A5068428203- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Atmospheric aerosols and clouds
- Ionosphere and magnetosphere dynamics
- Spectroscopy and Laser Applications
- Climate variability and models
- Meteorological Phenomena and Simulations
- Astro and Planetary Science
- Geochemistry and Geologic Mapping
- Air Quality Monitoring and Forecasting
- Gas Dynamics and Kinetic Theory
- Planetary Science and Exploration
- Radiation Therapy and Dosimetry
- Health, Environment, Cognitive Aging
- MRI in cancer diagnosis
- Ocean Waves and Remote Sensing
- Fire effects on ecosystems
- Aeolian processes and effects
- Urban Heat Island Mitigation
- Pulmonary Hypertension Research and Treatments
- Aerospace Engineering and Energy Systems
- earthquake and tectonic studies
- Geography Education and Pedagogy
- Calibration and Measurement Techniques
NSF National Center for Atmospheric Research
2008-2025
Laboratory for Atmospheric and Space Physics
2015-2024
University of Colorado Boulder
2015-2024
University of Colorado System
2022-2023
Langley Research Center
1992-2012
University of Wyoming
2000
Hampton University
2000
Palo Alto Research Center
1996
Centre National de la Recherche Scientifique
1992-1996
National Oceanic and Atmospheric Administration
1996
Nineteen ninety-eight marks the 25th anniversary of release first HITRAN database. is recognized as international standard fundamental spectroscopic parameters for diverse atmospheric and laboratory transmission radiance calculations. There have been periodic editions over past decades database has expanded improved with respect to molecular species spectral range covered, number included, accuracy this information. The 1996 edition not only includes customary line-by-line transition...
Tracer variability above the Asian summer monsoon anticyclone is investigated using Aura Microwave Limb Sounder (MLS) measurements of carbon monoxide, ozone, water vapor, and temperature during Northern Hemisphere (June to August) 2005. Observations show persistent maxima in monoxide minima ozone within upper troposphere–lower stratosphere (UTLS) throughout summer, variations these tracers are closely related intensity underlying deep convection. Temperatures UTLS also coupled convection...
Abstract. Atmospheric carbon monoxide (CO) distributions are controlled by anthropogenic emissions, biomass burning, transport and oxidation reaction with the hydroxyl radical (OH). Quantifying trends in CO is therefore important for understanding changes related to all of these contributions. Here we present a comprehensive record satellite observations from 2000 through 2011 total column using available measurements nadir-viewing thermal infrared instruments: MOPITT, AIRS, TES IASI. We...
High Resolution Dynamics Limb Sounder (HIRDLS) temperature profiles are analyzed to derive global properties of gravity waves. We describe a wavelet analysis technique that determines covarying wave amplitude in adjacent profile pairs, the vertical wavelength as function height, and horizontal number along line joining each pair. The allows local estimate magnitude momentum flux geographic location height on daily basis. examine distributions these monthly mean an individual day, we also...
Abstract. The present study investigates effects of wildfire emissions on air quality in Europe during an intense fire season that occurred summer 2003. A meso-scale chemistry transport model CHIMERE is used, together with ground based and satellite aerosol optical measurements, to assess the dispersion quantify associated radiative effects. has been improved take into account a MODIS-derived daily smoke emission inventory as well injection altitude particles. simulated properties are put...
Convective clouds produce a significant proportion of the global precipitation and play an important role in energy water cycles. We quantify changes convective cloud ice mass-weighted altitude centroid (ZIWC) as function aerosol optical thickness (AOT). Analyses are conducted smoke, dust polluted continental environments over South America, Central Africa Southeast Asia, using latest measurements from CloudSat CALIPSO satellites. find aerosols can inhibit or invigorate convection, depending...
Daily values of Halogen Occultation Experiment (HALOE) aerosol extinction and Climate Diagnostics Center (CDC) outgoing longwave radiation (OLR) data are used to quantify the statistical geographical relationships tenuous cirrus OLR for pressure levels near equatorial tropopause. locations deep convection identified by analysis CDC data. Analysis HALOE demonstrates that is larger over than clearer regions a factor 3. Deep convection, however, occupies only 7% region. Ninety percent clouds...
Emission inventories indicate that the largest increases in SO 2 emissions have occurred Asia during last 20 years. By inference, aerosol, produced primarily by conversion of to sulfate, should same time period. Decadal changes regional aerosol optical depths are calculated analyzing Total Ozone Mapping Spectrometer (TOMS) vertical (converted 550 nm) from 1979 2000 on a 1° global grid. The anthropogenic component TOMS record is maximized examining seasonal cycles desert dust and boreal fire...
UARS observations of O 3 and ClO (Microwave Limb Sounder), ClONO 2 HNO (Cryogenic Array Etalon Spectrometer), NO, NO , HCl (Halogen Occultation Experiment), model calculations are used to produce an exposition the different processes through which reservoir gases reformed at end polar winter. Comparison within vortices shows that increases more rapidly in Antarctic vortex spring than Arctic vortex. Model analysis this occurs because concentrations southern fall well below those northern The...
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...
Cirrus formation and geometrical optical properties of tropical cirrus as a function height temperature are studied on the basis INDOEX (Indian Ocean Experiment) lidar radiosonde measurements satellite observations deep convection causing generation anvil cirrus. Lidar were conducted at Hulule (4.1°N, 73.3°E), Maldives, during four field campaigns carried out in February–March 1999 March 2000 (northeast (NE) monsoon season, characterized by increased concentrations anthropogenic aerosols...
Global distributions of nitrous oxide, methane, ozone, and carbon 14 are used to estimate four sets stratospheric eddy diffusion coefficients. A photochemical equilibrium model calculates O( 3 P ), 1 D H, HO 2 , OH, H O NO, NO densities, as a function altitude, latitude, time. The calculated observed Cl densities obtain the profiles associated with methane oxide distributions, for altitudes between 10 40 km. Application constant flux condition seasonally averaged ozone data yields values...
Abstract. The presence of 3D cloud radiative effects in OCO-2 retrievals is demonstrated from an analysis 2014–2019 XCO2 raw retrievals, bias-corrected XCO2bc data, ground-based Total Carbon Column Observation Network (TCCON) XCO2, and Moderate Resolution Imaging Spectroradiometer (MODIS) radiance fields. In approximate terms, 40 % (quality flag – QF = 0, land or ocean) 73 (QF 1, the observations are within 4 km clouds. transfer calculations indicate that perturbations at this distance, for...
A trajectory model coupled to a simple micro‐physical is used explore the observed relationship between convection, water vapor and cirrus clouds in tropical tropopause layer (TTL). Horizontal transport associated with local Hadley circulation leads minima winter hemisphere separated from convective regions region of minimum temperatures. These spatial signatures are consistent observations TTL Halogen Occultation Experiment (HALOE). In simulations, one third ice formed due horizontal...
Abstract. Satellite observations show that ice cloud effective radius (re) increases with water content (IWC) but decreases aerosol optical thickness (AOT). Using least-squares fitting to the observed data, we obtain an analytical formula describe variations of re IWC and AOT for several regions distinct characteristics re-IWC-AOT relationships. As directly relates convective strength represents loading, our empirical provides a means quantify relative roles dynamics aerosols in controlling...
Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence aerosols meteorological conditions on lifetime mesoscale convective systems (MCSs). Our results show that MCSs' increases by 3-24 h when vertical wind shear (VWS) available potential energy (CAPE) are moderate to high ambient aerosol optical depth (AOD) 1 SD (1σ). However, this is not as strong CAPE, humidity, VWS,...
Abstract The standard deviations of the distributions Orbiting Carbon Observatory (OCO‐2) measurements CO 2 (i.e., XCO2) increase in size presence clouds. XCO2 and Moderate Resolution Imaging Spectroradiometer (MODIS) radiance cloud fields, OCO‐2 A‐band radiances, are analyzed order to determine if this behavior is best described as a radiance‐level retrieval artifact or by 3‐D radiative transfer effects. Observations clear‐sky fair weather cumulus scenes analyzed. Scatter diagrams versus...
Meteorological data from the United Kingdom Office (UKMO), produced using a assimilation system, and U.S. National Center (NMC), an objective analysis procedure, are compared for dynamically active periods during Arctic Antarctic winters of 1992. The differences seen these generally similar to those other winter periods. Both UKMO NMC analyses capture large‐scale evolution stratospheric circulation northern hemisphere (NH) southern (SH) winters. Stronger vertical horizontal temperature...