A5000834407- Atmospheric Ozone and Climate
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Astro and Planetary Science
- Planetary Science and Exploration
- Climate variability and models
- Geophysics and Gravity Measurements
- Meteorological Phenomena and Simulations
- Geomagnetism and Paleomagnetism Studies
- Earthquake Detection and Analysis
- Methane Hydrates and Related Phenomena
- Geotechnical and Geomechanical Engineering
- Tunneling and Rock Mechanics
- Atmospheric aerosols and clouds
- Spaceflight effects on biology
- Spacecraft Design and Technology
- Structural Response to Dynamic Loads
- Geophysical Methods and Applications
- GNSS positioning and interference
- Rock Mechanics and Modeling
- Gamma-ray bursts and supernovae
- Spacecraft and Cryogenic Technologies
- Oceanographic and Atmospheric Processes
Computational Physics (United States)
2022-2025
United States Naval Research Laboratory
2015-2024
Naval Research Laboratory Space Science Division
2010-2022
Laboratory for Atmospheric and Space Physics
1987-2018
United States Navy
2016
University of Wuppertal
1997
Johns Hopkins University
1997
Hampton University
1997
Langley Research Center
1991-1994
University of Michigan
1989-1991
Abstract NRLMSIS® 2.0 is an empirical atmospheric model that extends from the ground to exobase and describes average observed behavior of temperature, eight species densities, mass density via a parametric analytic formulation. The inputs are location, day year, time day, solar activity, geomagnetic activity. NRLMSIS major, reformulated upgrade previous version, NRLMSISE‐00. now couples thermospheric densities entire column, effective profile transitions each fully mixed region below ~70 km...
Measurements by the Atmospheric Chemistry Experiment show that amount of NO x (NO + 2 ) produced energetic particle precipitation (EPP) descended from Arctic mesosphere and lower thermosphere into stratosphere in early 2009 was up to ∼50 times higher than average 2005, 2007 2008. This is note because level EPP preceding months very low, suggesting excess production not cause enhancements. Rather, enhancements are attributed unusually strong descent middle atmosphere. third time on record...
We have studied the mesospheric response to two recent stratospheric warmings by performing short‐term forecasts at medium (1.5°) and high (0.5°) spatial resolution under different gravity wave drag (GWD) scenarios. validated our models with high‐altitude analysis that extends from 0 90 km. For minor warming of January 2008, reduced upper‐level orographic GWD weakened downward residual circulation cooled mesosphere. Parameterized nonorographic increased simulated cooling. prolonged major...
Atomic oxygen (O) is a fundamental component in chemical aeronomy of Earth's mesosphere and lower thermosphere region extending from approximately 50 km to over 100 altitude. notoriously difficult measure, especially with remote sensing techniques orbiting satellite sensors. It typically inferred measurements the ozone concentration day or Meinel band emission hydroxyl radical (OH) at night. The Sounding Atmosphere using Broadband Emission Radiometry (SABER) instrument on NASA...
Abstract We have developed an empirical model of nitric oxide (NO) number density at altitudes from ∼73 km to the exobase, as a function altitude, latitude, day year, solar zenith angle, activity, and geomagnetic activity. The is part NRLMSIS® 2.1 atmospheric temperature species densities; this upgrade NRLMSIS 2.0 consists solely addition NO. MSIS assimilates observations six space‐based instruments: UARS/HALOE, SNOE, Envisat/MIPAS, ACE/FTS, Odin/SMR, AIM/SOFIE. additionally evaluated new...
A 9‐month‐long series of measurements ozone in the upper stratosphere and mesosphere is reported. The are presented as monthly averages profiles blocks roughly 20 min local time night‐to‐day ratios. An error analysis predicts accuracies 5–26% for 2.5–9% data compared to historical from SME limb infrared monitor (LIMS), it shown how remove effect different vertical resolution comparisons. microwave typically agree better than 10% with nighttime LIMS at all altitudes below 0.1‐mbar surface....
Observations from the Sounding of Atmosphere with Broadband Emission Radiometry (SABER) experiment on NASA/Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite show an unusual vertical displacement winter Arctic stratopause in 2006 zonal mean temperatures at 0.01 hPa (∼78 km) exceeding 250 K. By contrast, conventional location near 0.7 (∼50 km), were unusually cold. Simulations NOGAPS‐ALPHA model suggest that these are coupled to warm disturbed lower stratosphere...
Water vapor measurements made by the Halogen Occultation Experiment (HALOE) from 1991 to 1997 are compared with ground‐based observations Vapor Millimeter‐wave Spectrometers (WVMS) taken 1992 at Table Mountain, California (34.4°N, 242.3°E), and Lauder, New Zealand (45.0°S, 169.7°E). The HALOE show that an upward trend in middle atmospheric water is present all latitudes. average retrievals latitudes 40–60 km range 0.129 ppmv/yr, while observed WVMS instruments this altitude 0.148 ppmv/yr....
Meteoric material entering Earth's atmosphere ablates in the mesosphere and is then expected to recondense into tiny so‐called “smoke particles.” These particles are thought be of great importance for middle phenomena like noctilucent clouds, polar mesospheric summer echoes, metal layers, heterogeneous chemistry. Commonly used one‐dimensional (1‐D) meteoric smoke profiles refer average global conditions yield order a thousand nanometer sized per cubic centimeter at mesopause, independent...
We used temperature data from the Sounding of Atmosphere with Broadband Emission Radiometry (SABER) on NASA TIMED satellite to quantify connection between temperatures in stratosphere and mesosphere lower thermosphere. Specifically, we studied three winter periods where stratospheric were dynamically disturbed: February 2002, August, 2003. The SABER show a clear signature mesospheric coolings concert warmings. Mesospheric 0.7 hPa 0.01 significant anticorrelation temperatures. For pressures...
As measured by the Solar Mesosphere Explorer satellite, density of nitric oxide at low latitudes (30°S to 30°N) and 110 km (E‐region) decreased from a mean value 3 × 10 7 molecules/cm³ in January 1982 4 6 April 1985. In addition, varied ±50% with 27‐day period during times high solar activity. The variation correlates variations Lyman‐alpha irradiance which is also satellite. Lyman alpha interpreted as an index EUV soft X‐ray flux. hypothesis proposed that flux between 20 100 Å has larger...
This work describes the first remote observations of meteoric smoke particles (MSPs) from satellite, by Solar Occultation For Ice Experiment (SOFIE) onboard Aeronomy in Mesosphere (AIM) platform. The measurements show a layer MSPs roughly 35 to 85 km altitude, and indicate seasonal cycle with reduced MSP abundance during polar summer. agree favorably model results, confirm that transport global meridional circulation causes dramatic reduction These new represent major advance our ability...
Abstract Observations of polar mesospheric clouds (PMC) from the solar backscatter ultraviolet (SBUV) satellite instruments are used to characterize variability and trends 1979 2014. The SBUV PMC record indicates decadal oscillations during 1980s 1990s, which expected result 11 year cycle. This oscillation is absent in recent decade, however, we speculate that cycle effects at altitudes 1990s may have been fortuitously amplified by stratospheric warming due volcanic eruptions occurred near...
Satellite observations by the Middle Atmosphere High Resolution Spectrograph Investigation (MAHRSI) have produced global measurements of hydroxyl (OH) in atmosphere. These reveal a sharp peak OH density near an altitude 65 to 70 km and are thus consistent with from Halogen Occultation Experiment (HALOE) on NASA Upper Research (UARS), which showed unexplained H 2 O layer at same level. Analysis stratopause (about 50 kilometers) coincident ozone Cryogenic Infrared Spectrometers Telescopes for...
Data from the Halogen Occultation Experiment (HALOE) are used to evaluate contribution of upper atmospheric NO x stratospheric polar vortex. Using CH 4 and potential vorticity as tracers, an isolated region enhanced is shown occur in Southern Hemisphere (SH) vortex almost every spring 1991–1996. The magnitude this enhancement varies according A p auroral activity index. Up half mid‐stratospheric SH may be due particle precipitation. peak occurred 1991 with a 3–5% y , source N 2 O oxidation.
Photodissociation of nitric oxide in the middle and upper atmosphere is examined using a line‐by‐line approach to describe absorption NO δ bands O 2 Schumann‐Runge bands. The new analysis results greater transmission ultraviolet radiation (5–0) band comparison with previous studies, leading increased rates for photolysis δ(0–0) band. Reduced (9–0) (10–0) produces smaller δ(1–0) Absorption strong lines shown make nonnegligible contribution atmospheric opacity at wavelengths which are...
The Solar Mesosphere Explorer (SME) satellite observed thermospheric nitric oxide (NO) during the period September 17–20, 1984, using resonance fluorescence technique. Altitude profiles from 100 to about 130 km were obtained for 1500 LT along two orbital tracks: one over United States and Europe. An auroral storm occurred on 19. A comparison of data 20 with 18 revealed a factor 3 increase in NO at mid‐latitudes States. Little enhancement was seen Europe or equatorial latitudes. larger higher...
Abstract Advective processes that couple planetary waves with tides have long been proposed as sources of nonmigrating diurnal tides. This paper reports observations short‐term variability in global predicted to arise from the interaction migrating tide (DW1) a quasi‐stationary wave number one (PW1). PW1 and tidal definitions are extracted satellite temperatures high‐altitude meteorological analyses. During winter months, evolution westward traveling zonal 2 (DW2) generally tracks...
Abstract The strong global semiannual oscillation (SAO) in thermospheric density has been observed for five decades, but definitive knowledge of its source elusive. We use the National Center Atmospheric Research thermosphere‐ionosphere‐mesosphere electrodynamics general circulation model (TIME‐GCM) to study how middle atmospheric dynamics generate SAO thermosphere‐ionosphere (T‐I). “standard” TIME‐GCM simulates, from first principles, SAOs mass and ionospheric total electron content that...
Atomic hydrogen (H) is a fundamental component in the photochemistry and energy balance of terrestrial mesopause region (80–100 km). H generated primarily by photolysis water vapor participates highly exothermic reaction with ozone. This significant source heat also creates vibrationally excited hydroxyl (OH) from which Meinel band radiative emission features originate. Concentrations (cm−3) volume mixing ratios are derived observations infrared OH (υ = 9 + 8, Δυ 2) vibration-rotation bands...
Abstract Arctic winter observations in 2013 by the Solar Occultation for Ice Experiment (SOFIE) show significant transport from lower‐thermosphere to stratosphere of air enriched nitric oxide, but depleted water and methane. The is triggered Stratospheric Sudden Warming (SSW) on 11 January continuously tracked over 3 months. Ultimately, evidence lower thermospheric seen at 40 km mid‐April. Area integrated oxide (NO) fluxes are compared with previous events 2004, 2006, 2009, that this event...