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Articles 1 - 4 of 4
Full-Text Articles in Physical Sciences and Mathematics
The Impact Of High-Resolution Sea Surface Temperatures On The Simulated Nocturnal Florida Marine Boundary Layer, Katherine M. Lacasse, Michael E. Splitt, Steven M. Lazarus, William M. Lapenta
The Impact Of High-Resolution Sea Surface Temperatures On The Simulated Nocturnal Florida Marine Boundary Layer, Katherine M. Lacasse, Michael E. Splitt, Steven M. Lazarus, William M. Lapenta
Ocean Engineering and Marine Sciences Faculty Publications
High- and low-resolution sea surface temperature (SST) analysis products are used to initialize the Weather Research and Forecasting (WRF) Model for May 2004 for short-term forecasts over Florida and surrounding waters. Initial and boundary conditions for the simulations were provided by a combination of observations, large-scale model output, and analysis products. The impact of using a 1-km Moderate Resolution Imaging Spectroradiometer (MODIS) SST composite on subsequent evolution of the marine atmospheric boundary layer (MABL) is assessed through simulation comparisons and limited validation. Model results are presented for individual simulations, as well as for aggregates of easterly- and westerlydominated low-level flows. …
High-Energy Electron Beams Launched Into Space By Thunderstorms, Joseph R. Dwyer, Brian W. Grefenstette, David M. Smith
High-Energy Electron Beams Launched Into Space By Thunderstorms, Joseph R. Dwyer, Brian W. Grefenstette, David M. Smith
Aerospace, Physics, and Space Science Faculty Publications
Using CGRO/BATSE data, a possible new source of high-energy electrons and positrons in the earth's inner magnetosphere is presented. These particles are generated within the upper atmosphere by Compton scattering and pair-production of gamma-rays originating from near the tropopause as Terrestrial Gamma-ray Flashes (TGFs). Once created, these energetic electrons and positrons follow the geomagnetic field into the inner magnetosphere where they can be detected in low-earth orbit, either near the TGF magnetic foot point or at the conjugate point several thousand kilometers away. Approximately 17% of CGRO/BATSE events previously identified as terrestrial gamma-ray flashes are, in fact, such electrons and …
Co-Location Of Lightning Leader X-Ray And Electric Field Change Sources, John J. Howard, Martin A. Uman, Joseph R. Dwyer, Dustin Hill, Christopher J. Biagi, Ziad H. Saleh, Jason E. Jerauld, Hamid K. Rassoul
Co-Location Of Lightning Leader X-Ray And Electric Field Change Sources, John J. Howard, Martin A. Uman, Joseph R. Dwyer, Dustin Hill, Christopher J. Biagi, Ziad H. Saleh, Jason E. Jerauld, Hamid K. Rassoul
Aerospace, Physics, and Space Science Faculty Publications
Using an eight-station time of arrival (TOA) network composed of NaI(Tl) scintillation detectors and wideband electric field derivative (dE/dt) antennas covering approximately 1 km² on the ground, we have located both the sources of X-ray emissions and electric field changes produced during the leader phase of both downward negative natural and rocket-triggered lightning strokes. We show that the sources of X rays and leader step electric field changes are co-located in space within 50 m and that the located X rays are emitted 0.1 to 1.3 μs after the origin of the leader step electric field changes.
Time Evolution Of Terrestrial Gamma Ray Flashes, Brian W. Grefenstette, David M. Smith, Joseph R. Dwyer, Gerald Jerry Fishman
Time Evolution Of Terrestrial Gamma Ray Flashes, Brian W. Grefenstette, David M. Smith, Joseph R. Dwyer, Gerald Jerry Fishman
Aerospace, Physics, and Space Science Faculty Publications
We present a study of the time evolution of TGFs observed by both RHESSI and BATSE and compare the data with Monte Carlo simulations of relativistic runaway electron avalanches that record the time of flight for individual photons. Our analysis of the RHESSI data shows that the average delay between the main, hard peak and the secondary, soft tail in the RHESSI data is 28 ± 3 μs. We show that this is consistent with Compton downscattering of hard photons in the atmosphere in our simulations when the source region is located at or below 21 km, which is consistent …