Physical Sciences and Mathematics Commons^™

Automated Detection And Characterization Of Mesocyclones In X-Band Radar Observations, Raychel E. Nelson

The Journal of Purdue Undergraduate Research

No abstract provided.

High Wind Alerts: A System Created With Observations From The X-Band Teaching And Research Radar, Lauren Warner

The Journal of Purdue Undergraduate Research

Following the August 13, 2011, Indiana State Fair stage collapse tragedy, caused by a wind gust from an approaching thunderstorm, Purdue University enforced a wind speed restriction of 30 mph (13 m s-1) for tents at outdoor events. During these events, volunteers stand outside with handheld anemometers, measuring and reporting when the wind speeds exceed this limit. In this study, we report testing of a new system to automate high-wind alerts based on observations from a Doppler radar, the X-band Teaching and Research Radar (XTRRA), near Purdue’s campus. XTRRA scans over campus at low elevations approximately every 5 minutes. Using …

Hydroclimate Drivers And Atmospheric Dynamics Of Floods, Nasser Najibi

Dissertations and Theses

Our preliminary survey showed that most of the recent flood-related studies did not formally explain the physical mechanisms of long-duration and large-peak flood events that can evoke substantial damages to properties and infrastructure systems. These studies also fell short of fully assessing the interactions of coupled ocean-atmosphere and land dynamics which are capable of forcing substantial changes to the flood attributes by governing the exceeding surface flow regimes and moisture source-sink relationships at the spatiotemporal scales important for risk management. This dissertation advances the understanding of the variability in flood duration, peak, volume, and timing at the regional to the …

Air Pressure, Clouds, And Weather, Laura Shofield

Science and Engineering Saturday Seminars

1) What are basis characteristics of the atmosphere?

2) What is the horizontal and vertical movement of air in a “High” and “Low?”

3) How do clouds form and what can they tell us?

4) How are temperature, pressure and clouds related?

5) Applying concepts to real-time data

Drought And Land-Cover Conditions In The Great Plains, Heather Tollerud, Jesslyn Brown, Thomas Loveland, Rezaul Mahmood, Norman Bliss

High Plains Regional Climate Center: Personnel Publications

Land–atmosphere interactions play a critical role in the Earth system, and a better understanding of these interactions could improve weather and climate models. The interaction among drought, vegetation productivity, and land cover is of particular significance. In a semiarid environment, such as the U.S. Great Plains, droughts can have a large influence on the productivity of agriculture and grasslands, with serious environmental and economic impacts. Here, we used the vegetation drought response index (VegDRI) drought indicator to investigate the response of vegetation to weather and climate for landcover types in the Great Plains in the United States from 1989 to …

Ace-Fts Observations Of Acetonitrile In The Lower Stratosphere, J. J. Harrison, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

This work reports the first infrared satellite remote-sensing measurements of acetonitrile (CH₃CN) in the Earth's atmosphere using solar occultation measurements made by the Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) between 2004 and 2011. The retrieval scheme uses new quantitative laboratory spectroscopic measurements of acetonitrile (Harrison and Bernath, 2012). Although individual ACE-FTS profile measurements are dominated by measurement noise, median profiles in 10 degrees latitude bins show a steady decline in volume mixing ratio from similar to 150 ppt (parts per trillion) at 11.5 km to < 40 ppt at 25.5-29.5 km. These new measurements agree well with the scant available air-and balloon-borne data in the lower stratosphere. An acetonitrile stratospheric lifetime of 73 ± 20 yr has been determined.

Variability Of Atmospheric Hydrocarbon Concentrations And Deposition Rates, Charles Thomas Farmer

OES Theses and Dissertations

The atmospheric hydrocarbon concentration was determined at various locations throughout Southeastern Virginia from July 1981 to February 1983. During this period the concentration ranged from 0.4 to 5.5 μg/m³ . From October 1982 to February 1983, WET and dry deposition samples were collected in conjunction with these air samples. Total hydrocarbon dry deposition rates ranged from deposition rates ranged from 4 to 189 μg/m² /day, while WET 22 to 670 μg/m² /day. Hydrocarbon concentrations found were within the ranges reported in the literature for wet, dry and atmospheric hydrocarbon concentrations.

Linear trend analysis revealed no correlation between …