| South China Sea Wave Characteristics During Typhoon Muifa Passage in Winter 2004 |
01-Jan-2008 |
49 pages |
| Authors:
Kuo-Feng Cheng; Peter C Chu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA NAVAL OCEAN ANALYSIS AND PREDICTION LAB
|
 | Ocean wave characteristics in the western Atlantic Ocean (Hurricane Region) to tropical cyclones have been investigated extensively, but not the regional seas in the western Pacific such as the South China Sea (Typhoon Region). This is due to the lack of observational and modeling studies in western Pacific regional seas. To fill this gap, Wavewatch-III (WW3) is used to study the response of the South China Sea (SCS) to Typhoon ... |
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| The Interaction of Jet/Front Systems and Mountain Waves: Implications for Lower Stratospheric Aviation Turbulence |
01-Jan-2008 |
217 pages |
| Authors:
David R Vollmer; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| The role of jet streaks and their associated upper-level structures (fronts, troughs, thermal fields, etc.) in enhancing orographically-induced aviation turbulence near and above the tropopause is investigated. The primary hypothesis for this research suggests that there is an optimal configuration for the positioning of upper-level circulations leading to vertically confluent flow and differential thermal advection, forming an intense inversion. Such a configuration may be associated with vertically-intersecting ageostrophic jet circulations ... |
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| 3D Time Dependent Stokes Vector Radiative Transfer in an Atmosphere-Ocean System Including a Stochastic Interface |
Jan 2008 |
13 pages |
| Authors:
George W Kattawar; TEXAS A AND M UNIV COLLEGE STATION DEPT OF PHYSICS
|
| The major objective of this proposal is to calculate the 3-D, time dependent radiation field both within the ocean and in the atmosphere in the presence of a stochastically varying interface which may also be perturbed by sea foam, air bubbles, surfactants, rain, etc. This study will serve as the genesis to the future evolution of an inversion algorithm whereby one could reconstruct images that have been distorted by the ... |
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| High-Power Fiber Lasers for Directed-Energy Applications |
Jan 2008 |
12 pages |
| Authors:
P Sprangle; A Ting; J Penano; R Fischer; B Hafizi; NAVAL RESEARCH LAB WASHINGTON DC PLASMA PHYSICS DIV
|
| High-power fiber lasers can be incoherently combined to form the basis of a high-energy laser system for directed-energy applications. These applications include tactical directed energy and power beaming. Incoherent combining of fiber lasers has a number of advantages over other laser beam combining methods. The incoherently combined laser system is relatively simple, highly efficient, compact, robust, low-maintenance, and reliable. In this article, we characterize the atmospheric propagation of incoherently combined, ... |
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| SHIMMER: Innovative Technology Enabling Unprecedented Science |
Jan 2008 |
4 pages |
| Authors:
C R Englert; M H Stevens; D E Siskind; S D Eckermann; J M Harlander; K Nielsen; F L Roesler; NAVAL RESEARCH LAB WASHINGTON DC SPACE SCIENCE DIV
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| On March 9, 2007, the first ultraviolet spectrometer using the innovative optical technique known as spatial heterodyne spectroscopy was launched into low Earth orbit from Cape Canaveral, FL. The Spatial Heterodyne Imager for Mesospheric Radicals (SHIMMER) is a deskjet printer-sized rugged spectrometer designed to measure solar resonance fluorescence of hydroxyl (OH) in the Earth's middle atmosphere between 30 and 100 km altitude. It is optimized for high spectral resolution, low ... |
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| On Tropical Cyclone Formation |
Jan 2008 |
3 pages |
| Authors:
M S Peng; B Fu; T Li; NAVAL RESEARCH LAB WASHINGTON DC
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| The formation (genesis) of tropical cyclones (TCs) is a complicated process that involves interactions among multi-scale circulations. While tropical disturbances exist all the time, only a few of them may develop into TCs. In this study, the daily global analysis from the Navy Operational Global Atmospheric Prediction System (NOGAPS) is examined to understand why some disturbances develop into TCs while others do not. Significantly different characteristics of atmospheric variables associated ... |
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| National Security and Global Climate Change |
Jan 2008 |
6 pages |
| Authors:
Sean C Maybee; DEPUTY CHIEF OF NAVAL OPERATIONS (MANPOWER PERSONNEL AND TRAINING) WASHINGTON DC
|
| The uncertainty, confusion, and speculation about the causes, effects, and implications of global climate change (GCC) often paralyze serious discussion by polarizing decision makers and the public into camps of believers and skeptics. The intention of this article is not to present a case for or against scientific indications of global climate change, but to consider how it would pose challenges to national security, explore options for facing those challenges, ... |
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| Variability of Irradiance in the Wave Boundary Layer |
Jan 2008 |
6 pages |
| Authors:
W S Pegau; Hemantha W Wijesekera; OREGON STATE UNIV CORVALLIS COLL OF OCEANIC AND ATMOSPHERIC SCIENCES
|
| Our primary goal is improve our understanding of the role of surface waves, bubble clouds, and near surface oceanic processes on the spatial distribution of oceanic irradiance. The objectives are to: 1. Measure the variance in the oceanic light field. 2. Associate the variance in the light field with surface waves and variance in the inherent optical properties and physical properties. We are using an autonomous underwater vehicle (AUV) to ... |
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| In-Scene-Based Atmospheric Correction of Uncalibrated VISible-SWIR (VIS-SWIR) Hyper- and Multispectral Imagery |
Jan 2008 |
9 pages |
| Authors:
L S Bernstein; S M Adler-Golden; R L Sundberg; A J Ratkowski; SPECTRAL SCIENCES INC BURLINGTON MA
|
| The QUAC (Quick Atmospheric Correction) algorithm for in-scene-based atmospheric correction of VIS-SWIR (VISible-Short Wave InfraRed) Multi- and Hyperspectral Imagery (MSI and HSI) is reviewed and applied to radiometrically uncalibrated data. Quite good agreement was previously demonstrated for the retrieved pixel spectral reflectances between QUAC and the physics-based atmospheric correction code FLAASH (Fast Line-of-sight Atmospheric Analysis of Spectral Hypercubes) for a variety of HSI and MSI data cubes. In these code-to-code ... |
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| A Study of Spectral Element and Discontinuous Galerkin Methods for the Navier-Stokes Equations in Nonhydrostatic Mesoscale Atmospheric Modeling: Equation Sets and Test Cases |
2008 |
31 pages |
| Authors:
F. X. Giraldo; M. Restelli; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF APPLIED MATHEMATICS
|
| We present spectral element (SE) and discontinuous Galerkin (DG) solutions of the Euler and compressible Navier-Stokes (NS) equations for stratified fluid flow which are of importance in nonhydrostatic mesoscale atmospheric modeling. We study three different forms of the governing equations using seven test cases. Three test cases involve flow over mountains which require the implementation of non-reflecting boundary conditions, while one test requires viscous terms (density current). Including viscous stresses ... |
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| Modeling Obscurants in an Urban Environment |
Dec 2007 |
16 pages |
| Authors:
Hoock; Donald W Jr; ARMY RESEARCH LAB WHITE SANDS MISSILE RANGE NM BATTLEFIELD ENVIRONMENT DIRECTORATE
|
| Line of Sight obscuration effects of smoke, dust and debris on target acquisition are difficult to model in an urban environment. Wind flow and buoyancy in urban street canyons can be complex. This paper outlines the obscuration model being developed by the U. S. Army Research Laboratory for the NATICK RDEC to support the next generation of the Infantry Warrior Simulation (IWARS). It uses the legacy COMBIC obscuration model sources ... |
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| Atmospheric Polarization Imaging |
01 NOV 2007 |
63 pages |
| Authors:
Joseph A. Shaw; MONTANA STATE UNIV BOZEMAN
|
| A full-sky imaging polarimeter has been developed to measure the four Stokes parameters in each pixel of a full-sky image. The Stokes image set can be acquired in typically less than 1 sec., making possible polarimetric measurements in a partly cloudy sky without creating artifacts from moving clouds. This instrument was used to study the variation of atmospheric polarization with cloudiness, finding that the degree of polarization is consistently less ... |
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| Passive Imaging System for Measuring Atmospheric Scattering: Quarterly Report October 2007 |
01 NOV 2007 |
3 pages |
| Authors:
J. E. Shields; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| This quarterly report describes the work done for the "Passive Imaging System for Measuring Atmospheric Scattering and CFLOS", under ONR Contract N00014-07-1-1060, between 1 August 2007 and 31 October 2007. |
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| Influence of the Atmosphere on a Rubidium Clock's Frequency Aging |
Nov 2007 |
7 pages |
| Authors:
James Camparo; Charles Klimcak; AEROSPACE CORP LOS ANGELES CA
|
| A number of mechanisms have been proposed to explain the phenomenon of frequency aging in the rubidium atomic clock. Helium permeation is one such mechanism. Briefly, the four millitorr of helium in the Earth's atmosphere can permeate into the resonance cell, changing the clock frequency via the pressure shift of the 0-0 hyperfine transition. On orbit, any He in the resonance cell would permeate out, again changing the buffer gas ... |
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| Statistics of the MASIV 5 GHZ VLA Scintillation Survey |
01-Oct-2007 |
6 pages |
| Authors:
David Jauncey; Cliff Senkbeil; Tapio Pursimo; Lucyna Kedziora-Chudczer; Roopesh Ojha; Hayley Bignall; Jean-Pierre Macquart; Barney Rickett; James Lovell; Stanislav Shabala; NAVAL OBSERVATORY WASHINGTON DC
|
| We are undertaking a large-scale VLA 5 GHz variability survey of the northern sky searching for rapid intra-day variability. From four epochs of observations spread over a year we find 56% of the flat-spectrum sources showed significant variability on time-scales from hours to days, with many sources varying episodically on only one epoch during the year. We find that the weaker sources show more frequent variability as well as fractionally ... |
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| Our Changing Planet: The U.S. Climate Change Science Program for Fiscal Year 2008 |
Oct 2007 |
221 pages |
| Authors:
Samuel W Bodman; Carlos M Gutierrez; Marburger; John H III; CLIMATE CHANGE SCIENCE PROGRAM WASHINGTON DC
|
| Our Changing Planet: The U.S. Climate Change Science Program for Fiscal Year 2008 describes the activities and plans of the Climate Change Science Program (CCSP), which incorporates the U.S. Global Change Research Program established under the Global Change Research Act of 1990, and the Climate Change Research Initiative that was established by the President in 2001. CCSP coordinates and integrates scientific research on climate and global change supported by 13 ... |
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| Next-Generation Tropical Cyclone Model |
30 Sep 2007 |
6 pages |
| Authors:
Richard M Hodur; NAVAL RESEARCH LAB MONTEREY CA
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| The long-term goal of this project is to develop a robust and hardened high-resolution air-ocean coupled tropical cyclone (TC) data assimilation and prediction system that is able to assimilate the wide variety of available in-situ and remotely-sensed observations in order to analyze and predict TC structure and intensity changes in an operational environment. Significant gains have been made in TC track prediction over the past three decades. This considerable achievement ... |
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| Aerosol-Cloud-Radiation Interactions in Atmospheric Forecast Models |
30 SEP 2007 |
8 pages |
| Authors:
John H. Seinfeld; CALIFORNIA INST OF TECH PASADENA
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| The long-term goal of this project is to gain a deep understanding of the role of atmospheric aerosols in affecting transmission of radiation through the atmosphere and in influencing cloud properties. |
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| Impacts of Ocean Waves on the Atmospheric Surface Layer: Simulations and Observations |
30 SEP 2007 |
9 pages |
| Authors:
Peter P. Sullivan; James C. McWilliams; NATIONAL CENTER FOR ATMOSPHERIC RESEARCH BOULDER CO
|
| The long term objective of our research is to advance the understanding of air-sea interaction and the coupling between the atmospheric and oceanic boundary layers (the ABL and OBL) mediated by the surface gravity wave field, in order ultimately to develop better parameterizations of the boundary layers and surface fluxes for coupled, large-scale numerical models. Turbulence-resolving, large-eddy and direct numerical simulations (LES and DNS) are the main tools to be ... |
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| Aerosol Microphysics and Radiation Integration |
30 SEP 2007 |
11 pages |
| Authors:
Jeffrey S. Reid; NAVAL RESEARCH LAB MONTEREY CA
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| This project works toward the development and support of real time global prognostic aerosol and visibility models for the benefit of the Department of Defense and civilian research communities. The Aerosol Microphysics and Radiation program was established to lend support to these models through the development of physical to optical transfer functions to bridge the gap between observables (in situ and satellites) and models as well as lay the foundations ... |
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| Monsoon Disturbances Over Southeast and East Asia and the Adjacent Seas |
30 SEP 2007 |
8 pages |
| Authors:
C.P. Chang; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
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| To study weather disturbances over the East Asian - Western Pacific monsoon region and vicinity using Navy and NCEP data and forecast models. The primary goal is to advance the understanding of the weather-producing systems in the region, in order to improve forecast capabilities. |
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| Atmospheric Optical Propagation |
30 Sep 2007 |
8 pages |
| Authors:
Stephen Hammel; Dimitri Tsintikidis; Alexander M Van Eijk; SPACE AND NAVAL WARFARE SYSTEMS CENTER PACIFIC SAN DIEGO CA
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| This project provides a description of the propagation of optical (visible and infrared) waves in the marine atmospheric surface layer by developing and testing a comprehensive optical propagation assessment model suite. The project combines model development and field experimentation with a particular emphasis on coastal environments. |
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| Deducing Air-Sea Fluxes from CBLAST Dropwindsonde Data |
30 Sep 2007 |
6 pages |
| Authors:
Kerry Emanuel; MASSACHUSETTS INST OF TECH CAMBRIDGE
|
| Our ultimate objective is to understand and be able to predict changes in the intensities of hurricanes and to understand and be able to predict surface fluxes of enthalpy and momentum and hurricane wind speeds. |
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| Analysis of Near-Surface Atmospheric Measurements Obtained During CBLAST-LOW |
30 Sep 2007 |
8 pages |
| Authors:
James B Edson; CONNECTICUT UNIV AVERY POINT
|
| The long-range goal of the proposed research is to understand air-sea interaction and coupled atmospheric and oceanic boundary layer dynamics at low wind speeds where the dynamic processes are driven and/or strongly modulated by thermal forcing. The low wind regime extends from the extreme situation where wind stress is negligible and thermal forcing dominates up to wind speeds where wave breaking and Langmuir circulations are also expected to play a ... |
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| Modeling Turbulent Air-Sea Exchange in High Winds |
30 Sep 2007 |
11 pages |
| Authors:
Edgar L Andreas; NORTHWEST RESEARCH ASSOCIATES INC REDMOND WA
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| The goal is to investigate, theoretically and through analyzing existing data, the role that sea spray plays in transferring heat, moisture, and momentum across the air-sea interface, especially in high winds. Ultimately, I plan to develop simple, fast, physics-based parameterizations for these air-sea fluxes for use in large-scale models, especially those simulating tropical and extratropical storms. |
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| The Potential for Carbon Sequestration in the United States |
SEP 2007 |
32 pages |
| Authors:
Natalie Tawil; CONGRESSIONAL BUDGET OFFICE (U S CONGRESS) WASHINGTON DC
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| Various analyses suggest that avoiding future climate-related damage by starting to reduce the atmospheric concentration of CO2 would have greater benefits than costs. Options for doing that include not only curbing activities that generate emissions but also sequestering CO2 for example, by encouraging its absorption from the atmosphere into vegetation and soil (biological sequestration) and by trapping CO2 at power plants and industrial facilities before it is emitted and injecting ... |
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| Climate Change Research. Agencies Have Data-Sharing Policies but Could Do More to Enhance the Availability of Data from Federally Funded Research |
SEP 2007 |
62 pages |
| Authors:
John Stephenson; Diane Raynes; Kyle Browning; Kate Cardamone; John Delicath; Carolyn Garvey; Richard Johnson; Lynn Musser; Katherine M. Raheb; GOVERNMENT ACCOUNTABILITY OFFICE WASHINGTON DC
|
| Much of the nearly $2 billion annual climate change research budget supports grants from the Department of Energy (DOE), National Aeronautics and Space Administration (NASA), National Oceanic and Atmospheric Administration (NOAA), and National Science Foundation (NSF). Some of the data generated by this research are stored in online archives, but much remains in a less accessible format with individual researchers. As a result, some researchers are concerned about the availability ... |
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| Performance of Hybrid Eulerian-Lagrangian Semi-Implicit Time-Integrators for Nonhydrostatic Mesoscale Atmospheric Modeling |
SEP 2007 |
73 pages |
| Authors:
Thomas J. De Luca; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| In this thesis, the performance and accuracy of explicit, semi-implicit, and Hybrid Eulerian-Lagrangian Semi-Implicit (HELSI) time-integration methods for use in atmospheric modeling are examined. Four test cases are analyzed: A density current, an inertial gravity wave, a rising thermal bubble, and a hydrostatic mountain wave. Strict attention is paid to computational time, stability criteria, and accuracy. The project aims to show increased efficiency using the HELSI method over semi implicit ... |
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| Sensor Model Requirements for TAWS/IRTSS Operation |
SEP 2007 |
123 pages |
| Authors:
Rachel Hughes; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| Possible improvements to the minimum resolvable temperature difference (MRTD) entered into TAWS are considered. FLIR92 is modified to include atmospheric turbulence that depends on height in the atmosphere. Resultant MRTDs are compared to the operational FLIR92 MRTD predictions excluding atmospheric turbulence. The difference in the MRTD is only apparent in the higher frequency regime and is less than 0.05% of the MRTD values for a typical test case. MRTD is ... |
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| Understanding Recent Variability in the Arctic Sea Ice Cover -- Synthesis of Model Results and Observations |
SEP 2007 |
83 pages |
| Authors:
John Whelan; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| This thesis provides a continuation of the analysis of the diminishing sea ice trend in the Arctic Ocean by examining results from the NPS 1/12 degree pan-Arctic coupled ice-ocean model. While many previous studies have analyzed changes in ice extent and concentration, this research focuses on ice thickness as it gives a better representation of ice volume variability. The skill of the model is examined by comparing its ice thickness ... |
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| An Improved Method of Back Azimuth Determination with a Multi-Arm OFIS |
Sep 2007 |
12 pages |
| Authors:
Kristoffer T Walker; Mark Zumberge; Jonathan Berger; Michael A Hedlin; Peter M Shearer; CALIFORNIA UNIV SAN DIEGO LA JOLLA
|
| The detection of infrasound in the presence of wind is challenging. Increasing wind speeds lead to higher noise floors. While the exact nature of the noise is still a subject of investigation, several technologies and array configurations have been developed to maximize the signal to noise ratio and lower the detection threshold. Optical fiber infrasound sensors (OFIS) are long compliant tubes wrapped with two optical fibers that integrate pressure change ... |
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| OFIS Experiments at Camp Elliott: Paving the Way to Infrasonic Radar and a Portable Infrasonic Sensor Calibrator |
Sep 2007 |
11 pages |
| Authors:
Kristoffer T Walker; Mark Zumberge; Matthew A Dzieciuch; CALIFORNIA UNIV SAN DIEGO LA JOLLA
|
| Optical fiber infrasound sensors (OFIS) are long compliant tubes wrapped with two optical fibers that integrate pressure variation along the length of the tubes via laser interferometry at the speed of light. We have previously shown that several OFIS arms can resolve the back azimuth and elevation angle of infrasound signals due to the spectral fingerprint of the instrument response in the recorded signal and the time separation provided by ... |
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| Improved Infrasound Event Location |
Sep 2007 |
11 pages |
| Authors:
Michael S O'Brien; Douglas P Drob; J R Bowman; SCIENCE APPLICATIONS INTERNATIONAL CORP MCLEAN VA
|
| The purpose of this project is to improve the ability to locate infrasound events by improving the Horizontal Wind Model (HWM) used in the prediction of infrasound observables, in particular, travel time and back azimuth. Our general approach uses new wind data to develop a higher-resolution and more accurate HWM and tests the performance of Ground to Space (G2S) specifications based on the new HWM, relative to those based on ... |
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| Radioxenon Atmospheric Measurements in North Las Vegas, NV |
Sep 2007 |
9 pages |
| Authors:
Brian D Milbrath; Matthew W Cooper; Lance S Lidey; Theodore W Bowyer; James C Hayes; Justin I McIntyre; Lynn Karr; David Shafer; Jeff Tappen; PACIFIC NORTHWEST NATIONAL LAB RICHLAND WA
|
| Pacific Northwest National Laboratory (PNNL) deployed the Automated Radioxenon Sampler/Analyzer (ARSA) in North Las Vegas for two weeks in February and March 2006 for the purpose of measuring the radioxenon background at a level of sensitivity much higher than previously obtained in the vicinity of the Nevada Test Site (NTS). The measurements establish what might be expected if future measurements were ever taken at the NTS itself and investigate improved ... |
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| Controlled Precipitation of Radiation Belt Particles |
23 AUG 2007 |
6 pages |
| Authors:
Umran S. Inan; Timothy F. Bell; Timothy W. Chevalier; STANFORD UNIV CA SPACE TELECOMMUNICATIONS AND RADIOSCIENCE LAB (STAR)
|
| The Air Force Grant documented here directly resulted in the purchase of hardware eight VLF receivers. Five of these receivers have been deployed successfully and are operating regularly and reliably. The remaining are pending imminent deployment. The new receiver sites have enabled Stanford to jumpstart a fully-funded THY program, with funds from Stanford University and NASA, which will enable a great expansion of this network, and in addition, provides a ... |
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| Adaptive Optics Performance Model for Optical Interferometry |
10 JUL 2007 |
11 pages |
| Authors:
D. Mozurkewich; S. R. Restaino; J. T. Armstrong; G. C. Gilbreath; NAVAL RESEARCH LAB WASHINGTON DC OPTICAL SCIENCES DIV
|
| The optical interferometry community has discussed the possibility of using adaptive optics (AO) on apertures much larger than the atmospheric coherence length in order to increase the sensitivity of an interferometer, although few quantitative models have been investigated. The aim of this paper is to develop an analytic model of an AO-equipped interferometer and to use it to quantify, in relative terms, the gains that may be achieved over an ... |
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| Using Limited Time Periods as a Means to Elucidate Microwave Sounding Unit Derived Tropospheric Temperature Trend Methods |
JUL 2007 |
109 pages |
| Authors:
Robb M. Randall; ARIZONA UNIV TUCSON
|
| Limited Time Period (LTP) running trends are used to elucidated Microwave Sounding Unit (MSU) derived tropospheric temperature trend methods. Regression derived coefficients were used to combine lower stratosphere (LS) and mid-troposphere to lower stratosphere (MT) simulated MSU channels from RATPAC radiosonde data using sites not found to have long-term cooling biases. This combination is used to estimate tropospheric temperature trends and then is compared to the actual RATPAC derived tropospheric ... |
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| Formation of an F3 Layer in the Equatorial Ionosphere: A Result from Strong IMF Changes |
Jul-2007 |
31 pages |
| Authors:
V V Paznukhov; B W Reinisch; P Song; X Huang; T W Bullett; O Veliz; MASSACHUSETTS UNIV LOWELL CENTER FOR ATMOSPHERIC RESEARCH
|
| We analyzed ionospheric observations made with digisondes in Jicamarca, Ramey, Wallops Island, Ascension Island, and Kwajalein Island during the major magnetic storm of November 9-10, 2004 that was associated with rapid interplanetary magnetic field (IMF) Bz changes. The strongest ionospheric responses to the southward IMF Bz turning were observed at the dip equator at Jicamarca where during the magnetic disturbance a dramatic F2 peak density depletion occurred around 1500 local ... |
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| An Overview of Atmospheric Data Assimilation |
20 Jun 2007 |
38 pages |
| Authors:
Paul Homan; Bob Wacker; AIR FORCE ACADEMY COLORADO SPRINGS CO
|
| Purpose: Convey how weather forecasting models incorporate diverse observational data * Governing Equations * Introduction to Meteorological Observations * Introduction to Numerical Weather Prediction (NWP) * Methods of Data Assimilation * Optimal Interpolation (OI) * 3-Dimensional Variational Assimilation (3DVAR) * 4-Dimensional Variational Assimilation (4DVAR) * Kalman Filter |
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| Evaluation of WRF Performance for Depicting Orographically-Induced Gravity Waves in the Stratosphere |
15-Jun-2007 |
10 pages |
| Authors:
Douglas C Hahn; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| Orographically-induced gravity (buoyancy) waves can propagate through the tropopause to the lower stratosphere causing disruptions to high altitude aircraft operations. To forecast this high altitude turbulence (HAT) in real time, there is a need to determine optimal model nesting, vertical resolution, upper boundary conditions and diffusion to be able to detect these situations. Besides investigating the above mentioned model options, the WRF-ARW will be closely configured to the operational version ... |
|
| Design of a Compact, Optically Guided, Pinched, Megawatt Class Free-Electron Laser |
08 JUN 2007 |
31 pages |
| Authors:
Phillip Sprangle; Joseph Penano; Bahman Hafizi; NAVAL RESEARCH LAB WASHINGTON DC
|
| A conceptual design for a compact megawatt class FEL operating within atmospheric transmission windows is presented. The proposed FEL consists of an optically guided, pinched amplifier configuration driven by an RF linac. The gain length, efficiency, electron pulse slippage and the distance between the wiggler and first relay mirror are determined for a megawatt class design. Of particular concern in the design is the overall length of the optical system, ... |
|
| Propagation of High Energy Laser Beams in Various Environments |
08 JUN 2007 |
61 pages |
| Authors:
Phillip Sprangle; Joseph Penano; Bahman Hafizi; NAVAL RESEARCH LAB WASHINGTON DC
|
| We report the results of our theoretical study on the key physical processes that affect the propagation of nigh energy lasers in the atmosphere. The main objective of this study is to discuss the optimum laser wavelength and power for efficient propagation in maritime, desert, rural and urban atmospheric environments. The theoretical/numerical model used in this study includes the effects of aerosol and molecular scattering, aerosol heating and vaporization, thermal ... |
|
| Basis of Ionospheric Modification by High-Frequency Waves |
JUN 2007 |
21 pages |
| Authors:
S. P. Kuo; POLYTECHNIC UNIV BROOKLYN NY DEPT OF ELECTRICAL ENGINEERING AND COMPUTER SCIENCE
|
| The requirements of achieving ionospheric modification by ground-transmitted HF heating waves are discussed. The directly relevant processes including linear mode conversion and parametric instabilities are explained physically. The nonline & Schrodinger equation for Langmuir waves is reviewed and the initial conditions of two types of nonlinear solutions are discussed; from which the criterion for Langmuir soliton generation is pointed out. |
|
| Thermospheric Space Weather Modeling |
JUN 2007 |
13 pages |
| Authors:
Frank A. Marcos; William J. Burke; Shu T. Lai; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| We review impacts of satellite drag and describe past, current and future capabilities designed to meet evolving operational requirements. Historically, thermospheric research has been data starved. Thus, from the early space age to the end of the 20th century little progress was made in satellite-drag modeling. This condition improved greatly with the development of empirical assimilative models and recent availability of comprehensive drag measurements. With the new Jacchia-Bowman 2006 model ... |
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| Precipitation of Trapped Relativistic Electrons by Amplified Whistler Waves in the Magnetosphere |
JUN 2007 |
8 pages |
| Authors:
S. P. Kuo; Steven S. Kou; James T. Huynh; Paul Kossey; POLYTECHNIC UNIV BROOKLYN NY DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Numerical study of a loss-cone negative mass instability to amplify whistler waves by energetic electrons in the radiation belts is presented. The results show that a very low intensity whistler wave can be amplified by 50 keV electrons more than 25 dB, consistent with the Siple experimental result [Helliwell et al., J. Geophys. Res. 85, 3360 (1980)]. The dependencies of the amplification factor on the energetic electron density and on ... |
|
| Theoretical Studies of Gas Phase Elementary Reactions |
Jun 2007 |
8 pages |
| Authors:
Keiji Morokuma; EMORY UNIV ATLANTA GA DEPT OF CHEMISTRY
|
| This final technical report begins with the objective the project, followed by summary reports on new accomplishments and findings obtained in the project. They are presented in four sections: A. Potential Energy Surfaces of Ion-Molecule Reactions and Ionic Species, B. Potential Energy Surfaces for Elementary Reactions of Atmospheric Importance, C. Potential Energy Surfaces for Electronic Spectroscopy, Photochemical Reactions and Nonadiabatic Processes. D. Interaction of Oxygen and Other Small Molecules with ... |
|
| Multi-scale Predictability of High-Impact Weather in the Battlespace Environment |
Jun 2007 |
5 pages |
| Authors:
James Doyle; Carolyn Reynolds; Justin McLay; Teddy Holt; Joao Teixeira; Craig Bishop; NAVAL RESEARCH LAB MONTEREY CA
|
| Objectives of our study include: i) examination of the predictability of regional-scale weather phenomenon that have a high impact on military missions, ii) exploration of new methods to initialize ensembles for global and mesoscale atmospheric models, and iii) diagnosis of mohourdel error and uncertainty, and inclusion in ensemble design. For the global ensembles, the Ensemble Transform initial perturbation method is superior to the current operational method, and work is underway ... |
|
| The Supreme Court's Climate Change Decision: Massachusetts v. EPA |
18 MAY 2007 |
|
| Authors:
Robert Meltz; LIBRARY OF CONGRESS WASHINGTON DC CONGRESSIONAL RESEARCH SERVICE
|
 | On April 2, 2007, the Supreme Court handed down "Massachusetts v. EPA," its first pronouncement on climate change. By 5-4, the Court held the following: (1) Massachusetts had standing to sue, (2) Section 202 of the Clean Air Act authorizes the Environmental Protection Agency (EPA) to regulate emissions from new motor vehicles on the basis of their possible climate change impacts, and (3) Section 202 does not authorize EPA to ... |
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| A Space-Based Proxy for the Dst Index |
18 MAY 2007 |
8 pages |
| Authors:
F. J. Rich; J. M. Bono; W. J. Burke; L. C. Gentile; AIR FORCE RESEARCH LAB HANSCOM AFB MA
|
| The Dst index was created to monitor and quantify disturbances in the inner magnetosphere using ground-based, magnetic field measurements. The phases and strengths of geomagnetic storms are usually defined by the evolution of Dst. The standard Dst database is computed and maintained at the World Data Center for Geomagnetism, Kyoto. We demonstrate that the Dst index can also be approximated using magnetometers on spacecraft in near-Earth orbit. Measurements used in ... |
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| Influence of Different Solar Drivers on the Winds in the Middle Atmosphere and on Geomagnetic Disturbances |
18-May-2007 |
27 pages |
| Authors:
Katya Y Georgieva; BULGARIAN ACADEMY OF SCIENCES SOFIA
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| This report results from a contract tasking Bulgarian Academy of Sciences as follows: The grantee will investigate the effects of various solar drivers on the dynamics of the stratosphere and on the geomagnetic disturbances to the earth. To accomplish this, the grantee will create a database of all registered coronal mass ejections, magnetic clouds, solar flares, and high speed solar streams; neutral wind measurements at different atmospheric levels in the ... |
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Atmospheric Physics
