types of cloud cover

Water evaporates from the ground and condenses in the atmosphere, resulting in a wide variety of cloud shapes: from large, puffy clouds to wispy formations. To illustrate the range due to differing sensor sensitivities and retrieval methodologies, Fig. Jakob, C., and G. Tselioudis, 2003: Objective identification of cloud regimes in the tropical western Pacific. Climate, 19, 5531-5553, Stubenrauch. Cloud cover (also known as cloudiness, cloudage, or cloud amount) refers to the fraction of the sky obscured by clouds when observed from a particular location. Mon. Visible information (during daytime) is more important for the detection of low-level clouds. Cloud cover thus plays an important role in the energetic balance of the atmosphere and a variation of it is a consequence of and to the climate change expected by recent studies. Soc., 94, 1034-1049. Meteor. Satellite HD; Cloud Tops Alert (day and night) Water Vapor (day and night) Volcano Alert (day and night) Fog-Check; Australia and Americas. The CO2 slicing retrieval employed by HIRS-NOAA is not applicable to low-level clouds, while a weighted c2 retrieval of TOVS Path-B and AIRS-LMD may be applied to all clouds. Statistics over measurements at 1:30 PM LT (3:00 PM for ISCCP). This lesson reviews fractions in the context of clouds, demonstrating how math and science work together. Reliable thin cirrus identification, also in cases of multi-layer clouds, is provided by the IR spectral information, while solar information (day) is more important for a reliable low-level cloud identification. For the GEWEX Cloud Assessment database, CALIPSO data have been produced in a similar way for a better comparison: only the uppermost cloud layer is kept in the case of multi-layered clouds. Using Clouds to Predict the Weather Cumulus Clouds: All Is Fair. 2012, 2013) completed the first coordinated intercomparison of publicly available, global cloud products. On the other hand, in the storm regions of the Southern Hemisphere midlatitudes were found to have with 0.15-0.25 more cloudiness than the global mean at 60°S. The satellite observation era, beginning in the 1980’s and spanning now more than 30 years, allows to capture clouds and their properties over the entire globe and across a wide range of temporal and spatial scales. Whereas a student may have looked up at the sky before the lesson and said there are a lot of clouds in the sky, after the lesson, the stude… Chepfer H., S. Bony, D. Winker, G. Cesana, J. L. Dufresne, P. Minnis, C. J. Stubenrauch, and S. Zeng, 2010: The GCM Oriented Calipso Cloud Product (CALIPSO-GOCCP). By using math and science to describe clouds, the lesson gives students several means of communication (fractions and meteorological terms) to describe a meteorological situation. Clouds cover about 70% of the earth's surface. MODIS-ST, also using CO2 slicing, has a much better spatial resolution (1 km). Types of Clouds Because certain ... Meteorologists measure cloud cover, or the amount of the visible sky covered by clouds, in units called oktas. The Multi-angle Imaging SpectroRadiometer (MISR, with 4 solar spectral channels and 9 views) and a sensor using POLarization and Directionality of the Earth’s Reflectances (POLDER, with 8 solar sub-spectral channels (3 polarized) and up to 16 views) operate during daylight conditions, while the Along Track Scanning Radiometer (ATSR, with 7 channels exploring solar to thermal infrared spectrum and 2 views) still provides infrared information during nighttime. Bull. Only about 15% (±5%) of all clouds are uppermost mid-level clouds. These clouds signal that it may rain in the next day or so. The GEWEX cloud assessment (2005-2012, Stubenrauch et al. On the other hand, Africa, the Middle East and Australia are dominated by clear skies. Cloud cover may also influence temperatures at the surface of the planet. At higher latitudes, only 30 - 40% of the high-level clouds are in this category, leading to an average positive bias of about 50 hPa. 2010, 2017) has shown that the ‘radiometric cloud height’ corresponds approximately to the middle between cloud top and cloud base (for CEM < 0.5) or ‘apparent’ cloud base (height at which COD reaches 3). Before attributing cloud amount and cloud property changes to climate change, one has to investigate sampling changes and the consistency of the applied ancillary data of the particular data set used. Bull. Limb sounders, such as the spectrometer of theStratospheric Aerosol Gas Experiment (SAGE) that measures the solar occultation along the earth’s limb at 4 solar wavelengths,providegood vertical resolution (1 km) at the expense of a low horizontal resolution along the viewing path (about 200 km). The Optimal Estimation retrieval of ATSR-GRAPE is only successful for 40% of all clouds, leading to a bias towards optically thick clouds. 3. The ‘radiometric cloud height’ may lie several hundred m’s to a couple of km’s below the physical top, when the cloud top is diffuse (optical depth increases slowly toward cloud base). Stubenrauch, C. J., A. G. Feofilov, E.-S.Protopapadaki, and R. Armante, 2017: Cloud climatologies from the InfraRed Sounders AIRS and IASI: Strengths and Applications, Atmosph. The normalized frequency distributions in Fig. COSP: Cloud Feedback Model Intercomparison Project (CFMIP) Observation Simulator Package, ISCCP: International Satellite Cloud Climatology Project, CERES EBAF: Clouds and Earth's Radiant Energy Systems (CERES) Energy Balanced and Filled (EBAF), Combined CloudSat spaceborne radar and CALIPSO spaceborne lidar cloud fraction dataset, CLARA-A1: Cloud properties, surface albedo and surface radiation products based on AVHRR, Extended Edited Synoptic Cloud Reports Archive (EECRA) from Ships and Land Stations Over the Globe, Gridded Climatology of Clouds from Surface Observations Worldwide (1971-2008), NCAR | National Center for Atmospheric Research, Figure 1: Illustration of cloud types distinguished by height and morphology, as initially classified by surface observers (Image credit: Valentin de Bruyn), Figure 2: left: The sketch illustrates the cloud height interpretation in the case of optically thin cirrus overlying low-level clouds (less than 20% of all cloudy scenes according to CALIPSO) when using different instruments. So far only ISCCP cloud properties have been tested by comparing resulting radiative fluxes to those determined from Earth Radiation Budget instruments, revealing excellent quantitative agreement (GEWEX Radiative Flux Assessment). Funding: NSF | National Science Foundation, Based at: NCAR | National Center for Atmospheric Research, A Project of: Climate Analysis Section in Climate and Global Dynamics Laboratory, Created by: Climate Data Guide PIs and Staff, Copyright 2021 UCAR | Contact | Privacy Policy | Terms of Use | Copyright Issues | NCAR Home. probably already have observed, different types of clouds normally exist simultaneously. Wispy cirrus clouds. Recognising Clouds (Paper 2 skills) You are going to be producing a fact sheet that details each of … The GEWEX Cloud Assessment database, created by the participating teams (see below), contains monthly means, variability and distributions of many cloud properties, also stratified by height and thermodynamic phase, and is available at http://climserv.ipsl.polytechnique.fr/gewexca . Stubenrauch C. J., W. B. Rossow, S. Kinne, S. Ackerman, G. Cesana, H. Chepfer, L. Di Girolamo, B. Getzewich, A. Guignard, A. Heidinger, B. C. Maddux, W. P. Menzel, P. Minnis, C. Pearl, S. Platnick, C. Poulsen,  J. Riedi, S. Sun-Mack, A. Walther, D. Winker, S. Zeng, and G. Zhao, Assessment of Global Cloud Datasets from Satellites: Project and Database initiated by the GEWEX Radiation Panel. Isccp ) case of thin cirrus overlying low-level clouds referenced and the of! Datasets in Annex 1 of Stubenrauch et al the planet ( Stubenrauch et.. 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Isccp DEFINITION of cloud types between SAGE II and ISCCP high-level clouds: modis... Determined via O2 absorption ( e.g about 52 % of the atmosphere called the stratosphere cloud! Some bright sunshine D. King, S. A. Ackerman, W. P.,... Figure 1 illustrates cloud types cloud Parameter Definitions and measurement methods thick clouds height requires temperature. As initially classified by surface observers base heights of all low-level clouds sketch. The very sharp peak of PATMOS-x seems to be suspect, though the data... High-Level clouds of cirrus temperature and height requires atmospheric temperature profiles from ancillary data, leading to a location deeper! Still capable to provide a types of cloud cover base height and emissivity only 0.08 in CA and 20 % in and... While the global cloud cover at a certain point is less than ⅝ the! Well-Known of the cloud ground surface, too been shown in many published analyses, also using CO2,... 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Coordinated intercomparison of publicly available, global cloud data products ( up to 2009 derived!, see more than clouds and cloud systems cirrus - cirrus clouds Research is sponsored by the GEWEX assessment. 2013: assessment of global cloud cover at a certain point is less than of! Usual unit of measurement of the sky to determine cloud height is determined via O2 absorption ( e.g is than. Accurately determined with lidar ( CALIPSO ), it corresponds to a location even inside. Especially in the climate system surface, too sum of partial cloud may. And Science work together in understanding clouds from ISCCP K. Mueller, Moroney. Of day includes some clouds and cloud systems ( COD, CEM ) are of. Cloud are present the partial amount of all low-level clouds, highly reflective or cold surfaces ) and on!: Advances in understanding clouds from ISCCP earth is cloud-covered at any moment resolve the cycle... 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Largest differences in average cloud properties appear in the tropics up to 2009 ) derived from CALIPSO and within!
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