Lake-effect snowstorms in northern Utah and western New York with and without lightning/thunder are examined. Lake-effect snowstorms with lightning have significantly higher temperatures and dewpoints in the lower troposphere and significantly lower lifted indices than lake-effect snowstorms without lightning. In contrast, there is little difference in dewpoint depressions between events with a...

Employing reanalysis datasets, several threshold temperatures at 850 hPa are used tomeasure the wintertime [December–February (DJF)] areal extent of the lower-tropospheric, Northern Hemisphere, cold-air pool over the past 66 cold seasons. The analysis indicates a systematic contraction of the cold pool at each of the threshold temperatures. Special emphasis is placed on analysis of the trends i...

Satellite-based observations provide great opportunities for improving weather forecasting. Physical retrieval of atmospheric profiles from satellite observations is sensitive to the uncertainty of the first guess and other factors. In order to improve the accuracy of the physical retrieval, an ensemble methodology was developed with an emphasis on perturbing the first guess. In the methodology...

Four divers were exposed successively for ten minute periods to pure tones of 5600, 1400, and 700 hertz (Hz) (in that order) in air at 100 decibels above 20 raicropascal and in water at various sound pressure levels between 125 and 150 decibels above 20 micropascal. Divers incurred moderate temporary auditory-threshold shifts (TTS) from all exposures. Equivalent amounts of TTS are produced in w...

Title Part Symbols d mean temperature dierence, K, (see eq. (1)) m sample size p pressure, hPa (or 100 Pa) s sample standard deviation, K, (see eq. (2)) T temperature, K t Student's t-test statistic (see eq. (3)) x station temperature value from single sounding, K Z geopotential height, km z geometric altitude, km Subscripts: j pair number (see eq. (1)) m sample size (see eq. (3)) 1 satellite (...

Based on the tracking of the movement of the tropopause over the whole year, the extent/depth of stratosphere-troposphere exchange (STE) events and their seasonal variations is investigated. It is found that a stratospheric signature can be observed at pressures as high as 400 hPa in a hemisphere during its winter to spring period, while a tropospheric signature can be observed at pressures as ...

Hemispheric transport of air pollutants can have a significant impact on regional air quality, as well as on the effect of air pollutants on regional climate. An accurate representation of hemispheric transport in regional chemical transport models (CTMs) depends on the specification of the lateral boundary conditions (LBCs). This study focuses on the methodology for evaluating LBCs of two mode...

in this study, the daily total ozone column (toc) measured by the instruments of toms (2001) and omi (2005-2011) satellites and brewer ground station (2002-2004) is used to investigate the extreme ozone mini-holes over esfahan. based on previous reports on validation of the toc data products, it is found that there is no problem with homogenization of data records, which was provided by the abo...

Propane combustion in a trapped vortex combustor (TVC) is characterized via large eddy simulation coupled with filtered mass density function. A computational algorithm based on high order finite difference (FD) schemes, is employed to solve the Eulerian filtered compressible Navier-Stokes equations. In contrast, a Lagrangian Monte-Carlo solver based on the filtered mass density function is inv...

A rapid, senstive method for NO2 analysis utilizing the chemiluminescence reaction of NO and O3 is provided by the use of the Scott Model 125 Chemiluminescense NO/NOI, Analyzer. Measurement of NO2 in the air sample by reducing it to NO by passage tgrough a converter before it enters the reaction chamber. Thermal converter will also convert, partially or completly, NH3 (and other N-componds) dep...