PhD University of Washington
It is not difficult to come across the opinion, voiced by some members of the research community, that “the cyclone problem has been solved.” Nothing could be farther from the truth! Issues as seemingly clear- cut as the 3-D structure and evolution of mid- latitude cyclones are hotly debated topics. My research interests include diagnosis of the structure of winter cyclones and the effect that that structure has on both the production and distribution of precipitation within these cyclones. This work involves a combination of observational analysis (in which a multi-scale approach is used) as well as the use of high resolution mesoscale numerical model simulations of selected storms. The “multi-scale” approach means that we consider processes that vary in scale from the planetary scale effects of the Rocky Mountain cordillera on the baroclinically unstable westerly flow, down to the micron-sized cloud microphysical processes responsible for the production of individual precipitation particles. This approach is compelled by the fact that the precipitation production and distribution in cyclones is the result of a scale interaction between all scales of motion in the atmosphere and that a consistent description of how the mid-latitude cyclone really works cannot be given without considering all of these scale-dependent processes.
Recently our group has placed research emphasis on the structure, dynamics and variability of the tropopause-level jet streams; both polar and subtropical. We have also produced the first synoptic-climatology of the relatively rare, but consequential, vertical superposition of the polar and subtropical jets. We are considering measures of the waviness of the jet stream and interrogating trends in this characteristic of the jet flow from a number of different starting points. This work is part of a broader consideration of the variability of the north Pacific jet stream that has led us to questions concerning the nature of the East Asian Winter Monsoon, the Siberian-Mongolian High and the areal extent of the wintertime cold pool. This rich collection of questions places our work at the interface of weather and climate studies and encourages broad thinking and collaborative discussion.
Our research group uses a variety of tools to conduct its research including fine-scale numerical models, local energetics diagnostics, quasi-geostrophic diagnostics, piecewise potential vorticity diagnostics, as well as a variety of statistical and compositing software packages developed specifically for the questions at hand. A student with an interest in observational as well as, or in combination with, dynamical/theoretical meteorology would be well served by the palette of research questions we are currently entertaining.