The association of frontal formation, development, and movement with large scale baroclinity is well documented. This investigation deals with the mean large-scale baroclinic zones near the Asian East Coast for the last two weeks of February 1975. Two deep, large-scale baroclinic zones are found to be situated along the axis of the zones of high frontal frequencies depicted by previous investigations of the region's frontal climatology. The "southern baroclinic zone" lies along the path of the warm Kuroshio ocean current and beneath the climatological location of the upper level jet stream. A frontogenesis equation is developed to assess the role of mean fields and perturbation fields upon maintaining the mean baroclinity. Analyses contained within demonstrate the various effects of those fields. It is shown that to the north and to the south of the southern baroclinic zone the mean diabatic heating and mean horizontal advection (of mean potential temperature) are the dominant terms in the equation, but that they tend to cancel each other. Within the southern baroclinic zone the frontogenetic effect of the mean diabatic heating term is negligible as is the effect of the perturbation vertical advection term. While the frontogenetic effect of the mean horizontal advection term is smaller within the zone than outside, it is important for the maintenance of the baroclinity there. The effects of mean vertical advection and perturbation horizontal advection were the other important terms within the zone and oppose the effects of the mean horizontal advection term. / Graduation date: 1981

Upper air soundings taken every three hours are used to examine a cold front of average intensity over a period of 24 hours. Vertical cross sections of potential temperature and wind and horizontal analyses are compared and adjusted until they are consistent with one another. These analyses are then used to study the evolution of the front. The front is found to consist of a complex system of fronts occurring at all levels of the troposphere. Low level fronts are strongest at the surface and rapidly weaken with height. Fronts in the middle and upper troposphere are much more intense. The warm air ahead of the fronts is nearly barotropic while the cold air behind the fronts is baroclinic through deep layers. A deep mixed layer is observed to grow in this cold air. Examination of cross sections of potential temperature and potential vorticity indicates that the air in at least the upper portions of the upper level fronts originates in the stratosphere. No evidence is found, however, of an extrusion of stratospheric air to very low levels. Diabatic processes seem to destroy the extrusion as it descends. The structure of the upper level fronts is complex. These fronts are observed to split apart, recombine, and descend to low elevations. This descent is due to the incorporation into the front of pre-existing stable/baroclinic layers. An equation for parcel-following frontogenesis in isentropic coordinates is developed and applied. No single process was found to be dominant in changing frontal intensity. Frontogenesis occurs on the leading edge of the fronts and frontolysis on the trailing edge. The magnitudes of the computed frontogenesis decrease downstream from the axis of the upper level trough. Isentropic trajectories are constructed in order to verify the computed values of parcel-following frontogenesis. Poor correlations are found between the computed and trajectory-following values of frontogenesis. This is believed to be due to nonlinearities in the field of frontogenesis and to errors in the trajectories. Such nonlinearities cast doubt on the usefulness of conventional data for the study of frontogenesis. Vertical velocities are computed using a kinematic technique. Reasonable fields of vertical velocity are obtained in the vicinity of the fronts and jet streaks. Good correlations are found between the vertical displacement between endpoints of the trajectories and the value of computed vertical velocity integrated over the path of the trajectory. The field of vertical velocity is also found to be highly nonlinear. / Graduation date: 1977

No description available.

No description available.

Thesis (Ph.D.)--University of Oklahoma, 1987. / Bibliography: leaves 180-185.

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [216]-221).

Thesis (M.S.)--University of Wisconsin, 1974. / Bound typescript (Photocopy). eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 55-56).

Thesis--Wisconsin. / Includes bibliographical references (leaf 82).

Thesis. 1975. Sc.D.--Massachusetts Institute of Technology. Dept. of Meteorology. / Vita. / Bibliography: leaves 82-83. / by Dean G. Duffy. / Sc.D.

Thesis (Ph. D.)--University of Adelaide, 1986. / Includes bibliographical references (leaves 163-172).