scholarly journals Global maps of aerosol single scattering albedo using combined CERES-MODIS retrieval

2021 ◽  
Author(s):  
Archana Devi ◽  
Sreedharan Krishnakumari Satheesh
Keyword(s):  
Climate Models ◽  
Radiant Energy ◽  
Energy System ◽  
Single Scattering ◽  
Global Scale ◽  
Single Scattering Albedo ◽  
Accurate Information ◽  
Climatic Impact ◽  
Aerosol Absorption ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract. Single Scattering Albedo (SSA) is a leading contributor to the uncertainty in aerosol radiative impact assessments. Therefore accurate information on aerosol absorption is required on a global scale. In this study, we have applied a multi-satellite algorithm to retrieve SSA using the concept of ‘critical optical depth.’ Global maps of SSA were generated following this approach using spatially and temporally collocated data from Clouds and the Earth’s Radiant Energy System (CERES) and Moderate Resolution Imaging Spectroradiometer (MODIS) sensors on board Terra and Aqua satellites. The method has been validated using the data from aircraft-based measurements of various field campaigns. The retrieval uncertainty is ±0.03 and depends on both the surface albedo and aerosol absorption. Global mean SSA estimated over land and ocean is 0.93 and 0.97, respectively. Seasonal and spatial distribution of SSA over various regions are also presented. The global maps of SSA, thus derived with improved accuracy, provide important input to climate models for assessing the climatic impact of aerosols on regional and global scales.

Aerosol Characterization and Direct Radiative Forcing Assessment over the Ocean. Part II: Application to Test Cases and Validation

2004 ◽  
Vol 43 (12) ◽  
pp. 1818-1833 ◽  
Author(s):  
Maria João Costa ◽  
Vincenzo Levizzani ◽  
Ana Maria Silva
Keyword(s):  
Radiative Forcing ◽  
Radiant Energy ◽  
Energy System ◽  
Single Scattering ◽  
Space Time ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Aerosol Radiative Forcing ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract A method based on the synergistic use of low earth orbit and geostationary earth orbit satellite data for aerosol-type characterization and aerosol optical thickness (AOT: τa) retrieval and monitoring over the ocean is presented in Part I of this paper. The method is now applied to a strong dust outbreak over the Atlantic Ocean in June 1997 and to two other relevant transport events of biomass burning and desert dust aerosol that occurred in 2000 over the Atlantic and Indian Oceans, respectively. The retrievals of the aerosol optical properties are checked against retrievals from sun and sky radiance measurements from the ground-based Aerosol Robotic Network (AERONET). The single-scattering albedo values obtained from AERONET are always within the error bars presented for Global Ozone Monitoring Experiment (GOME) retrievals, resulting in differences lower than 0.041. The retrieved AOT values are compared with the independent space–time-collocated measurements from the AERONET, as well as to the satellite aerosol official products of the Polarization and Directionality of the Earth Reflectances (POLDER) and the Moderate Resolution Imaging Spectroradiometer (MODIS). A first estimate of the AOT accuracy derived from comparisons with AERONET data leads to ±0.02 ± 0.22τa when all AOT values are retained or to ±0.02 ± 0.16τa for aerosol transport events (AOT > 0.4). The upwelling flux at the top of the atmosphere (TOA) was computed with radiative transfer calculations and used to estimate the TOA direct shortwave aerosol radiative forcing; a comparison with space–time-collocated measurements from the Clouds and the Earth's Radiant Energy System (CERES) TOA flux product was also done. It was found that more than 90% of the values differ from CERES fluxes by less than ±15%.

scholarly journals Surface Irradiances Consistent with CERES-Derived Top-of-Atmosphere Shortwave and Longwave Irradiances

2013 ◽  
Vol 26 (9) ◽  
pp. 2719-2740 ◽  
Author(s):  
Seiji Kato ◽  
Norman G. Loeb ◽  
Fred G. Rose ◽  
David R. Doelling ◽  
David A. Rutan ◽  
...  
Keyword(s):  
Radiant Energy ◽  
Energy System ◽  
Global Scale ◽  
Atmospheric Infrared Sounder ◽  
Surface Irradiance ◽  
Uncertainty Estimates ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Rms Error ◽  
Moderate Resolution Imaging Spectroradiometer

Abstract The estimate of surface irradiance on a global scale is possible through radiative transfer calculations using satellite-retrieved surface, cloud, and aerosol properties as input. Computed top-of-atmosphere (TOA) irradiances, however, do not necessarily agree with observation-based values, for example, from the Clouds and the Earth’s Radiant Energy System (CERES). This paper presents a method to determine surface irradiances using observational constraints of TOA irradiance from CERES. A Lagrange multiplier procedure is used to objectively adjust inputs based on their uncertainties such that the computed TOA irradiance is consistent with CERES-derived irradiance to within the uncertainty. These input adjustments are then used to determine surface irradiance adjustments. Observations by the Atmospheric Infrared Sounder (AIRS), Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), CloudSat, and Moderate Resolution Imaging Spectroradiometer (MODIS) that are a part of the NASA A-Train constellation provide the uncertainty estimates. A comparison with surface observations from a number of sites shows that the bias [root-mean-square (RMS) difference] between computed and observed monthly mean irradiances calculated with 10 years of data is 4.7 (13.3) W m−2 for downward shortwave and −2.5 (7.1) W m−2 for downward longwave irradiances over ocean and −1.7 (7.8) W m−2 for downward shortwave and −1.0 (7.6) W m−2 for downward longwave irradiances over land. The bias and RMS error for the downward longwave and shortwave irradiances over ocean are decreased from those without constraint. Similarly, the bias and RMS error for downward longwave over land improves, although the constraint does not improve downward shortwave over land. This study demonstrates how synergetic use of multiple instruments (CERES, MODIS, CALIPSO, CloudSat, AIRS, and geostationary satellites) improves the accuracy of surface irradiance computations.

scholarly journals Vertical profiles of sub-micron aerosol single scattering albedo over Indian region immediately before monsoon onset and during its development: Research from the SWAAMI field campaign

2019 ◽  
Author(s):  
Mohanan R. Manoj ◽  
Sreedharan K. Satheesh ◽  
Krishnaswamy K. Moorthy ◽  
Hugh Coe
Keyword(s):  
Active Phase ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Development Research ◽  
Aerosol Absorption ◽  
South West ◽  
Aerosol Scattering ◽  
First Time ◽  
Geographical Locations

Abstract. Vertical structures of aerosol single scattering albedo (SSA), from near the surface through the free troposphere, have been estimated for the first time at distinct geographical locations over the Indian mainland and adjoining oceans, using in-situ measurements of aerosol scattering and absorption coefficients aboard the FAAM BAe-146 aircraft during the South West Asian Aerosol Monsoon Interactions (SWAAMI) campaign from June to July 2016. These are used to examine the spatial variation of SSA profiles and also to characterize its transformation from just prior to the onset of Indian Summer Monsoon (June 2016) to its active phase (July 2016). Very strong aerosol absorption, with SSA values as low as 0.7, persisted in the lower altitudes (

scholarly journals Vertical profiles of submicron aerosol single scattering albedo over the Indian region immediately before monsoon onset and during its development: research from the SWAAMI field campaign

2020 ◽  
Vol 20 (6) ◽  
pp. 4031-4046
Author(s):  
Mohanan R. Manoj ◽  
Sreedharan K. Satheesh ◽  
Krishnaswamy K. Moorthy ◽  
Hugh Coe
Keyword(s):  
Active Phase ◽  
Single Scattering ◽  
Monsoon Onset ◽  
Single Scattering Albedo ◽  
Transfer Model ◽  
Heating Rates ◽  
Atmospheric Measurements ◽  
Middle Troposphere ◽  
Submicron Aerosol ◽  
Aerosol Absorption

Abstract. Vertical structures of aerosol single scattering albedo (SSA), from near the surface through the free troposphere, have been estimated for the first time at distinct geographical locations over the Indian mainland and adjoining oceans, using in situ measurements of aerosol scattering and absorption coefficients aboard the Facility for Airborne Atmospheric Measurements (FAAM) BAe-146 aircraft during the South West Asian Aerosol Monsoon Interactions (SWAAMI) campaign from June to July 2016. These are used to examine the spatial variation of SSA profiles and also to characterize its transformation from just prior to the onset of Indian Summer Monsoon (June 2016) to its active phase (July 2016). Very strong aerosol absorption, with SSA values as low as 0.7, persisted in the lower altitudes (<3 km) over the Indo-Gangetic Plains (IGP), prior to the monsoon onset, with a west-to-east gradient; lower values occurred in the north-western arid regions, peaking in the central IGP and somewhat decreasing towards the eastern end. During the active phase of the monsoon, the SSA is found to increase remarkably, indicating far less absorption. Nevertheless, significant aerosol absorption persisted in the lower and middle troposphere over the IGP. Inputting these SSA and extinction profiles into a radiative transfer model, we examined the effects of using height-resolved information in estimating atmospheric heating rates due to aerosols, over similar estimates made using a single columnar value. It was noted that use of a single SSA value leads to an underestimation (overestimation) of the heating rates over regions with low (high) SSA, emphasizing the importance of height-resolved information. Further, the use of realistic profiles showed significant heating of the atmosphere by submicron aerosol absorption at the middle troposphere, which may have strong implications for clouds and climate.

scholarly journals Estimates of aerosol absorption over India using multi-satellite retrieval

2013 ◽  
Vol 31 (10) ◽  
pp. 1773-1778 ◽  
Author(s):  
D. Narasimhan ◽  
S. K. Satheesh
Keyword(s):  
Regional Distribution ◽  
Single Scattering ◽  
Ozone Monitoring Instrument ◽  
Satellite Retrieval ◽  
Aerosol Absorption ◽  
Moderate Resolution ◽  
Indian Landmass ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
First Time

Abstract. Aerosol absorption is poorly quantified because of the lack of adequate measurements. It has been shown that the Ozone Monitoring Instrument (OMI) aboard EOS-Aura and the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard EOS-Aqua, which fly in formation as part of the A-train, provide an excellent opportunity to improve the accuracy of aerosol retrievals. Here, we follow a multi-satellite approach to estimate the regional distribution of aerosol absorption over continental India for the first time. Annually and regionally averaged aerosol single-scattering albedo over the Indian landmass is estimated as 0.94 ± 0.03. Our study demonstrates the potential of multi-satellite data analysis to improve the accuracy of retrieval of aerosol absorption over land.

scholarly journals Evaluation of Five Satellite Top-of-Atmosphere Albedo Products over Land

2019 ◽  
Vol 11 (24) ◽  
pp. 2919
Author(s):  
Chuan Zhan ◽  
Richard P. Allan ◽  
Shunlin Liang ◽  
Dongdong Wang ◽  
Zhen Song
Keyword(s):  
High Latitude ◽  
Radiant Energy ◽  
Energy System ◽  
Moderate Resolution ◽  
Resolution Imaging ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Regional Product ◽  
Changes Over Time ◽  
Year 2000 ◽  
Energy Pathways

Five satellite top-of-atmosphere (TOA) albedo products over land were evaluated in this study including global products from the Advanced Very High Resolution Radiometer (AVHRR) (TAL-AVHRR), Moderate Resolution Imaging Spectroradiometer (MODIS) (TAL-MODIS), and Clouds and the Earth’s Radiant Energy System (CERES); one regional product from the Climate Monitoring Satellite Application Facility (CM SAF); and one harmonized product termed Diagnosing Earth’s Energy Pathways in the Climate system (DEEP-C). Results showed that overall, there is good consistency among these five products, particularly after the year 2000. The differences among these products in the high-latitude regions were relatively larger. The percentage differences among TAL-AVHRR, TAL-MODIS, and CERES were generally less than 20%, while the differences between TAL-AVHRR and DEEP-C before 2000 were much larger. Except for the obvious decrease in the differences after 2000, the differences did not show significant changes over time, but varied among different regions. The differences between TAL-AVHRR and the other products were relatively large in the high-latitude regions of North America, Asia, and the Maritime Continent, while the differences between DEEP-C and CM SAF in Europe and Africa were smaller. Interannual variability was consistent between products after 2000, before which the differences among the three products were much larger.

scholarly journals Angular Distribution Models for Top-of-Atmosphere Radiative Flux Estimation from the Clouds and the Earth’s Radiant Energy System Instrument on the Terra Satellite. Part I: Methodology

2005 ◽  
Vol 22 (4) ◽  
pp. 338-351 ◽  
Author(s):  
Norman G. Loeb ◽  
Seiji Kato ◽  
Konstantin Loukachine ◽  
Natividad Manalo-Smith
Keyword(s):  
Angular Distribution ◽  
Radiant Energy ◽  
Tropical Rainfall Measuring Mission ◽  
Energy System ◽  
Distribution Models ◽  
Radiative Fluxes ◽  
Earth Observing System ◽  
Moderate Resolution ◽  
Moderate Resolution Imaging Spectroradiometer ◽  
Terra Satellite

Abstract The Clouds and Earth’s Radiant Energy System (CERES) provides coincident global cloud and aerosol properties together with reflected solar, emitted terrestrial longwave, and infrared window radiative fluxes. These data are needed to improve the understanding and modeling of the interaction between clouds, aerosols, and radiation at the top of the atmosphere, surface, and within the atmosphere. This paper describes the approach used to estimate top-of-atmosphere (TOA) radiative fluxes from instantaneous CERES radiance measurements on the Terra satellite. A key component involves the development of empirical angular distribution models (ADMs) that account for the angular dependence of the earth’s radiation field at the TOA. The CERES Terra ADMs are developed using 24 months of CERES radiances, coincident cloud and aerosol retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), and meteorological parameters from the Global Modeling and Assimilation Office (GMAO)’s Goddard Earth Observing System (GEOS) Data Assimilation System (DAS) V4.0.3 product. Scene information for the ADMs is from MODIS retrievals and GEOS DAS V4.0.3 properties over the ocean, land, desert, and snow for both clear and cloudy conditions. Because the CERES Terra ADMs are global, and far more CERES data are available on Terra than were available from CERES on the Tropical Rainfall Measuring Mission (TRMM), the methodology used to define CERES Terra ADMs is different in many respects from that used to develop CERES TRMM ADMs, particularly over snow/sea ice, under cloudy conditions, and for clear scenes over land and desert.

scholarly journals The Observed Hemispheric Symmetry in Reflected Shortwave Irradiance

2013 ◽  
Vol 26 (2) ◽  
pp. 468-477 ◽  
Author(s):  
Aiko Voigt ◽  
Bjorn Stevens ◽  
Jürgen Bader ◽  
Thorsten Mauritsen
Keyword(s):  
Northern Hemisphere ◽  
Atmospheric Aerosols ◽  
Degrees Of Freedom ◽  
Climate Models ◽  
Radiant Energy ◽  
Energy System ◽  
Hemispheric Differences ◽  
Satellite Measurements ◽  
Planetary Albedo ◽  
Accurate Observation

Abstract While the concentration of landmasses and atmospheric aerosols on the Northern Hemisphere suggests that the Northern Hemisphere is brighter than the Southern Hemisphere, satellite measurements of top-of-atmosphere irradiances found that both hemispheres reflect nearly the same amount of shortwave irradiance. Here, the authors document that the most precise and accurate observation, the energy balanced and filled dataset of the Clouds and the Earth’s Radiant Energy System covering the period 2000–10, measures an absolute hemispheric difference in reflected shortwave irradiance of 0.1 W m−2. In contrast, the longwave irradiance of the two hemispheres differs by more than 1 W m−2, indicating that the observed climate system exhibits hemispheric symmetry in reflected shortwave irradiance but not in longwave irradiance. The authors devise a variety of methods to estimate the spatial degrees of freedom of the time-mean reflected shortwave irradiance. These are used to show that the hemispheric symmetry in reflected shortwave irradiance is a nontrivial property of the Earth system in the sense that most partitionings of Earth into two random halves do not exhibit hemispheric symmetry in reflected shortwave irradiance. Climate models generally do not reproduce the observed hemispheric symmetry, which the authors interpret as further evidence that the symmetry is nontrivial. While the authors cannot rule out that the observed hemispheric symmetry in reflected shortwave irradiance is accidental, their results motivate a search for mechanisms that minimize hemispheric differences in reflected shortwave irradiance and planetary albedo.

Global OMI Aerosol Single Scattering Albedo evaluation using ground-based AERONET

2020 ◽  
Author(s):  
Periklis Drakousis ◽  
Marios-Bruno Korras-Carraca ◽  
Hiren Jethva ◽  
Omar Torres ◽  
Nikos Hatzianastassiou
Keyword(s):  
Optical Properties ◽  
Climate Models ◽  
Spatial Scales ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Absolute Difference ◽  
Ozone Monitoring Instrument ◽  
Seasonal Basis ◽  
Radiance Data ◽  
The Impact

&lt;p&gt;Aerosol measurements are carried out worldwide in order to reduce the uncertainties about the impact of aerosols on climate. Over the past two decades, different methods (ground- or satellite-based) for measuring aerosol properties have been developed, covering a variety of approaches with different temporal and spatial scales, which can be considered complementary. Aerosol optical properties are essential for assessing the effects of aerosols on radiation and climate. Aerosol single scattering albedo (SSA), along with optical depth and asymmetry parameter, is one of the three key optical properties that are necessary for radiation transfer and climate models. At the same time, SSA strongly depends on different aerosol types, thus enabling the identification of these different aerosol particles. However, despite the strong need for aerosol SSA products with global and climatological coverage, and the significant progress in retrieving SSA from satellite measurements, the satellite SSA retrievals are still subjected to uncertainties.&lt;/p&gt;&lt;p&gt;In this study, we perform an evaluation of the OMAERUVd (PGE Version V1.8.9.1) daily L3 (1&amp;#176; x 1&amp;#176; latitude-longitude) aerosol SSA data, which are based on the enhanced two-channel OMAERUV algorithm that essentially uses the ultraviolet radiance data from Aura/Ozone Monitoring Instrument (OMI), through comparisons against daily SSA products from 541 globally distributed Aerosol Robotic Network (AERONET) stations for a 15-year period (2005-2019). The comparison is performed between the available OMAERUVd SSA data at 354 nm, 388 nm, and 500 nm, and the AERONET SSA data at 440 nm (or 443 nm). The comparison is made on an annual and seasonal basis in order to reveal possible seasonally dependent patterns, as well as on a climatological and a year-to-year basis. The statistical metrics, such as Coefficient of Correlation (R) and Bias, are computed for individual AERONET stations as well as for all stations. The effect of availability of common OMI and AERONET data pairs on the comparison is assessed by making comparisons when at least 10, 50 and 100 common pairs are available.&lt;/p&gt;&lt;p&gt;The results show that about 50% (75%) of OMI-AERONET matchups agree within the absolute difference of &amp;#177;0.03 (&amp;#177;0.05) for the 500 nm OMI SSA and the 440 nm (or 443 nm) AERONET SSA. The corresponding percentage for the 388 nm OMI SSA and the 440 nm (or 443 nm) AERONET SSA increases to 58% (81%), while the corresponding numbers for the 354 nm SSA OMI and the 440 nm (or 443 nm) AERONET are 43% (67%). It is found that in overall, OMI tends mainly to overestimate (underestimate) SSA for the 500 nm (354 nm) products in comparison to AERONET 440 nm (or 443 nm) with a total bias of 0.025 (-0.024), or 2.7% (2.6%) in relative percentage terms with respect to AERONET (mean AERONET value equal to 0.908), and an overall R value of 0.399 (0.386). At 388 nm, OMI tends to retrieve higher SSA over regions where biomass burning occurs, against lower SSA values elsewhere, with overall bias and R values equal to -0.002 (0.22%) and 0.395, respectively.&lt;/p&gt;

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