An Analysis of Cloud Property Retrieval Using Infrared Sounder Data PDF Download

Author: Bruce Anthony Wielicki
Publisher:
ISBN:
Category : Clouds
Languages : en
Pages : 288

View

Book Description

Author: Gary B. Gustafson
Publisher:
ISBN:
Category : Cloud physics
Languages : en
Pages : 0

View

Book Description
A basic research program was conducted for the Air Force Research Laboratory, consisting of three tasks: (1) develop extensible cloud property retrieval algorithms suitable for expanding existing cloud analysis capabilities to utilize data from new and future environmental satellite sensing systems; (2) develop advanced algorithms for retrieval of cloud properties that are insufficiently resolved to satisfy Air Force requirements using existing techniques; and (3) validate cloud property retrieval algorithms using real data from existing meteorological satellite platforms. Under task 1 a series of algorithms developed under previous AFRL programs were modified to expand capabilities in several areas including improved transmissive cirrus detection and classification, cloud phase retrieval, snow/cloud discrimination, and transition across the terminator. In task 2 new capabilities were developed to retrieve cloud radiative and microphysical properties from multispectral data available from environmental satellites including the newly launched MODIS. Under task 3 the new algorithms were implemented in software and applied to real data acquired from the GOES 8 satellite in support of two field programs conducted or supported by AFRL.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 60

View

Book Description
The main objective of the proposed study was to investigate the complementary information provided by microwave and infrared sensors in order to enhance both the microwave retrieval and the current cloud analysis. This primary task investigated and assessed the impact of incorporating cloud horizontal and vertical spatial distribution information on the performance and accuracy of simultaneous physical retrievals of atmospheric profiles from microwave sensors. The second task explored additional attributes of the microwave measurements, particularly related to ice clouds, to investigate the possibility of identifying multi-layer clouds from simultaneous microwave, visible and infrared data, and to provide infrared emission properties needed for threshold-based cloud detection. We also applied the UR approach to DMSP data to provide the basis for screening out cases where the infrared/visible-derived low cloud properties were uncertain and to assess ability to characterize the vertical structure of multi-layer clouds. The third task investigated the feasibility of predicting infrared emission properties using the microwave data, and assessed if this information could be used to enhance low cloud and thin high cloud identification in totally overcast conditions, especially at night. This task included deriving empirical relationships between microwave and infrared surface emission based on dependent clear data sets, and performing exploratory cloud analyses using both the surface temperature data from the current surface temperature data base and the microwave derived surface emission properties. The last task addressed the application of the UR algorithm to land and to snow/ice backgrounds and assessed the algorithm's capability using new data collected over the Northern Hemisphere in the winter.

Author: Gary B. Gustafson
Publisher:
ISBN:
Category : Cloud physics
Languages : en
Pages : 48

View

Book Description

Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781792712197
Category :
Languages : en
Pages : 28

View

Book Description
An accurate satellite retrieval of cloud properties depends upon the detection and analysis of multilayered, overlapping cloud systems that surface observations show to be common. Multiple cloud layers are often found, for instance, in frontal situations, where cirrus overlays boundary layer convective cloud or low-to mid-level stratus cloud. Surface observers (Hahan et al., 1982) indicate that over ocean in the Northern Hemisphere between 30 deg. N and 60 deg. N, 51 percent of observations are of multilevel clouds. A satellite analysis by Coakley (1983) over the Pacific Ocean finds that more than 50 percent of 500 (250 sq km) frames exhibit evidence of multilayered cloud systems. The questions addressed in this study are the following: What error is introduced when inferring the cloud pressure from a Field-Of-View (FOV) that contains some arbitrary amount of transparent cloud overlaying a lower-level black cloud, such as stratus, by making the assumption that there is only a single cloud layer in the FOV, and what may be done to improve the cloud retrieval? The CO2 slicing methods (e.g. McCleese and Wilson, 1976; Smith and Platt, 1978; Chahine, 1974) have been shown to provide accurate means of inferring cirrus cloud altitude from passive infrared radiance measurements. The CO2 techniques have been applied to radiometric data from several instruments, notably the High Resolution Infrared Radiometric Sounder (HIRS/2, hereafter referred to as HIRS), the VISSR Atmospheric Sounder (VAS) (e.g., Menzel et al., 1983; Wylie and Menzel, 1989), and most recently to the High Resolution Interferometer Sounder (HIS) (Smith and Frey, 1990). The methods take advantage of the fact that infrared CO2 sounding channels spaced closely in wavenumber each have varying opacity to CO2, thereby causing each channel to be sensitive to a different level in the atmosphere. The techniques have been shown to be effective for single-layered, nonblack, mid- to high-level clouds such as cirrus, bu...

Author: Yong-Keun Lee
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
This dissertation reports on three different yet related topics in light scattering computation, radiative transfer simulation, and remote sensing implementation, regarding the cloud properties and the retrieval of cloud properties from satellite-based infrared radiometric measurements. First, the errors associated with the use of circular cylinders as surrogates for hexagonal columns in computing the optical properties of pristine ice crystals at infrared (8-12 [micron]) wavelengths are investigated. It is found that the differences between the results for circular cylinders and hexagonal columns are on the order of a few percent at infrared wavelengths. Second, investigated in this dissertation are the outgoing broadband longwave and window channel radiances at the top-of-atmosphere under clear-sky conditions on the basis of the data acquired by the Cloud and the Earth's Radiant Energy System (CERES) instrument onboard the NASA Terra satellite platform. Based on the comparison of the observed broadband radiances with those obtained from rigorous radiative transfer simulations, it is found that the theoretical results tend to be larger than their measured counterparts. Extensive sensitivity studies regarding the uncertainties of various parameters were carried out. Within the considered uncertainties of various factors, the computed radiances are still larger than the observed radiances if thin cirrus clouds are excluded. Thus, a potential cause for the differences could be associated with the presence of thin cirrus clouds whose visible optical thickness is smaller than approximately 0.3. Third, presented in this dissertation is an illustration of the application of hyperspectral infrared channel observations to the retrieval of the cloud properties. Specifically, the hyperspectral measurements acquired from the Atmospheric Infrared Sounder (AIRS) aboard the NASA Aqua platform are used to infer cloud top pressure, effective cloud amount, cloud thermodynamic phase, cloud optical thickness, and the effective size of cloud particles. The AIRS-based retrievals are compared with the counterparts of the operational cloud products derived from the Moderate Resolution Imaging Spectroradiometer (MODIS). The two retrievals agree reasonably well except for the retrieved cloud effective particle size. Furthermore, the diurnal and seasonal contrasts of cloud properties are also investigated on the basis of the cloud properties retrieved from the AIRS data.

Author: Erik R. Olson
Publisher:
ISBN:
Category :
Languages : en
Pages : 146

View

Book Description

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

View

Book Description
The problems addressed by this work include cloud optical depth retrieval from satellite and surface data and 3D radiative transfer in dynamical models.

Author: Rand E. Feind
Publisher:
ISBN:
Category : Carbon dioxide
Languages : en
Pages : 178

View

Book Description

Author: Grant Buster
Publisher:
ISBN:
Category : Cloud computing
Languages : en
Pages : 4

View

Book Description