The three most important orographic influences on weather and climate are: mountain induced winds and gravity waves, orographic precipitation and thermal circulations. For these three phenomena, some of the basic physical elements are understood but there remain serious difficulties in connecting formal theory with the real world. In all three subjects, the problem is the same. The theories have not advanced enough to connect with results from full numerical modeling and observation. Without this connection, scientific progress has slowed. In recent months, new analytical approaches in all three areas have been developed by the Principal Investigator; promising to provide a more solid theoretical foundation for mesoscale mountain meteorology. The extension and testing of these theoretical approaches against field data and numerical models is a goal of this current project. The Principal Investigator will attack three topics:
* Mountain waves and Boundary Layers (BL): A new theoretical approach to the interactions of BLs and mountain waves will be investigated. The goal is to understand how BLs control the generation of waves, wave drag and wave momentum flux, orographic precipitation, and surface winds fields in complex terrain. * Orographic precipitation: Using a combination of satellite data, isotope data and special data from field projects, a new theory of orographic precipitation will tested and, if necessary, extended. * Thermal circulations: A new theory of diurnal thermal circulations is being developed; including rotation and shear. This theory will be tested against conventional surface pressure data in sea breeze and mountain regions.
In the course of this research the Principal Investigator will contribute to the Terrain Induced Rotor Experiment.
Intellectual Merit: The approach differs from that of other groups by its emphasis on theoretical analysis and new observational techniques. When successful theories can be developed, the dissemination of new knowledge is accelerated. Applications of atmospheric dynamics to questions of regional climate will be emphasized.
Broader Impacts: By advancing knowledge of atmospheric physics, the research will contribute to numerical model development and testing for weather and climate forecasting. The work will also have an impact on broad areas of geoscience such as regional climate, paleo-climate, paleoaltimetry, glaciology, landscape evolution, middle atmosphere dynamics, tracer dispersal, and wind energy. Students will gain experience and motivation from participation in field, laboratory and data analysis activities.
