BACKGROUND

The GAPP program (GEWEX [Global Energy and Water Cycle Experiment] America Prediction Project) objectives are to make monthly to seasonal predictions of the hydrological cycle and to use these improved predictions for better water resources management. The first objective largely involves improving the land surface, hydrology, and boundary layer representations of models used for climate prediction through improved understanding of the hydrological processes, feedbacks between the land and atmosphere, model transferability, and development of a comprehensive modeling system. The second objective involves scaling the climate model output to make it useful for water resource managers, improved understanding of the links between hydrologic predictions and water resources management, including the use of demonstration projects, and better understanding of the effects of land surface changes on the regional hydrology. Two major new initiatives will be the effect of orography on the hydrological cycle of the Rocky Mountain region and the predictability of the North American Monsoon (NAMS) and its effects on summer precipitation over the USA. The other components all relate to improving the predictability of the hydrological cycle with special regards to the land surface and the role of predictions for water resources management.

To meet its objectives, GAPP will require data from observations, satellite remote sensing, models, and will also include reanalysis of certain data products (e.g. NEXRAD, GOES radiation). For the purpose of planning, GAPP data management activities will concentrate its initial efforts on the NAMS element and the continuation of the essential elements of its GCIP activities. The monsoonal circulation occurs when land/sea contrasts create temperature and pressure differentials, resulting in seasonal circulation and precipitation patterns. The summer monsoon is associated with changes in the Great Plains and Gulf of California Low Level Jets, and is highly regulated by land surface characteristics such as vegetation and soil moisture. The goal of the GAPP study is to better understand the hydrological cycle and spatial and temporal (seasonal-to-interannual) variability of the summer monsoon with respect to land surface characteristics to improve model predictions of the monsoon and its effects.

THE ROLE OF THE DATA MANAGEMENT COMMITTEE

There are a number of data-related activities that need to be defined and undertaken at the outset of GAPP. Consequently, there is urgency in implementing a data collection and management committee. This committee is expected to address the following activities:

• Coordinate with the GAPP scientific community to define the needs for GAPP data

• Design a distributed data management system to provide access to existing datasets

• Prepare a data management document describing the GAPP data strategy and implementation

• Review and recommend augmentation of existing GCIP datasets to include the continental-scale region required of GAPP

• Recommend assembly and oversee the production of new datasets as needed to achieve the GAPP objectives

• Collection of data to ensure a permanent archive upon completion of the program

• Coordinate and collaborate with other field projects/programs (i.e. CLIVAR/VAMOS and CLIVAR/PACS-GEWIX/GCIP North American warm season precipitation initiative through the North American Monsoon Experiment (NAME)) for data collection and exchange.

LOGISTICS

A key purpose of this committee will be to ensure that the data needs of the GAPP research community are met. The NOAA GAPP program will secretariate support. We anticipate that only a limited number of meetings will be required, perhaps annually, since email exchange and document distribution over the www can help facilitate more regular interaction. The data committee should also take advantage of other GAPP meetings. As the GAPP program gets underway, the data committee should play a role in the development of the GAPP implementation plan. Members will be appointed to the committee for three years subject to renewal.

MEMBERSHIP

Major agency involvement will probably include NASA for remote sensing expertise, NOAA and USGS for expertise in in-situ observational data (possibly through UCAR), and NSF for modeling expertise at its NCAR facility. The community will also have a representative from the science community. The following list contains initial members:

Steve Williams (UCAR): chair
Roy Jenne (NCAR)
Ray McCord (DOE/ARM)
Bill Kirby (USGS)
Pat Hrubiak (NASA/GSFC)
Tilden Meyers (NOAA/ARL)
Rick Lawford (OGP)
Benjamin Felzer (OGP)