Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 47 for “"tropopause"”.
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The tropopause region thermal structure and tropical cyclones
… influence the thermal structure of the tropopause region? Second, what sets the thermodynamic limits of tropical cyclone intensity across the seasonal cycle? The link between these subjects is tropical cyclone outflow, which often reaches into the tropopause region, allowing the thermal …
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Trapped disturbances and effects of tropopause height in stratified flow over topography
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2001.
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Understanding the Lowermost Stratosphere in Current and Future Climates: Composition, Definition, and Tropopause-Overshooting Convection
… from the lower stratosphere by an identified ‘tropopause’, and any transfer of air across this interface is therefore considered to be stratosphere- troposphere exchange (STE). The difference in composition between the troposphere and the stratosphere makes processes that facilitate STE …
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On the mechanism of the large-scale seasonally varying upwelling in the region of the tropical tropopause
… the large-scale upwelling through the tropical tropopause, one of the principal components of stratosphere-troposphere mass exchange. The global-scale mean meridional circulation in the lower stratosphere and the upward branch of the tropospheric Hadley circulation which form the two …
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Transport and Distribution of the Short-Lived Halocarbons in the Tropical Tropopause Layer in the Pacific Ocean: the Role of Convection
… halogenated organic substances in the tropical tropopause layer (TTL) in the Pacific Ocean. Short-lived halocarbons are one of the major groups of the ozone depleting substances as they provide a source for the active halogens which decrease ozone in the atmosphere. The TTL serves as the primary …
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The impact of upper tropospheric temperatures and radiation on idealized tropical cyclones
Potential intensity (PI) theory predicts that the tropopause temperature acts as a powerful constraint on tropical cyclone (TC) intensity and structure. The physical mechanisms by which the upper tropospheric thermal structure and radiative forcing impact TC intensity and structure have not been …
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Timescales of processes controlling water vapour entry to the stratosphere
… and large-scale transport through the tropical tropopause layer to be the key factors that determine stratospheric water vapour. However, their relative importance at different timescales, and the role of the other influences such as detailed ice microphysics, are not yet well known. It is a …
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Tracer-Independent Approaches to Stratosphere-Troposphere Exchange and Tropospheric Air Mass Composition
… partitioning the one-way flux across the thermal tropopause according to stratospheric residence time τ and the regions where air enters and exits the stratosphere, the one-way flux is quantified robustly without being rendered ill-defined by the short-τ eddy-diffusive singularity. Diagnostics are …
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Study on impacts of aviation emissions and related dynamics and chemistry
… on the atmospheric composition near the tropopause were investigated. The separate contributions of nitrogen oxides (NOx), carbon monoxide (CO) emissions and the combined effects of NOx and hydrocarbons (HC) from surface traffic emissions to UTLS ozone (O3) were considered. The analyses …
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Dynamical and radiative processes in the Upper Troposphere/Lower Stratosphere
… is a region of stable air located just above the tropopause known as the tropopause inversion layer (TIL) which appears as a peak in the stratification. The first main chapter of the thesis focuses on elucidating the large scale dynamical mechanisms which lead to the formation of the TIL by …
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Investigation of Inorganic Stratospheric Bromine using Balloon-Borne DOAS Measurements and Model Simulations
… amount of inorganic bromine observed around the tropopause and the rapid increase above the tropopause, all indicate that short-lived organic bromine source gases have to be taken into account. These results were confirmed by comparing the DOAS BrO data with different SLIMCAT model runs. …
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A comparison of upper front strength as analyzed by NORAPS and as observed by ACARS-equipped aircraft
… the portion of the upper front above the tropopause was examined in greater detail than the portion below the tropopause, although the latter would be expected to contain stronger temperatui->h(0g(2gd4i((*"
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INVESTIGATION OF TRACER GAS VARIABILITY FROM OBSERVATIONS AND MODELS
… on the tropical total column ozone, the tropical tropopause pressure, and the 3.5-yr ozone signal in the mid-latitude were also investigated. Both the observations and Goddard Earth Observing System Chemistry-Climate Model (GEOS CCM) show tropical tropopause pressure to be related to the ENSO …
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Dynamic and Thermodynamic Controls on the Amount and Distribution of Orographic Precipitation
… simulations are used to investigate how the tropopause affects the vertical structure of mountain waves, and in turn orographic precipitation. In idealized numerical simulations, variations in the height of the tropopause are found to strongly modulate the depth and magnitude of windward …
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Limb scatter measurements of high altitude cloud distributions
… Cirrus clouds occur at high altitude around the tropopause level and, despite their thin appearance and low optical thickness, they contribute to the radiative balance of the atmosphere. The processes in this region of the atmosphere have become increasingly important for a clear understanding of …
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On the maintenance of weak meridional temperature gradients during warm climates
… but stationary eddy energy does not. The polar tropopause rises, which supports a weaker temperature gradient in the lower stratosphere, a weaker stratospheric jet, and an increase in the wave activity vertically propagating into the stratosphere.
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The Aquatic Geochemistry of the Particle-Reactive Radionuclides PO-210, PB-210, and BE-7
… of Be-7 of statospheric origin into the tropopause during the vernal tropopause break. Pb-210 exhibited a slightly weaker seasonal trend, with ca. 35 percent delivered between February and April, which appears to be related to the rate at which its parent, Rn-222, emanates from the earth. …
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The Isotopic Composition of Water Vapor in the Upper Troposphere/Lower Stratosphere Region : Modeling, Analysis and Sampling
… the isotopic composition of water vapor in the tropopause region and the stratosphere provides important information for the understanding of atmospheric transport and photochemistry. The presented thesis describes with the help of models the processes governing the isotopic composition of …
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