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Thompson, A. H.

Publications and source records attributed to Thompson, A. H..

15 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

Identification and recovery of discontinuous synoptic features in satellite-retrieved brightness temperatures using a radiative transfer model

An attempt is made to recover and identify discontinuous synoptic features from satellite-retrieved brightness temperatures, with attention to near-discontinuities in temperature and moisture that are typically found in fronts and inversions. Efforts are made to ascertain whether the vectors of satellite channel brightness temperatures can be classified according to synoptic source, and whether those sources are amenable to quantification.

White, G. A., III↗
NASA NTRS1988

Tropical synoptic signatures in composited 6.7 micrometer water vapor imagery

A model of the signatures of a synoptic development as seen in 6.7-micron water vapor channel imagery has been constructed from a composite of cases for a moisture burst over the eastern Pacific Ocean. The characteristics revealed in these composites are discussed and compared with the signatures of the moisture bursts as seen in satellite-derived visual and window channel IR imagery. A test of the forecast capability of the model was performed on 120 consecutive days, including 29 moisture bursts. After 2 hours of training, a meteorologist was able to forecast 19 (65 percent) of the bursts at least 24 hours in advance. In 6 cases, bursts were forecast when none occurred.

Thompson, A. H.↗
NASA NTRS1986

Tropical synoptic interpretation of inter-channel correlations from Tiros N

Synoptic variability contained in a set of Tiros N channel brightness temperatures was analyzed for a nine-day period during January 1979, between the dateline and 90 deg W and between 30 deg N and 20 deg S. In the procedure, the spatial coherence of each channel is first described in terms of functions of interchannel differences and geographic and synoptic variations. Second, horizontal and vertical pattern of individual channels are examined through empirical orthogonal functional decomposition. Finally, response surface regression models are developed to predict missing Tiros N channels from available Tiros N and NOAA-5 data. The percentage variance was predicted for each channel from the Tiros N microwave and stratospheric channels. Generally speaking, about 80 percent of the variance in each channel can be predicted for the Tiros model, excepting the two tropospheric moisture channels, where prediction was less successful.

Mcguirk, J. P.↗
NASA NTRS1986

Comparisons of FGGE IIb and IIIb winds in a tropical synoptic system

The ECMWF wind analysis of a moisture burst over the NE Pacific Ocean occurring during a 9-day period in January 1979 is discussed. The availability of the data in synoptically active regions, and the horizontal, vertical, and temporal correlations of the data are considered. The accuracy of the wind data and the divergence in the tropics are examined. It is noted that it is necessary to maximize wind accuracy, and procedures for relating divergence to synoptic activity and satellite imagery to data correction are needed.

Mcguirk, J. P.↗
NASA NTRS1986

Wintertime disturbances in the tropical Pacific - FGGE IIIb and satellite comparisons

The synoptic development of moisture fields associated with moisture bursts near the ITCZ is described. Dropsonde and satellite (Tiros and GOES) data for the moisture structure along the winter ITCZ North Pacific are presented and examined. These observations were compared with ECMWF analysis along the ITCZ; consideration is given to relative humidity and burst dynamics. It is observed that the ECMWF analysis reproduces the synoptic variations reasonably well.

Mcguirk, J. P.↗
NASA NTRS1986

Moisture transports and budgets of 'moisture bursts'

The paper discusses moisture fluxes and budgets associated with a pair of 'moisture bursts' in the eastern North Pacific Ocean area, described by Smith et al. (1985). The moisture fluxes were calculated using data obtained during the first Special Observing Period (SOP-1) of the FGGE. The area specifically examined extended from the equator to the latitude 20 deg N and from longitude 180 deg to 100 deg W, with concentration on the region south and southeast of the Hawaiian Islands. From the comparison of the calculations based on dropwindsonde and radiosonde data and reports from commercial and military aircraft, it is concluded that the calculations of water vapor flow across latitude lines probably provide a fair representation of reality, especially when based on the dropwindsonde data. However, water vapor flow out of small volumes is not well represented by the results from either data.

Thompson, A. H.↗
NASA NTRS1985

Application of satellite data to tropic/subtropic moisture coupling

The objective is to develop analysis tools for use of satellite data to interpret synoptic-scale systems in data-void regions. Interim goals are to: (1) quantify the synoptic information content of satellite data; and (2) utilize these data in the diagnosis of moisture bursts in the eastern tropical Pacific Ocean. Researchers developed and implemented a statistical procedure for using TIROS N microwave data to infer infrared channel data for overcast conditions; they used the same procedure for deducing full TIROS N channel radiance profiles from NOAA 5 VTPR channel data over regions where the TIROS N data are missing. An empirical orthogonal function analysis of twice-daily channel radiance fields over the tropical eastern Pacific was completed. The vertically oriented eigenfunctions were interpreted in terms of typical meteorological events. The horizontal distribution of the eigenfunction amplitudes relates these meteorological signals to moisture bursts. A pair of moisture burst climatologies is complete: one of four years using infrared imagery (including the highly anomalous 1982 to 83 cold season); the other implementing 850 to 200 mb wind analyses in conjunction with GOES imagery. A number of different evaluations of the synoptic evolution of moisture fields (enhanced infrared imagery, moisture channel data, FGGE humidity analysis, and in situ station and sounding observations) are compared. All have limitations; all can be utilized together; all together are still less than adequate in the tropical Pacific.

Mcguirk, J. P.↗
NASA NTRS1985

Satellite-derived synoptic climatology in data-sparse regions

Synoptic-scale 'moisture bursts' are defined, based on infrared GOES imagery, and their synoptic climatology is developed. Quantitative analysis of satellite-derived individual channel radiance data and vertical eigenfunctions of complete channel data yield rich structural detail; these details do not appear in FGGE analyses in regions void of conventional meteorological data.

Mcguirk, J. P.↗
NASA NTRS1984

Application of satellite data to tropic/subtropic moisture coupling

The objective is to utilize various satellite products from a number of satellites together with data observed from platforms available during the FGGE Special Observing Periods to diagnose synoptic scale events in date void regions. The focus is on episodes of northeastward traveling cloud bands which move out of the ITCZ over the eastern North Pacific Ocean. These events are called moisture bursts.

Thompson, A. H.↗
NASA NTRS1984

Analysis of tropical synoptic disturbances using satellite-derived soundings and radiance data from selected channels

Some of the results of comparing and combining conventional meteorological data with data retrieved from satellite radiance measurements in determining the atmospheric structure associated with a portion of the life cycle of an eastern Pacific moisture burst are presented. The satellite-derived data, consisting of microwave and water vapor channel brightness temperature fields and cloud-tracked winds, detect synoptic scale patterns of temperature, moisture, and wind. The microwave channel temperatures provide 'all weather' coverage but require special interpretation in rain areas. The need for further investigations to improve the accuracy of inferring structure from satellite-derived information is emphasized.

Thompson, A. H.↗
NASA NTRS1979

Convective rainfall estimation from digital GOES-1 infrared data

An investigation was conducted to determine the feasibility of developing and objective technique for estimating convective rainfall from digital GOES-1 infrared data. The study area was a 240 km by 240 km box centered on College Station, Texas (Texas A and M University). The Scofield and Oliver (1977) rainfall estimation scheme was adapted and used with the digital geostationary satellite data. The concept of enhancement curves with respect to rainfall approximation is discussed. Raingage rainfall analyses and satellite-derived rainfall estimation analyses were compared. The correlation for the station data pairs (observed versus estimated rainfall amounts) for the convective portion of the storm was 0.92. It was demonstrated that a fairly accurate objective rainfall technique using digital geostationary infrared satellite data is feasible. The rawinsonde and some synoptic data that were used in this investigation came from NASA's Atmospheric Variability Experiment, AVE 7.

Sickler, G. L.↗