2018 CIRA Seminars
The 2017 North Atlantic hurricane season was an extremely active one, with 17 named storms (1981-2010 median is 12.0), 10 hurricanes (median is 6.5), 6 major hurricanes (median is 2.0) and 245% of the 1981-2010 median Accumulated Cyclone Energy occurring. The combination of a hurricane-enhancing large-scale environment and a stronger western Atlantic subtropical high led to one of the most damaging Atlantic hurricane seasons on record.
In this seminar, I will describe the general properties of graupel (rimed particles < 0.5 cm) and hail, based on observations. I will then report on my work that uses novel approaches to estimate the fall characteristics of hail. Three-dimensional volume scans of hailstones of sizes from 2 to 7 cm were printed in 3D models (I’ll show some in my seminar) using ABS plastic, and their terminal velocities were measured in the Mainz vertical wind tunnel. To simulate graupel, some of the hailstone models were printed with dimensions of 0.2-0.5 cm, and their terminal velocities measured.
The Land-Atmosphere Feedback Experiment (LAFE) was conducted at the ARM Southern Great Plains (SGP) site in north-central Oklahoma from 1-31 August 2017. This experiment deployed multiple scanning wind, temperature, and humidity lidar systems, additional surface energy balance stations, an Unmanned Aerial System, and a fixed wind aircraft to characterize the role of surface inhomogeneity and its impact on the atmospheric surface layer, the convective boundary layer above it, and the entrainment zone.
Hurricanes and tropical storms can cause substantial economic and human health impacts. These impacts occur through a number of hazard pathways, including severe winds, rain, flooding, and tornadoes. In the United States, hurricane impacts are often assessed at the county level, often the level at which health and economic data are available. I will describe results from assessing hurricane exposure in U.S. counties by distance and four hazard-specific metrics to measure how well exposure classification agrees across metrics.
Air pollution is linked to lung and heart disease and other human health problems. It is also linked to regional climate change impacts with urban areas bearing the greatest burden of those impacts. In the United States its estimated costs range between $71B – $277B (0.7% – 2.8% of the 2005 GDP) annually. Clearly air pollution is an important social and scientific problem.