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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 253 records · Page 14

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NASA NTRS1975

Interdisciplinary study of atmospheric processes and constituents of the mid-Atlantic coastal region. Attachment 4: Data set for background investigation of atmospheric constituents for Nansemond River site

Background data was provided for the assessment of the environmental impact of a proposed oil refinery location. Climatic background, particulate data, digitized portrayal of site molecular and meteorological data, graphical portrayal of molecular data, hourly meteorological data, and streamflow charts and radiosonde data are given

Kindle, E. C.↗

NASA NTRS1975

Interdisciplinary study of atmospheric processes and constituents of the mid-Atlantic coastal region. Attachment 5: Data set for background investigation of atmospheric constituents for Richmond, Virginia area

Background data is provided for the photochemical oxident problem in the Richmond area. Particulate data, digitized portrayal of site molecular and meteorological data, and graphical portrayal of molecular data, hourly meteorological data, and streamflow charts and radiosonde data are also given.

Kindle, E. C.↗

NASA NTRS1975

A simple method to incorporate water vapor absorption in the 15 microns remote temperature sounding

The water vapor absorption in the 15 micron CO2 band, which can affect the remotely sensed temperatures near the surface, are estimated with the help of an empirical method. This method is based on the differential absorption properties of the water vapor in the 11-13 micron window region and does not require a detailed knowledge of the water vapor profile. With this approach Nimbus 4 IRIS radiance measurements are inverted to obtain temperature profiles. These calculated profiles agree with radiosonde data within about 2 C.

Dallu, G.↗

NASA NTRS1976

Wind velocity measurement

Homodyne laser-Doppler system determines three-component wind velocity at altitudes of several kilometers in clear-air conditions. There is no need for deployment of towers, radiosondes, or for seeding airflows.

Cliff, W. C.↗

NASA NTRS1975

Hot, cold, and annual reference atmospheres for Edwards Air Force Base, California (1975 version)

Reference atmospheres pertaining to summer (hot), winter (cold), and mean annual conditions for Edwards Air Force Base, California, are presented from surface to 90 km altitude (700 km for the annual model). Computed values of pressure, kinetic temperature, virtual temperature, and density and relative differences percentage departure from the Edwards reference atmospheres, 1975 (ERA-75) of the atmospheric parameters versus altitude are tabulated in 250 m increments. Hydrostatic and gas law equations were used in conjunction with radiosonde and rocketsonde thermodynamic data in determining the vertical structure of these atmospheric models. The thermodynamic parameters were all subjected to a fifth degree least-squares curve-fit procedure, and the resulting coefficients were incorporated into Univac 1108 computer subroutines so that any quantity may be recomputed at any desired altitude using these subroutines.

Johnson, D. L.↗

NASA NTRS1976

A single field of view method for retrieving tropospheric temperature profiles from cloud-contaminated radiance data

An iterative method is presented to retrieve single field of view (FOV) tropospheric temperature profiles directly from cloud-contaminated radiance data. A well-defined temperature profile may be calculated from the radiative transfer equation (RTE) for a partly cloudy atmosphere when the average fractional cloud amount and cloud-top height for the FOV are known. A cloud model is formulated to calculate the fractional cloud amount from an estimated cloud-top height. The method is then examined through use of simulated radiance data calculated through vertical integration of the RTE for a partly cloudy atmosphere using known values of cloud-top height(s) and fractional cloud amount(s). Temperature profiles are retrieved from the simulated data assuming various errors in the cloud parameters. Temperature profiles are retrieved from NOAA-4 satellite-measured radiance data obtained over an area dominated by an active cold front and with considerable cloud cover and compared with radiosonde data. The effects of using various guessed profiles and the number of iterations are considered.

Hodges, D. B.↗

NASA NTRS1975

University of Utah (Wallops) precision meteorological data digitizer

The data digitizing system takes pulsed signals from meteorological rocket sondes and radiosondes and converts the information (the time interval between pulses) into a digital form for magnetic recording and further processing by digital computer. The basic digitizer configuration contains a master sequencer that allows for data storage and release in an accumulator. Thus, the digitizer provides for convenient interfacing in real time monitoring.

Staffanson, F. L.↗

NASA NTRS1975

Remote sensing of atmospheric temperature profiles with the Nimbus 5 microwave spectrometer

The paper discusses the accuracy of atmospheric vertical temperature profile measurements performed by the Nimbus 5 microwave spectrometer and compares results obtained during the first 6 months of its operation with independent ground-truth measurements (coincident radiosonde measurements). The microwave spectrometer can measure temperature profiles averaged over the instrument weighting function (about 10 km) layers with a root-mean-square accuracy of a few tenths of a degree K for measurement integration times of 16 s. Lower tropospheric temperature data from the spectrometer measurements is used in the numerical weather prediction model of the National Meteorological Center.

Waters, J. W.↗

NASA NTRS1976

An equivalent potential vorticity theory applied to the analysis and prediction of severe storm dynamics

Potential vorticity theory is developed in a description of an equivalent potential temperature topography, and a new theory suited to the description of scale interaction is elaborated. Macroscale triggering of ageostrophic flow fields at the mesoscale, in turn leading to release of convective instability along narrow zones at the microscale, is examined. Correlation of appreciable decrease in potential vorticity with such phenomena as cumulonimbi, tornados, and duststorms is examined. The relevance of a multiscale energy-momentum cascade in numerical prediction of severe mesoscale and microscale phenomena from radiosonde data is reviewed. Hypotheses for mesoscale dynamics are constructed.

Paine, D. A.↗

NASA NTRS1976

Atmospheric refraction errors in laser ranging systems

The effects of horizontal refractivity gradients on the accuracy of laser ranging systems were investigated by ray tracing through three dimensional refractivity profiles. The profiles were generated by performing a multiple regression on measurements from seven or eight radiosondes, using a refractivity model which provided for both linear and quadratic variations in the horizontal direction. The range correction due to horizontal gradients was found to be an approximately sinusoidal function of azimuth having a minimum near 0 deg azimuth and a maximum near 180 deg azimuth. The peak to peak variation was approximately 5 centimeters at 10 deg elevation and decreased to less than 1 millimeter at 80 deg elevation.

Gardner, C. S.↗

NASA NTRS1976

Temperature gradients and clear-air turbulence probabilities

In order to forecast clear-air turbulence (CAT) in jet aircraft flights, a study was conducted in which the data from a special-purpose instrument aboard a Boeing 747 jet airliner were compared with satellite-derived radiance gradients, conventional temperature gradients from analyzed maps, and temperature gradients obtained from a total air temperature sensor on the plane. The advantage of making use of satellite-derived data is that they are available worldwide without the need for radiosonde observations, which are scarce in many parts of the world. Major conclusions are that CAT probabilities are significantly higher over mountains than flat terrain, and that satellite radiance gradients appear to discriminate between CAT and no CAT better than conventional temperature gradients over flat lands, whereas the reverse is true over mountains, the differences between the two techniques being not large over mountains.

Bender, M. A.↗

NASA NTRS1976

Effects of horizontal refractivity gradients on the accuracy of laser ranging to satellites

Numerous formulas have been developed to partially correct laser ranging data for the effects of atmospheric refraction. All the formulas assume the atmospheric refractivity profile is spherically symmetric. The effects of horizontal refractivity gradients are investigated by ray tracing through spherically symmetric and three-dimensional refractivity profiles. The profiles are constructed from radiosonde data. The results indicate that the horizontal gradients introduce an rms error of approximately 3 cm when the satellite is near 10 deg elevation. The error decreases to a few millimeters near zenith.

Gardner, C. S.↗

NASA NTRS1976

Examples of synoptic changes in ozone and circulation in the stratosphere

The Backscatter Ultraviolet (BUV) experiment on board the Nimbus 4 polar orbiting satellite has been measuring the total ozone content and high-level atmospheric ozone profiles since early 1970. Synoptic type analyses of these data are now being accomplished and compared with appropriate constant-pressure analyses of stratospheric circulation. Ozone changes during a stratospheric warming of early 1971 are investigated by comparison with circulation changes in the layer between 30 mb (24 km) and 2 mb (42 km). A general increase in ozone concentrations, more pronounced in the higher latitudes, is noted during the warming period. Plans for future investigation are discussed, including analysis of ozone observations beginning from 1970 on every two-day basis for comparison with constant-pressure height, temperature, and wind charts analyzed with the aid of radiosonde, rocketsonde, and satellite data.

Finger, F. G.↗

NASA NTRS1977

Remote sounding of cloudy atmospheres. III - Experimental verifications

The cloud-filtering technique developed in Parts I and II of this study is experimentally verified in this paper. The verification is based on radiance data measured in the 4.3 and 15 micron CO2 bands using a multidetector sounder mounted on an aircraft. The results presented here show that, from the aircraft height of 7.6 km and in the presence of multiple cloud formations, it is possible to recover simultaneously: (1) the clear-column atmospheric temperature profile with an rms error of 1 K with respect to radiosondes, (2) the land and sea surface temperature at all sun zenith angles. The accuracy of the recovered sea-surface temperature is 0.5-1 K with respect to measured bucket temperatures, (3) the humidity profile (water vapor mixing ratio) with a precision of 10%, (4) the fractional covers and heights of up to three cloud formations, and (5) the types of clouds, i.e., whether convective or nonconvective.

Chahine, M. T.↗

NASA NTRS1977

Inversion climatology at San Jose, California

Month-to-month variations in the early morning surface-based and near-noon elevated inversions at San Jose, Calif., were determined from slow rise radiosondes launched during a four-year period. A high frequency of shallow, radiative, surface-based inversions were found in winter during the early morning hours, while during the same period in summer, a low frequency of deeper based inversions arose from a combination of radiative and subsidence processes. The frequency of elevated inversions in the hours near noon was lowest during fall and spring, while inversion bases were highest and thicknesses least during these periods.

Morgan, T.↗

NASA NTRS1977

Deriving mesoscale temperature and moisture fields from satellite radiance measurements over the United States

The ability to provide mesoscale temperature and moisture fields from operational satellite infrared sounding radiances over the United States is explored. High-resolution sounding information for mesoscale analysis and forecasting is shown to be obtainable in mostly clear areas. An iterative retrieval algorithm applied to NOAA-VTPR radiances uses a mean radiosonde sounding as a best initial-guess profile. Temperature soundings are then retrieved at a horizontal resolution of about 70 km, as is an indication of the precipitable water content of the vertical sounding columns. Derived temperature values may be biased in general by the initial-guess sounding or in certain areas by the cloud correction technique, but the resulting relative temperature changes across the field when not contaminated by clouds will be useful for mesoscale forecasting and models. The derived moisture, affected only by high clouds, proves to be reliable to within 0.5 cm of precipitable water and contains valuable horizontal information. Present-day applications from polar-orbiting satellites as well as possibilities from upcoming temperature and moisture sounders on geostationary satellites are noted.

Hillger, D. W.↗

NASA NTRS1977

Antarctic ice topography and 150 mb circulation from the Nimbus-6 TWERL Experiment

Many TWERLE balloons floating at an altitude of about 12.5 km, traversed the Antarctic during its 1975/6 summer. The balloons' positions were accurately determined by the Nimbus-6 satellite, which also received their sensors' data: radio altimeter, pressure and temperature. Subtracting the altimeter readings from the calculated balloon altitude above sea-level (a.s.l.) provides the Antarctic surface elevation at the balloon subtrack. The balloon altitude a.s.l. is calculated from daily synoptic maps covering latitudes south of 45 deg S. These maps are prepared using the regular radiosonde network supplemented by four times as many TWERLE balloons.

Levanon, N.↗

NASA NTRS1977

Investigations with satellite data. 2: Temperature retrievals

A method for retrieving atmospheric temperatures in a severe storm situation was investigated. Retrieval was accomplished through the aid of satellite radiance measurements and nearby radiosondes. A set of coefficients was derived which when multiplied by the measured radiances, yielded smaller temperature retrieval errors than the minimum-information retrieval method.

Fritz, S.↗