Increasing computational power has greatly improved our understanding of atmospheric phenomena and our ability to predict weather. However, every question answered only drives us to ask more difficult questions, pushing the limits of this computational power. Our desire to increase the prediction lead-time of weather over the United States is just such an endeavor. Research has shown that our ability to make medium-range (two-week) forecasts is impaired by our inability to understand the manner in which tropical weather phenomena impact midlatitudes.

On the other hand, computational models are themselves limited by the enormous number of temporal and spatial scales, and thereby the enormous number of computed variables, inherent in the global weather system. Furthermore, since computers can only perform computations on a finite number of variables, some of the infinite number of variables in the weather system must be discarded. Careful mathematical analysis, using a technique called multi-scale asymptotics, can often be used to simplify the equations governing the weather system by isolating essential phenomena before costly computations are performed.

In previous work, Biello (along with A. Majda at the Courant Institute) has used just such an analysis to isolate a particular resonant interaction between tropical waves, which are guided by tropical storm systems, and mid-latitude waves, which drive and interact with high- and low-pressure systems over North America. In other work using these techniques, Biello and Majda have developed a theory for the structure of a large-scale pattern of tropical weather organization called the Madden-Julian Oscillation (MJO).

Biello first proposes to extend his work on tropical/midlatitude connections to account for the effects of moisture and clouds on the existing theory. Since tropical dynamics are driven by moisture through condensation and rain, this will be an important step in making the original model more useful to the numerical simulation community. Second, Biello proposes to study tropical/midlatitude interactions on smaller scales (mesoscale) where the previously dominant effect of the Earth's rotation is less important than wind shear and condensation. Finally, the effect on midlatitudes of the breakup of the MJO will be studied, and this will be achieved by bridging the gap in spatial and temporal scales between the Biello/Majda theory of the MJO and that of tropical/midlatitude connections.

Agency
National Science Foundation (NSF)
Institute
Division of Mathematical Sciences (DMS)
Type
Standard Grant (Standard)
Application #
0604947
Program Officer
James Curry
Project Start
Project End
Budget Start
2006-07-01
Budget End
2011-06-30
Support Year
Fiscal Year
2006
Total Cost
$118,564
Indirect Cost
Name
University of California Davis
Department
Type
DUNS #
City
Davis
State
CA
Country
United States
Zip Code
95618