A5031904325- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Atmospheric and Environmental Gas Dynamics
- Atmospheric Ozone and Climate
- Meteorological Phenomena and Simulations
- Aeolian processes and effects
- Remote Sensing and LiDAR Applications
- Remote Sensing in Agriculture
- Advanced Optical Sensing Technologies
- Fire effects on ecosystems
- Air Quality Monitoring and Forecasting
- Calibration and Measurement Techniques
- Precipitation Measurement and Analysis
- Air Quality and Health Impacts
- Ocular and Laser Science Research
- Planetary Science and Exploration
- Solar Radiation and Photovoltaics
- Geophysics and Gravity Measurements
- Climate variability and models
- Icing and De-icing Technologies
- Urban Heat Island Mitigation
- Plant Surface Properties and Treatments
- Laser Design and Applications
- Methane Hydrates and Related Phenomena
- Space Satellite Systems and Control
Goddard Space Flight Center
2015-2024
University of Maryland, Baltimore County
2001-2024
National Aeronautics and Space Administration
2010-2024
United States Naval Research Laboratory
2022
University Corporation for Atmospheric Research
2008
Bay Area Environmental Research Institute
2002
University of Maryland, College Park
2001
University of Maryland, Baltimore
2001
Science Systems and Applications (United States)
2000
University of Miami
1998-2000
Measurements and models show that enhanced aerosol concentrations can augment cloud albedo not only by increasing total droplet cross-sectional area, but also reducing precipitation thereby water content coverage. Aerosol pollution is expected to exert a net cooling influence on the global climate through these conventional mechanisms. Here, we demonstrate an opposite mechanism which aerosols reduce cover thus significantly offset aerosol-induced radiative at top of atmosphere regional...
Abstract. The Aerosol Robotic Network (AERONET) has provided highly accurate, ground-truth measurements of the aerosol optical depth (AOD) using Cimel Electronique Sun–sky radiometers for more than 25 years. In Version 2 (V2) AERONET database, near-real-time AOD was semiautomatically quality controlled utilizing mainly cloud-screening methodology, while additional data contaminated by clouds or affected instrument anomalies were removed manually before attaining quality-assured status (Level...
Abstract The Aerosol, Radiation and Clouds in southern Africa (AEROCLO-sA) project investigates the role of aerosols on regional climate Africa. This is a unique environment where natural anthropogenic semipermanent widespread stratocumulus (Sc) cloud deck are found. aims to understand dynamical, chemical, radiative processes involved aerosol–cloud–radiation interactions over land ocean under various meteorological conditions. AEROCLO-sA field campaign was conducted August September 2017...
Long-term global radiation programs, such as AERONET and BSRN, have shown success in monitoring column averaged cloud aerosol optical properties. Little attention has been focused on measurements of vertically resolved Lidar systems are the preferred instrument for measurements. However, usage lidar not achieved because limits imposed by older that were large, expensive, logistically difficult to use field. Small, eye-safe, autonomous now currently available overcome problems associated with...
Atmospheric radiative forcing, surface radiation budget, and top-of-the-atmosphere radiance interpretation involve knowledge of the vertical height structure overlying cloud aerosol layers. During last decade, U.S. Department Energy, through Radiation Measurement (ARM) program, has constructed four long-term atmospheric observing sites in strategic climate regimes (north-central Oklahoma; Barrow, Alaska; Nauru Manus Islands tropical western Pacific). Micropulse lidar (MPL) systems provide...
Smoke and pollutants from Canadian forest fires are sometimes transported over the United States at low altitudes behind advancing cold fronts. An unusual event occurred in July 2002 which smoke Quebec was observed by satellite, lidar, aircraft to arrive Washington, D.C., area high altitudes. This elevated plume subsequently mixed surface as it entrained into turbulent planetary boundary layer had adverse effects on air quality region. Trajectory three‐dimensional model calculations...
Micropulse lidar (MPL) systems were used to measure aerosol properties during the Indian Ocean Experiment (INDOEX) 1999 field phase. Measurements made from two platforms: NOAA ship R/V Ronald H. Brown , and Kaashidhoo Climate Observatory (KCO) in Maldives. Sun photometers provide optical depths (AOD) needed calibrate MPL. This study focuses on height distribution (at 523 nm) of aerosols observed campaign. The highest (top height) was calculated found be below 4 km for most cruise. marine...
For 26 days in mid‐June and July 2000, a research group comprised of U.S. Navy, NASA, university scientists conducted the Puerto Rico Dust Experiment (PRIDE). In this paper we give brief overview mean meteorological conditions during study. We focus on our findings African dust transported into Caribbean utilizing Navajo aircraft AERONET Sun photometer data. During study midvisible aerosol optical thickness (AOT) averaged 0.25, with maximum >0.5 clean marine periods ∼0.08. AOTs near coast...
Global space borne lidar profiling of atmospheric clouds and aerosol began in 2003 following the launch Geoscience Laser Altimeter System (GLAS) on Ice, Cloud land Elevation Satellite. GLAS obtains nadir profiles through atmosphere two wavelength channels, day night, at a fundamental resolution 76.8 m vertical 172 along track. The 532 nm channel uses photon‐counting detectors resolves observed backscatter cross sections to 10 −7 1/m‐sr. 1064 employs analog detection adequate −6 1/m‐sr with...
Nabro volcano (13.37°N, 41.70°E) in Eritrea erupted on 13 June 2011 generating a layer of sulfate aerosols that persisted the stratosphere for months. For first time we report ground-based lidar observations same event from every continent Northern Hemisphere, taking advantage synergy between global networks such as EARLINET, MPLNET and NDACC with independent groups satellite CALIPSO to track evolution stratospheric aerosol various parts globe. The globally averaged optical depth (AOD) due...
Abstract One year of continuous ground-based lidar observations (2012) is analyzed for single-layer cirrus clouds at the NASA Micro Pulse Lidar Network site Goddard Space Flight Center to investigate top-of-the-atmosphere (TOA) annual net daytime radiative forcing properties. A slight positive estimated (i.e., warming): 0.07–0.67 W m −2 in sample-relative terms, which reduces 0.03–0.27 absolute terms after normalizing unity based on a 40% midlatitude occurrence frequency rate from satellite...
Abstract. Between 27 June and 14 July 2019 aerosol layers were observed by the United Kingdom (UK) Raman lidar network in upper troposphere lower stratosphere. The arrival of these late caused some concern within London Volcanic Ash Advisory Centre (VAAC) as according to dispersion simulations volcanic plume from 21 eruption Raikoke was not expected over UK until early July. Using Met Office Numerical Atmospheric-dispersion Modelling Environment (NAME), supporting evidence satellite situ...
Abstract. In May–June 2019, smoke plumes from wildfires in Alberta, Canada, were advected all the way to Europe. To analyze evolution of and estimate amount aerosols transported Europe, retrievals spaceborne lidar CALIOP (Cloud-Aerosol LIdar with Orthogonal Polarization) used. The located help a trajectory analysis, masses retrieved observations. accuracy mass was compared ground-based lidars/ceilometer near source North America after long-range transport Overall, produced comparable...
Elastic backscatter lidars are used to determine the vertical distribution of cloud and aerosol layers. One such lidar is micropulse (MPL). A recent paper by Campbell et al. described an algorithm process MPL signals. The presented procedures that correct for various instrument effects present in raw primary include afterpulse (detector noise induced from firing laser) overlap (poor near-range data collection). outgoing energy laser pulses statistical uncertainty detector must also be...
A micro-pulse lidar system (MPL) was used to measure the vertical and horizontal distribution of aerosols during Aerosol Characterization Experiment 2 (ACE-2) in June July 1997. The MPL measurements were made at Izaña observatory (IZO), a weather station located on mountain ridge (28°18' N, 16°30' W, 2367 m asl) near center island Tenerife, Canary Islands. acquire aerosol backscatter, extinction, optical depth profiles for normal background periods influenced by Saharan dust from North...
During the Asian Pacific Regional Aerosol Characterization Experiment (ACE‐Asia) intensive field campaign conducted in spring of 2001, aerosol properties were measured on board R/V Ronald H. Brown to study effects atmospheric chemistry and climate downwind regions. marine boundary layer included chemical composition; number size distribution; light scattering, hemispheric backscattering, absorption coefficients. In addition, optical depth vertical profiles 180° backscatter measured. within...
As part of the Indian Ocean Experiment (INDOEX) 1999 Intensive Field Phase, measurements aerosol properties were made on board R/V Ronald H. Brown in north and south Intertropical Convergence Zone (ITCZ) Arabian Sea Bay Bengal. On basis air mass trajectories, eight source regions identified including southern hemisphere Atlantic; Ocean; northern east subcontinent where trajectories came from near Calcutta, through portion India, then to ship; across central India Arabia; Arabia/Indian...
During the dry season airborne campaign of Southern African Regional Science Initiative (SAFARI 2000), coordinated observations were made massive thick aerosol layers. These layers often dominated by aerosols from biomass burning. We report on Sun photometer measurements optical depth (λ = 0.354–1.557 μm), columnar water vapor, and vertical profiles extinction vapor density that obtained aboard University Washington's Convair‐580 research aircraft. compare these with ground‐based AERONET...
The capability to detect the presence of absorbing aerosols in atmosphere using space‐based near‐UV observations has been demonstrated last few years, as indicated by widespread use atmospheric sciences community Total Ozone Mapping Spectrometer (TOMS) aerosol index a qualitative representation absorption. An inversion procedure developed convert unique spectral signature generated interaction molecular scattering and particle absorption into quantitative measure In this work we evaluate...