A5030928276- Atmospheric and Environmental Gas Dynamics
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric aerosols and clouds
- Spectroscopy and Laser Applications
- Meteorological Phenomena and Simulations
- Calibration and Measurement Techniques
- Aeolian processes and effects
- Laser Design and Applications
- Arctic and Antarctic ice dynamics
- Cryospheric studies and observations
- Solar and Space Plasma Dynamics
- Groundwater and Isotope Geochemistry
- Ionosphere and magnetosphere dynamics
- Air Quality Monitoring and Forecasting
- Air Quality and Health Impacts
- Vehicle emissions and performance
- Marine and coastal ecosystems
- Planetary Science and Exploration
- Remote Sensing and LiDAR Applications
- Advanced Optical Sensing Technologies
- Advanced Sensor Technologies Research
- Additive Manufacturing and 3D Printing Technologies
- Combustion and flame dynamics
- Solar Radiation and Photovoltaics
Goddard Space Flight Center
2002-2024
University of Maryland, College Park
2010-2024
Earth System Science Interdisciplinary Center
2012-2024
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2013-2014
University of Maryland, Baltimore County
2002-2012
Universities Space Research Association
2011
Goddard College
2010
General Sciences (United States)
1998
Applied Research Corporation (United States)
1993-1995
Colorado State University
1988-1990
We report initial measurements of atmospheric CO2 column density using a pulsed airborne lidar operating at 1572 nm. It uses measurement technique being developed NASA Goddard Space Flight Center as candidate for the in Active Sensing Emissions over Nights, Days and Seasons (ASCENDS) space mission. The multiple-wavelength approach offers several new capabilities with respect to passive spectrometer other techniques high-precision measurements. an fibre laser transmitter photon counting...
We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The measures backscatter profiles samples shape 1,572.33 nm CO2 absorption line. participated in ASCENDS science flights on NASA DC-8 aircraft during August 2011 report here measurements made four over variety surface cloud conditions near US. These included stratus deck Pacific Ocean, dry lake bed surrounded by mountains Nevada, desert area with coal-fired...
We report results of initial space mission simulation studies for a laser-based, atmospheric CO<sub>2</sub> sounder, which are based on real-time carbon cycle process modelling and data analysis. The concept corresponds to the Active Sensing Emissions over Nights, Days Seasons (ASCENDS) recommended by US National Academy Sciences' Decadal Survey. As pre-requisite meaningful quantitative evaluation, we employ model that has representative spatial temporal gradients across wide range scales....
We determine the direct radiative forcing of Saharan dust aerosols by combining aerosol information derived from Nimbus‐7 TOMS with radiation measurements observed at top atmosphere (TOA) NOAA‐9 ERBE made during February‐July 1985. Cloud parameters and precipitable water HIRS2 were used to aid in screening for clouds vapor analyses. Our results indicate that under “cloud‐free” “dry” conditions there is a good correlation between TOA outgoing longwave fluxes index over both land ocean areas...
We report on airborne CO(2) column absorption measurements made in 2009 with a pulsed direct-detection lidar operating at 1572.33 nm and utilizing the integrated path differential technique. demonstrated these different altitudes from an aircraft July August flights over four locations central eastern United States. The results show clear line shape signals, which follow expected changes altitude 3 to 13 km. measurement statistics were also calculated for each flight as function of altitude....
Atmospheric dust particles actually comprise a small number of mineral assemblages. We determined the composition these assemblages and their geographic distribution by statistical analysis mineralogy data. Air mass trajectory was used to identify transport paths possible source regions for samples. Three types trajectories are most common, each displays different proportions four The first indicates outflow air from central Asia is associated with an illite‐rich mineralogy. second type...
We report on a lidar approach to measure atmospheric CO2 column concentration being developed as candidate for NASA's ASCENDS mission. It uses pulsed dual-wavelength measurement based the integrated path differential absorption (IPDA) technique. demonstrated using CO<sub>2</sub> from aircraft in July and August 2009 over various locations. The results show clear line shape signals, which follow expected changes with altitude 3 13 km. measurements dependence good agreement number density...
The wind fields from the NASA Goddard stratospheric data assimilation procedure are used in a three‐dimensional chemistry and transport model to produce an ozone simulation for year September 11, 1991 10, 1992. Photochemical production loss taken two‐dimensional model. calculated is compared with observations total mapping spectrometer (TOMS) onboard Nimbus 7 microwave limb sounder on upper atmospheric research satellite. Although about 50 Dobson units (DU; =2.69 × 10 −16 molecules cm −2 )...
A combined atmospheric chemistry-meteorology experiment, the Dynamics and Chemistry of Marine Stratocumulus (DYCOMS), was carried out during summer 1985 over eastern Pacific Ocean using NCAR Electra aircraft. The objectives were to 1) study budgets several trace reactive species in a relatively pristine, steady-state, horizontally homogeneous, well-mixed boundary layer capped by strong inversion 2) formation, maintenance dissipation marine stratocumulus that persists off California coast (as...
This study uses information on Saharan aerosol from a dust transport model to calculate radiative forcing values. The is driven by assimilated meteorological fields the Goddard Earth Observing System Data Assimilation System. produces global three-dimensional spatial for four different mineral sizes. These are input an offline transfer calculation obtain direct due fields. estimates of shortwave reduction radiation at top atmosphere (TOA) compare reasonably well with TOA reductions derived...
An upper limit for aircraft‐produced perturbations to aerosols and gaseous exhaust products in the troposphere lower stratosphere (UT/LS) is derived using 1992 aviation fuel tracer simulation performed by eleven global atmospheric models. Key findings are that subsonic aircraft emissions: 1) have not be responsible observed water vapor trends at 40°N; 2) could a significant source of soot mass near 12 km, but 20 3) might cause noticeable increase background sulfate aerosol surface area...
The NASA/Goddard three-dimensional chemistry and transport model is driven by winds from a stratospheric data assimilation system. Synoptic- planetary-scale patterns, apparent in satellite observations of trace constituents, are successfully reproduced for seasonal integrations. As integrations proceed, however, the quality simulations decreases, systematic differences between calculation measurement appear. explained examining zonal-mean residual circulation. vertical velocity w̄*...
Abstract In this paper results are presented from a simple offline assimilation system that uses radiances the Moderate Resolution Imaging Spectroradiometer (MODIS) channels sense atmospheric aerosols over land and ocean. The MODIS information is directly inserted into Goddard Chemistry Aerosol Radiation Transport model (GOCART), which simulates following five aerosol types: dust, sea salt, black carbon, organic sulfate. goal to produce three-dimensional fields of these types for radiative...
Abstract. Measured upwelling radiances from Nimbus-7 SBUV (Solar Backscatter Ultraviolet) and seven NOAA SBUV/2 instruments have been used to calculate the 340 nm Lambertian equivalent reflectivity (LER) of Earth 1979 2011 after applying a common calibration. The LER is highly correlated with cloud aerosol cover because low surface land oceans (typically 2 6 RU, units, where 1 RU = 0.01 1.0%) relative much higher clouds plus nonabsorbing aerosols 10 90 RU). Because nearly constant seasonal...
We used an airborne pulsed integrated path differential absorption lidar to make spectroscopic measurements of the pressure-induced line broadening and center shift atmospheric carbon dioxide at 1572.335 nm line. scanned wavelength over 13 GHz (110 pm) measured lineshape 30 discrete wavelengths in vertical column between aircraft ground. A comparison our calculations based on HIgh-resolution TRANsmission molecular database shows excellent agreement with peak optical depth accurate within...
Since mineral aerosols absorb significant amounts of infrared radiation, they may contribute to errors in the retrievals atmospheric and surface parameters from TIROS Operational Vertical Sounder (TOVS) High‐Resolution Infrared Radiation (HIRS) if atmosphere is assumed clear. TOVS an operational sounder on NOAA polar satellites. To see observed brightness temperatures are reduced by aerosol, we analyzed results Data Assimilation Office (DAO) Finite Volume System (fvDAS). Every 6 hours...
The interaction between the tropics and middle latitudes is studied using a tracer emitted at 50 hPa along great circle route Los Angeles, USA Sydney, Australia. Though designed to examine impact of stratospheric aircraft, study more generally addresses transport for three month period from January through March 1989. results show that air transported by planetary scale tropospheric cyclonic waves. Except intrusions these wave events, are substantially isolated throughout lower stratosphere....
A two‐dimensional (2D) model, which uses a residual circulation and diffusion, three‐dimensional (3D) winds from stratospheric data assimilation system, have been used to estimate the transport dispersion of aircraft exhaust (tracer) in lower stratosphere. Four month calculations using 2D model with tracer injected continuously between 40°–50° north south latitudes are compared similar 3D for same time period. The seasonal behavior fields two models is similar. zonal mean distribution...
Abstract. We investigate the sensitivity of future spaceborne lidar measurements to changes in surface methane emissions. use observations from nine European ground stations and a Lagrangian transport model infer emissions for 2010. Our inversion shows strongest Netherlands, coal mines Upper Silesia, Poland, wetlands southern Finland. The simulated concentrations capture at least half daily variability observations, suggesting that is correctly simulating regional pathways over Europe. With...
A series of isentropic trajectory calculations has been performed for emissions by stratospheric aircraft moving across the northern midlatitude oceanic flight corridors. Emission exhaust is simulated daily initialization air parcels along a path on 500 K surface. Parcels are tracked during first three weeks each January from 1980 to 1994 in order determine interannual variability spatial distribution and likelihood exposure cold temperatures. Few emitted these paths at this time year were...
Ozone simulations are performed in an attempt to simulate laminar events with the frequency observed balloon ozone sondes. The winds taken from Goddard Earth Observing System Data Assimilation (GEOS DAS); importance of horizontal and vertical resolution production lamina investigated. A simulation a high reolution (grid spacing 1° latitude by 1.25° longitude) (∼300 m grid spacing) isentropic model produces lamination frequencies close sonde climatology near polar vortex edge but exhibits too...
We have demonstrated airborne measurements of CO2 column absorption at 1571.4 nm from 10 km altitudes with a wavelength-scanned lidar using pulsed diode-seeded EDFA transmitter and photon counting receiver.
A 5‐year simulation of supersonic aircraft exhaust using a three‐dimensional transport model has been completed winds from the NASA/Goddard data assimilation system. tracer based on emission rates reactive nitrogen species (NO y ) for all forecasted flight routes is continuously injected into model. parameterized upper stratospheric loss mechanism and tropospheric sink due to rainout approximately balance emissions after several years integration. Maximum values NO occur during northern...