scholarly journals Comparison of ISS–CATS and CALIPSO–CALIOP Characterization of High Clouds in the Tropics

2020 ◽  
Vol 12 (23) ◽  
pp. 3946
Author(s):  
Pasquale Sellitto ◽  
Silvia Bucci ◽  
Bernard Legras
Keyword(s):  
Optical Properties ◽  
Space Station ◽  
Satellite Observation ◽  
Observation Data ◽  
Upper Troposphere ◽  
Cloud Properties ◽  
Synchronous Orbit ◽  
The Tropics ◽  
High Clouds

Clouds in the tropics have an important role in the energy budget, atmospheric circulation, humidity, and composition of the tropical-to-global upper-troposphere–lower-stratosphere. Due to its non-sun-synchronous orbit, the Cloud–Aerosol Transport System (CATS) onboard the International Space Station (ISS) provided novel information on clouds from space in terms of overpass time in the period of 2015–2017. In this paper, we provide a seasonally resolved comparison of CATS characterization of high clouds (between 13 and 18 km altitude) in the tropics with well-established CALIPSO (Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observation) data, both in terms of clouds’ occurrence and cloud optical properties (optical depth). Despite the fact that cloud statistics for CATS and CALIOP are generated using intrinsically different local overpass times, the characterization of high clouds occurrence and optical properties in the tropics with the two instruments is very similar. Observations from CATS underestimate clouds occurrence (up to 80%, at 18 km) and overestimate the occurrence of very thick clouds (up to 100% for optically very thick clouds, at 18 km) at higher altitudes. Thus, the description of stratospheric overshoots with CATS and CALIOP might be different. While this study hints at the consistency of CATS and CALIOP clouds characterizaton, the small differences highlighted in this work should be taken into account when using CATS for estimating cloud properties and their variability in the tropics.

scholarly journals High Cloud Properties from Three Years of MODIS Terra and Aqua Collection-4 Data over the Tropics

2007 ◽  
Vol 46 (11) ◽  
pp. 1840-1856 ◽  
Author(s):  
Gang Hong ◽  
Ping Yang ◽  
Bo-Cai Gao ◽  
Bryan A. Baum ◽  
Yong X. Hu ◽  
...  
Keyword(s):  
Cloud Fraction ◽  
South Pacific Convergence Zone ◽  
Convergence Zone ◽  
Ice Clouds ◽  
High Cloud ◽  
Convective Clouds ◽  
Cloud Properties ◽  
Deep Convective Clouds ◽  
The Tropics ◽  
High Clouds

Abstract This study surveys the optical and microphysical properties of high (ice) clouds over the Tropics (30°S–30°N) over a 3-yr period from September 2002 through August 2005. The analyses are based on the gridded level-3 cloud products derived from the measurements acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard both the NASA Earth Observing System Terra and Aqua platforms. The present analysis is based on the MODIS collection-4 data products. The cloud products provide daily, weekly, and monthly mean cloud fraction, cloud optical thickness, cloud effective radius, cloud-top temperature, cloud-top pressure, and cloud effective emissivity, which is defined as the product of cloud emittance and cloud fraction. This study is focused on high-level ice clouds. The MODIS-derived high clouds are classified as cirriform and deep convective clouds using the International Satellite Cloud Climatology Project (ISCCP) classification scheme. Cirriform clouds make up more than 80% of the total high clouds, whereas deep convective clouds account for less than 20% of the total high clouds. High clouds are prevalent over the intertropical convergence zone (ITCZ), the South Pacific convergence zone (SPCZ), tropical Africa, the Indian Ocean, tropical America, and South America. Moreover, land–ocean, morning–afternoon, and summer–winter variations of high cloud properties are also observed.

scholarly journals Trends in Global Cloud Cover in Two Decades of HIRS Observations

2005 ◽  
Vol 18 (15) ◽  
pp. 3021-3031 ◽  
Author(s):  
Donald Wylie ◽  
Darren L. Jackson ◽  
W. Paul Menzel ◽  
John J. Bates
Keyword(s):  
Cloud Cover ◽  
Cloud Amount ◽  
Cloud Detection ◽  
Total Cloud Cover ◽  
Infrared Observation ◽  
Upper Troposphere ◽  
Polar Orbiting Satellite ◽  
The Tropics ◽  
High Clouds ◽  
Infrared Radiometer

Abstract The frequency of cloud detection and the frequency with which these clouds are found in the upper troposphere have been extracted from NOAA High Resolution Infrared Radiometer Sounder (HIRS) polar-orbiting satellite data from 1979 to 2001. The HIRS/2 sensor was flown on nine satellites from the Television Infrared Observation Satellite-Next Generation (TIROS-N) through NOAA-14, forming a 22-yr record. Carbon dioxide slicing was used to infer cloud amount and height. Trends in cloud cover and high-cloud frequency were found to be small in these data. High clouds show a small but statistically significant increase in the Tropics and the Northern Hemisphere. The HIRS analysis contrasts with the International Satellite Cloud Climatology Project (ISCCP), which shows a decrease in both total cloud cover and high clouds during most of this period.

scholarly journals Comment on "Clouds and the Faint Young Sun Paradox" by Goldblatt and Zahnle (2011)

2012 ◽  
Vol 8 (2) ◽  
pp. 701-703 ◽  
Author(s):  
R. Rondanelli ◽  
R. S. Lindzen
Keyword(s):  
Radiative Forcing ◽  
Cirrus Clouds ◽  
Climate Feedback ◽  
Cloud Radiative Forcing ◽  
Convective Clouds ◽  
Cloud Properties ◽  
Deep Convective Clouds ◽  
The Tropics ◽  
High Clouds

Abstract. Goldblatt and Zahnle (2011) raise a number of issues related to the possibility that cirrus clouds can provide a solution to the faint young sun paradox. Here, we argue that: (1) climates having a lower than present mean surface temperature cannot be discarded as solutions to the faint young sun paradox, (2) the detrainment from deep convective clouds in the tropics is a well-established physical mechanism for the formation of high clouds that have a positive radiative forcing (even if the possible role of these clouds as a negative climate feedback remains controversial) and (3) even if some cloud properties are not mutually consistent with observations in radiative transfer parameterizations, the most relevant consistency (for the purpose of hypothesis testing) is with observations of the cloud radiative forcing. Therefore, we maintain that cirrus clouds, as observed in the current climate and covering a large region of the tropics, can provide a solution to the faint young sun paradox, or at least ease the amount of CO2 or other greenhouse substances needed to provide temperatures above freezing during the Archean.

scholarly journals Systematic Changes in Cloud Radiative Forcing with Aerosol Loading for Deep Clouds in the Tropics

2015 ◽  
Vol 73 (1) ◽  
pp. 231-249 ◽  
Author(s):  
Jie Peng ◽  
Zhanqing Li ◽  
Hua Zhang ◽  
Jianjun Liu ◽  
Maureen Cribb
Keyword(s):  
Radiative Forcing ◽  
Observation Data ◽  
Cloud Radiative Forcing ◽  
Aerosol Loading ◽  
Cloud Properties ◽  
Aqua Satellite ◽  
Aerosol Effects ◽  
The Tropics ◽  
Mixed Phase Clouds ◽  
Aerosol Index

Abstract It has been widely recognized that aerosols can modify cloud properties, but it remains uncertain how much the changes and associated variations in cloud radiative forcing are related to aerosol loading. Using 4 yr of A-Train satellite products generated from CloudSat, the Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations satellite, and the Aqua satellite, the authors investigated the systematic changes of deep cloud properties and cloud radiative forcing (CRF) with respect to changes in aerosol loading over the entire tropics. Distinct correlations between CRF and aerosol loading were found. Systematic variations in both shortwave and longwave CRF with increasing aerosol index over oceans and aerosol optical depth over land for mixed-phase clouds were identified, but little change was seen in liquid clouds. The systematic changes are consistent with the microphysical effect and the aerosol invigoration effect. Although this study cannot fully exclude the influence of other factors, attempts were made to explore various possibilities to the extent that observation data available can offer. Assuming that the systematic dependence originates from aerosol effects, changes in CRF with respect to aerosol loading were examined using satellite retrievals. Mean changes in shortwave and longwave CRF from very clean to polluted conditions ranged from −192.84 to −296.63 W m−2 and from 18.95 to 46.12 W m−2 over land, respectively, and from −156.12 to −170.30 W m−2 and from 6.76 to 11.67 W m−2 over oceans, respectively.

Retrieval of martian dust and cloud properties from ground-based radiance dust sensors

2020 ◽  
Author(s):  
Daniel Toledo ◽  
Victor Apéstigue ◽  
Laura Gómez ◽  
Javier Martinez-Oter ◽  
Juan Jose Jiménez ◽  
...  
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Solar Radiation ◽  
Radiation Balance ◽  
Number Density ◽  
Airborne Dust ◽  
Cloud Properties ◽  
Time Periods ◽  
Radiative Feedbacks

<p>On Mars, dust and clouds are primary elements for studying the interactions of solar radiation with the atmosphere and surface and their influence on the radiation balance. Depending on the dust opacity and other properties such as the particle size distribution, airborne dust can provide positive or negative radiative feedbacks into dynamical processes. This role played by dust in the circulation of the atmosphere points out the need of retrieving the dust optical properties at different time periods and locations. In order to perform these observations a number of ground-based radiance dust sensors were selected for Exomars and Mars 2020 missions (e.g. Arruego et al., Advances in Space Research, 60, 2016; Apéstigue et al., EPSC 2015). These instruments measure the solar flux at different wavelengths and sky locations along the day. From radiative transfer simulations of these observations, dust properties such as the number density or particles radius can be inferred. In this work, we will present and discuss different retrieval procedures developed for the characterization of dust and clouds on Mars.</p>

scholarly journals A 6-year global cloud climatology from the Atmospheric InfraRed Sounder AIRS and a statistical analysis in synergy with CALIPSO and CloudSat

2010 ◽  
Vol 10 (3) ◽  
pp. 8247-8296
Author(s):  
C. J. Stubenrauch ◽  
S. Cros ◽  
A. Guignard ◽  
N. Lamquin
Keyword(s):  
Single Layer ◽  
Cloud Amount ◽  
Cloud Detection ◽  
Atmospheric Infrared Sounder ◽  
Backscatter Signal ◽  
The Real ◽  
Cloud Properties ◽  
The Tropics ◽  
Cloud Thickness ◽  
High Clouds

Abstract. We present a six-year global climatology of cloud properties, obtained from observations of the Atmospheric Infrared Sounder (AIRS) onboard the NASA Aqua satellite. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) combined with CloudSat observations, both missions launched as part of the A-Train in 2006, provide a unique opportunity to evaluate the retrieved AIRS cloud properties such as cloud amount and height as well as to explore the vertical structure of different cloud types. AIRS-LMD cloud detection agrees with CALIPSO about 85% over ocean and about 75% over land. Global cloud amount has been estimated as about 66% to 74%, depending on the weighting of not cloudy AIRS footprints by partial cloud cover (0 or 0.3). 40% of all clouds are high clouds, and about 44% of all clouds are single layer low-level clouds. The "radiative" cloud height determined by the AIRS-LMD retrieval corresponds well to the height of the maximum backscatter signal and of the "apparent middle" of the cloud. Whereas the real cloud thickness of high opaque clouds often fills the whole troposphere, their "apparent" cloud thickness (at which optical depth reaches about 5) is on average only 2.5 km. The real geometrical thickness of optically thin cirrus as identified by AIRS-LMD is identical to the "apparent" cloud thickness with an average of about 2.5 km in the tropics and midlatitudes. High clouds in the tropics have slightly more diffusive cloud tops than at higher latitudes. In general, the depth of the maximum backscatter signal increases nearly linearly with increasing "apparent" cloud thickness. For the same "apparent" cloud thickness optically thin cirrus show a maximum backscatter about 10% deeper inside the cloud than optically thicker clouds. We also show that only the geometrically thickest opaque clouds and (the probably surrounding anvil) cirrus penetrate the stratosphere in the tropics.

scholarly journals A 6-year global cloud climatology from the Atmospheric InfraRed Sounder AIRS and a statistical analysis in synergy with CALIPSO and CloudSat

2010 ◽  
Vol 10 (15) ◽  
pp. 7197-7214 ◽  
Author(s):  
C. J. Stubenrauch ◽  
S. Cros ◽  
A. Guignard ◽  
N. Lamquin
Keyword(s):  
Single Layer ◽  
Cloud Amount ◽  
Cloud Detection ◽  
Atmospheric Infrared Sounder ◽  
Backscatter Signal ◽  
The Real ◽  
Cloud Properties ◽  
The Tropics ◽  
Cloud Thickness ◽  
High Clouds

Abstract. We present a six-year global climatology of cloud properties, obtained from observations of the Atmospheric Infrared Sounder (AIRS) onboard the NASA Aqua satellite. Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) combined with CloudSat observations, both missions launched as part of the A-Train in 2006, provide a unique opportunity to evaluate the retrieved AIRS cloud properties such as cloud amount and height. In addition, they permit to explore the vertical structure of different cloud types. AIRS-LMD cloud detection agrees with CALIPSO about 85% over ocean and about 75% over land. Global cloud amount has been estimated from 66% to 74%, depending on the weighting of not cloudy AIRS footprints by partial cloud cover from 0 to 0.3. 42% of all clouds are high clouds, and about 42% of all clouds are single layer low-level clouds. The "radiative" cloud height determined by the AIRS-LMD retrieval corresponds well to the height of the maximum backscatter signal and of the "apparent middle" of the cloud. Whereas the real cloud thickness of high opaque clouds often fills the whole troposphere, their "apparent" cloud thickness (at which optical depth reaches about 5) is on average only 2.5 km. The real geometrical thickness of optically thin cirrus as identified by AIRS-LMD is identical to the "apparent" cloud thickness with an average of about 2.5 km in the tropics and midlatitudes. High clouds in the tropics have slightly more diffusive cloud tops than at higher latitudes. In general, the depth of the maximum backscatter signal increases nearly linearly with increasing "apparent" cloud thickness. For the same "apparent" cloud thickness optically thin cirrus show a maximum backscatter about 10% deeper inside the cloud than optically thicker clouds. We also show that only the geometrically thickest opaque clouds and (the probably surrounding anvil) cirrus penetrate the stratosphere in the tropics.

scholarly journals Lidar ratios of stratospheric volcanic ash and sulfate aerosols retrieved from CALIOP measurements

2017 ◽  
Vol 17 (13) ◽  
pp. 8599-8618 ◽  
Author(s):  
Andrew T. Prata ◽  
Stuart A. Young ◽  
Steven T. Siems ◽  
Michael J. Manton
Keyword(s):  
Volcanic Ash ◽  
Satellite Observation ◽  
Stratospheric Aerosol ◽  
Orthogonal Polarization ◽  
Observation Data ◽  
Volcanic Aerosol ◽  
Time Period ◽  
Lidar Ratio ◽  
Sarychev Peak

Abstract. We apply a two-way transmittance constraint to nighttime CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) observations of volcanic aerosol layers to retrieve estimates of the particulate lidar ratio (Sp) at 532 nm. This technique is applied to three volcanic eruption case studies that were found to have injected aerosols directly into the stratosphere. Numerous lidar observations permitted characterization of the optical and geometric properties of the volcanic aerosol layers over a time period of 1–2 weeks. For the volcanic ash-rich layers produced by the Puyehue-Cordón Caulle eruption (June 2011), we obtain mean and median particulate lidar ratios of 69 ± 13 sr and 67 sr, respectively. For the sulfate-rich aerosol layers produced by Kasatochi (August 2008) and Sarychev Peak (June 2009), the means of the retrieved lidar ratios were 66 ± 19 sr (median 60 sr) and 63 ± 14 sr (median 59 sr), respectively. The 532 nm layer-integrated particulate depolarization ratios (δp) observed for the Puyehue layers (δp = 0.33 ± 0.03) were much larger than those found for the volcanic aerosol layers produced by the Kasatochi (δp = 0.09 ± 0.03) and Sarychev (δp = 0.05 ± 0.04) eruptions. However, for the Sarychev layers we observe an exponential decay (e-folding time of 3.6 days) in δp with time from 0.27 to 0.03. Similar decreases in the layer-integrated attenuated colour ratios with time were observed for the Sarychev case. In general, the Puyehue layers exhibited larger colour ratios (χ′ = 0.53 ± 0.07) than what was observed for the Kasatochi (χ′ = 0.35 ± 0.07) and Sarychev (χ′ = 0.32 ± 0.07) layers, indicating that the Puyehue layers were generally composed of larger particles. These observations are particularly relevant to the new stratospheric aerosol subtyping classification scheme, which has been incorporated into version 4 of the level 2 CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) data products.

Simulation of runoff for the Black Volta Basin using satellite observation data

2012 ◽  
Vol 10 (3) ◽  
pp. 245-254 ◽  
Author(s):  
Salamatu Shaibu ◽  
Samuel Nii Odai ◽  
Kwaku Amaning Adjei ◽  
Edward Matthew Osei ◽  
Frank Ohene Annor
Keyword(s):  
Satellite Observation ◽  
Observation Data ◽  
Volta Basin

Variational assimilation of observation data in the mathematical model of the Baltic Sea dynamics

2015 ◽  
Vol 30 (4) ◽  
Author(s):  
Valeriy I. Agoshkov ◽  
Eugene I. Parmuzin ◽  
Vladimir B. Zalesny ◽  
Victor P. Shutyaev ◽  
Natalia B. Zakharova ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Heat Flux ◽  
Baltic Sea ◽  
Satellite Observation ◽  
Sea Surface ◽  
Observation Data ◽  
The Baltic Sea ◽  
Variational Assimilation ◽  
The Baltic ◽  
The Mathematical Model

AbstractA mathematical model of the dynamics of the Baltic Sea is considered. A problem of variational assimilation of sea surface temperature (SST) data is formulated and studied. Based on variational assimilation of satellite observation data, an algorithm solving the inverse problem of heat flux restoration on the interface of two media is proposed. The results of numerical experiments reconstructing the heat flux functions in the problem of variational assimilation of SST observation data are presented. The influence of SST assimilation on other hydrodynamic parameters of the model is considered.

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