A5059899688- Geology and Paleoclimatology Research
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Pleistocene-Era Hominins and Archaeology
- Geological and Geophysical Studies
- Ionosphere and magnetosphere dynamics
- Atmospheric chemistry and aerosols
- Geological formations and processes
- Geophysics and Gravity Measurements
- Methane Hydrates and Related Phenomena
- Climate change and permafrost
- Pacific and Southeast Asian Studies
- Solar and Space Plasma Dynamics
- Geological and Geophysical Studies Worldwide
- Evolution and Paleontology Studies
- Calibration and Measurement Techniques
- Meteorological Phenomena and Simulations
- Climate variability and models
- Oceanographic and Atmospheric Processes
- Hydrocarbon exploration and reservoir analysis
- Planetary Science and Exploration
- Cryospheric studies and observations
- Geological Studies and Exploration
- Paleontology and Stratigraphy of Fossils
- Fire effects on ecosystems
John Brown University
2012-2015
Hampton University
1998-2014
California State University, Fullerton
1978-1992
New York Psychoanalytic Society and Institute
1992
Jet Propulsion Laboratory
1986-1987
Langley Research Center
1985-1986
California Institute of Technology
1986
University of Liège
1986
Data from the Nimbus 7 Limb Infrared Monitor of Stratosphere (LIMS) for period 25 October 1978–28 May 1979 are used in a descriptive study ozone variations middle stratosphere. It is shown that distribution strongly influenced by irreversible deformation associated with large amplitude planetary-scale waves. This process, which has been described McIntyre and Palmer as planetary wave breaking, takes place throughout 3–30 mb layer, poleward transport within this layer occurs narrow tongues...
The Halogen Occultation Experiment (HALOE) experiment on Upper Atmosphere Research Satellite (UARS) performs solar occultation (sunrise and sunset) measurements to infer the composition structure of stratosphere mesosphere. Two HALOE channels, centered at 5.26 μm 6.25 μm, are designed concentrations nitric oxide nitrogen dioxide respectively. NO extend from lower up 130 km, while 2 results typically range 50 km higher near winter terminator. Comparison with various instruments presented,...
Abstract. Equatorial planetary scale wave modes such as Kelvin waves or Rossby-gravity are excited by convective processes in the troposphere. In this paper an analysis for these and other equatorial is carried out with special focus on stratosphere using temperature data from SABER satellite instrument well ECMWF temperatures. Space-time spectra of symmetric antisymmetric spectral power derived to separate different types contribution gravity determined background space-time spectra. Both...
Measurements of the temporal and spatial variations in HNO 3 , particularly those from Nimbus 7 limb infrared monitor stratosphere (LIMS) satellite experiment, are compared to both a two‐dimensional chemical/dynamical model chemistry/parcel trajectory analyses. Significant discrepancies found between observed modeled winter season, especially polar night region. The study evolution suggests that an important source exists for this species high‐latitude is not included presently accepted...
A two‐dimensional chemical transport model has been used to examine the physical processes governing of high levels thermospheric nitric oxide (NO) downward into middle atmosphere. Three different facets this are studied. The first facet involves diffusion from thermosphere summertime mesopause region. second advection by mean meridional circulation in wintertime mesosphere and effects planetary wave mixing on latitudinal gradient NO. third is residual amount NO deposited springtime upper...
Infrared solar absorption spectra of the stratosphere recorded at a resolution 0.01 cm −1 by ATMOS (Atmospheric Trace Molecule Spectroscopy) instrument from onboard Spacelab 3 (04/30 to 05/6/85) have revealed existence many previously unobserved features in 1925 1960 and 1249 1255 regions one 774 . On basis comparisons with laboratory spectra, these been identified as belonging ν 1 , 4 ; 6 bands carbonyl fluoride, respectively. Volume mixing ratios COF 2 between 17 40 km deduced analysis bands.
Ozone observed by seven satellite instruments, the Atmospheric Trace Molecule Spectroscopy instrument (ATMOS), Stratospheric Aerosol and Gas Experiment (SAGE) II, Polar Measurement (POAM) II instrument, Halogen Occultation (HALOE), Microwave Limb Sounder (MLS), Cryogenic Infrared Spectrometers Telescopes for Atmosphere (CRISTA), Millimeter‐wave (MAS), during early November 1994 is mapped in equivalent latitude/potential temperature (EqL/θ) space to facilitate nearly global comparisons of...
Volume mixing ratio profiles of ethane (C 2 H 6 ) in the lower stratosphere and upper troposphere acetylene have been deduced from analysis 0.01‐cm −1 ‐resolution infrared solar absorption spectra recorded between 25°N 31°N latitude. The spectral data were obtained by ATMOS (Atmospheric Trace Molecule Spectroscopy) Fourier transform spectrometer during Spacelab 3 shuttle mission on April 30 to May 1, 1985. investigation was based nonlinear least squares curve fitting ν 7 ; band P Q subbranch...
Stratospheric solar absorption spectra recorded at ∼0.01 cm −1 resolution by the ATMOS (Atmospheric Trace Molecule Spectroscopy) Fourier transform spectrometer during Spacelab 3 Shuttle mission (4/30‐5/6/85) show a weak feature covering ∼802.5‐803.3 . We identify this as unresolved Q branch of 802.7‐cm band HO 2 NO and report profiles for 31°N 47°S.
The long‐term temperature data sets obtained by Rayleigh lidars at six different locations from low to high latitudes within the Network for Detection of Atmospheric Composition Change (NDACC) were used derive annual oscillations (AO) and semiannual (SAO) middle atmosphere temperature: Reunion Island (21.8°S); Mauna Loa Observatory, Hawaii (19.5°N); Table Mountain Facility, California (34.4°N); Observatoire de Haute Provence, France (43.9°N); Hohenpeissenberg, Germany (47.8°N); Sondre...
Abstract. We have derived ozone and temperature trends from years 2002 through 2012, 20 to 100 km altitude, 48° S N latitude, based on measurements the Sounding of Atmosphere using Broadband Emission Radiometry (SABER) instrument Thermosphere, Ionosphere, Mesosphere Energetics Dynamics (TIMED) satellite. For first time, measured at same times locations are obtained, their correlations should provide useful information about relative importance photochemistry versus dynamics over longer term....
Ground‐based solar absorption spectra were measured from Fairbanks, Alaska (65°N, 148°W) March to September 1997 by the Jet Propulsion Laboratory (JPL) MkIV Fourier transform infrared (FTIR) spectrometer. The derived column abundances of O 3 declined 35% over this period (20% in April and May, 15% during summer), whereas those HF, a long‐lived tracer, changed less than 5%. High‐latitude, summertime balloon observations reveal similar shapes for volume mixing ratio profiles HF lower...
The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard the Envisat satellite provides temperature and various gas profiles from limb‐viewing midinfrared emission measurements. stratospheric temperatures retrieved at Institut für Meteorologie und Klimaforschung (IMK) September/October 2002 October/November 2003 are compared with a number of reference data sets, including global radiosonde (RS) observations, radio occultation (RO) measurements Global Positioning System...
Absorptions due to the ν 1 band of CH 3 Cl have been identified for first time in infrared solar absorption spectra upper troposphere and lower stratosphere. The spectral data were obtained with ATMOS Fourier transform spectrometer onboard Spacelab May 1985 during four occultation events near latitudes 30°N, 26°N, 25°N, 49°S. Volume mixing ratio profiles retrieved altitude range 12 23 km at these do not show appreciable differences. Vertical distributions vary from 6 × 10 −10 ‐10 an average...
The photochemical theory of the partitioning hetween chlorine species ClONO 2 and ClO in lower mid stratosphere is tested for first time using simultaneous measurements ClO, NO , . suggests that over most day production through three‐body reaction balanced by loss photolysis. Our analysis tests this utilizing these from instruments aboard Upper Atmosphere Research Satellite (UARS), as well calculations photolysis rate laboratory constant between Between 32 10 hPa (∼24 km), averaged...
This paper presents an analysis of odd nitrogen partitioning determined from instruments aboard the Upper Atmosphere Research Satellite (UARS). The UARS data set provides first global maps and best temporal coverage to date NO x /NO y . Our spans latitudes 60°S 60°N altitudes between 22 35 km for three separate, month‐long periods August 1992 March 1993. These are characterized by substantial stratospheric aerosol loading as a result eruption Mount Pinatubo in June 1991. Active (NO ) is...
Abstract. Severe chemical ozone loss has been detected in the Arctic winter and spring of 1995-96 by a variety methods. Extreme reductions column due to halogen catalysed chemistry were derived from measurements Halogen Occultation Experiment (HALOE) on board Upper Atmosphere Research Satellite vortex. Here, we discuss further aspects HALOE observations over this period. Potential problems, both data themselves methodology analysis are considered reason for differences between losses deduced...
The sunset/sunrise NO x ratios measured in 1994 by the Halogen Occultation Experiment (HALOE) onboard Upper Atmosphere Research Satellite (UARS) peak at up to 2.8 tropics around 30 km and decrease 1 stratopause. These are interpreted using a fully diurnal one‐dimensional model, which considers gas phase reactive nitrogen chemistry, two‐dimensional includes more complete set of chemical reactions. cycle nighttime N 2 O 5 formation followed daytime photolysis entirely accounts for observed...
The variability of nitric oxide has not been fully quantified. Particle precipitation is known to enhance oxide; however, a detailed understanding this process lacking, and its importance In paper, we present measurements between 80 200 km altitudes from the Halogen Occultation Experiment (HALOE) on UARS during November 1993 space weather special study period, near solar minimum conditions. mass mixing ratio routinely varies by 3 orders magnitude above altitudes. variation NO with magnetic...
Abstract. Equatorial planetary scale wave modes such as Kelvin waves or Rossby-gravity are excited by convective processes in the troposphere. In this paper an analysis for these and other equatorial is carried out with special focus on stratosphere using temperature data from SABER instrument well ECMWF temperatures. Space-time spectra of symmetric antisymmetric spectral power derived to separate different types contribution gravity determined background space-time spectra. Both main...
Abstract. No abstract available. doi:10.2204/iodp.sd.14.08.2012
Models are useful tools for integrating different processes involved in nitrogen transport soil and can be usedin forecasting how a system will behave without actually making measurements the physical system. Lately, computersimulation models have become tool understanding of water solutes through into thegroundwater. Transport solute under field conditions is research area continuous interest. In this study,LEACHN, submodule LEACHM (leaching estimation chemistry model), was used to simulate...
Stratospheric ozone, HCl, NO, and NO 2 observed by the Halogen Occultation Experiment (HALOE) on Upper Atmosphere Research Satellite (UARS) in late summer at high latitudes show nonuniform distributions their volume mixing ratios along a latitude circle, while of long‐lived tracers, such as CH 4 HF, are to be quite uniform. These anomalous reactive gases confined approximately 20–35 km. It is found that latitudes, isosurfaces tracers nearly coincide with isentropes. On basis meridional these...
Summary Pinyon–juniper woodlands are dry ecosystems defined by the presence of juniper ( Juniperus spp.) and pinyon pine Pinus spp.), which stretch over 400 000 km 2 across 10 US states. Certain areas have become unnaturally dense moved into former shrub grasslands, while others experienced widespread mortality. To properly manage these woodlands, sites must be evaluated individually decisions made based on scientific information that is often not available. Many species utilize...