12.1.1 Since the last TOPC meeting (1996), considerable progress has been achieved. Some of the achievements were discussed at the meeting, and most confirmed the importance of the ground-laying activities in previous years. Based on the discussion, revised 5-year goals and a new work plan was prepared. For clarity, ease of communication and effective collaboration with other groups, the role of TOPC in each activity and the lead TOPC member were also identified for each task. The complete plan for the next year is provided in Annex 8.
12.2.1 The primary activities of GEWEX (the Global Energy and Water Cycle Experiment) are global data set development, process studies, and model development support. Of particular relevance to TOPC is GEWEX’s support of ISLSCP (International Satellite Land Surface Climatology Project), a project that focuses on large-scale field experiments and the development of global data sets associated with land surface processes. ISLSCP has already generated a widely-used collection of CD ROMs (the “Initiative 1 dataset”) containing a wide assortment of earth-system fields covering 2 years at consistent spatial (1o) and temporal resolution (some are included in Annex II.). The ISLSCP Initiative 2 dataset, which covers 10 years at higher (0.5o) spatial resolution, is currently under construction.
12.2.2 Dialogue between TOPC and GEWEX/ISLSCP is appropriate given their common interests. One contribution of GEWEX/ISLSCP to the G3OS goals is through the support of large-scale field experiments. These experiments lead to improved algorithms for interpreting ongoing satellite measurements, and they provide the potential sites for continuing surface measurements (e.g., via flux towers).
12.2.3 It was agreed that GEWEX activities are important in view of the TOPC terms of reference. In addition to maintaining scientific contacts through cross-membership in both groups, a possibility of a joint meeting with ISLSCP should be considered. Furthermore, the transformation of research sites into long-term observation stations should be examined with GEWEX.
Recommendation 27: TOPC should work with GEWEX to assist in the transition of research sites into long-term observing stations where feasible and appropriate.
12.3.1 Dr. Ken’ichi Kuma presented information on the Global Soil Wetness Project (GSWP). The project is part of the ISLSCP/GEWEX/WCRP program. It is a pilot study of the feasibility of producing a global data set of soil wetness and related surface flux estimates using meteorological observations and analyses to drive global circulation models. The GSWP uses as basic input the ISLSCP Initiative 1 land-surface climatology data set. Soil moisture conditions as well as other products such as run-off, net evaporation, and snow water equivalent are being obtained by integration of land surface parameterizations with hourly atmospheric forcing. Eight centres are producing pilot data sets for 1987-1988, which are collected jointly and intercompared at the Inter-Comparison Centre, operated by the Japan Meteorological Agency and the Centre for Climate System Research of the University of Tokyo. The products are validated with the soil moisture data from in situ and satellite. Global runoff data provides the key assessment for the large scale hydrological cycle of GSWP. GSWP found that the temporal variation of the soil moisture agrees well among models and observation, although some biases are present.
12.3.2 The second phase of GSWP, GSWPII, is proposed to consist of 4 parts:
Model intercomparison experiments as is in phase I.
Rescue of the data sets related to GSWP.
Four dimensional data assimilation (FDDA) for the land surface processes using both in situ and satellite data.
Predictability studies with GCMs based upon global land surface data sets produced in this project.
12.3.3 ISLSCP Initiative 2 data will be used as an input to the land surface model. The period of the analysis will be from 1986 to 1995 with the horizontal resolution of 0.5ox0.5o. In addition to the model intercomparison, it is proposed to rescue observation data for soil moisture, runoff, soil temperature, fluxes, etc. which can be used for the validation of the GSWP II. It is also feasible to extend the GSWP II project to create the global dataset for CO2 flux over the land in a similar way as for moisture. FLUXNET observation can be used to validate water, heat, and CO2 fluxes, subject to overcoming the scale gap between the model and FLUXNET measurements.
12.3.4 FDDA and GCM predictability studies are required for the global land surface monitoring and for successful short-term climate prediction based upon the model. In order to meet operational requirements, observation data affecting the predictability must be exchanged on near-real time basis, 0-12 hours after the observation. With this requirement, NWP model will be able to assimilate the observations, which is important not only for operational weather forecast but also for climate applications.
12.3.5 The exchange of data in real time for NWP models is important in the climate application for several reasons. First, good climate models are often based upon NWP models. This is particularly true for land surface description, since the characteristic time scale of the land surface starts from diurnal variation. The development of land surface models for the NWP model is greatly facilitated by the real time availability of the land surface observation. Secondly, most sophisticated methods of the data assimilation are usually developed at NWP centers. The availability of the data in real time, including satellite radiance data, will immeasurably ehnance the global monitoring for the land surface with FDDA. Thirdly, the re-analysis (based on NWP) yields powerful data sets for the various time scale of the climate changes.
12.3.6 The GSWP and other GEWEX projects are both producers and users of global terrestrial data sets. TOPC should maintain contact with these activities and use the results to refine G3OS terrestrial observation requirements.
12.4.1 The coordination and cooperation with various IGBP projects is important to the TOPC mission. These project provide the scientific understanding that is required to design optimum long-term observation programs, and also produce some valuable global data sets for the terrestrial environment. On the other hand, the global observing systems work towards long-term observations of critical climate-related processes and to produce data sets needed for scientific as well as policy and other purposes. The global observing systems also have an important role in pursuing continuity of observations for sites/transects initiated by various IGBP projects. At the present time, this mutually advantageous dependence is not reflected in the sponsorship of TOPC. This is unlike e.g. the Ocean Observation Panel for Climate (OOPC) which is co-sponsored by the World Climate Research Programme (WCRP).
Recommendation 28: It is recommended that GCOS and GTOS approach IGBP to become a formal cosponsor of TOPC.
12.5.1 Dr. Kirk Dawson noted that he had observed significant progress in the development of the Terrestrial Observing Panel for Climate since the inception of work on GCOS some five or so years ago. This had to be a result of the commitment of the participants at this and earlier meetings. At the same time he suggested that the participants should not loose sight of the needs of the individual sponsors and governments around the world for information not only on the impact of climate change on the terrestrial ecosystem but also on the "rate" at which those changes might be occurring and also on any changes in the nature of "extreme events". He acknowledged that a basic observing system was needed in order to address the main question of whether or not there was an impact and that there was clearly a need to "walk before running". However, the need to answer questions such as rate of change imposed additional and important constraints on the observing system that needed to be addressed at an early stage. Specifically, he noted that it imposed a very strong need for a long term commitment to the operation of the observing system over periods of decades not just years and that this had a significant impact on the financial commitment of participating agencies such as the space agencies. One of the key measures of our success he noted would be the ability of future generations of scientists to provide informed answers to such questions. He also observed that there was considerable speculation at this time on changes of extreme events within the basic climate system, such as severe weather events, that was leading policy makers to ask whether or not there were associated changes occurring within the ecosystem. An early ability of the global observing systems to address aspects of this question was vital if the program was to be relevant to today’s issues. For example were there changes in the frequency of fires in specific regions of the world?
12.5.2 Dr. Dawson also encouraged TOPC to continue its current thrust towards the identification of pilot projects that could assist in the implementation phase. He strongly urged that such pilot projects involve specific clients at the early stages to ensure that the outputs of those pilot projects were indeed relevant to the user community. The involvement of clients in pilot projects could also lead to the identification of funding opportunities beyond the traditional sources of research and observing systems funding within governments. Specifically, the identification of developing country clients willing to participate in development projects revealed potential candidates for support from a variety of sources.
12.5.3 The above issue was briefly discussed. It was agreed that the rates of change are a very important consideration, and that with the initial planning completed by the TOPC, attention needs to be given to this question.
Recommendation 29: TOPC should examine the requirements and issues regarding the detection of rates of change in terrestrial ecosystems and should make appropriate recommendations to GCOS and GTOS.
12.6.1 It was agreed that while the TOPC work has provided a sound basis for terrestrial climate-related observations, there is a need to increase the awareness of the scientific community and other groups regarding the importance of making long-term terrestrial observations, the conceptual approaches developed so far, and the progress in initial implementation. Several specific opportunities were identified, including:
Presentations at the General assembly of the International Union of Geodesy and Geophysics (IUGG) in Birmingham, UK (19-30 July, 1999). The relevant events include the general plenary sessions, Symposium 2 (Interactions between the Cryosphere, Climate and Greenhouse Gases), and WORKSHOP 1 (Global Data Bases).
An article for the EOS Newsletter (American Geophysical Union) or other scientific journals.
A poster (posters) which could be used in sessions at various meetings.
Recommendation 30: TOPC should actively communicate with the scientific community and the public regarding the issues in its area of responsibility and results of the work to date, using the above and other opportunities.
