Thesis (Ph. D.)--University of Wisconsin, 1967. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1970. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--Joint Program in Oceanography/ Applied Ocean Science and Engineering, Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution, 2006. / "September 2006." Bibliography: p. 74-79.

Thesis (Ph. D.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (p. 181-201). Also available via the World Wide Web.

Thesis (M.S.)--University of Wyoming, 2007. / Title from PDF title page (viewed on Mar. 5, 2009). Includes bibliographical references.

No description available.

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Synoptic and climatological dynamic studies generally rely on bulk aerodynamic flux formulae to describe air-sea heat and momentum exchange on synoptic and climatological scales. Barometric pressure maps (which involve an intrinsic temporal averaging of the wind) and wind roses provide two sources of spatial and temporal wind information for flux calculations. Several investigators have shown that, due to the non-linear dependence of the bulk aerodynamic formulae on the winds, time-averaged estimates of the fluxes based on vector averaged winds systematically underestimate the actual time-averaged fluxes. Using 10 to 21 years of three-hourly sampled sea surface meteorological observations from 9 weatherstations in the North Atlantic Ocean and 2 weatherstations in the North Pacific Ocean, the three-hourly stresses, latent heat fluxes and sensible heat fluxes were calculated. The sampled data and the calculated fluxes were then averaged over periods varying up to 28 days. The estimates of the averaged fluxes based on the vector averaged winds were then compared to the directly averaged values. A simple analysis revealed that an upper bound for the difference in the two stress calculations was directly proportional to the sum of the x and y component wind variances lost through the averaging process (in agreement with Fofonoff, 1960) and inversely proportional to the square of the vector averaged wind speed. The wind averaged and directly averaged flux estimates were grouped according to the Beaufort wind speed category and the period over which the variates were averaged. .A multivariate regression was then performed to optimize a transformation from the wind averaged to the directly averaged case. For all fluxes, the transformation dramatically improved the wind averaged estimates of the climatological means and variances of the directly averaged fluxes. The residual error between the two estimates was decreased up to a factor of 5 over the uncorrected case and the correlation coefficients showed a moderate increase. The regression coefficients showed similar values for all temperate latitude stations. Based on consistencies observed in the wind speed and averaging period dependencies of the multivariate coefficients, an empirical formula was found which interpolated the wind speed and averaging dependence and duplicated the multivariate regression results. The data from the ten temperate latitude stations were grouped and a single formula found which only moderately increased the errors between the wind-averaged and directly averaged estimates. The geographically averaged formula was not applicable at Station N, located at the northern extremity of the North Pacific Trade Wind- region. Analysis of the 28 day wind-averaged flux spectral estimates showed that they underestimated the 28 day directly averaged flux spectral estimates. Application of the specific ship empirical formula greatly improved agreement between the two spectral densities and reduced the residual series power density at all frequencies. High latent heat flux errors at Station N, could be reduced by application of a seasonal correction. The data were also grouped into monthly wind rose configurations and the wind rose monthly flux estimates were compared to the directly calculated long-term monthly mean fluxes. In all cases, the wind rose fluxes compared favourably with the directly calculated fluxes. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

Blocking is generally understood as the obstruction on a large scale of the normal west - to - east motion of mid-latitude pressure systems. It is a persistent phenomenon lasting from one to several weeks and the resulting prolonged weather regimes may have serious economic and social consequences. The recent Northern Hemisphere winters, starting with 1976-77, featured unusually large circulation anomalies, many of which can be directly related to prolonged episodes of large scale blocking. The intent of this study is to investigate the statistics and certain diagnostics of blocking in the Northern Hemisphere. The first of the three primary objectives is to present and interpret the spatial and temporal distribution of blocking during the past 33 years. We develop objective identification criteria, adaptable to machine processing methods, by relating the blocking anticyclone to its associated positive anomaly of 5-day mean 500MB height. Anomalies meeting the criteria are called 'blocking signatures.’ We present the seasonal frequency of occurrence of these signatures by longitude and by area. The results are in good agreement with published studies for the oceans, but they also reveal a high frequency of blocking signatures over the Northeastern Canadian Archipelago. This result, dubbed the 'Baffin Island Paradox' is further investigated and rationalized. A catalogue has been prepared which identifies the date, centre location and magnitude of every blocking signature which occurred from January 1, 1946 to December 31, 1978. A supplementary Catalogue identifies sequences of these signatures corresponding to actual blocking episodes The second objective is to investigate whether regions with high incidence of blocking, in either the developing or the mature stage, feature non-Gaussian distributions of 5-day mean geopotential. During winter, fields of significantly low kurtosis are found in certain mid-latitude regions where the genesis and amplification of blocking ridges are-frequently observed. Fields of significantly positive skewness are found in higher latitude regions where mature blocking episodes often interrupt the smaller fluctuations about the normal geopotential height. The final objective is to examine the association between the first six harmonics of the long wave pattern and the temporal and spatial characteristics of concurrent blocking episodes. Harmonics are calculated from profiles of daily 500MB height around latitude zones centred at 40°N and 60°N. Results for the northern zone are emphasized. It is found that there are spectral signatures distinctive to the regions where blocking anticyclones occur. Our results for the oceans are in general agreement with those of Austin (1980). During the strongly amplified meridional flow patterns associated with major blocking, we found that, at 60°N, more than 90% of the spatial variance of 500MB height is accounted for by wave components one to four. When the meridional regime gives way to predominantly zonal flow there is a marked reduction of spatial variance of 500MB height. During such regimes the higher harmonics (waves five and six) often make significant contributions (15 to 25%) to the total variance. The 'Baffin Island Paradox' is also studied using harmonics. It is found that in the majority of cases Baffin blocks originate from retrograding North Atlantic blocks. Finally, full latitude zonal harmonic analyses (15°N to pole, waves 1 to 4) are presented for three case studies of major blocking - (a) Greenland-North Atlantic, (b) Pacific Ocean-Alaska, and (c) Double Blocking. The harmonics often reveal two wave structures, one in the higher and other in the lower latitudes. The motion and growth characteristics of the two structures can be interpreted in terms of well-known features of total blocking systems. / Arts, Faculty of / Geography, Department of / Graduate

The Microwave Remote Sensing Laboratory (MIRSL) st the University of Massachusetts has developed a unique single antenna, dual-frequency polarimetric Cloud Profiling Radar System (CPRS). This project was funded by the Department of Energy's Atmospheric Radiation Measurement (ARM) program, and was intended to help fill the void of ground-based remote sensors capable of characterizing cloud microphysical properties. CPRS is unique in that it can simultaneously measure the complex power backscattered from clouds at 33 GHz and 95 GHz through the same aperture. Both the 33 GHz and 95 GHz channels can transmit pulse-to-pulse selectable vertical or horizontal polarization, and simultaneously record both the copolarized and crosspolarized backscatter. CPRS Doppler, polarimetric and dual-wavelength reflectivity measurements combined with in situ cloud measurements should lead to the development of empirical models that can more accurately classify cloud-particle phase and habit, and make better quantitative estimates of particle size distribution parameters. This dissertation describes the CPRS hardware, and presents colocated 33 GHz and 95 GHz measurements that illustrate the use of dual-frequency measurements to estimate particle size when Mie scattering, is observed in backscatter from rain and ice-phase clouds. Polarimetric measurements are presented as a means of discriminating cloud phase (ice-water) and estimating crystal shape in cirrus clouds. Polarimetric and dual-wavelength observations of insects are also presented with a brief discussion of their impact on the interpretation of precipitation and liquid cloud measurements. In precipitation, Diermendjian's equations for Mie backscatter (1) and the Marshal-Palmer drop-size distribution are used to develop models relating differences in the reflectivity and mean velocity at 33 GHz and 95 GHz to the microphysical parameters of rain. These models are then used to estimate mean droplet size from CPRS measurements of drizzle, which were collected in July, 1993 during the system's first field test in Lincoln, NE. The dissertation also presents cirrus cloud and other measurements collected during the DOE-sponsored Remote Cloud Sensing Intensive Operations Period (RCS-IOP) experiment in April, 1994. Zenith-pointing cirrus measurements show small differences in 33 GHz and 95 GHz reflectivity, as models have predicted (2). Depolarization was also detected in a few cases when ice crystals precipitated from the base of a cloud. On May 29, 1994 CPRS observed a convective storm that produced a cirrus anvil cloud and hail. These storms are one 'engine' producing cirrus clouds and are currently a topic of intensive research by climatologists. Both zenith-pointing and range-height data formats are presented. Measurements of depolarization above the melting/layer are compared to in situ observations of particle size and shape. The RCS-IOP experiment also provided a first opportunity to verify our calibration with aircraft in situ measurements, and to compare our cloud measurements to those collected by other remote sensors. (Abstract shortened by UMI.)