Numerical simulation of the January and July global climate with the OSU two-level atmospheric general circulation model has generated time series of the global distribution of selected climatic variables. Analyses of these data for the kinetic energy and available potential energy based on 31-day time mean statistics have been made in the form of the zonal mean and the transient and stationary eddies. The generation and dissipation rates of the various forms of energy in this model are also computed, and the energy cycle for January and July is presented in comparison with the corresponding results from observation and from other models. / Graduation date: 1980

An analytical two-layer model consisting of a time-dependent stratified boundary layer topped by stratified free flow is developed in order to study atmospheric boundary layer production of vertical motion. To avoid use of a constant eddy viscosity, the boundary layer equations are layer-integrated over a fixed depth, and surface stress is parameterized using a linearized drag law. For flows driven by periodic, differential surface heating, it is found that the influence of accelerations, stratification, and friction are to concentrate the maximum convergence near a preferred latitude. The preferred horizontal length scale for boundary layer production of vertical motion increases with boundary layer stratification and decreases with distance from the preferred latitude. / Graduation date: 1980

Aerosol particles are likely important contributors to our future climate. Further, during recent years, effects on human health arising from emissions of particulate material have gained increasing attention. In order to quantify the effect of aerosols on both climate and human health we need to better quantify the interplay between sources and sinks of aerosol particle number and mass on large spatial scales. So far long-term, regional observations of aerosol properties have been scarce, but argued necessary in order to bring the knowledge of regional and global distribution of aerosols further. In this context, regional studies of aerosol properties and aerosol dynamics are truly important areas of investigation. This thesis is devoted to investigations of aerosol number size distribution observations performed through the course of one year encompassing observational data from five stations covering an area from southern parts of Sweden up to northern parts of Finland. This thesis tries to give a description of aerosol size distribution dynamics from both a quantitative and qualitative point of view. The thesis focuses on properties and changes in aerosol size distribution as a function of location, season, source area, transport pathways and links to various meteorological conditions. The investigations performed in this thesis show that although the basic behaviour of the aerosol number size distribution in terms of seasonal and diurnal characteristics is similar at all stations in the measurement network, the aerosol over the Nordic countries is characterised by a typically sharp gradient in aerosol number and mass. This gradient is argued to derive from geographical locations of the stations in relation to the dominant sources and transport pathways. It is clear that the source area significantly determine the aerosol size distribution properties, but it is obvious that transport condition in terms of frequency of precipitation and cloudiness in some cases even more strongly control the evolution of the number size distribution. Aerosol dynamic processes under clear sky transport are however likewise argued to be highly important. Southerly transport of marine air and northerly transport of air from continental sources is studied in detail under clear sky conditions by performing a pseudo-Lagrangian box model evaluation of the two type cases. Results from both modelling and observations suggest that nucleation events contribute to integral number increase during southerly transport of comparably clean marine air, while number depletion dominates the evolution of the size distribution during northerly transport. This difference is largely explained by different concentration of pre-existing aerosol surface associated with the two type cases. Mass is found to be accumulated in many of the individual transport cases studied. This mass increase was argued to be controlled by emission of organic compounds from the boreal forest. This puts the boreal forest in a central position for estimates of aerosol forcing on a regional scale.

Inom Försvarsmaktens vädertjänst används ett PC-program för att beräkna illuminansen från måne och stjärnor under loppet av en vald natt. Korrektion för moln görs därefter genom ett schematiskt förfarande. I detta arbete ges förslag till två förändringar av ljusprognosmodellen. 1. Parametern ”markytans tillstånd” införlivas i modellen, samtidigt som hänsyn tas till mängden (och typen av) moln. Det sammanlagt tillgängliga ljuset under eventuella moln, S, kan beräknas genom sambandet S=(1+Am)(I0*(1-N*Aso))/(1-Am*Asu*N) där N är molnmängden, Aso molnöversidans albedo, Asu molnundersidans albedo, Am markens albedo och I0 den inkommande strålningen ovan eventuella moln. 2. Det artificiella ljuset och dess spridning under molnfria förhållanden införlivas i modellen. Detta sker lämpligtvis genom användande av satellitbilder som visar det artificiella ljusets spridning under molnfria nätter, vid genomsnittliga absorptions- och spridningsförhållanden. Ett ytterligare förslag är att illuminansen för artificiellt ljus vid icke molnfria förhållanden införlivas i modellen i ett senare skede. Detta görs förslagsvis genom att man utgår ifrån satellitbilder som visar artificiellt ljus, men som inte är justerade med avseende på ljusets spridning vid molnfria förhållanden. Denna information kombineras med en enklare modell som beskriver ett samband mellan molnbas, sikt, ljusspridning och avståndet till artificiella ljuskällor. Samtidigt sker förbättringar i den grafiska presentationen.

Hourly precipitation data from thirty cooperative stations in Kentucky from 1965 to 1996 were used to determine the diurnal distribution of precipitation rates. Descriptive summaries for the diurnal distribution for each climate division in Kentucky and for Kentucky as a whole were calculated. In each case, the trends were similar. Precipitation rates increased into the afternoon and then decreased until sunrise. A stochastic model was developed to estimate mean seasonal precipitation rates in Kentucky by using regional and localized parameters. More than half of the variation (r2 = 0.57) in precipitation rates can be explained by the following variables: 1) Distance away from the moisture source, the Gulf of Mexico; 2) Roughness of topography; 3) Degree of urbanization. Precipitation rates decrease in a northeasterly direction across Kentucky as air moves farther away from the Gulf of Mexico along its path of migration. The maritime tropical air mass migrating out of the Gulf of Mexico loses its water vapor over its path of migration. As a result, less water vapor is available for precipitation processes in areas farther away. As a precipitation event moves over rougher terrain and more urbanized areas, precipitation rates decrease as well. A rougher terrain absorbs more solar radiation because it has more surface area. An urbanized area absorbs more solar radiation because of the urban structures (e.g., buildings, asphalt, roofs). As a result, both will radiate more heat causing the air to be buoyant at the surface to either enhance convection or increase vertical air motions. Increased vertical air motions will cause an increase in air resistance acting upon precipitation falling, thereby, causing a decrease in the amount falling to the surface per hour.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 193-207).

Thesis (M.S. in Meteorology and Oceanography)--Naval Postgraduate School, December 2009. / Thesis Advisor: Harr, Patrick. Second Reader: Elsberry, Russell. "December 2009." Description based on title screen as viewed on January 27, 2010. Author(s) subject terms: Electra Doppler Radar (ELDORA), Tropical Cyclone Structure (TCS08), TCS08, tropical cyclone formation, Tropical Circulation System (TCS), TCS025. Includes bibliographical references (p. 75-76). Also available in print.

Thesis (M.S.)--Naval Postgraduate School, 2002. / Thesis advisor(s): Kenneth L. Davidson, Peter Guest. Includes bibliographical references (p. 45). Also available online.

Thèse--Zurich. / Vita. "Extrait de la Revue geofisica pura e applicata, vol. 24 (1953)." Summary in French, German and English. Bibliography: p. 55-58.

Thesis (M. Sc.(Meteorology)) -- University of Pretoria, 2000. / Includes summary. Includes bibliographical references