Frederick B. House

On the Inversion of Limb Radiance Measurements I: Temperature and Thickness

The calculation of limb radiance as a function of tangent height is shown to require information about the vertical distribution of temperature and the pressure at one level. Conversely, given the limb radiance curve and the pressure corresponding to one tangent point, it is possible to determine the temperature profile as a function of height relative to the given level, using an iterative technique. Results of inverting synthesized realistic data are presented. The data include the effects of water vapor and ozone contamination of the carbon dioxide signal, instrument field of view, and random and systematic noise for real atmospheres having small-scale vertical structure.

Sounding the Stratosphere and Mesosphere by Infrared Limb Scanning from Space

Inversion of the measurements obtained by the infrared limb scanner on the Nimbus 6 satellite has demonstrated that the stratospheric and mesospheric temperatures and ozone concentrations may be obtained remotely from space with accuracy and precision comparable to in situ methods. Such global data have many applications in middle atmospheric research and operational temperature sounding.

Measurements of the earth radiation budget from satellites during the first GARP global experiment

Abstract Two special measurements of the energy exchange between earth and space were made in connection with the FGGE. A global monitoring program using wide-field-of-view and scanner detectors from NASAs NIMBUS-7 satellite successfully returned measurements during the entire FGGE. This experiment system also used a black cavity detector to measure the total energy output of the sun to very high precision. A second set of high frequency time and space estimates of the radiation budget were determined from selected geostationary satellite data. Preliminary results from both radiation budget data sets and the solar “constant” measurements will be presented.

N-stream approximations to radiative transfer

Abstract Schusters two-stream approximation is first derived from Chandrasekhars radiative transfer equation, and then generalized to an arbitrary number of streams. The resulting technique for solving the transfer equation that is similar to the discrete ordinate and spherical harmonic methods, is found to be especially useful for modeling atmospheres with complicated phase functions and moderate optical depths. To illustrate the method, a four-stream approximation is evaluated for a Henyey-Greenstein phase function with asymmetry factor g = 0.5.

Observing the earth radiation budget from satellites - Past, present, and a look to the future

Abstract Satellite measurements of the radiative exchange between the planet Earth and space have been the objective of many experiments since the beginning of the space age in the late 1950s. The on-going mission of the Earth Radiation Budget (ERB) experiments has been and will be to consider flight hardware, data handling and scientific analysis methods in a single design strategy. Research and development on observational data has produced an analysis model of errors associated with ERB measurement systems on polar satellites. Results show that the variability of reflected solar radiation from changing meteorology dominates measurement uncertainties. As an application, model calculations demonstrate that measurement requirements for the verification of climate models may be satisfied with observations from one polar satellite, provided we have information on diurnal variations of the radiation budget from the ERBE mission.

An intercomparison of longwave measurements by ERBE radiometers on the NOAA-9 and ERBS satellites

Two instrument modules of each satellite on which ERBE is orbiting observe components of the earth radiation budget with three different scales of earth view. An intercomparison of longwave measurements by these instruments provides relative information concerning radiometric performance at satellite altitude, techniques of estimating upwelling exitances, and an end-to-end evaluation of the data processing system. Results indicate that the ERBE radiometers are mildly sensitive to varying thermal loads from the spacecraft and/or the earth-space environment. Radiometric variations at the satellite and methods of data interpretation contribute about equally to the uncertainty of radiant exitances from the earth. The RMS uncertainty of observed differences between instruments is about ±4 W/m2 for irradiances at satellite altitude, ±7 W/m2 for exitances at the top-of-the-atmosphere, and ±7 W/m2 for monthly averages after time and space averaging. Overall, the longwave observational consistency is about ±3.0% for individual measurements and ±3.0 % for monthly estimates.

EMPIRICAL MODEL OF THE EARTH'S RESPONSE TO ASTRONOMICAL VARIATIONS OF INSOLATION

An empirical model of the Earth-atmosphere system is formulated from satellite observations of the response to monthly variations of insolation. Observations of reflectance at different latitude zones are portrayed as functions of insolation magnitude, its spatial gradient and variation in time during the year. Assuming heat transport and storage terms remain the same as today, conservation demands a radiant emittance (and corresponding surface temperature) which balances the energy equation.