B.S. (Meteorology), 1975, The Pennsylvania State University.
M.S. (Meteorology), 1977, The Pennsylvania State University.
Ph.D. (Meteorology), 1981, The Pennsylvania State University.
Research Interests:
My long-term research interests are concerned with understanding the
structure, evolution, and dynamics of synoptic- and mesoscale
atmospheric phenomena and processes. Phenomenological and process
studies on these scales not only have the potential of contributing to
progress in short-range weather forecasting through advances in
understanding, but also through refinement and extension of conceptual
models used in forecasting practice. In conducting these studies, I
have attempted to bridge the perennial gap between theory and
observation through the application of dynamical models and
diagnostics to selected types of weather systems, such as
extratropical and tropical cyclones, fronts, jet streaks, coherent
tropopause disturbances, and inertia-gravity waves. The dynamical
models have included quasi-geostrophic, semi-geostrophic, and
primitive-equation models of frontogenesis in two dimensions;
primitive-equation channel models of frontogenesis and cyclogenesis in
relation to baroclinic-wave life cycles; barotropic, shallow-water,
and stratified quasi-geostrophic models of jet streaks represented in
terms of coherent structures; and a three-layer shallow-water model of
idealized tropical-cyclone-like vortices. The diagnostics have
emphasized three-dimensional ageostrophic and vertical circulations in
baroclinic disturbances, and have been applied to gridded datasets
routinely available from operational numerical weather prediction
centers, such as the National Centers for Environmental Prediction and
the European Centre for Medium-Range Weather Forecasts.
Topics of recent or current research interest include: diagnostic
studies of large-scale weather systems in atmospheric general
circulation models; prediction of cool- and warm-season heavy
precipitation events in the northeastern United States;
phenomenological studies of atmospheric predictability; and
fire-atmosphere interactions and development of fire-weather indices.
Selected Publications:
Schultz, D. M., D. Keyser, and L. F. Bosart, 1998: The effect of large-scale flow on low-level frontal structure and evolution in midlatitude cyclones. Mon. Wea. Rev., 126, 1767-1791.
Keyser, D., 1999: On the representation and diagnosis of frontal circulations in two and three dimensions. The Life Cycles of Extratropical Cyclones, M. A. Shapiro and S. Gronas, Eds., Amer. Meteor. Soc., 239-264.
Dengler, K., and D. Keyser, 2000: Intensification of tropical-cyclone-like vortices in uniform zonal background-flows. Quart. J. Roy. Meteor. Soc., 126, 549-568.
Cunningham, P., and D. Keyser, 2000: Analytical and numerical modelling of jet streaks: Barotropic dynamics. Quart. J. Roy. Meteor. Soc., 126, 3187-3217.
Hakim, G. J., and D. Keyser, 2001: Canonical frontal circulation patterns in terms of Green's functions for the Sawyer-Eliassen equation. Quart. J. Roy. Meteor. Soc., 127, 1795-1814.
Cunningham, P., and D. Keyser, 2003: Jet streaks. Encyclopedia of Atmospheric Sciences, J. R. Holton, J. A. Pyle, and J. A. Curry, Eds., Academic Press, 1043-1055.
Cunningham, P., and D. Keyser, 2004: Dynamics of jet streaks in a stratified quasi-geostrophic atmosphere: Steady-state representations. Quart. J. Roy. Meteor. Soc., 130, 1579-1609.
Pyle, M. E., D. Keyser, and L. F. Bosart, 2004: A diagnostic study of jet streaks: Kinematic signatures and relationship to coherent tropopause disturbances. Mon. Wea. Rev., 132, 297-319.
Novak, D. R., L. F. Bosart, D. Keyser, and J. S. Waldstreicher, 2004: An observational study of cold season-banded precipitation in northeast U.S. cyclones. Wea. Forecasting, 19, 993-1010.
Novak, D. R., J. S. Waldstreicher, D. Keyser, and L. F. Bosart, 2006: A forecast strategy for anticipating cold season mesoscale band formation within eastern U.S. cyclones. Wea. Forecasting, 21, 3-23.