Defenses for Fall 2018

Impact of the Boreal Summer Intraseasonal Oscillation on the Diurnal Cycle of Precipitation in the Island of Luzon

December 17, 2018

Kyle Chudler

The Asian Summer Monsoon (ASM) is a major component of the global weather system with impacts across multiple scales. Driven by the thermal contrast between the Asian continent and the Indian and Pacific Oceans, the monsoon winds bring warm, moist air into the south Asian and maritime continents, along with copious amounts of rain. One striking feature in rainfall climatology of the ASM is the…

Intraseasonal Variability in the Diurnal Cycle of Precipitation in the Philippines

November 14, 2018

Michael Natoli

Precipitation in the region surrounding the South China Sea (SCS) over land and coastal waters exhibits a strong diurnal cycle associated with a land-sea temperature contrast that drives a sea-breeze circulation. The boreal summer intraseasonal oscillation (BSISO) is an important modulator of the daily mean precipitation rate and the amplitude of the diurnal cycle. Using 19 years of the CMORPH…

Interactions Between the Madden-Julian Oscillation and Mesoscale to Global Scale Phenomena

November 12, 2018

Ben Toms

The Madden-Julian Oscillation (MJO) influences and interacts with atmospheric phenomena across the globe, from the tropics to the poles. In this two-part study, the interactions of the MJO with other phenomena across a broad range of scales are considered, including mesoscale convective structures within the tropics and global teleconnection patterns. While the two studies are distinct in the…

MULTIPLE SCALES OF SURFACE-ATMOSPHERE COUPLING IN AN EARTH SYSTEM MODEL

October 17, 2018

Morgan Phillips

An Earth System Model that had been modified to use three distinct scales of coupling between the surface and atmosphere was used to simulate conditions that would be present under past and future climate scenarios of fixed Sea Surface Temperature forcing. The first of these was the Community Atmosphere Model coupled to the Community Land Model at a relatively coarse resolution of 2.5 degrees…

A New Post-Processing Paradigm? Improving High-Impact Weather Forecasts with Machine Learning

October 15, 2018

Gregory Herman

High-impact weather comes in many different shapes, sizes, environments, and storm types, but all pose threats to human life, property, and the economy. Because of the significant societal hazards inflicted by these events, having skillful forecasts of the risks with sufficient lead time to make appropriate precautions is critical. In order to occur, these extreme events require a special…

Assessing the Impacts of Microphysical and Environmental Controls on Simulated Supercell Storms

October 11, 2018

Sean Freeman

Supercell thunderstorms are some of the most dangerous single-cell storms on the planet. These storms produce many hazards to life and property, including tornadoes, floods, damaging straightline winds, strong updrafts and downdrafts, and lightning. Although these hazards are not unique to supercells, they are often at their strongest when supercell-produced. Because of the destructive power of…

Estimating spatiotemporal trends in wildfire smoke concentrations in the western United States

October 09, 2018

Kate O'Dell

The United States (US) has seen significant improvements in seasonal air quality over the past several decades. However, particulate air quality in summer over the majority of the western US has seen little improvement in recent decades. Particulate matter with diameters < 2.5 microns (PM2.5) is a large component of ambient air quality that is associated with negative health effects and…

On the Environments and Dynamics of Nocturnal Mesoscale Convective Systems

October 04, 2018

Stacey Hitchcock

The 2015 Plains Elevated Convection at Night (PECAN) field campaign was motivated by unanswered questions about key processes in elevated mesoscale convective systems (MCSs) and the difficulty in accurately forecasting them. During the campaign, 15 MCS environments were sampled by an array of instruments including radiosondes launched by fixed and mobile sounding teams. Cluster analysis of…