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Major Disaster Declarations for Snow Assistance and Severe Winter Storms: An Overview

Description: This report describes snow assistance and assistance for severe winter storms, including the declaration process, the criteria used to make eligibility determinations, and the types of assistance that are provided after the President has issued a major disaster declaration for the incident. This report also provides historical data on winter incidents since 2009 including obligations for the incidents from FEMA's Disaster Relief Fund (DRF). The DRF is the main account used to fund a wide variety of programs, grants, and other forms of emergency and disaster assistance to states, local governments, certain nonprofit entities, and families and individuals affected by disasters.
Date: March 13, 2017
Creator: Lindsay, Bruce R.
Partner: UNT Libraries Government Documents Department

Major Disaster Declarations for Snow Assistance and Severe Winter Storms: An Overview

Description: This report describes snow assistance and assistance for severe winter storms, the declaration process, the criteria used to make eligibility determinations, and the types of assistance that are provided after the President has issued a major disaster declaration for the incident. This report also provides historical data on winter incidents since 2009 including obligations for the incidents from FEMA's Disaster Relief Fund (DRF). The DRF is the main account used to fund a wide variety of programs, grants, and other forms of emergency and disaster assistance to states, local governments, certain nonprofit entities, and families and individuals affected by disasters.
Date: December 1, 2014
Creator: Lindsay, Bruce R.
Partner: UNT Libraries Government Documents Department

EVIDENCE FOR COMET STORMS IN METEORITE AGES

Description: Clustering of cosmic-ray exposure ages of H chondritic meteorites occurs at 7 {+-} 3 and 30 {+-} 6 Myr ago. There is independent evidence that comet storms have occurred at the same times, based on the fossil record of family and genus extinctions, impact craters and glass, and geomagnetic reversals. We suggest that H chondrites were formed by the impact of shower comets on asteroids. The duration of the most recent comet shower was {le} 4 Myr, in agreement with storm theory.
Date: October 1, 1987
Creator: Perlmutter, S. & Muller, R.A.
Partner: UNT Libraries Government Documents Department

Kinetic Ballooning Instability for Substorm Onset and Current Disruption Observed by AMPTE/CCE

Description: A new scenario of AMPTE/CCE observation of substorm onset and current disruption and the corresponding physical processes is presented. Toward the end of late growth phase plasma beta increases to greater than or equal to 50 and a low-frequency instability with a wave period of 50-75 seconds is excited and grows exponentially to a large amplitude at the onset of current disruption. At the current disruption onset, higher-frequency instabilities are excited so that the plasma and electromagnetic magnetic field form a turbulent state. Plasma transport takes place to modify the ambient plasma pressure and velocity profiles so that the ambient magnetic field recovers from a tail-like geometry to a more dipole-like geometry. To understand the excitation of the low-frequency global instability, a new theory of kinetic ballooning instability (KBI) is proposed to explain the high critical beta threshold (the high critical beta threshold is greater than or equal to 50) of the low-frequency global instability observed by the AMPTE/CCE. The stabilization is mainly due to kinetic effects of trapped electrons and finite ion Larmor radii which give rise to a large parallel electric field and hence a parallel current that greatly enhances the stabilizing effect of field line tension to the ballooning mode. As a result, the high critical beta threshold for excitation of KBI is greatly increased over the ideal-MHD ballooning instability threshold by greater than or equal to O(10 exp 2). The wave-ion magnetic drift resonance effect produces a perturbed resonant ion velocity distribution with a duskward velocity roughly equal to the average ion magnetic (gradient B and curvature) drift velocity. Higher-frequency instabilities such as cross-field current instability (CCI) can be excited by the additional velocity space free energy associated with the positive slope in the perturbed resonant ion velocity distribution in the current disruption phase.
Date: May 1, 1998
Creator: Cheng, C.Z. & Lui, A.T.Y., PPPL
Partner: UNT Libraries Government Documents Department

Observations and Inferred Physical Characteristics of Compact Intracloud Discharges

Description: Compact intracloud discharges (CIDS) represent a distinct class of electrical discharges that occur within intense regions of thunderstorms. They are singular discharges that produce brief (typically 3 µs in duration) broadband RF emissions that are 20 to 30 dB more powerful than radiation from all other recorded lightning processes in the HF and VHF radio spectrum. Far field electric field change recordings of CIDS consist of a single, large-amplitude bipolar pulse that begins to rise during the RF-producing phase of the CID and typically lasts for 20 µs. During the summer of 1998 we operated a 4-station array of electric field change meters in New Mexico to support FORTE satellite observations of transient RF and optical sources and to learn more about the phenomenology and physical characteristics of CIDS. Over 800 CIDS were detected and located during the campaign. The events were identified on the basis of their unique field change waveforms. CID source heights determined using the relative delays of ionospherically reflected source emissions were typically between 4 and 11 km above ground level. Events of both positive and negative polarity were observed with events' of initially- negative polarity (indicative of discharges occurring between underlying positive and overlying negative charge) occurring at slightly higher altitudes. Within CID field change waveforms the CID pulse was often followed within a few ms by one or more smaller-amplitude pulses. We associate these subsequent pulses with the initial activity of a "normal" intracloud flash, the inference being that some fraction of the time, a CID initiates an intracloud lightning flash.
Date: February 1, 1999
Creator: Argo, P.E.; Eack, K.B.; Holden, D.N.; Massey, R.S.; Shao, X.; Smith, D.A. et al.
Partner: UNT Libraries Government Documents Department

Remote sensing of thundercloud electric fields

Description: Theoretical and experimental work was performed on emission of photons from the air within and above thunderclouds and within lightning channels. Predictions were made of the telltale emissions from ionized nitrogen molecules and these emissions were recorded. The measurements will be utilized to help to understand the nature of thundercloud-produced airglow.
Date: August 1, 1997
Creator: Borovsky, J.; Buchwald, M. & Suszcynsky, D.
Partner: UNT Libraries Government Documents Department

Hurricanes! USGCRP Seminar, 11 December 1995.

Description: In this USGRP Seminar, speakers try to answers questions like:What is the current status of hurricane track prediction? What caused the record number of Atlantic tropical storms in 1995? Are we witnessing a change in the number and frequency of tropical storms? Do these storms represent a changing climate? What will tropical storms be like in a greenhouse warmer world?
Date: December 11, 1995
Creator: Baker, James
Partner: UNT Libraries

Federal Evacuation Policy: Issues for Congress

Description: This report discusses federal evacuation policy and analyzes potential lessons learned from the evacuation of individuals from Hurricane Katrina. Several issue areas that might arise concerning potential lawmaking and oversight on evacuation policy are also highlighted. This report will be updated as significant legislative or administrative changes occur.
Date: March 30, 2009
Creator: Lindsay, Bruce R.
Partner: UNT Libraries Government Documents Department

Federal Evacuation Policy: Issues for Congress

Description: This report discusses federal evacuation policy and analyzes potential lessons learned from the evacuations of individuals in response to the Gulf Coast hurricanes of 2005. Several issue areas that might arise concerning potential lawmaking and oversight on evacuation policy are also highlighted.
Date: January 18, 2011
Creator: Lindsay, Bruce R.
Partner: UNT Libraries Government Documents Department

Federal Evacuation Policy: Issues for Congress

Description: This report discusses federal evacuation policy and analyzes potential lessons learned from the evacuations of individuals in response to the Gulf Coast hurricanes of 2005. It also highlights several issue areas that might arise concerning potential lawmaking and oversight on evacuation policy.
Date: April 29, 2010
Creator: Lindsay, Bruce R.
Partner: UNT Libraries Government Documents Department

Physical Processes of Substorm Onset and Current Disruption Observed by AMPTE/CCE

Description: A new scenario of AMPTE/CCE observation of substorm onset and current disruption and the corresponding physical processes is presented. Toward the end of the late growth phase, plasma beta increases to greater than or equal to 50 and a low-frequency instability with a wave period of 50-75 seconds is excited and grows exponentially to a large amplitude at the onset of current disruption. At the current disruption onset, higher-frequency instabilities are excited so that the plasma and electromagnetic field form a turbulent state. Plasma transport and heating take place to reduce plasma beta and modify the ambient plasma pressure and velocity profiles so that the ambient magnetic field recovers from a tail-like geometry to a more dipole- like geometry. To understand the excitation of the low-frequency global instability, a new theory of kinetic ballooning instability (KBI) is proposed to explain the high critical beta threshold (greater than or equal to 50) of the low-frequency global instability observed by the AMPTE/CCE. The stabilization kinetic effects of trapped electron and finite ion Larmor radii give rise to a large parallel electric field and hence a parallel current that greatly enhances the stabilizing effect of field line tension to the ballooning mode. As a result, the high critical beta threshold for excitation of KBI is greatly increased over the ideal MHD ballooning instability threshold by greater than O(10 squared). The wave-ion magnetic drift resonance effect typically reduces the high critical beta threshold by up to 20% and produces a perturbed resonant ion velocity distribution with a duskward velocity roughly equal to the average ion magnetic drift velocity as the KBI grows to a large amplitude. Higher-frequency instabilities, such as the cross-field current instability (CCI), can be excited by the additional velocity space free energy associated with the positive slope in the perturbed resonant ...
Date: March 1998
Creator: Cheng, C. Z. & Lui, A. T. Y.
Partner: UNT Libraries Government Documents Department

Satellite observations of transient radio impulses from thunderstorms

Description: Transient radio emissions from thunderstorms detected by satellites were first reported in 1995. The nature and source of these emissions remained a mystery until the launch of the FORTE satellite in 1997. FORTE, with its more sophisticated triggering and larger memory capacity showed that these emissions were connected to major thunderstorm systems. The analysis reported here, connecting FORTE RF events with ground based lightning location data from the National Lightning Detection Network (NLDN), shows that localized regions within thunderstorms are responsible for the creation of the satellite detected rf signals. These regions are connected with the areas of strong radar returns from the NEXRAD Doppler radar system, indicating that they are from regions of intense convection. The authors will also show data from several storms detected in the extended Caribbean, in which the height profile of the source regions can be determined. Although as a single low earth orbit satellite FORTE cannot provide global coverage of thunderstorm/lightning events, follow-on satellite constellations should be able to provide detailed information on global lightning in near real-time.
Date: June 1, 1999
Creator: Argo, P. E.; Kirkland, M.; Jacobson, A.; Massey, R.; Suszynsky, D.; Eack, K. et al.
Partner: UNT Libraries Government Documents Department

Thunderstorm and Lightning Studies using the FORTE Optical Lightning System (FORTE/OLS)

Description: Preliminary observations of simultaneous RF and optical emissions from lightning as seen by the FORTE spacecraft are presented. RF/optical pairs of waveforms are routinely collected both as individual lightning events and as sequences of events associated with cloud-to-ground (CG) and intra-cloud (IC) flashes. CG pulses can be distinguished from IC pulses based on the properties of the RF and optical waveforms, but mostly based on the associated RF spectrograms. The RF spectrograms are very similar to previous ground-based VHF observations of lightning and show signatures associated with return strokes, stepped and dart leaders, and attachment processes,. RF emissions are observed to precede the arrival of optical emissions at the satellite by a mean value of 280 microseconds. The dual phenomenology nature of these observations are discussed in terms of their ability to contribute to a satellite-based lightning monitoring mission.
Date: February 1, 1999
Creator: Argo, P.; Franz, R.; Green, J.; Guillen, J.L.; Jacobson, A.R.; Kirkland, M. et al.
Partner: UNT Libraries Government Documents Department