GEWEX Contributions to Large-Scale Hydrometeorology

Abstract

This paper describes how the articles in this special issue support the Global Energy and Water Cycle Experiment (GEWEX) priorities with a specific focus on the advancement of hydrometeorological sciences. It explores how hydrometeorological research has been used to improve process understanding and forecast models, provide datasets for model validation, and support water resource applications. In particular, in this collection of papers, the water balance is considered at both global and watershed scales. In this process the limitations of reanalysis products and inputs to hydrologic models are identified. Some of these limitations arise from the lack of understanding of orographic processes and the best way to incorporate them into models. Several modeling studies reported in this special issue address different aspects of the role of topography in land?atmosphere interaction over mountain systems including the mountains in Asia and North America. Other land processes are considered as well including soil and vegetation processes. A limitation in these modeling studies arises from issues related to model initialization and validation data. One precipitation paper in this collection considers the information on extreme precipitation events that can be extracted from these data while another reports on a new algorithm for observing light rain and drizzle events. As phase II of GEWEX progresses, more emphasis will be placed on the use of GEWEX products to explore climate science questions related to the global energy and water cycle and its applications. Some areas of opportunity for future GEWEX activities include the development of high-resolution integrated products, flux estimates from satellites, and open processes (or test beds) for product improvement.