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Kaplan, L. D.

Publications and source records attributed to Kaplan, L. D..

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Advanced Moisture and Temperature Sounder (AMTS) study

Retrieval of tropospheric humidity profiles from satellite-based upwelling radiances are shown to be improved by using physical methods for obtaining first-guess profiles as well as for inverting the radiative transfer equation by relaxation. The first guess is based on an empirically verified hypothesis, from theoretical considerations, that the brightness temperature corresponding to the radiance should be approximately equal to the actual temperatue at a channel-invariant optical depth provided that the surface and stratospheric contributions to the radiance are small. Even greater improvement of retrieved humidity profiles can be accomplished by increasing the number of channels used and by selecting their spectral location and bandpass to obtain sharper independent weighting functions. For example, the AMTS system, with high resolution water channels at 1650, 1700, 1839, 1850 and 1930 cm, is shown to be capable of reducing the retrieved water vapor errors in 200 mb thick layers by a factor of two or three relative to the HIRS-2 system errors. Expected AMTS errors in tropical layer water content are particularly low, less than 20% at all levels, and of the order of 10% or less in the middle troposphere.

Kaplan, L. D.↗
NASA NTRS1983

Effects of high altitude clouds on the earth's infrared radiation flux

Attention is given to the results of a study of cirrus cloud properties which employed the Goddard Laboratory for Atmospheric Sciences' general circulation model and concentrated on the effects of the nonblackness of high clouds on the IR radiation flux. Although the thermal radiation flux is very sensitive to the treatment of cirrus optical properties in the IR, a more realistic assessment will depend on better parameterizations for cirrus cloud formation, persistence, and dissipation.

Wang, W.-C.↗
NASA NTRS1981

Concentration of carbon monoxide in the upper stratosphere

The concentration of telluric carbon monoxide has been determined in the upper stratosphere from infrared solar spectra recorded by balloon in October 1978 and September 1979, over Texas. The average mixing ratios were found to be (2.1 plus or minus 3) x 10 to the -8th ppv and (3.7 plus or minus 0.4) x 10 the the -8th ppv above the float altitudes of 30.6 and 36.8 km, respectively. The concentration profile deduced from all the measurements indicates that the CO mixing ratio increases in the upper stratosphere, from (1 plus or minus 0.3) x 10 to the -8th ppv at 30.6 km, to about 4 x 10 to the -8th ppv above 41 km.

Zander, R.↗
NASA NTRS1979

Advanced risk assessment of the effects of graphite fibers on electronic and electric equipment, phase 1

A model was developed to generate quantitative estimates of the risk associated with the release of graphite fibers during fires involving commercial aircraft constructed with graphite fiber composite materials. The model was used to estimate the risk associated with accidents at several U.S. airports. These results were then combined to provide an estimate of the total risk to the nation.

Pocinki, L. S.↗
NASA NTRS1979

Advanced Meteorological Temperature Sounder (AMTS) simulations

Simulation studies are reported on temperature retrievals from AMTS and their effect on atmospheric analysis. Observations are simulated from radiosonde reports and observed cloud cover. Temperature retrievals are performed and RMS temperature and thickness errors are calculated relative to the radiosonde profiles and compared to similarly generated HIRS statistics. Significant improvement over HIRS is found throughout the atmosphere but especially in the stratosphere and lower troposphere.

Susskin, J.↗
NASA NTRS1978

Influence of systematic radiation differences on the dynamics of a model atmosphere

Numerical experiments were run on the Goddard Laboratory for Atmospheric Sciences (GLAS) nine-level GCM using two different long-wave radiation routines - the Hogan routine and the Wu-Kaplan routine - to determine whether systematic radiation difference is important in the modeling of the general circulation of the atmosphere. The climatologies produced from GCM runs using the different radiation routines were compared for both winter and summer. Systematic differences were found in the mean zonal temperatures, in the location and shape of the zonal west wind maximum, in the strength of the Hadley and Ferrel cells, in the cloud and precipitation distributions, and in the mass distributions. On the basis of comparisons with observations, it was found that the Wu-Kaplan routine had a positive impact or at least made improvements in the right direction in most respects.

Wu, M.-L. C.↗
NASA NTRS1977

Spectral band passes for a high precision satellite sounder

Atmospheric temperature soundings with significantly improved vertical resolution can be obtained from carefully chosen narrow band-pass measurements in the 4.3-micron band of CO2 by taking advantage of the variation of the absorption coefficients, and thereby the weighting functions, with pressure and temperature. A set of channels has been found in the 4.2-micron region that is capable of yielding about 2-km vertical resolution in the troposphere. The concept of a complete system is presented for obtaining high resolution retrievals of temperature and water vapor distribution, as well as surface and cloud top temperatures, even in the presence of broken clouds.

Kaplan, L. D.↗
NASA NTRS1977

Temperature sensing: The direct road to information

The retrievability of detailed temperature soundings from remote measurements of emission spectra depends not so much on how the data are treated as on what the data are. It is shown that the shape of the weighting functions depends on the nature of the pressure and temperature dependence of the transmittance, which differ from one part of the spectrum to another as well as with spectral resolution. It is shown that careful selection of channels results in much narrower weighting functions than those corresponding to channels that have actually been used.

Kaplan, L. D.↗
NASA NTRS1969

The use of high frequency infrared radiometry for remote atmospheric probing with high vertical resolution

The necessity of obtaining soundings of temperature and water vapor content of the lower troposphere with sufficient vertical resolution to determine the exchange of heat and moisture between the surface and the atmosphere is discussed. The means for solving the problem will be emission measurements in the high frequency end of the thermal infrared. The means for solving another problem is supplementary scanning with high area resolution.

Kaplan, L. D.↗