Download or read book Retrieval of Optical and Microphysical Properties of Ice Clouds Using Atmospheric Radiation Measurement ARM Data written by Jacqueline Anne Kinney and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented here retrieves the cloud optical thickness and particle effective size of cirrus clouds using surface radiation measurements obtained during the Atmospheric Radiation Measurement (ARM) field campaign. The algorithm used is based on a method proposed by Yang et al. (2005). The research examines single-layer ice clouds in the midlatitude and polar regions. The retrieved information in the midlatitudes is then verified using retrievals from the Moderate-resolution Imaging Spectroradiometer (MODIS) onboard the Terra and Aqua satellites.
Download or read book The Microphysics of Ice Clouds written by Rosemary M. Dyer and published by . This book was released on 1979 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Published results of observations of crystal habits, particle sizes and numbers of ice particles in clouds are summarized and discussed. There are systematic variations with cloud type, and in some instances, with cloud age and location within a cloud system. However, the body of data available is insufficient to formulate a climatology of ice cloud microphysics. The several measurement techniques in current use are evaluated, as are some of the techniques now under consideration for future use. The particle enhancement observed on some occasions is discussed, and the various theories accounting for it presented. Finally, recommendations are made concerning future field programs and theoretical studies required before accurate predictions of the ice cloud microphysical environment can be made. (Author).
Download or read book Retrieval of Cloud Phase Using the Moderate Resolution Imaging Spectroradiometer Data During the Mixed Phase Arctic Cloud Experiment written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Improving climate model predictions over Earth's polar regions requires a comprehensive knowledge of polar cloud microphysics. Over the Arctic, there is minimal contrast between the clouds and background snow surface, making it difficult to detect clouds and retrieve their phase from space. Snow and ice cover, temperature inversions, and the predominance of mixed-phase clouds make it even more difficult to determine cloud phase. Also, since determining cloud phase is the first step toward analyzing cloud optical depth, particle size, and water content, it is vital that the phase be correct in order to obtain accurate microphysical and bulk properties. Changes in these cloud properties will, in turn, affect the Arctic climate since clouds are expected to play a critical role in the sea ice albedo feedback. In this paper, the IR trispectral technique (IRTST) is used as a starting point for a WV and 11-[micro]m brightness temperature (T11) parameterization (WVT11P) of cloud phase using MODIS data. In addition to its ability to detect mixed-phase clouds, the WVT11P also has the capability to identify thin cirrus clouds overlying mixed or liquid phase clouds (multiphase ice). Results from the Atmospheric Radiation Measurement (ARM) MODIS phase model (AMPHM) are compared to the surface-based cloud phase retrievals over the ARM North Slope of Alaska (NSA) Barrow site and to in-situ data taken from University of North Dakota Citation (CIT) aircraft which flew during the Mixed-Phase Arctic Cloud Experiment (MPACE). It will be shown that the IRTST and WVT11P combined to form the AMPHM can achieve a relative high accuracy of phase discrimination compared to the surface-based retrievals. Since it only uses MODIS WV and IR channels, the AMPHM is robust in the sense that it can be applied to daytime, twilight, and nighttime scenes with no discontinuities in the output phase.
Download or read book Study of Ice Cloud Properties Using Infrared Spectral Data written by Kevin James Garrett and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this thesis involves the study of ice cloud microphysical and optical properties using both hyperspectral and narrowband infrared spectral data. First, ice cloud models are developed for the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the METOP-A satellite, which provide the bulk-scattering properties of these clouds for the 8461 IASI channels between 645 and 2760 cm-1. We investigate the sensitivity of simulated brightness temperatures in this spectral region to the bulk-scattering properties of ice clouds containing individual ice crystal habits as well as for one habit distribution. The second part of this thesis describes an algorithm developed to analyze the sensitivity of simulated brightness temperatures at 8.5 and 11.0 ℗æm to changes in effective cloud temperature by adjusting cloud top height and geometric thickness in a standard tropical atmosphere. Applicability of using these channels in a bi-spectral approach to retrieve cirrus cloud effective particle size and optical thickness is assessed. Finally, the algorithm is applied to the retrieval of these ice cloud properties for a case of single-layered cirrus cloud over a tropical ocean surface using measurements from the Moderate Resolution Infrared Spectroradiometer (MODIS). Cloud top height and geometric thickness in the profile are adjusted to assess the influence of effective cloud temperature on the retrieval.
Download or read book Retrieve Optically Thick Ice Cloud Microphysical Properties by Using Airborne Dual Wavelength Radar Measurements written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-06 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The NASA Technical Reports Server (NTRS) houses half a million publications that are a valuable means of information to researchers, teachers, students, and the general public. These documents are all aerospace related with much scientific and technical information created or funded by NASA. Some types of documents include conference papers, research reports, meeting papers, journal articles and more. This is one of those documents.
Download or read book Global Ice Cloud Observations written by Kerry Glynne Meyer and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Ice clouds occur quite frequently, yet so much about these clouds is unknown. In recent years, numerous investigations and field campaigns have been focused on the study of ice clouds, all with the ultimate goal of gaining a better understanding of microphysical and optical properties, as well as determining the radiative impact. Perhaps one of the most recognized instruments used for such research is the Moderate-resolution Imaging Spectroradiometer (MODIS), carried aboard the NASA EOS satellites Terra and Aqua. The present research aims to support ongoing efforts in the field of ice cloud research by use of observations obtained from Terra and Aqua MODIS. First, a technique is developed to infer ice cloud optical depth from the MODIS cirrus reflectance parameter. This technique is based on a previous method developed by Meyer et al. (2004). The applicability of the algorithm is demonstrated with retrievals from level-2 and -3 MODIS data. The technique is also evaluated with the operational MODIS cloud retrieval product and a method based on airborne ice cloud observations. From this technique, an archive of daily optical depth retrievals is constructed. Using simple statistics, the global spatial and temporal distributions of ice clouds are determined. Research has found that Aqua MODIS observes more frequent ice clouds and larger optical depths and ice water paths than does Terra MODIS. Finally, an analysis of the time series of daily optical depth values revealed that ice clouds at high latitudes, which are most likely associated with synoptic scale weather sytems, persist long enough to move with the upper level winds. Tropical ice clouds, however, dissipate more rapidly, and are in all likelihood associated with deep convective cells.
Download or read book An Analysis of Cloud Property Retrieval Using Infrared Sounder Data written by Bruce Anthony Wielicki and published by . This book was released on 1980 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Implication of Atmosphere and Cloud State Uncertainties on the Global Retrieval of Ice Cloud Microphysical Properties written by Steven James Cooper and published by . This book was released on 2004 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microphysical Properties of Single and Mixed phase Arctic Clouds Derived from Ground based AERI Observations written by David D. Turner and published by . This book was released on 2003 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Provisional Annotated Agenda for the 28th Session to be Held at the Palais Des Nations Geneva Starting on Tuesday 5 July 1994 and Concluding on Friday 8 July 1994 written by and published by . This book was released on 1994 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Final Report written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The report on the final phase of the project describes improvements in the ice and liquid cloud retrieval algorithms due to the use of three-parameter particle size distributions in which all three parameters may vary with height, testing of the improved retrievals by comparisons of measured and calculated fluxes, and further improvement in liquid retrievals obtained by adding liquid water path information from the microwave radiometer to radar and visible optical depth information.
Download or read book Case Evaluations of NWP Model Ice Clouds by Comparison to Retrieved Ice Cloud Properties Using ARM Data written by Urszula J. Jambor and published by . This book was released on 2000 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Microphysical Properties of Ice Clouds as Inferred from the Polarization of Electromagnetic Waves written by Benjamin Cole and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncertainties associated with the microphysical and radiative properties of ice clouds remain an active research area because of the importance these clouds have in atmospheric radiative transfer problems and the energy balance of the Earth. In this study, an adding/doubling model is used to simulate the top of atmosphere (TOA) radiance and full Stokes vector from an ice cloud at the wavelength lambda = 865 nm with many different combinations of assumed ice habits (shapes) and different degrees of ice surface roughness, and the polarized radiance at a wide range of scattering angles is derived. Simulated results are compared with polarized radiance data from the POLDER (POLarization and Directionality of the Earth's Reflectances) instrument on board the PARASOL (Polarization and Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar) satellite. Bulk ice scattering properties are obtained by using five different size distributions collected during field campaigns ranging in effective diameter from 10 micrometers to 90 micrometers. Bulk scattering properties for the MODIS Collection 5 ice cloud product are used in this study, along with properties for two mid-latitude ice cloud models, a polar/mid-latitude ice model, and a model built for ice clouds over deep convection. Solid columns and hollow columns are used as well. The polarized radiance simulation results for the moderate surface roughness level best fit the satellite measurements for all ice models, though severely roughened ice crystals do fare well in a few cases. Hollow columns are the best fit to the satellite polarization measurements, but of the ensemble ice models, the polar/mid-latitude model at an effective diameter of 90 micrometers best fits the polarized radiance measurements for the one day of PARASOL data considered. This model should be the best to simulate ice cloud properties on a global scale.
Download or read book Determining Best Estimates and Uncertainties in Cloud Microphysical Parameters from ARM Field Data written by and published by . This book was released on 2015 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: We proposed to analyze in-situ cloud data collected during ARM/ASR field campaigns to create databases of cloud microphysical properties and their uncertainties as needed for the development of improved cloud parameterizations for models and remote sensing retrievals, and for evaluation of model simulations and retrievals. In particular, we proposed to analyze data collected over the Southern Great Plains (SGP) during the Mid-latitude Continental Convective Clouds Experiment (MC3E), the Storm Peak Laboratory Cloud Property Validation Experiment (STORMVEX), the Small Particles in Cirrus (SPARTICUS) Experiment and the Routine AAF Clouds with Low Optical Water Depths (CLOWD) Optical Radiative Observations (RACORO) field campaign, over the North Slope of Alaska during the Indirect and Semi-Direct Aerosol Campaign (ISDAC) and the Mixed-Phase Arctic Cloud Experiment (M-PACE), and over the Tropical Western Pacific (TWP) during The Tropical Warm Pool International Cloud Experiment (TWP-ICE), to meet the following 3 objectives; derive statistical databases of single ice particle properties (aspect ratio AR, dominant habit, mass, projected area) and distributions of ice crystals (size distributions SDs, mass-dimension m-D, area-dimension A-D relations, mass-weighted fall speeds, single-scattering properties, total concentrations N, ice mass contents IWC), complete with uncertainty estimates; assess processes by which aerosols modulate cloud properties in arctic stratus and mid-latitude cumuli, and quantify aerosol's influence in context of varying meteorological and surface conditions; and determine how ice cloud microphysical, single-scattering and fall-out properties and contributions of small ice crystals to such properties vary according to location, environment, surface, meteorological and aerosol conditions, and develop parameterizations of such effects. In this report we describe the accomplishments that we made on all 3 research objectives.
Download or read book Refinement of Cloud Optical and Microphysical Properties and Gridded Atmosphere Products from MODIS written by and published by . This book was released on 2014 with total page 2 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Retrieval of Cloud Properties and Direct Testing of Cloud and Radiation Parameterizations Using ARM Observations written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The problems addressed by this work include cloud optical depth retrieval from satellite and surface data and 3D radiative transfer in dynamical models.
Download or read book Ice Microdynamics written by Pao K. Wang and published by . This book was released on 2002 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atmospheric ice particles play crucial roles in cloud and storm dynamics, atmospheric chemistry, climatological processes, and other atmospheric processes. Ice Microdynamics introduces the elementary physics and dynamics of atmospheric ice particles in clouds; subsequent sections explain their formation from water vapor, why ice crystal shape and concentration in cirrus clouds influence the heating of air, and describe how ice crystals cleanse the atmosphere by scavenging aerosol particles. Pao Wang's lucid writing style will appeal to atmospheric scientists, climatologists, and meteorologists with an interest in understanding the role of ice particles in the atmosphere of our planet.
