GCIP has evolved from its beginning as largely an international project to a largely national project with participation from many different agencies in the USA. This evolution has fostered the development of cooperative and collaborative activities in many different areas.

8.1 Collaboration with Other GEWEX Projects

The GCIP research program has connectivity to GEWEX as a whole and to its components through a commonality of scientific objectives. For example the Project for the Intercomparison of Land-Surface Parameterizartion Schemes (PILPS) is partially supported by the GCIP program. The mesoscale convective cloud modeling tasks are coordinated with the theoretical and observational tasks of the GEWEX Cloud Systems Study, and surface flux studies and modeling of the atmospheric planetary boundary-layer research will be carried out in close collaboration with ISLSCP.

During 1995, GCIP and other similar continental-scale projects were combined under a Hydrometeorology Panel within GEWEX. The principal research task for this panel is to assist GEWEX in demonstrating skill in predicting changes in water resources and soil moisture on time scales up to seasonal and annual as an integral part of the climate system. GCIP will benefit from this coordination of continental-scale experiments. The results of the Canadian Mackenzie GEWEX Study (MAGS) will contribute to an improved understanding of cold-region, high-latitude hydrological and meteorological processes, and the role they play in the global climate system. An essential goal of the GEWEX Asian Monsoon Experiment (GAME) is to understand the physical basis of the seasonal forecast of the Asian monsoon and to improve the modeling techniques related to predicting and assessing the regional hydrometeorological conditions under anthropogenic as well as natural climate changes. The key scientific issues in the Baltic Experiment (BALTEX) relate to coupling between the atmosphere and hydrological processes over relatively complicated terrain, sea, and ice.

Adequate description of hydrologic processes is required in global models of the ocean-atmosphere-land system to improve the prediction of weather and climate at all time scales. Research is required to make best use of the data available from GCIP and other GEWEX large-scale observational programs to guide the formulation and validation of such hydrologic submodels. Improving the description of hydrologic processes in global models is a priority issue for GCIP which will be best addressed in collaboration with PILPS, ISLSCP, and the GEWEX Hydrometeorology Panel.

8.2 Collaboration with the Atmospheric Radiation Measurement Program

Since 1993, GCIP has been coordinating many of its data collection activities with the Atmospheric Radiation Measurement (ARM) to achieve synergistic benefits from the outstanding observation facilities established by ARM at the southern great plains Clouds and Radiation Testbed (CART) in Oklahoma and Kansas. In this regard, the soil water and temperature system (SWATS) is a joint venture between the GCIP and ARM. The GCIP has provided the SWATS and data loggers, and ARM will install and operate the system.

Given the fact that the ARM program is investigating radiative transfer processes in the atmosphere as its highest priority at a site within the GCIP study area, GCIP will continue to collaborate with ARM via the existing GCIP-ARM working group. However, there is a need for GCIP to take a more active role in developing a new joint focus of interest between ARM and GCIP in the area of measuring and modeling the warm season convective production of clouds and precipitation. This is an emerging joint interest of high priority to both scientific programs that should be addressed as a collaborative initiative over the next few years.

8.3 Collaboration with NASA Initiatives in the Mississippi River Basin

Several aspects of the NASA program relate direct to priority science of GCIP. The upcoming field studies on soil moisture in the Little Washita catchment in 1997 relate directly to some of the science discussed in Section 6, and active collaboration should be sought between GCIP coupled modeling scientists and NASA observational scientists to secure maximum scientific benefit from that study. Equally, NASA and NOAA share an interest in providing improved management of water resources in the GCIP LSA-E, most probably through the Tennessee Valley Authority. Both agencies also share an important common interest in documenting, understanding and, to the extent possible, predicting seasonal-to-interannual variability in the southwest monsoon season, and evaluating the consequences of that variability on the vulnerable human management systems in that region.

8.4 Collaboration with PACS and GOALS

Prediction of weather and climate is made with models which include description of the entire global domain and which, in consequence of technical constraints, necessarily operate with a level of spatial and temporal precision that is inconsistent with the hydrological interpretation of their predictions over continents. Increased specificity in space and time is possible using regional models which operate over a more limited continental domain. In order to allow hydrological interpretation of weather predictions at seasonal-to-interannual time scales, research is required to foster and demonstrate effective coupling between regional models of atmospheric and hydrologic systems on the one hand and global models of atmospheric and oceanic systems on the other.

GCIP is working with the Pan-American Climate Studies (PACS) portion of the GOALS project to develop a plan for joint studies centered on the North American monsoon system. Such research will include interfacing regional coupled atmosphere- land system models with global coupled ocean-atmosphere models as an important scientific focus.

8.5 Collaboration with the US Weather Research Program

The US Weather Research Program (USWRP), which is jointly funded by NOAA and NSF, has as one of its major goals the development of techniques to improve quantitative precipitation forecasts over short time scales. As part of this process the USWRP has been holding small workshops on relevant issues including precipitation prediction. GCIP is exploring areas of common interest to the USWRP with a view to initiating some joint studies in precipitation estimation and prediction. The data collection for ESOP-95 was carried out as a joint undertaking with the USWRP WAVE project.