Comparison of the University of California at Los Angeles Line-by-Line Equivalent Radiative Transfer Model and the Moderate-Resolution Transmission Model for accuracy assessment of the National Polar-Orbiting Operational Environmental Satellite System’s Visible–Infrared Imager–Radiometer Suite cloud algorithms

2005 ◽  
Vol 44 (29) ◽  
pp. 6274 ◽  
Author(s):  
S. C. Ou ◽  
K. N. Liou ◽  
Y. Takano ◽  
E. Wong ◽  
K. Hutchison ◽  
...  
Keyword(s):  
Los Angeles ◽  
Radiative Transfer ◽  
Accuracy Assessment ◽  
University Of California ◽  
Transmission Model ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Infrared Imager ◽  
Moderate Resolution ◽  
The University

scholarly journals Comparison of PARASOL Observations with Polarized Reflectances Simulated Using Different Ice Habit Mixtures

2013 ◽  
Vol 52 (1) ◽  
pp. 186-196 ◽  
Author(s):  
Benjamin H. Cole ◽  
Ping Yang ◽  
Bryan A. Baum ◽  
Jerome Riedi ◽  
Laurent C.-Labonnote ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Ice Crystal ◽  
Ice Clouds ◽  
Atmospheric Sciences ◽  
Reflection Data ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Polarized Reflectance

AbstractInsufficient knowledge of the habit distribution and the degree of surface roughness of ice crystals within ice clouds is a source of uncertainty in the forward light scattering and radiative transfer simulations of ice clouds used in downstream applications. The Moderate Resolution Imaging Spectroradiometer (MODIS) collection-5 ice microphysical model presumes a mixture of various ice crystal shapes with smooth facets, except for the compact aggregate of columns for which a severely rough condition is assumed. When compared with Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar (PARASOL) polarized reflection data, simulations of polarized reflectance using smooth particles show a poor fit to the measurements, whereas very rough-faceted particles provide an improved fit to the polarized reflectance. In this study a new microphysical model based on a mixture of nine different ice crystal habits with severely roughened facets is developed. Simulated polarized reflectance using the new ice habit distribution is calculated using a vector adding–doubling radiative transfer model, and the simulations closely agree with the polarized reflectance observed by PARASOL. The new general habit mixture is also tested using a spherical albedo differences analysis, and surface roughening is found to improve the consistency of multiangular observations. These results are consistent with previous studies that have used polarized reflection data. It is suggested that an ice model incorporating an ensemble of different habits with severely roughened surfaces would potentially be an adequate choice for global ice cloud retrievals.

scholarly journals Improved OSIRIS NO<sub>2</sub> retrieval algorithm: Description and validation

2016 ◽  
Author(s):  
Christopher E. Sioris ◽  
Landon A. Rieger ◽  
Nicholas D. Lloyd ◽  
Adam E. Bourassa ◽  
Chris Z. Roth ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Nitrogen Dioxide ◽  
Polar Vortex ◽  
Bias Reduction ◽  
Radiative Transfer Model ◽  
Retrieval Algorithm ◽  
Transfer Model ◽  
Reconstruction Technique ◽  
Spectral Fitting ◽  
Infrared Imager

Abstract. A new retrieval algorithm for OSIRIS (Optical Spectrograph and Infrared Imager System) nitrogen dioxide (NO2) profiles is described and validated. The algorithm relies on spectral fitting to obtain line-of-sight (LOS) column densities of NO2 followed by inversion using an algebraic reconstruction technique and the SaskTran spherical radiative transfer model to obtain vertical profiles of local number density. The validation covers different latitudes (tropical to polar), years (2002–2012), all seasons (winter, spring, summer, and autumn), different concentrations of nitrogen dioxide (from deNOxified polar vortex to polar summer), a large range of solar zenith angles (68.6 to 90.5°) and altitudes between 10.5 and 39 km, thereby covering the full retrieval range of a typical OSIRIS NO2 profile. The use of a larger spectral fitting window than used in previous retrievals reduces retrieval uncertainties and the scatter in the retrieved profiles due to noisy radiances. Improvements are also demonstrated through the validation in terms of bias reduction at 15–17 km relative to the OSIRIS operational v3.0 algorithm. By accounting for the diurnal variation along the LOS in the two-dimensional radiative transfer model, the scatter of the differences relative to the correlative balloon NO2 profile data is reduced.

scholarly journals Odin/OSIRIS observations of stratospheric NO<sub>3</sub> through sunrise and sunset

2008 ◽  
Vol 8 (2) ◽  
pp. 5901-5917
Author(s):  
C. A. McLinden ◽  
C. S. Haley
Keyword(s):  
Radiative Transfer ◽  
Strong Dependence ◽  
Rapid Evolution ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Nitrate Radical ◽  
Signal To Noise ◽  
Spectral Fitting ◽  
Infrared Imager ◽  
Fitting In

Abstract. The nitrate radical (NO3) has been detected in visible limb-scattered spectra measured by the Optical Spectrograph and InfraRed Imager System (OSIRIS) on-board the Odin satellite when observing at large solar zenith angles (91–97°). Apparent slant column densities of NO3 at tangent heights between 10 and 45 km are derived via spectral fitting in the 590–680 nm window. Using observations from multiple scans spanning solar zenith angles of 91–97°, the rapid evolution of NO3 through sunrise and sunset can be traced. Slant column densities are found to be consistent with those simulated using a radiative transfer model with coupled photochemistry. In addition, a strong dependence of NO3 with temperature is observed. These results indicate that OSIRIS possesses signal-to-noise sufficient to make useful measurements of scattered sunlight out to solar zenith angles of 96–97° and suggests the possibility of retrieving profile information for NO3 and other species at large solar zenith angles.

scholarly journals Volcanic Ash Retrieval Using a New Geostationary Satellite

2015 ◽  
Vol XL-7/W4 ◽  
pp. 67-74
Author(s):  
K. H. Lee ◽  
K. T. Lee
Keyword(s):  
Remote Sensing ◽  
Radiative Transfer ◽  
Volcanic Ash ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
New Era ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Aerosol Remote Sensing ◽  
Moderate Resolution Imaging Spectroradiometer

The paper presents currently developing method of volcanic ash detection and retrieval for the Geostationary Korea Multi-Purpose Satellite (GK-2A). With the launch of GK-2A, aerosol remote sensing including dust, smoke, will begin a new era of geostationary remote sensing. The Advanced Meteorological Imager (AMI) onboard GK-2A will offer capabilities for volcanic ash remote sensing similar to those currently provided by the Moderate Resolution Imaging Spectroradiometer (MODIS) satellite. Based on the physical principles for the current polar and geostationary imagers are modified in the algorithm. Volcanic ash is estimated in detection processing from visible and infrared channel radiances, and the comparison of satellite-observed radiances with those calculated from radiative transfer model. The retrievals are performed operationally every 15 min for volcanic ash for pixel sizes of 2 km. The algorithm currently under development uses a multichannel approach to estimate the effective radius, aerosol optical depth (AOD) simultaneously, both over water and land. The algorithm has been tested with proxy data generated from existing satellite observations and forward radiative transfer simulations. Operational assessment of the algorithm will be made after the launch of GK-2A scheduled in 2018.

Characteristics of atmospheric moderate resolution spectral radiation in representative regions based on satellite ground measurement and radiative transfer model

2011 ◽  
Vol 23 (9) ◽  
pp. 2335-2340
Author(s):  
范伟 Fan Wei ◽  
鲁俊 Lu Jun ◽  
荀尚培 Xun Shangpei ◽  
张宏群 Zhang Hongqun ◽  
何彬方 He Binfang ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Spectral Radiation ◽  
Ground Measurement ◽  
Moderate Resolution

scholarly journals Odin/OSIRIS observations of stratospheric NO<sub>3</sub> through sunrise and sunset

2008 ◽  
Vol 8 (18) ◽  
pp. 5529-5534 ◽  
Author(s):  
C. A. McLinden ◽  
C. S. Haley
Keyword(s):  
Radiative Transfer ◽  
Current Knowledge ◽  
Strong Dependence ◽  
Rapid Evolution ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Spectral Fitting ◽  
Infrared Imager ◽  
Fitting In ◽  
Radiative Transfer Modeling

Abstract. The nitrate radical (NO3) has been detected in visible limb-scattered spectra measured by the Optical Spectrograph and InfraRed Imager System (OSIRIS) on-board the Odin satellite when observing at large solar zenith angles (91–97°). Apparent slant column densities of NO3 at tangent heights between 10 and 45 km are derived via spectral fitting in the 610–680 nm window. Using observations from multiple scans spanning solar zenith angles of 91–97°, the rapid evolution of NO3 through sunrise and sunset can be traced. Slant column densities are found to be generally consistent with those simulated using a radiative transfer model with coupled photochemistry. In addition, a strong dependence of NO3 with temperature is observed. These results indicate that our current knowledge of NO3 photochemistry is generally consistent with OSIRIS observations to within the limitations of the radiative transfer modeling. Furthermore, they reveal that OSIRIS possesses signal-to-noise sufficient to make useful measurements of scattered sunlight out to solar zenith angles of 91–97° and suggest the possibility of retrieving profile information for NO3 and other species at large solar zenith angles.

Dialogues

2020 ◽  
Vol 2 (3) ◽  
pp. 53-59
Keyword(s):  
Los Angeles ◽  
New Spain ◽  
American Art ◽  
Historical Trauma ◽  
State Building ◽  
University Of California ◽  
Religious Experiences ◽  
Political Space ◽  
California Missions ◽  
The University

The California missions, whose original church spaces and visual programs were produced by Iberian, Mexican, and Native artisans between 1769 and 1823, occupy an ambiguous chronological, geographical, and political space. They occupy lands that have pertained to conflicting territorialities: from Native nations, to New Spain, to Mexico, to the modern multicultural California. The physical and visual landscapes of the missions have been sites of complex and often incongruous religious experiences; historical trauma and romantic vision; Indigenous genocide, exploitation, resistance, and survivance; state building and global enterprise. This Dialogues section brings together critical voices, including especially the voices of California Indian scholars, to interrogate received models for thinking about the art historical legacies of the California missions. Together, the contributing authors move beyond and across borders and promote new decolonial strategies that strive to be responsive to the experience of California Indian communities and nations. This conversation emerges from cross-disciplinary relationships established at a two-day conference, “‘American’ Art and the Legacy of Conquest: Art at California’s Missions in the Global 18th–20th Centuries,” sponsored by the Terra Foundation for American Art and held at the University of California, Los Angeles, in November 2019.

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