scholarly journals When Will MISR Detect Rising High Clouds?

2022 ◽  
Author(s):  
Travis Aerenson ◽  
Roger Marchand ◽  
Hélène Chepfer ◽  
Brian Medeiros
Keyword(s):  
High Clouds

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.

Photographs of high clouds

Weather ◽  
2012 ◽  
Vol 67 (9) ◽  
pp. 239-239
Keyword(s):  
High Clouds

scholarly journals Thermodynamic Control on the Poleward Shift of the Extratropical Jet in Climate Change Simulations: The Role of Rising High Clouds and Their Radiative Effects

2019 ◽  
Vol 32 (3) ◽  
pp. 917-934 ◽  
Author(s):  
Ying Li ◽  
David W. J. Thompson ◽  
Sandrine Bony ◽  
Timothy M. Merlis
Keyword(s):  
Climate Change ◽  
Radiative Effects ◽  
Considerable Uncertainty ◽  
Surface Warming ◽  
Thermodynamic Constraint ◽  
Poleward Shift ◽  
Cloud Radiative Effects ◽  
Underlying Mechanisms ◽  
High Clouds

Extratropical eddy-driven jets are predicted to shift poleward in a warmer climate. Recent studies have suggested that cloud radiative effects (CRE) may enhance the amplitude of such shifts. But there is still considerable uncertainty about the underlying mechanisms, whereby CRE govern the jet response to climate change. This study provides new insights into the role of CRE in the jet response to climate change by exploiting the output from six global warming simulations run with and without atmospheric CRE (ACRE). Consistent with previous studies, it is found that the magnitude of the jet shift under climate change is substantially increased in simulations run with ACRE. It is hypothesized that ACRE enhance the jet response to climate change by increasing the upper-tropospheric baroclinicity due to the radiative effects of rising high clouds. The lifting of the tropopause and high clouds in response to surface warming arises from the thermodynamic constraints placed on water vapor concentrations. Hence, the influence of ACRE on the jet shift in climate change simulations may be viewed as an additional “robust” thermodynamic constraint placed on climate change by the Clausius–Clapeyron relation. The hypothesis is tested in simulations run with an idealized dry GCM, in which the model is perturbed with a thermal forcing that resembles the ACRE response to surface warming. It is demonstrated that 1) the enhanced jet shifts found in climate change simulations run with ACRE are consistent with the atmospheric response to the radiative warming associated with rising high clouds, and 2) the amplitude of the jet shift scales linearly with the amplitude of the ACRE forcing.

scholarly journals Application of high frequency filtration to remove cloudiness in Earth remote sensing images

2020 ◽  
Vol 223 ◽  
pp. 02010
Author(s):  
Valeriy Tutatchikov ◽  
Mikhail Noskov
Keyword(s):  
Remote Sensing ◽  
Image Quality ◽  
Image Enhancement ◽  
High Frequency ◽  
Digital Processing ◽  
Remote Sensing Images ◽  
Earth Remote Sensing ◽  
High Clouds

At present, methods of digital processing of Earth remote sensing images are widely used to improve the image quality. For example, many images are discarded due to high clouds in the images, which obscure objects of interest. In this paper, the possibility of using high- frequency global filters to reduce cloudiness in the image is considered, and the results of image enhancement are shown.

scholarly journals THE MOVEMENTS OF THE HIGH CLOUDS IN THE WEST INDIES

1904 ◽  
Vol 32 (7) ◽  
pp. 309-311
Author(s):  
JOHN T. QUINN
Keyword(s):  
West Indies ◽  
The West ◽  
High Clouds

scholarly journals Total and partial cloud amount detection during summermonths 2005 at Westerland (Sylt, Germany)

2008 ◽  
Vol 8 (4) ◽  
pp. 13479-13505 ◽  
Author(s):  
N. H. Schade ◽  
A. Macke ◽  
H. Sandmann ◽  
C. Stick
Keyword(s):  
Cloud Cover ◽  
Cloud Amount ◽  
Cirrus Clouds ◽  
Total Cloud Amount ◽  
The North ◽  
Seaside Resort ◽  
The North Sea ◽  
Sky Imager ◽  
Downward Radiation ◽  
High Clouds

Abstract. The detection of cloudiness is investigated by means of partial and total cloud amount estimations from pyrgeometer radiation measurements and all-sky imager observations. The measurements have been performed in Westerland, a seaside resort on the North Sea island of Sylt, Germany, during summer 2005. An improvement to previous studies on this subject results from the fact that for the first time partial cloud amount (PCA), defined as total cloud amounts without high clouds, calculations from longwave downward radiation (LDR) according to the APCADA-Algorithm (Dürr and Philipona, 2004) are validated against both human observations from the German Weather Service DWD at the nearby airport of Sylt and digital all-sky imaging. Differences between the resulting total cloud amounts (TCA's), defined as total cloud amount for all-cloud situations, derived from the camera images and from human observations are within ±1 octa in 72% and within ±2 octa in 85% of the cases. Compared to human observations PCA measurements according to APCADA underestimate the observed cloud cover in 47% of all cases and the differences are within ±1 octa in 60% and ±2 octa in 74% of all cases. Since high cirrus clouds can not be derived from LDR, separate comparisons for all cases without high clouds have been performed showing an agreement within ±1(2) octa in 73(90)% for PCA and also for camera derived TCA. For this coastal mid-latitude site under investigation we find similar though slightly smaller agreements to human observations as reported in Dürr and Philipona (2004). Though limited to day-time the cloud cover retrievals from the sky imager are not much affected by cirrus clouds and provide a more reliable cloud climatology for all-cloud conditions than APCADA.

Remote Sounding of High Clouds. V: Infrared Properties and Structures of Tropical Thunderstorm Anvils

1984 ◽  
Vol 23 (9) ◽  
pp. 1296-1308 ◽  
Author(s):  
C. M. R. Platt ◽  
A. C. Dilley ◽  
J. C. Scott ◽  
I. J. Barton ◽  
G. L. Stephens
Keyword(s):  
Remote Sounding ◽  
High Clouds

Subvisual Cirrus

Cirrus ◽  
2002 ◽  
Author(s):  
David K. Lynch ◽  
Kenneth Sassen
Keyword(s):  
World War Ii ◽  
Solar Limb ◽  
Stratospheric Aerosol ◽  
Defense Meteorological Satellite Program ◽  
Passive Sensors ◽  
The Tropics ◽  
Anvil Cirrus ◽  
High Clouds ◽  
Meteorological Satellite

Starting during World War II, pilots flying high over the tropics reported “a thin layer of cirrus 500ft above us”. Yet as they ascended, they still observed more thin cirrus above them, leading to the colloquialism “cirrus evadus.” With the coming of lidar in the early 1960s, rumors and unqualified reports of subvisual cirrus were replaced with validated detections, in situ sampling, and the first systematic studies (Uthe 1977; Barnes 1980, 1982). Heymsfield (1986) described observations over Kwajalein Atoll in the western tropical Pacific Ocean, where pilots and lidars could clearly see the cloud but DMSP (U.S. Defense Meteorological Satellite Program) radiance measurements and ground observers could not. The term “subvisual” is a relatively recent appellation. Prior terminology included cirrus haze, semitransparent cirrus, subvisible cirrus veils, low density clouds, fields of ice aerosols, cirrus, anvil cirrus, and high altitude tropical (HAT) cirrus. Subvisual cirrus clouds (SVC) are widespread (Winker and Trepte 1998; see chapter 12, this volume) and virtually undetectable with existing passive sensors. Orbiting solar limb occupation systems such as the Stratospheric Aerosol and Gas Experiment (SAGE) can detect these clouds, but only by looking at them horizontally where the optical depths are significant. SVC appear to affect climate primarily by heating the planet, though to what extent this may happen is unknown. Much of what we know is based on work by Heymsfield (1986), Platt et al. (1987), Sassen et al. (1989, 1992), Flatau et al. (1990), Liou et al. (1990), Hutchinson et al. (1991, 1993), Dalcher (1992), Sassen and Cho (1992), Takano et al. (1992), Lynch (1993), Schmidt et al. (1993), Schmidt and Lynch (1995), and Winker and Trepte (1998). SVC are defined as any high clouds composed primarily of ice (WMO 1975) and whose vertical visible optical depth is 0.03 or less (Sassen and Cho 1992). Such clouds are usually found near the tropopause and are less than about 1 km thick vertically. SVC do not appear to be fundamentally different from ordinary, optically thicker cirrus. They do, however, differ from average cirrus by being colder (-50-90°C), thinner (<0.03 optical depths at 0.694 μm), and having smaller particles (typically about <50μm diameter).

scholarly journals An evaluation of clouds and radiation in a large-scale atmospheric model using a cloud vertical structure classification

2020 ◽  
Vol 13 (2) ◽  
pp. 673-684
Author(s):  
Dongmin Lee ◽  
Lazaros Oreopoulos ◽  
Nayeong Cho
Keyword(s):  
Large Scale ◽  
Vertical Structure ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Atmospheric Model ◽  
Radiative Effects ◽  
Surface Cooling ◽  
Vertical Location ◽  
High Clouds

Abstract. We revisit the concept of the cloud vertical structure (CVS) classes we have previously employed to classify the planet's cloudiness (Oreopoulos et al., 2017). The CVS classification reflects simple combinations of simultaneous cloud occurrence in the three standard layers traditionally used to separate low, middle, and high clouds and was applied to a dataset derived from active lidar and cloud radar observations. This classification is now introduced in an atmospheric global climate model, specifically a version of NASA's GEOS-5, in order to evaluate the realism of its cloudiness and of the radiative effects associated with the various CVS classes. Such classes can be defined in GEOS-5 thanks to a subcolumn cloud generator paired with the model's radiative transfer algorithm, and their associated radiative effects can be evaluated against observations. We find that the model produces 50 % more clear skies than observations in relative terms and produces isolated high clouds that are slightly less frequent than in observations, but optically thicker, yielding excessive planetary and surface cooling. Low clouds are also brighter than in observations, but underestimates of the frequency of occurrence (by ∼20 % in relative terms) help restore radiative agreement with observations. Overall the model better reproduces the longwave radiative effects of the various CVS classes because cloud vertical location is substantially constrained in the CVS framework.

Remote sounding of atmospheric temperature from satellites IV. The selective chopper radiometer for Nimbus 5

1973 ◽  
Vol 334 (1597) ◽  
pp. 149-170 ◽  
Keyword(s):  
Water Vapour ◽  
Near Infrared ◽  
Far Infrared ◽  
Atmospheric Temperature ◽  
Horizontal Resolution ◽  
Ice Clouds ◽  
New Instrument ◽  
Remote Sounding ◽  
Complete Set ◽  
High Clouds

An improved version of the selective chopper radiometer which has successfully flown for three years on the Nimbus 4 satellite has been built for the Nimbus 5 satellite which was launched in December 1972. The new instrument has 16 channels, eight of which observe emission from the 15 μm band of carbon dioxide for remote temperature sounding, two observe emission from water-vapour and ice clouds in the far infrared, one observes emission from low atmospheric water-vapour, three are in spectral regions where the atmosphere is substantially transparent, i.e. window regions, and two observe reflected sunlight from high clouds near to 2.7 μm in the near infrared. The horizontal resolution of the instrument is about 25 km and a complete set of measurements is made every 4 s. The design, construction and calibration of the instrument are described.

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