A5072347577- Atmospheric aerosols and clouds
- Atmospheric chemistry and aerosols
- Astrophysics and Cosmic Phenomena
- Gamma-ray bursts and supernovae
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Astrophysical Phenomena and Observations
- Dark Matter and Cosmic Phenomena
- Pulsars and Gravitational Waves Research
- Air Quality Monitoring and Forecasting
- Particle Detector Development and Performance
- Calibration and Measurement Techniques
- Radio Astronomy Observations and Technology
- Air Quality and Health Impacts
- Particle Accelerators and Free-Electron Lasers
- Solar Radiation and Photovoltaics
- Neutrino Physics Research
- Remote Sensing in Agriculture
- Astronomical Observations and Instrumentation
- Cosmology and Gravitation Theories
- Corporate Identity and Reputation
- Banking, Crisis Management, COVID-19 Impact
- Galaxies: Formation, Evolution, Phenomena
- Analytical Chemistry and Chromatography
- Radiation Therapy and Dosimetry
Friedrich-Alexander-Universität Erlangen-Nürnberg
1994-2024
Goddard Space Flight Center
2002-2020
Science Systems and Applications (United States)
2002-2019
Naval Research Laboratory Information Technology Division
2002-2014
Sigma Space (United States)
2011-2014
Innsbruck Medical University
2013
National Aeronautics and Space Administration
2003
RTX (United States)
1998-2001
Brookhaven National Laboratory
1997
Long‐term measurements by the AERONET program of spectral aerosol optical depth, precipitable water, and derived Angstrom exponent were analyzed compiled into an properties climatology. Quality assured monthly means are presented described for 9 primary sites 21 additional multiyear with distinct regimes representing tropical biomass burning, boreal forests, midlatitude humid climates, dry oceanic sites, desert background sites. Seasonal trends each these nine discussed climatic averages presented.
Partitioning of mineral dust, pollution, smoke, and mixtures using remote sensing techniques can help improve accuracy satellite retrievals assessments the aerosol radiative impact on climate. Spectral optical depth ( τ ) single scattering albedo ω o from Aerosol Robotic Network (AERONET) measurements are used to form absorption (i.e., Ångström exponent α abs )) size extinction ext fine mode fraction relationships infer dominant types. Using long‐term AERONET data set (1999–2010), 19 sites...
The AERONET inversion products provide powerful information for understanding column integrated aerosol properties particularly given the wide global distribution of sites and 13 year record some sites. Significant evolution instrument, data quality, ancillary input algorithm has necessitated release Version 2.0 establishment criteria quality assured products. This paper documents version 1.0 assurance analysis entire retrieval available to revise criteria. result is an improvement in number...
Measurements of the column‐integrated aerosol optical properties in southern African region were made by Aerosol Robotic Network (AERONET) Sun‐sky radiometers at several sites August–September 2000 as a part Southern Regional Science Initiative (SAFARI) dry season field campaign. Fine mode biomass burning aerosols dominated northern study (Zambia), which is an active region, and other including fossil fuel burning, industrial, aeolian coarse types also contributed to mixture regions (South...
The optical properties of aerosols such as smoke from biomass burning vary due to aging processes and these particles reach larger sizes at high concentrations. We compare the spectra aerosol depth (τ a ), column‐integrated volume size distributions, refractive indices, single scattering albedo retrieved AERONET observations for four selected events very ∼ 2 500 nm). Two case studies are tropical regions (Brazil Zambia) two cases boreal forest peat fire transported long distances sites in US...
Abstract As a representative site of the southern African biomass‐burning region, sun‐sky data from 15 year Aerosol Robotic Network (AERONET) deployment at Mongu, Zambia, was analyzed. For season months (July–November), we investigate seasonal trends in aerosol single scattering albedo (SSA), size distributions, and refractive indices almucantar sky scan retrievals. The monthly mean 440 nm Mongu found to increase significantly ~0.84 July ~0.93 November (from 0.78 0.90 675 these same months)....
Abstract. MODerate resolution Imaging Spectroradiometer (MODIS) instruments aboard the Terra and Aqua satellites have provided a rich dataset of aerosol information at 10 km spatial scale. Although originally intended for climate applications, air quality community quickly became interested in using MODIS data. However, is not sufficient to resolve local scale features. With this mind, Collection 6 includes global product with 3 resolution. Here, we evaluate over Baltimore–Washington D.C.,...
A mesoscale network of 14 AERONET Sun photometers was established in the UAE and adjacent Arabian Gulf from August through September 2004 as a component United Arab Emirates Unified Aerosol Experiment (UAE 2 ). These measurements allowed for spatial, temporal spectral characterization complex aerosol mixtures present this environment where coarse mode desert dust aerosols often mix with fine pollution largely produced by petroleum industry. loading relatively high 2‐month averages optical...
Large fine mode–dominated aerosols (submicron radius) in size distributions retrieved from the Aerosol Robotic Network (AERONET) have been observed after fog or low‐altitude cloud dissipation events. These column‐integrated obtained at several sites many regions of world, typically evaporation such as stratocumulus fog. Retrievals with cloud‐processed aerosol are sometimes bimodal accumulation mode larger‐size often ∼0.4–0.5 μ m radius (volume distribution); smaller mode, ∼0.12 to ∼0.20 m,...
The AErosol RObotic NETwork (AERONET) estimates of instantaneous solar broadband fluxes (F) at surface have been validated through comparison with ground‐based measurements Mauna Loa Observatory (MLO) and by the Baseline Surface Radiation (BSRN) Solar Networks (SolRad‐Net) during period 1999–2005 1999–2006, respectively. uncertainties in calculated aerosol radiative forcing (ΔF) efficiency (ΔF eff ) bottom atmosphere were also assessed. stations selected attempting to cover different...
We present a new climatology of atmospheric aerosols (primarily pyrogenic and biogenic) for the Brazilian tropics on basis high‐quality data set spectral aerosol optical depth directional sky radiance measurements from Aerosol Robotic Network (AERONET) Cimel Sun‐sky radiometers at more than 15 sites distributed across Amazon basin adjacent Cerrado region. This network is only long‐term project (with record including observations 11 years some locations) ever to have provided ground‐based...
Analysis of sun photometer measured and satellite retrieved aerosol optical depth (AOD) data has shown that major pollution events with very high fine mode AOD (>1.0 in mid-visible) the China/Korea/Japan region are often observed to be associated significant cloud cover. This makes remote sensing these difficult even for temporal resolution measurements. Possible physical mechanisms have include a combination humidification, processing, meteorological co-variation atmospheric stability...
Abstract An extreme biomass burning event occurred in Indonesia from September through October 2015 due to severe drought conditions, partially caused by a major El Niño event, thereby allowing for significant of peatland that had been previously drained. This the highest sustained aerosol optical depths (AODs) ever monitored global Aerosol Robotic Network (AERONET). The newly developed AERONET Version 3 algorithms retain high AOD at longer wavelengths when associated with Ångström exponents...
Abstract. During the July 2011 Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field experiment in Maryland, significant enhancements Aerosol Robotic Network (AERONET) sun–sky radiometer measured aerosol optical depth (AOD) were observed immediate vicinity of non-precipitating cumulus clouds some days. Both Ångström exponents size distribution retrievals made before, during after development often suggest...
Several aerosol and solar flux monitoring sites were established in Brazil for the Large Scale Biosphere‐Atmosphere Experiment Amazônia project. CIMEL sunphotometers collocated pyranometers employed at two southern Amazonian order to quantify instantaneous reductions of total irradiance due high optical thickness (AOT) smoke events (relative values modeled background conditions). Results from Brazilian are presented 1999 comparison, a similar analysis is discussed data three south‐central...
Abstract. Biomass burning activities emit high concentrations of aerosol particles to the atmosphere. Such can interact with solar radiation, decreasing amount light reaching surface and increasing fraction diffuse radiation through scattering processes, thus has implications for photosynthesis within plant canopies. This work reports results from photosynthetically active (PAR) optical depth (AOD) measurements conducted simultaneously at Reserva Biológica do Jaru (Rondonia State, Brazil)...
Single-scattering albedo (SSA) retrievals obtained with CIMEL Sun-sky radiometers from the Aerosol Robotic Network (AERONET) aerosol monitoring network were used to make comparisons simultaneous in situ sampling aircraft profiles carried out by NASA Langley Group Experiment (LARGE) team summer of 2011 during coincident DRAGON-MD (Distributed Regional Gridded Observational Network-Maryland) and DISCOVER-AQ (Deriving Information on Surface conditions Column Vertically Resolved Observations...
A field experiment was conducted in western North Carolina to investigate the relationship between aerosol optical properties and atmospheric transmission. Two research measurement sites close horizontal proximity but at different altitudes were established measure transmission of UV radiation through a slab atmosphere. An identical set sensing instruments, including broadband UV‐B radiometer, direct Sun pyrheliometer, shadowband spectral photometer, placed both sites, mountaintop site...
Five aerosol and solar flux monitoring sites were established in Brazil for the Large Scale Biosphere–Atmosphere Experiment Amazônia (LBA) project. The first two developed states of Rondonia Mato Grosso January 1999, while others initiated September 1999 Amazonas, Para, near Brasilia (later relocated to Acre). Daily insolation [photosynthetically active radiation (PAR) total solar] 9 months 2000 was determined from measurements, daily fraction theoretical cloud‐free, background‐aerosol...
The results of what is to our knowledge the first intercomparison seven independent spectroradiometers measuring solar UV irradiances are presented. was carried out in GSF-Forschungszentrum für Umwelt und Gesundheit, Neuherberg (near Munich, Germany), on 13 July 1990. spectroradiometric measurements were supplemented by other meteorological, optical, and chemical at same time. As this day cloudless, data can be compared with taken Bener Switzerland 1960's radiative transfer models. measured...
Abstract Aerosol levels influence the wavelength dependent transmission properties of atmosphere. Variations in aerosol therefore affect amount Cherenkov light from air-showers that can reach an atmospheric detector. As detected is directly related to a primary shower particle’s energy, deviations between actual and assumed yield errors reconstructed particle energies as well energy axes instrument response functions. In this work, scheme presented assess potentially reduce air-shower...
A network of five automated and two handheld solar radiometers was operated during the 1994–1996 Boreal Ecosystem‐Atmosphere Study (BOREAS) in northern Saskatchewan Manitoba, Canada, order to characterize atmospheric aerosol properties. Direct measurements were used measure transmission infer optical thickness water vapor column abundance. Near‐Sun sky radiance (solar aureole) estimate size distribution. Aerosol conditions heavily influenced by presence or absence forest fires. In 1996, when...
A National Institute of Standards and Technology (NIST)-designed radiometer is being used to monitor the spherical integrating sources (SISs) radiometrically calibrate Enhanced Thematic Mapper Plus (ETM+), an Earth-imaging sensor on Landsat-7 satellite. This six-channel Landsat Transfer Radiometer (LXR) uses witness filter samples from first four bands ETM+ along with two 10 nm bandpass filters centred at 441 662 nm. The band 1 450 515 nm; 2 525 600 3 630 690 4 775 900 aids in characterizing...
Abstract. MODerate resolution Imaging Spectroradiometer (MODIS) instruments aboard the Terra and Aqua satellites have provided a rich dataset of aerosol information at 10 km spatial scale. Although originally intended for climate applications, air quality community quickly became interested in using MODIS data. However, is not sufficient to resolve local scale features. With this mind, Collection 6 including global product with 3 resolution. Here, we evaluate over Baltimore/Washington D.C.,...