Defenses for Spring 2015
Wake Vortices and Tropical Cyclogenesis Downstream of Sumatra over the Indian Ocean
June 26, 2015
Caitlin Fine
A myriad of processes acting singly or in concert may contribute to tropical cyclogenesis, including convectively coupled waves, breakdown of the inter-tropical convergence zone (ITCZ), or upper level troughs. This thesis investigates the role that topographic effects from the island of Sumatra may play in initiating tropical cyclogenesis (TC genesis) in the eastern Indian Ocean. If easterly…
Uncertainties in Global Aerosols and Climate Effects due to Biofuel Emissions
May 14, 2015
Jack Kodros
Prevalent combustion of biofuel as a source of energy for domestic tasks emits large quantities of black carbon and organic aerosol, causing potentially large impacts to air quality and climate. While reducing aerosol emissions through improving technologies is a necessary step for improving health and lifestyle in developing regions, the net effect on climate is largely unconstrained due to…
Cumulus Moistening, The Diurnal Cycle, and Large-Scale Tropical Dynamics
May 08, 2015
James Ruppert
Observations and modeling techniques are employed to diagnose the importance of the diurnal cycle in large-scale tropical climate. In the first part of the study, soundings, radar, and surface flux measurements collected in the Indian Ocean DYNAMO experiment (Dynamics of the Madden-Julian Oscillation, or MJO) are employed to study MJO convective onset. According to these observations, MJO…
TOWARD AN IMPROVED UNDERSTANDING OF THE SYNOPTIC AND MESOSCALE DYNAMICS GOVERNING NOCTURNAL HEAVY-RAIN-PRODUCING MESOCALE CONVECTIVE SYSTEMS
April 21, 2015
John Peters
In the first stage of this research, rotated principal component analysis was applied to the atmospheric fields associated with a large sample of heavy-rain-producing mesoscale convective systems (MCSs) that exhibited the training-line adjoining stratiform (TL/AS) morphology. Cluster analysis in the subspace defined by the leading two resulting principal components revealed two sub-types with…
Time-Filtered Inverse Modeling of Land-Atmosphere Carbon Exchange
April 03, 2015
Nick Geyer
The locations and changes of biospheric carbon dioxide sources and sinks represents one of the least understood processes regarding carbon science. The diagnosis of these sources and sinks come from carbon inversion models, which employ aggressive statistical regularizations in both space and time for stable flux estimation. These regularizations are focused toward estimating fluxes biases on…
On the Observed Relationships Between Variability in Sea Surface Temperatures and the Atmospheric Circulation in the Northern Hemisphere
April 03, 2015
Samantha Wills
The advent of increasingly high-resolution satellite observations and numerical models has led to a series of advances in our understanding of the role of midlatitude sea surface temperature (SST) in climate variability, especially near western boundary currents (WBC). For example, recent observational analyses suggest that ocean dynamics play a central role in driving interannual SST…
Tropical Tropopause Layer Variability Associated with the Madden-Julian Oscillation during DYNAMO
March 27, 2015
Erin Dagg
As the transition region between the troposphere and stratosphere, the tropical tropopause layer (TTL) has importance as the gateway to the stratosphere for atmospheric tracers such as water vapor. This has implications for Earth's radiative budget and climate. Observations in this region show time variations across multiple scales that are not fully understood, including the intraseasonal…
The Spatial and Temporal Properties of Precipitation Uncertainty Structures over Tropical Oceans
March 13, 2015
Jianbo Liu
The global distribution of precipitation has been measured from space using a series of passive microwave radiometers for over 40 years. However, our knowledge of precipitation uncertainty is still limited. While previous studies have shown that the uncertainty associated with the surface rain rate tends to vary with geographic location and season, most likely as a consequence of inappropriate…