Papers by Bruce Barkstrom
Earth Science Informatics
Physics Today, 1989
ABSTRACT
Astrophysical Journal, 1974
ABSTRACT During the past 4 years, data from the Earth Radiation Budget Experiment (ERBE) have bee... more ABSTRACT During the past 4 years, data from the Earth Radiation Budget Experiment (ERBE) have been undergoing detailed examination. There is no direct source of groundtruth for the radiation budget. Thus, this validation effort has had to rely heavily upon intercomparisons between different types of measurements. The ERBE SCIENCE Team chose 10 measures of agreement as validation criteria. Late in August 1988, the Team agreed that the data met these conditions. As a result, the final, monthly averaged data products are being archived. These products, their validation, and some results for January 1986 are described. Information is provided on obtaining the data from the archive.
Journal of Glaciology, 1972
Monthly Weather Review, 1987
Journal of Geophysical Research, 1974
The optical properties of a snowpack are calculated, giving relations between the asymptotic flux... more The optical properties of a snowpack are calculated, giving relations between the asymptotic flux extinction coefficient and albedo under diffuse illumination on the one hand and the density, grain size, and wavelength, on the other. A geometrical optics calculation of the properties of a single grain is used with approximate solutions of the radiative transfer problem. Most of the scattering
Science, 1989
The study of climate and climate change is hindered by a lack of information on the effect of clo... more The study of climate and climate change is hindered by a lack of information on the effect of clouds on the radiation balance ofthe earth, referred to as the cloud-radiative forcing. Quantitative estimates ofthe global distributions of cloud-radiative forcing have been obtained from the spaceborne Earth Radiation Budget Experiment (ERBE) launched in 1984. For the April 1985 period, the global shortwave doud forcing [-44.5 watts per square meter (W/m2)] due to the enhancement of planetary albedo, exceeded in magnitude the longwave cloud forcing (31.3 W/m2) resulting from the greenhouse effect of douds. Thus, clouds had a net cooling effect on the earth. This cooling effect is large over the mid-and high-latitude oceans, with values reaching -100 W/m2. The monthly averaged longwave cloud forcing reached maximum values of 50 to 100 W/m2 over the convectively disturbed regions of the tropics. However, this heating effect is nearly canceled by a correspondingly large negative shortwave cloud forcing, which indicates the delicately balanced state of the tropics. The size of the observed net cloud forcing is about four times as large as the expected value of radiative forcing from a doubling of CO2. The shortwave and longwave components ofcloud forcing are about ten times as large as those for a CO2 doubling. Hence, small changes in the cloud-radiative forcing fields can play a significant role as a climate feedback mechanism. For example, during past glaciations a migration toward the equator of the field of strong, negative cloudradiative forcing, in response to a similar migration of cooler waters, could have significantly amplified oceanic cooling and continental glaciation. C LOUDS ARE REGULATORS OF THE RADIATVE HEATING OF the planet. They reflect a large part of the incoming solar radiation, causing the albedo of the entire earth to be about twice what it wouild be in the absence of clouds (1). Clouds also absorb the longwave (LW) radiation (also known as infrared or thermal radiation) emitted by the warmer earth and emit energy to space at the colder temperatures of the cloud tops. Cloud LW absorption and emission are, in a sense, similar to the radiative effects of atmospheric gases. The combined effect of LW absorption and emission-that is, the greenhouse effect-is a reduction in the LW radiation emitted to space. The greenhouse effect ofclouds may be larger than that resulting from a hundredfold increase in the CO2 concentration of the atmosphere (2).
Journal of The Atmospheric Sciences, 1978
In this paper, we describe the need to consider how file formats affect the ease and effectivenes... more In this paper, we describe the need to consider how file formats affect the ease and effectiveness with which scientific and engineering data may be stored and accessed in long term archives. We identify a number of attributes of file formats that can help or hinder them as candidates for long-term digital preservation. We consider how these attributes appear to a number of different audiences for long-term archiving.
Reviews of Geophysics, 1986
This paper gives an overview of the Earth Radiation Budget Experiment. The experiment consists of... more This paper gives an overview of the Earth Radiation Budget Experiment. The experiment consists of scanning and nonscanning radiometer packages on three spacecraft. One is a satellite with a 57 ø inclination orbit which precesses around the earth once every 2 months. Packages are also flown on the sun-synchronous NOAA-F and NOAA-G operational meteorological satellites. The scanning radiometer includes three channels: shortwave, long-wave, and total. The nonscanner package encompasses a pair of wide-field-of-view radiometers and a pair of medium-field-of-view radiometers. Each pair consists of a total and a shortwave radiometer. The scientific importance and objectives of the mission are described, including the need for the three spacecraft and the utility of the complementary types of radiometers.
Journal of Geophysical Research, 1974
The optical properties of a snowpack are calculated, giving relations between the asymptotic flux... more The optical properties of a snowpack are calculated, giving relations between the asymptotic flux extinction coefficient and albedo under diffuse illumination on the one hand and the density, grain size, and wavelength, on the other. A geometrical optics calculation of the properties of a single grain is used with approximate solutions of the radiative transfer problem. Most of the scattering
Bulletin of The American Meteorological Society, 1993
... of a prototype data system for earth radiation budget, cloud, aerosol, and ... Creator/Author... more ... of a prototype data system for earth radiation budget, cloud, aerosol, and ... Creator/Author, Baum, BA ; Barkstrom, BR (NASA Langley Research Center ... 54 ENVIRONMENTAL SCIENCES; 99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION ...
IEEE Transactions on Geoscience and Remote Sensing, 1991
IEEE Transactions on Geoscience and Remote Sensing, 1998
Applied Optics, 1986
Earth radiation budget experiment (ERBE) nonscanner instruments are operating on both the Nationa... more Earth radiation budget experiment (ERBE) nonscanner instruments are operating on both the National Aeronautics and Space Administration's earth radiation budget satellite (ERBS) and the National Oceanic and Atmospheric Administration's NOAA-9 spacecraft. These instruments are designed to make highly accurate broadband measurements of the earth's energy budget on spatial scales ranging from 100 earth central angle to global over temporal scales ranging from 30 days to annual averages. As part of the in-flight calibration of these instruments, the four nominally earth viewing radiometric channels are periodically repositioned for solar viewing. At the same time, a fifth (solar monitor) channel is activated. These solar calibrations were performed weekly during the first two months of operation of each spacecraft and biweekly thereafter. Results from the first few months of operation show an extremely consistent set of solar measurements. Each of the ten channels has a precision of approximately 0.1% and a measurement uncertainty estimated to be 0.2%. The ERBS and NOAA-9 solar monitors have yielded provisional solar irradiance values of 1364.3 and 1363.5, agreement to within 0.06%. A description of the solar calibration process is presented along with engineering results from each of the ten radiometric channels over the first few months of operation. The solar calibration data reduction process is also discussed.
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Papers by Bruce Barkstrom