Study of Monsoon Processes Using Sounding Data from North American Monsoon Experiment (NAME)

Colorado State University, Fort Collins CO

Investigators

Abstract

The North American Monsoon Experiment (NAME) is a multi faceted research effort that strives to improve predictability of warm season precipitation over North America. As part of NAME, this research is directed toward an improved understanding of key processes in the North American Monsoon System. Diagnostic studies will focus on information derived from the deployment of four National Center for Atmospheric Research (NCAR) Integrated Sounding Systems (ISSs). The ISSs will be deployed for a six-week period in July and August 2004 along both sides of the Gulf of California and will constitute a major portion of a sounding network centered around the mouth of the Gulf. Other sounding sites include the operational sounding network of Mexico, upgraded to two soundings per day; however, in a central sounding hexagon, there will be four sounding per day, increasing to six-to-eight per day during Intensive Observing Periods (IOPs). The sounding data will be used to address three primary scientific objectives of NAME: the structure, evolution, and initiation mechanisms for Gulf of California southerly wind surges; the sources of moisture for precipitation in the Southwest; and the diurnal cycle of convection in complex, coastal environments. Sounding data and analyses also will form a basis for testing and validating multiscale numerical modeling studies of the monsoon. Following the field phase of the experiment, the sounding data will be analyzed using line-integral and multi quadric interpolation procedures to address the scientific objectives. Both raw sounding data and gridded analyses will be made publicly available at the Colorado State University NAME Website. With regard to the broader impacts of the research, it will address key issues pertaining to the North American Monsoon System, and is ultimately directed at improving the prediction of precipitation over North America. Current models do not handle moisture surges or the diurnal cycle of precipitation well. In fact, the problem of the diurnal cycle of precipitation is global in nature, so improved understanding of the diurnal cycle from NAME will have far-reaching implications. The ISS deployment will involve participation of graduate students from Colorado State University, as well as graduate students from Mexico, in the launching of rawinsondes. This activity will promote their understanding of the basic elements of the monsoon system and enhance their opportunities for conducting relevant research on the monsoon system.