trajectory analysis support.

  7. the need to better constrain estimates of the contributions of biogenic emissions to the budgets of aerosol and trace gases in the region.

Additional Points included the need to understand biogenic hydrocarbon production, especially during the critical time of vegetation leaf out. The Trace Gases working group also identified a number of questions and implementation strategies to address those questions in their group report.

The discipline groups, especially the Land-Modeling and Data group, expressed the need for involvement of regional scientists and their scientific input especially in the areas of identification of surface sites and processes of scientific interest to the SAFARI 2000 effort. There was also a feeling that those investigators new to the region should familiarize themselves with the science and data products of existing research efforts. Along these lines, it was suggested that those researchers in need of such information should contact the SAFARI 2000 webpage (http://safari.gecp.virginia.edu) and /or the regional coordination secretariat. The general feeling during the Boulder workshop was that the Gaborone meeting is an important vehicle to further interactions, discussions and negotiations involved with SAFARI 2000 collaborative research activities, especially in the area of strengthening the land components with the objective of being able to collaborate with local experts and further develop logistical arrangements.

Aircraft Breakout Groups

SAFARI 2000 intends to use the atmospheric gyre as a physically integrating mechanism. This is beneficial in that southern African climatologies exist that allow for the establishment of a relationship between information in the long-term satellite record and the local observation sites. Airborne measurements are essential to achieve the goals of the experiment. Aircraft platform availability and participation were discussed in detail. The platforms committed to involvement in SAFARI 2000 include the NASA ER-2; the University of Washington Convair 580; and the South African Weather Bureau Aerocommander 690s. The opportunity to have the Proteus, a newly-developed, high-altitude, high-endurance remote sensing platform received much interest by the workshop participants. Its availability to SAFARI 2000 is subject to the Proteus team’s success in securing additional resources.

Consensus was achieved among key US and regional scientists to consolidate the scientific decision making processes related to airborne operations during August-September 2000 campaign at Pietersburg, RSA. Coordination, communications and planning associated with aircraft missions will be conducted through the SAFARI 2000 aircraft mission control center at Pietersburg. For aircraft planning at the control center, it is essential to have daily meteorological forecasting and access to Meteosat Satellite Imagery. To initially facilitate this project coordination and planning, the August – September 2000 flying campaign will begin with all of the aircraft involved with SAFARI 2000 based at Pietersburg for at least one week.

The In-Situ Aircraft Group focused on design of the SAFARI 2000 dry season airborne campaigns. The experiments requiring in situ observations include:

Terra Underflights – radiometric calibration and data product validation for aerosol retrievals, smoke/cloud masking, and fire detection and characterization;

Namibian stratus studies – cloud retrievals and indirect effects;

Biomass burning studies – “box studies”, fire emission factors, chemical, physical and optical evolution of emissions downwind of fires;

Industrial source studies– flights of opportunity looking at possible direct and indirect forcing effects.

The types of proposed flight tracks to meet the above needs are as follows:

  1. Cross-section wall flight sampling of the gyre with multiple aircraft

  2. Probe investigation flights of the gyre, both Lagrangian and Eulerian, by single aircraft

  3. Biomass burning flights – fire detection and smoke/emission sampling flights

  4. Coordinated flights involving remote sensing observations platforms (satellite, ER-2, Proteus) and in-situ observational platforms (Convair 580, Aerocommander 690A’s)

  5. Marine Stratus

  6. Overwater flights

The various logistical needs for these different flight missions were discussed. There was general agreement concerning the utility of convening an airborne planning simulation exercise to be held in the region early next year in preparation of the August-September, 2000 intensive flying campaign.

Recommendations

Summary Recommendations were arrived at from the various discussions during the meeting:

  1. Need for the additional involvement and funding of interdisciplinary, integrative modeling activities linking land and atmosphere

  2. Need to strengthen links between ground observations and airborne observations

  • Augmentation of regional rawinsonde network to profile the free troposphere

  • Acoustic sounder and pilot balloon studies to describe the planetary boundary layer

  • Instrumentation of existing towers for flux studies of heat, moisture, momentum and aerosols/trace gases to describe interactions between vegetation and boundary layer

  • Aerosol and trace gas deposition studies to detail atmospheric contribution to vegetated systems

  1. Involvement of a TRMM validation activity within SAFARI 2000 was deemed highly desirable

  2. Coordination of all US-sponsored activities in SAFARI 2000 through the regional secretariat office and compliance with protocols and international agreements for in-country research

  3. Need for funding to support regional scientists, outside of South Africa to participate in SAFARI 2000

click to enlarge (12 KB)

Fig.1. Schematic of SAFARI 2000 Core Experiment


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