A5064771063- Atmospheric Ozone and Climate
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Atmospheric aerosols and clouds
- Astro and Planetary Science
- Geophysics and Gravity Measurements
- Climate variability and models
- Earthquake Detection and Analysis
- Planetary Science and Exploration
- Meteorological Phenomena and Simulations
- Geomagnetism and Paleomagnetism Studies
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Stellar, planetary, and galactic studies
- Air Quality Monitoring and Forecasting
- GNSS positioning and interference
- Methane Hydrates and Related Phenomena
- Spacecraft Design and Technology
- Spaceflight effects on biology
- Arctic and Antarctic ice dynamics
- Optical Polarization and Ellipsometry
- Space Satellite Systems and Control
- Solar Radiation and Photovoltaics
Laboratory for Atmospheric and Space Physics
2016-2025
University of Colorado Boulder
2016-2025
University of Colorado System
2020-2023
Raytheon Technologies (Netherlands)
2022
National Oceanic and Atmospheric Administration
2007-2008
Jet Propulsion Laboratory
2008
Langley Research Center
2006
Computational Physics (United States)
1997-2000
Royal Meteorological Institute of Belgium
1998
Cooperative Institute for Research in Environmental Sciences
1998
The Model for Ozone and Related Chemical Tracers, version 3 (MOZART‐3), which represents the chemical physical processes from troposphere through lower mesosphere, was used to evaluate representation of long‐lived tracers ozone using three different meteorological fields. fields are based on (1) Whole Atmosphere Community Climate Model, 1b (WACCM1b), (2) European Centre Medium‐Range Weather Forecasts (ECMWF) operational analysis, (3) a new reanalysis year 2000 ECMWF called EXP471....
The Nature of Light. Polarization Properties Devices for Control Polarized Introduction to the Jones Calculus, Mueller Calculus and Poincare Sphere. Sphere Revisited. Spectroscopy with Orientation Photoselection Effects. Light in Condensed Phases. Appendixes. Index.
Abstract The January 2022 Hunga Tonga–Hunga Ha’apai eruption was one of the most explosive volcanic events modern era 1,2 , producing a vertical plume that peaked more than 50 km above Earth 3 . initial explosion and subsequent triggered atmospheric waves propagated around world multiple times 4 A global-scale wave response this magnitude from single source has not previously been observed. Here we show details response, using comprehensive set satellite ground-based observations to quantify...
Upper stratospheric enhancements in NO x (NO and 2 ) were observed at high northern latitudes from March through least July of 2004. Multi‐satellite data analysis is used to examine the temporal evolution enhancements, place them historical context, investigate their origin. The a factor 4 higher than nominal some locations, are unprecedented hemisphere since 1985. They accompanied by reductions O 3 more 60% cases. suggests that energetic particle precipitation led substantial production...
Measurements from several different satellite instruments are used to estimate effects of energetic particle precipitation (EPP) on NO x (NO + 2 ) in the Southern Hemisphere stratosphere 1992 2005. The focus is EPP Indirect Effect (IE), whereby produced mesosphere or thermosphere via (EPP‐NO descends during polar winter, where it can participate catalytic ozone destruction. EPP‐NO entering found vary magnitude 0.1 2.6 gigamoles per year, with maximum values occurring 1994 and 2003....
Measurements from the Atmospheric Chemistry Experiment show pronounced downward transport of NO x (NO+NO 2 ) to Arctic stratosphere in Feb–Mar 2006. mixing ratios upper were 3–6 times larger than observed previously either or Antarctic, aside extraordinary winter 2003–2004. There was only minimal geomagnetic activity late 2005 and early 2006, however, suggesting that produced via energetic particle precipitation not significantly elevated. On other hand, polar vortex at stratopause altitudes...
Here we use the ERA‐40 and ECMWF operational surface level air temperature data sets from 1957 to 2006 examine polar variations during years with different levels of geomagnetic activity, as defined by A p index. Previous modeling work has suggested that NO x produced at high latitudes energetic particle precipitation can eventually lead detectable changes in temperatures (SATs). We find winter months, SATs index are than low index; differences statistically significant 2‐sigma range up...
Abstract. Solar eruptions sometimes produce protons, which impact the Earth's atmosphere. These solar proton events (SPEs) generally last a few days and high energy particles that precipitate into The protons cause ionization dissociation processes ultimately lead to an enhancement of odd-hydrogen odd-nitrogen in polar cap regions (>60° geomagnetic latitude). We have used Whole Atmosphere Community Climate Model (WACCM3) study atmospheric SPEs over period 1963–2005. very largest were...
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...
Abstract. This paper presents extensive {bias determination} analyses of ozone observations from the Atmospheric Chemistry Experiment (ACE) satellite instruments: ACE Fourier Transform Spectrometer (ACE-FTS) and Measurement Aerosol Extinction in Stratosphere Troposphere Retrieved by Occultation (ACE-MAESTRO) instrument. Here we compare latest data products ACE-FTS ACE-MAESTRO with coincident nearly 20 satellite-borne, airborne, balloon-borne ground-based instruments, analysing volume mixing...
We report a new parameterization of ionization in the Earth's atmosphere by isotropically precipitating monoenergetic (100 eV to 1 MeV) electrons. This is first one based on sophisticated first‐principle models, and represents significant improvement accuracy, particularly for incident auroral lower energies. Without previous need interpolate over source energy atmospheric range, provides an easier implementation with robust fit model calculations wide range energies conditions. By...
Abstract. We compare simulations from three high-top (with upper lid above 120 km) and five medium-top around 80 atmospheric models with observations of odd nitrogen (NOx = NO + NO2), temperature, carbon monoxide seven satellite instruments (ACE-FTS on SciSat, GOMOS, MIPAS, SCIAMACHY Envisat, MLS Aura, SABER TIMED, SMR Odin) during the Northern Hemisphere (NH) polar winter 2008/2009. The included in comparison are 3-D chemistry transport model 3dCTM, ECHAM5/MESSy Atmospheric Chemistry (EMAC)...
Unusually large planetary wave activity in the 2002 Antarctic winter stratosphere weakened and warmed polar vortex. Three minor warmings during August early September preceded a late‐September major warming when middle stratospheric zonal winds reversed to easterly temperature increased by an additional 25 K. Polar Ozone Aerosol Measurement (POAM III) ozone data at high southern latitudes show unusually variability compared previous POAM III years (1998–2001). Analyses of air parcel...
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...
The High Resolution Dynamics Limb Sounder (HIRDLS) experiment was designed to provide global temperature and composition data on the region from upper troposphere mesopause with vertical horizontal resolution not previously available. science objectives are study of small‐scale dynamics transports, including stratosphere‐troposphere exchange, troposphere/lower stratosphere chemistry, aerosol, cirrus PSC distributions, gravity waves. instrument features 21 channels, low noise levels, high...
The Whole Atmosphere Community Climate Model (WACCM3) has been used to study the long‐term (more than a few months) effects of solar proton events (SPEs). Extremely large occurred in 1972, 1989, 2000, 2001, and 2003 caused some longer‐lasting atmospheric changes. highly energetic protons produced odd hydrogen (HO x ) nitrogen (NO y ), which then led ozone variations. Some statistically significant on mesospheric were by HO increases due very active time period for SPEs (years 2000–2004),...
We present a new parameterization of the altitude profile ionization rate in Earth's atmosphere due to precipitating energetic electrons. Precipitating electrons are assumed have Maxwellian energy distribution and an isotropic pitch angle above atmosphere. In this study, two electron transport models (whose validity has been verified by observations) employed calculate rate, which we fit our parameterization. To derive parameterization, follow similar scheme that Roble Ridley (1987) but take...
We report GOMOS nighttime observations of middle atmosphere NO 2 and O 3 profiles during eight recent polar winters in the Arctic Antarctic. The measurements are used to study effects energetic particle precipitation further downward transport x . During seven observed enhancements occur good correlation with levels enhanced high‐energy and/or geomagnetic activity as indicated by A p index. find a nearly linear relationship between average winter time index upper stratospheric column density...
Abstract. The ACE-FTS (Atmospheric Chemistry Experiment – Fourier Transform Spectrometer) solar occultation instrument that was launched onboard the Canadian SCISAT-1 satellite in August 2003 is measuring vertical profiles from upper troposphere to lower mesosphere for a large number of atmospheric constituents. Methane one key species. version v2.2 data CH4 have been compared correlative satellite, balloon-borne and ground-based transform infrared remote sensing assess their quality....
Abstract. Solar eruptions in early 2005 led to a substantial barrage of charged particles on the Earth's atmosphere during 16–21 January period. Proton fluxes were greatly increased these several days and production HOx (H, OH, HO2) NOx (N, NO, NO2), which then caused destruction ozone. We focus Northern polar region, where satellite measurements simulations with Whole Atmosphere Community Climate Model (WACCM3) showed large enhancements mesospheric constituents, associated ozone reductions,...
Ozone profiles in the upper mesosphere (70–100 km) retrieved from nine instruments are compared. Sounding of Atmosphere using Broadband Emission Radiometry (SABER) instrument is used as basis comparison. Other measurements Halogen Occultation Experiment, High Resolution Doppler Imager, Michelson Interferometer for Passive Atmospheric Sounding, Global Monitoring by Stars, Chemistry Experiment—Fourier Transform Spectrometer, Solar For Ice Optical Spectrograph and InfraRed Imaging System,...
Abstract Energetic particle precipitation (EPP) during the 2003–2004 Arctic winter led to production and subsequent transport of reactive odd nitrogen (NO x = NO + 2 ) from mesosphere lower thermosphere (MLT) into stratosphere. This caused enhancements in polar upper stratosphere April 2004 that were unprecedented satellite record. Simulations with Whole Atmosphere Community Climate Model using Specified Dynamics (SD‐WACCM) are compared measurements assess our understanding observed...