Engineering topics

Spencer, Roy W.

Publications and source records attributed to Spencer, Roy W..

40 records · Page 3

NASA NTRS1988

The 1982-83 ENSO global convective precipitation anomaly derived from Nimbus-7 SMMR 37 GHz scattering measurements

The scattering algorithms of Spencer (1983, 1986) are applied to the December-May period from 1981-1984, to obtain the 1982-1983 December-May convective precipitation anomaly patterns associated with the El Nino/Southern Oscillation. It is shown that semiannual convective precipitation patterns over global land and ocean regions can be mapped using the volume scattering effect of precipitation-size ice on Nimbus-7 SMMR 37 GHz brightness temperature. It is suggested that the Defense Meteorological Satellite Program Special Sensor Microwave/Imager 85 GHz data (in combination with 37 and 19 GHz data) can be valuable in global surveys of precipitation patterns.

Spencer, Roy W.↗

NASA NTRS1988

Thunderstorm ice induced brightness temperature depressions at 18, 37, and 92 GHz during Cohmex and their implications for satellite precipitation retrievals

Measurements of thunderstorm ice scattering at 18, 37, and 92 GHz, and with high spatial and temporal resolution from the Cooperative Huntsville Meterorlogical Experiment (Cohmex) are discussed. The Cohmex experiment consisted of ground-based, airborne, and satellite experiments in June and July, 1986. The rainfall rates from the experiment are compared with other measurements and the implications of the results for satellite precipitation retrievals are examined.

Hood, Robbie E.↗

NASA NTRS1987

Severe storm identification with satellite microwave radiometry - An initial investigation with Nimbus-7 SMMR data

The use of satellite passive microwave observations for the detection of severe thunderstorms is investigated. Nimbus 7 SMMR data obtained from 1979 to 1980 over the U.S. east of 105 deg W are analyzed. The relative temperature brightnesses of the severe storms are examined; it is observed that temperature brightness decreases as the storm severity increases. The temperature brightness data were transformed into a quantitative measure of storm detection ability using the critical success index of Donaldson et al. (1975). Critical success indices of 0.32, 0.48, and 0.38 were obtained for the low-brightness-temperature thresholding of severe versus nonsevere storms during 1979, 1980, and 1979 and 1980 combined, respectively. The data reveal that the geostationary passive microwave imaging capability at 37 GHz is applicable to the detection and monitoring of severe convective storms.

Howland, Michael R.↗

NASA NTRS1986

Oceanic rain retrievals from satellite passive 37 GHz scattering measurements

A technique for estimating the effect of scattering on the average brightness temperature, T(B), is examined. This scattering method is based on the relation observed over land between the SMMR T(B) and radar-derived rain rate. The scattering algorithm was evaluated and a comparison of radar and SMMR images reveals a correlation between radar-reflectivity-derived rates and the SMMR rain rates. The limitations of the scattering technique are discussed. Graphs and images displaying the application of the scattering algorithm are presented.

Spencer, Roy W.↗