Multiscale Studies of Synoptic and Mesoscale Disturbances Over the North Pacific, North America, and North Atlantic

Suny At Albany, Albany NY

Investigators

Abstract

Under this award, the Principal Investigator will undertake multiscale (time and space) observational and numerical studies of the life cycles of mid-latitude and tropical disturbances. This research is motivated by the results of recently completed and ongoing NSF supported investigations that have demonstrated how: (1) the life cycles of significant mid-latitude weather systems can be controlled by long-lived coherent disturbances in the upper troposphere that circumnavigate the globe and in turn are influenced by the configuration and evolution of the planetary-scale flow; (2) mid-latitude disturbances can impact the tropics through cool surges that lead to an acceleration of the trade wind easterlies and the subtropical jet; (3) how the winter-season split jet in the Australia-New Zealand sector of the Southern Hemisphere owes its existence to the appearance and disappearance of the polar-front jet near the coast of Antarctica; (4) storms at the end of the Pacific storm track follow preferential pathways as they move across western North America, and (5) mesoscale potential vorticity anomalies aloft that rotate clockwise around warm-season, quasi-stationary mid-latitude continental anticyclones can trigger the formation of mesoscale convective systems that in some cases can become associated with incipient tropical storms. Ongoing research on these topics will continue. New research will focus primarily on studies of the extratropical transition of tropical cyclones. Advantage will be taken of new reanalysis data sets and new remotely sensed satellite observations (e.g., upper troposphere water vapor winds and advanced microwave sounder unit-radiances that can reveal warm cores in tropical cyclones). The availability of these new data sets and observations should permit, for example, an examination of the structure of transiting tropical cyclones (e.g., warm to cold core; symmetric to asymmetric) in an effort to understand the factors that may contribute to the explosive reintensification potential of the storms. Cases will be drawn from past and future difficult-to-predict transitioning storms. The research methodology will be based upon ongoing work and will involve both an observational and a modeling component.