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All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

A composite study of cloud, ozone and other data from recent satellite experiments

Pictorial data from the Image Dissector Camera System (IDCS) and Temperature-Humidity Infrared Radiometer (THIR) experiments on Nimbus 4 satellite are analyzed along with: (a) global total ozone maps prepared from Infrared Interferometer Spectrometer (IRIS) data and (b) total ozone and its vertical distribution as derived from Backscatter Ultraviolet (BUV) spectrometer data. A close relationship is generally observed between centers of high ozone and vortices in the IDCS and THIR montages. This is also confirmed by low centers in the 200 mb Northern Hemisphere charts. The vertical distribution of ozone indicates that the enhancement in ozone in these cases occurs in the lower stratosphere (and possibly to a minor extent in the troposphere) rather than in the upper stratosphere and mesosphere.

Rao, M. S. V.↗
NASA NTRS1974

The detection of dust storms over land and water with satellite visible and infrared measurements

The position of a large area of dust was successfully located over the Sahara Desert and off the west coast of Africa with infrared measurements from the Temperature Humidity Infrared Radiometer (THIR) and visible information from the Image Dissector Camera System (IDCS) on Nimbus 4 between 20 and 25 April 1970. Over land, near midday, the dust areas were associated with lower equivalent blackbody temperatures (TBB's) than in the surrounding areas due to the mixing of the dust with the cooler air just above the surface. Near midnight dust areas appeared to be located where the TBB's were higher than the surrounding regions. The TBB contrast was insufficient for dust detection over the ocean, but the contrast in the visible was great enough to track the movement of the dust for several days off the African west coast. Measurements from the THIR 6.5-7.2 micron channel were useful for detecting the presence of cirrus clouds which could have caused a misinterpretation of the 10.5-12.5 micron TBB's.

Shenk, W. E.↗
NASA NTRS1989

LAGEOS 3 and the gravitomagnetic field

The importance of the gravitomagnetic field is discussed. A never-measured field of nature, the foundations of inertia in Einstein General Relativity, and a key role in theories of quasars and active galactic nuclei are important aspects of this field and are discussed. In high energy astrophysics, some theories of energy storage, power generation, jet formation and jet alignment of quasars and active galactic nuclei are based on the existence of the gravitomagnetic field of a supermassive black hole (Thorne et al. 1986). LAGEOS 3 is discussed in terms of laser ranged satellites to detect the gravitomagnetic field and supplementary inclination satellites to avoid gravity field uncertainties. Many experiments have been proposed to measure the gravitomagnetic field. The GPB experiment intends to measure the Lense-Thirring-Schiff precession of gyroscopes orbiting the earth. Polar satellites have been proposed to measure the Lense-Thirring precession of the orbital plane (an enormous gyroscope and two guided, drag-free, counter-rotating, polar satellites have been suggested to avoid orbital inclination errors.) The new idea to measure the gravitomagnetic drag of the nodes of two nonpolar, supplementary inclination, satellites is summarized.

Ciufolini, Ignazio↗
NASA NTRS1994

Surface temperatures in the polar regions from Nimbus 7 temperature humidity infrared radiometer

Monthly surface temperatures in the Arctic and Antarctic regions have been derived from the 11.5 micrometer thermal infrared channel of the Nimbus 7 temperature humidity infrared radiometer (THIR) for a whole year in 1979 and for a winter and a summer month from 1980 through 1985. The data set shows interannual variability and provides spatial details that allow identification of temperature patterns over sea ice and ice sheet surfaces. For example, the coldest spot in the southern hemisphere is observed to be consistently in the Antarctic plateau in the southern hemisphere, while that in the northern hemisphere is usually located in Greenland, or one of three other general areas: Siberia, the central Arctic, or the Canadian Archipelago. Also, in the southern hemisphere, the amplitude of the seasonal fluctuation of ice sheet temperatures is about 3 times that of sea ice, while in the northern hemisphere, the corresponding fluctuations for the two surfaces are about the same. The main sources of error in the retrieval are cloud and other atmospheric effects. These were minimized by first choosing the highest radiance value from the set of measurements during the day taken within a 30 km by 30 km grid of each daily map. Then the difference of daily maps was taken and where the difference is greater than a certain threshold (which in this case is 12 C), the data element is deleted. Overall, the monthly maps derived from the resulting daily maps are spatially and temporally consistent, are coherent with the topograph y of the Antarctic continent and the location of the sea ice edge, and are in qualitative agreement with climatological data. Quantitatively, THIR data are in good agreement with Antarctic ice sheet surface air temperature station data with a correlation coefficient of 0.997 and a standard deviation of 2.0 C. The absolute values are not as good over the sea ice edges, but a comparison with Russian 2-m drift station temperatures shows very high correlation (with correlation coefficient at 0.998) and a standard deviation of 1.1 C. Overall, the rms error is estimated to be from 1 to 2 C, depending on the surface, while the average bias when compared with in situ data is less than 2 C.

Comiso, Josefino C.↗
NASA NTRS1997

Areal Distribution of the Oxygen-Isotope Ratio in Greenland

Mean values of the oxygen-isotope ratio relative to standard mean ocean water reported for 46 sites on the Greenland ice sheet are compiled together with data on mean annual surface temperature, latitude, 6180 elevation, and mean annual shortest distance to the open ocean denoted by the 10% sea-ice concentration boundary. Stepwise regression analyses, with 6180 as the dependent variable, define two robust models. In the forward mode at the 99.9% confidence level, only temperature enters the model. In the backward mode at the 95% confidence level, only temperature, latitude, and distance to the open ocean remain in the model. Inversions of the models on the basis of 160 gridpoint locations 100 km apart in the area delimited by the surface equilibrium line produce four contoured distributions of 6"0. Two distributions are based on the bivariate model and two on the multivariate model. The second distribution for each model is obtained substituting mean annual surface-temperature values obtained from the Nimbus-7 Temperature Humidity Infrared Radiometer (THIR) database. All four distributions are considered valid, and differences between them are evaluated using contoured anomaly maps. It is suggested that the inversion of the multivariate model using THIR data provides the more reliable pattern for studies of atmospheric advection or for the derivation of ice-flow adjustments for 6180 series obtained from deep-core or ablation-zone sites.

Zwally, H. Jay↗
NASA NTRS2000

"Cloud Slicing" : A New Technique to Derive Tropospheric Ozone Profile Information from Satellite Measurements

A new technique denoted cloud slicing has been developed for estimating tropospheric ozone profile information. All previous methods using satellite data were only capable of estimating the total column of ozone in the troposphere. Cloud slicing takes advantage of the opaque property of water vapor clouds to ultraviolet wavelength radiation. Measurements of above-cloud column ozone from the Nimbus 7 total ozone mapping spectrometer (TOMS) instrument are combined together with Nimbus 7 temperature humidity and infrared radiometer (THIR) cloud-top pressure data to derive ozone column amounts in the upper troposphere. In this study tropical TOMS and THIR data for the period 1979-1984 are analyzed. By combining total tropospheric column ozone (denoted TCO) measurements from the convective cloud differential (CCD) method with 100-400 hPa upper tropospheric column ozone amounts from cloud slicing, it is possible to estimate 400-1000 hPa lower tropospheric column ozone and evaluate its spatial and temporal variability. Results for both the upper and lower tropical troposphere show a year-round zonal wavenumber 1 pattern in column ozone with largest amounts in the Atlantic region (up to approx. 15 DU in the 100-400 hPa pressure band and approx. 25-30 DU in the 400-1000 hPa pressure band). Upper tropospheric ozone derived from cloud slicing shows maximum column amounts in the Atlantic region in the June-August and September-November seasons which is similar to the seasonal variability of CCD derived TCO in the region. For the lower troposphere, largest column amounts occur in the September-November season over Brazil in South America and also southern Africa. Localized increases in the tropics in lower tropospheric ozone are found over the northern region of South America around August and off the west coast of equatorial Africa in the March-May season. Time series analysis for several regions in South America and Africa show an anomalous increase in ozone in the lower troposphere around the month of March which is not observed in the upper troposphere. The eastern Pacific indicates weak seasonal variability of upper, lower, and total tropospheric ozone compared to the western Pacific which shows largest TCO amounts in both hemispheres around spring months. Ozone variability in the western Pacific is expected to have greater variability caused by strong convection, pollution and biomass burning, land/sea contrast and monsoon developments.

Ziemke, J. R.↗
NASA NTRS2001

Cloud Slicing: A New Technique to Derive Upper Tropospheric Ozone from Satellite Measurements

A new technique denoted cloud slicing has been developed for measuring upper tropospheric ozone. Cloud slicing takes advantage of the opaque property of water vapor clouds to ultraviolet wavelength radiation. Measurements of above-cloud column ozone from the Nimbus 7 total ozone mapping spectrometer (TOMS) instrument are combined together with Nimbus 7 temperature humidity and infrared radiometer (THIR) cloud-top pressure data to derive ozone column amounts in the upper troposphere. In this study tropical TOMS and THIR data for the period 1979-1984 are analyzed. By combining total tropospheric column ozone (denoted TCO) measurements from the convective cloud differential (CCD) method with 100-400 hPa upper tropospheric column ozone amounts from cloud slicing, it is possible to estimate 400-1000 hPa lower tropospheric column ozone and evaluate its spatial and temporal variability. Results for both the upper and lower tropical troposphere show a year-round zonal wave number 1 pattern in column ozone with largest amounts in the Atlantic region (up to 15 DU in the 100-400 hPa pressure band and around 25-30 DU in the 400-1000 hPa pressure band). Upper tropospheric ozone derived from cloud slicing shows maximum column amounts in the Atlantic region in the June-August and September-November seasons which is similar to the seasonal variability of CCD derived TCO in the region. For the lower troposphere, largest column amounts occur in the September-November season over Brazil in South America and also southern Africa. Localized increases in the tropics in lower tropospheric ozone are found over the northern region of South America around August and off the west coast of equatorial Africa in the March-May season. Time series analysis for several regions in South America and Africa show an anomalous increase in ozone in the lower troposphere around the month of March which is not observed in the upper troposphere. The eastern Pacific indicates weak seasonal variability of upper, lower, and total tropospheric ozone compared to the western Pacific which shows largest TCO amounts in both hemispheres around spring months. Ozone variability in the western Pacific is expected to have greater variability caused by strong convection, pollution and biomass burning, land/sea contrast and monsoon developments.

Ziemke, J. R.↗
NASA NTRS2001

"Cloud Slicing": A New Technique to Derive Upper Tropospheric Ozone from Satellite Measurements

A new technique called "cloud slicing" is introduced in this study to determine tropospheric ozone profile information. This method is unique because all previous methods incorporating satellite data were only capable of estimating the total column of ozone in the troposphere. Cloud slicing takes advantage of the opaque property of water vapor clouds to ultraviolet wavelength radiation. Measurements of above-cloud column ozone from the Nimbus 7 total ozone mapping spectrometer (TOMS) instrument are combined together with Nimbus 7 temperature humidity and infrared radiometer (THIR) cloud-top pressure data to derive ozone column amounts in the upper troposphere. In this study, tropical TOMS and THIR data for the period 1979-1984 are analyzed. Our investigation examines several case studies and illustrates the robust nature of this new technique for future satellite missions.

Chandra, Sushil↗
NASA NTRS1969

Validity of approximations used in mesonic atom calculations.

The Deser-Goldberger-Baumann-Thirring (DGBT) formula [a = 1/4B(ΔE 1S /|E 1S |)] and other various approximations commonly used to extract meson-nucleus scattering lengths from energy-level measurements on mesonic atoms are studied by means of a model calculation and are shown to be inadequate for most of the π − -mesonic atoms commonly considered. A simple empirical formula is obtained in place of the DGBT formula for the π − -mesonic atoms of the light nuclei. The DGBT formula is also examined for the case of the K − −He 4 atom and is found to be a good approximation.

Ryoichi Seki↗
NASA NTRS1972

Vertical motions inferred from satellite radiometry

Medium resolution radiometer measurements on Nimbus 2 and 3 and relatively high resolution measurements on Nimbus 4 have been made in 6.4 to 6.9 and 20 to 23 microns water vapor absorption regions where the weighed means in the observed radiation occur in the troposphere near the 400 and 600 mbar levels, respectively. An example of the imagery obtained from the Nimbus 4 temperature-humidity infrared radiometer (THIR) is shown. This example demonstrates clearly that there is a distinct pattern difference between the 6.7 microns observations coming from the midtroposphere and the more common 11.5 microns atmospheric window observations showing the emitted radiation associated with opaque surfaces such as the ground or optically thick clouds.

Salomonson, V. V.↗
NASA NTRS1972

Meteorological applications of the Nimbus 4 temperature-humidity infrared radiometer, 6.7 micron channel data.

Midtropospheric circulation features under essentially clear sky conditions have been noted in the data of the 6.7-micron channel of the Nimbus 4 temperature-humidity infrared radiometer (THIR), while at the same time these features were undetected by the 11.5-micron channel of the same instrument. The characteristic response of the 6.7-micron channel to atmospheric water vapor emission is primarily from the 250-mb (10.5 km) to 500-mb (5.5 km) levels with a peak contribution at 350 mb (8 km). Dry and moist patterns seen in the 6.7-micron data on Feb. 21, 1971, have been integrated into a 400-mb moisture analysis over the United States. This analysis provided more detailed and timely information than was conventionally available about the advection of dry air aloft prior to development of the Mississippi Tornado of February 1971.

Allison, L. J.↗
NASA NTRS1972

Study to determine cloud motion from meteorological satellite data

Processing techniques were tested for deducing cloud motion vectors from overlapped portions of pairs of pictures made from meteorological satellites. This was accomplished by programming and testing techniques for estimating pattern motion by means of cross correlation analysis with emphasis placed upon identifying and reducing errors resulting from various factors. Techniques were then selected and incorporated into a cloud motion determination program which included a routine which would select and prepare sample array pairs from the preprocessed test data. The program was then subjected to limited testing with data samples selected from the Nimbus 4 THIR data provided by the 11.5 micron channel.

Clark, B. B.↗
NASA NTRS1973

Analysis of the relativistic orbiting gyroscope experiment

A gyroscope experiment designed to measure both the geodetic and the Lense-Thirring precessions to an accuracy of 0.01 arc-second per year appears economically and technically feasible. It is estimated that an accuracy of about one part in 10 to the 11th power in an Eotvos experiment would be required to detect a situation in which the weak interaction contributed to the inertial masses but not the gravitational masses of nuclei; a correspondingly higher accuracy in the experiment is required to detect the situation where the weak interaction contributed to the gravitational masses some fraction between zero and one of its contribution to the inertial masses.

Coulter, A. C.↗
NASA NTRS1974

Tropical cyclone rainfall as measured by the Nimbus 5 electrically scanning microwave radiometer

A selected group of 1973 North Pacific Ocean tropical cyclones was studied by using data from the Nimbus 5 Electrically Scanning Microwave Radiometer (ESMR), the Temperature-Humidity Infrared Radiometer (THIR), NOAA-2 and USAF DMSP imageries. From the unique combination of infrared, visible, and microwave data, it was possible during various stages of storm development to differentiate between dense cirrus outflow and rain areas, to identify centers of circulation and areas of low-level moisture, and by the use of a theoretical model to estimate semi-quantitatively areas of light, moderate, and heavy rainfall rates.

Allison, L. J.↗
NASA NTRS1975

Relativity mission with two counter-orbiting polar satellites

In 1918, J. Lense and H. Thirring calculated that a moon in orbit around a massive rotating planet would experience a nodal dragging effect due to general relativity. We describe an experiment to measure this effect with two counter-orbiting drag-free satellites in polar earth orbit. For a 2 1/2 year experiment, the measurement accuracy should approach 1%. In addition to precision tracking data from existing ground stations, satellite-to-satellite Doppler ranging data are taken at points of passing near the poles. New geophysical information on both earth harmonics and tidal effects is inherent in the polar ranging data.

Van Patten, R. A.↗
NASA NTRS1975

The Nimbus 6 data catalog. Volume 1: 12 June 1975 through 31 August 1975. Data orbits 1 through 1082

Subsections 1.2 through 1.10 of this catalog summarize the operational highlights of the individual experiments, present preliminary experiment results, and call attention to known data anamolies. Section 2 lists the on-off times for each experiment and provides a method for determining the geographical coverage of each experiment. Section 3 shows selected HIRS, SCAMS and ESMR images, and Section 4 presents THIR montages. Section 5 presents corrections to The Nimbus 6 User's Guide.

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