Source: Dissertation Abstracts International, Volume: 25-12, page: 7330. / Thesis (Ph.D.)--The Florida State University, 1964.

The Asian monsoon heat sources during the Northern Hemisphere winter and summer are evaluated by a physical approach using the GFDL FGGE III-b analyses supplemented by a mix of independent measurements. For the winter component, the analysis covers the entire period of FGGE SOP-I (January 5-March 5, 1979), and for the summer component, the analysis spans a 40-day period in the early summer of FGGE year (May 22-June 30, 1979). The evolution of monsoon heat sources and the salient regional characteristics of diabatic heating over several key monsoon subdomains are examined. The relationship between the diabatic heating and large-scale monsoon circulations are then studied from the principle of energy, within the framework of the energetics of rotational and divergent flows, and Lorenz's available potential energy formulation. / The heat sources evaluated over the Winter and Summer MONEX domains are assessed by comparing the results with independent studies. This is followed by a detailed examination of the time mean and pentad (5-day mean) averaged vertically integrated heat sources over the analysis periods. In general, the distribution of monsoon heat sources resembles more-or-less the pattern of precipitation and the release of latent heat of condensation in cumulus convection is by far the most important diabatic process. The atmospheric cooling is almost entirely due to the longwave radiative transfer (aided sometimes by a reverse sensible heat transfer) which shows maximum amplitude in the upper troposphere. The tropospheric heating due to turbulent sensible heat exchanges follow closely the topographical distribution, it is very important over the desert zones, high mountains or plateaus, and regions of intense air-sea interactions. / The energetic calculations show the importance of the divergent circulation and its catalytic role for transferring the kinetic energy into the rotational component, almost immediately. The temporal variability of the available potential energy, its generation and conversion to kinetic energies are examined. Over the Summer MONEX domain, a substantial rise in APE precedes the large-scale dynamical onset (June 10, 1979) by almost one week and the internal conversion (APE to KE) is most pronounced over the regions of Bangladesh-Burma and Indochina. Furthermore, the analysis reveals that unlike its winter counterpart, the Asian summer monsoon circulations are internally forced. / Source: Dissertation Abstracts International, Volume: 46-10, Section: B, page: 3485. / Thesis (Ph.D.)--The Florida State University, 1985.

The effect of a planetary-scale, wavenumber 2 topography on baroclinically active disturbances is investigated for a channel domain in a two-layer, quasi-geostrophic context. When the lower-layer zonal velocity is nonzero, the topography influences the disturbances by forcing a stationary wave, and the topography and the forced wave influence the growth rates and spatial structures of the time-dependent solutions. The case of zero zonal velocity in the lower layer was also investigated, for which no forced wave exists. Asymptotic forms of the equations, valid when the topographic effect (governed by the ratio of the nondimensional topographic height to the rotational Froude number) is small, are used to obtain both the stationary and time-dependent solutions. The time-dependent solutions are also obtained using a numerical approach, in which is determined the eigenvalues and eigenfunctions of a matrix representing the dynamical equations. Agreement is good between these two approaches. / Recent laboratory experiments by Li, Kung, and Pfeffer, with a baroclinic annulus in which there is a false bottom with wavenumber 2 topography, are used to select governing parameters. The simultaneous presence of a stationary forced wave of wavenumber 2 and a time-dependent baroclinic wave of wavenumber 4, which has wavenumber 2 and 6 sidebands due to the topography, yields a flow field that exhibits some principal features of the laboratory experiments. The position of the forced wave and the location of an excursion in latitude of the storm track show qualitative resemblance to those features observed in the atmosphere. / Source: Dissertation Abstracts International, Volume: 47-12, Section: B, page: 4923. / Thesis (Ph.D.)--The Florida State University, 1986.

The climatology and energetics of atmospheric motions in different frequency regions are studied in the frequency domain using the ECMWF operational analysis. / Latitude-pressure cross sections of momentum flux and heat flux are discussed for different frequency bands (periods of 3 to 7 days, 10 to 25 days and 30 to 50 days). The distributions of band-passed fluxes generally resemble those of total transient fluxes. The horizontal distributions of variance have two distinctive patterns, the "storm track" pattern and the "land sea" pattern. The "storm track" patterns are associated with kinetic energy for all three frequency bands while the "land sea" patterns are identified in the case of available potential energy at lower levels and lower frequencies. When a power law is fitted to the spectral energy on a log-log scale, a slope of -1.04 results for KE and -1.3 for APE, in the period range of 2 to 25 days when integrated over the entire mass of the Northern Hemisphere. / When energetics are discussed spectrally the importance of nonlinear exchanges of APE and KE stands out. The effects of high frequency transients (with a period shorter than 10 days) on the low frequency transients (with a period between 10 days and 90 days, approximately) are a thermal dissipation and a barotropic enhancement. / A global spectral model of two constant (sigma) layers was integrated for two years. The energy was introduced by a heating field whose frequency harmonics in all frequencies were zero except those for the time mean and the annual cycle. When the annual cycle is included in the heating field, the simulated energetics are similar to those calculated from the atmospheric observations. The energy spectra show somewhat different slopes, ranging from -0.84 to 1.2 depending on parameters used. When the annual cycle is not included in the heating field, the nonlinear interactions of KE and APE are negligibly small as compared with the linear term . The shape of the energy spectrum resembles that of a white noise. / Source: Dissertation Abstracts International, Volume: 47-12, Section: B, page: 4923. / Thesis (Ph.D.)--The Florida State University, 1986.

Data taken by the Earth Radiation Budget (ERB) experiments on board the Nimbus-6 and Nimbus-7 satellites is examined. The goal is an understanding of the bounds of variability of the radiation budget components. This variability is examined on daily, monthly, and annual time scales. / An in-flight characterization of the instrument is performed, and a set of calibration adjustments for the Nimbus-7 ERB are developed that enable interannual climate studies to be made. A technique for the transfer of this calibration to the Nimbus-6 ERB experiment is derived that enables the creation of a decadal joint ERB data set. / For the first time, error bars for the data set are established. These show that the WFOV calibration is accurate to 7 W/m('2) regionally and 3 W/m('2) zonally. Based on a solar calibration transfer, the stability of this data is shown to be better than 1/2% over the entire period. / The radiation budget component (albedo and longwave emission) responses to the 1982 eruptions of the El Chichon volcano are examined. Based on the observations, an understanding of the global distribution, evolution, and persistence of the resultant aerosol cloud is achieved. Specific results include evidence that, although the eruptions occurred in the spring of 1982, the maximum optical depths at the higher latitudes in the northern hemisphere were not reached until the winter of 1982-1983. Further evident is the fact that the majority of the aerosols are retained in the northern hemisphere, with the aerosol content of the two hemispheres (as measured by the signal enhancements) not reaching equilibrium until two years after the eruption. / The evolution of the major 1982/1983 ENSO event is monitored for the first time by broad-band radiometers. Quasi-stationary, planetary-scale tropical and mid-latitude teleconnection patterns are shown to emerge as the event reaches its peak intensity. The onset, intensification, and withdrawal of drought over Indonesia, Australia, the Pacific Ocean island chains, and the Amazon River Valley is monitored based on inferred irrotational, three-dimensional flow fields. Anomalous subsidence, forced by the ENSO episode is noted over all drought regions. / Source: Dissertation Abstracts International, Volume: 47-06, Section: B, page: 2474. / Thesis (Ph.D.)--The Florida State University, 1986.

This study describes in detail the structure and evolution of two depressions observed during the 1979 Summer Monsoon Experiment with the objective of determining what changes took place during their intensification. The first depression was associated with the onset of the monsoon while the second formed over the Bay of Bengal in early July, 1979. / Detailed subjectively produced windfield analyses provided the basis for vorticity, heat and moisture budgets as well as the 4-dimensional description of both depressions. The principal deduction from the analyses was that both depressions had many important features in common. These included a southwest tilt with height, asymmetric distribution of cloudiness and vertical motions, a local maximum in mid-tropospheric temperature just northeast of the center and pronounced thermal advection patterns below 500 mb. / Both depressions propagated towards the west during their period of maximum intensity. Vorticity budgets of the rain areas west of each depression's center showed this motion to result from the dominance in the lower troposphere of the divergence term. Horizontal advection of vorticity opposed the divergence term but was smaller, giving a calculated westward motion in close agreement to that observed at and below 700 mb. Above this level discrepancies appeared between the calculated and observed tendencies but did not change the conclusion that vertical transport by cumulus appeared to be of secondary importance to the depression's propagation. / Heat budget calculations for the rain areas showed a balance between warm advection and adiabatic cooling at 850 mb, though diabatic heating was large above this level. Rainfall was closely coincident with the maximum of warm advection at lower-middle levels, both increased during cyclogenesis. In the suppressed northeast quadrant of both depressions subsidence warming was approximately balanced by cold advection; here a maximum in mid-tropospheric temperatures resembling a nascent tropical cyclone eye developed in both depressions. / Source: Dissertation Abstracts International, Volume: 48-07, Section: B, page: 2004. / Thesis (Ph.D.)--The Florida State University, 1987.

The West African Monsoon Experiment (WAMEX) took place between 1 May to 31 August, 1979, over an area from 10(DEGREES)S to 25(DEGREES)N and 25(DEGREES)W to 25(DEGREES)E. Data collected during WAMEX were analyzed by a WMO WAMEX scientific group which selected, for thorough investigation, four cases of monsoon disturbances that passed across West Africa during the WAMEX period. The disturbances were those that traversed the region during the periods (i) May 11-17, 1979; (ii) June 11-17, 1979; (iii) July 16-22, 1979; and (iv) August 21-27, 1979. / The four WAMEX cases have been subjected to detailed observational and numerical prediction studies. The prediction experiments are a series of real data numerical weather prediction carried out using two single level models and the FSU multilevel global spectral model. Both the FGGE III-b data and the objectively analysed FGGE III-b plus WAMEX data sets are separately utilized in the observational study and in the numerical integrations in order to evaluate the impact of the WAMEX data set and also to determine which data (FGGE III-b or merged III-b with WAMEX) produces wave structures and characteristics that are closest to actual observations. / Results of the comparative observational study indicate positive correlation between both data sets with no significant difference. However, wave structures are shown to be better described by the merged FGGE plus WAMEX data sets than by the FGGE III-b data sets. In addition the skills of the prediction models are slightly better enhanced when applied to the merged WAMEX data sets than to the FGGE III-b data sets. / Source: Dissertation Abstracts International, Volume: 46-08, Section: B, page: 2694. / Thesis (Ph.D.)--The Florida State University, 1985.

Three 20 day winter forecasts have been carried out using the Florida State University Global Spectral Model to examine the systematic errors of the model. Most GCM's and global forecast models exhibit the same kind of error patterns even though the model formulations vary somewhat between them. Some of the dominant errors are a breakdown of the trade winds in the low latitudes, an over-prediction of the subtropical jets accompanied by an upward and poleward shift of the jets, an error in the mean sea-level pressure with over-intensification of the quasi-stationary oceanic lows and continental highs and a warming of the tropical mid and upper troposphere. In this study, a number of sensitivity experiments have been performed for which orography, model physics and initialization are considered as possible causes of these errors. / A parameterization of the vertical distribution of momentum due to the sub-grid scale orography has been implemented in the model to address the model deficiencies associated with orographic forcing. This scheme incorporates the effects of moisture on the wave induced stress. The parameterization of gravity wave drag is shown to substantially reduce the large-scale wind and height errors in regions of direct forcing and well downstream of the mountainous regions. Also, a parameterization of the heat and moisture transport associated with shallow convection is found to have a positive impact on the errors particularly in the tropics. This is accomplished by the increase of moisture supply from the subtropics into the deep tropics and a subsequent enhancement of the secondary circulations. / A dynamic relaxation was carried out to examine the impact of the long wave errors on the shorter wave. By constraining the long wave error, improvement is shown for wavenumbers 5-7 on medium to extended range time intervals. Thus, improved predictability of the transient flow is expected by applying this initialization procedure. / Source: Dissertation Abstracts International, Volume: 48-07, Section: B, page: 2005. / Thesis (Ph.D.)--The Florida State University, 1987.

Infrared cooling rates over the Asian monsoon domain between 5$\sp\circ$S to 20$\sp\circ$N and 40$\sp\circ$E to 135$\sp\circ$E have been calculated for summer seasons of 1984 and 1987, using a medium band resolution infrared radiative transfer model. Cloudiness is specified using INSAT infrared measurements. Intraseasonal variability of cloudiness and cooling rates are examined. INSAT-derived cloud amounts have 20 to 50% of total variance in intraseasonal frequency band and the centers of maximum variance are found over the Arabian Sea, equatorial Indian Ocean, Bay of Bengal, South China Sea, and western Pacific Ocean. Intraseasonal variability of cloudiness is primarily due to variations in deep convective clouds on intraseasonal time scales. Infrared cooling rates are between 1 to 5$\sp\circ$C$\cdot$day$\sp{-1}$, and intraseasonal cooling rate anomalies have magnitudes between 0.5 to 1.5$\sp\circ$C$\cdot$day$\sp{-1}$. The centers of large intraseasonal variability of cooling rates are co-located with the centers of cloudiness variability. The cooling rate anomalies are directly associated with variability of deep convection such that cooling rates are maximum between 200 and 400 mb when deep convective clouds are present. In the absence of deep convective clouds, cooling rates are maximum lower in the troposphere. The dominant vertical mode of cooling rate anomalies has the structure in which lower and upper tropospheres have opposite phases. The difference between 1984 and 1987 monsoon seasons are primarily in the amplitudes and time periods associated with intraseasonal cloudiness and cooling rate anomalies. A conceptual model of equatorial Kelvin waves, with first baroclinic mode structure is used to show that cooling rate anomalies can modify phase speeds of planetary scale Kelvin waves by up to 12%. The change in phase speed is maximum for wave number 1 and for the faster radiative time scales. / Source: Dissertation Abstracts International, Volume: 52-08, Section: B, page: 4261. / Major Professor: Eric Smith. / Thesis (Ph.D.)--The Florida State University, 1991.

Source: Dissertation Abstracts International, Volume: 29-05, Section: B, page: 1798. / Thesis (Ph.D.)--The Florida State University, 1968.