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All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

AVE-Sesame 3: 25-MB sounding data

The rawinsonde sounding program for the AVE-SESAME 3 experiment is described and tabulated data at 25-mb intervals from the surface to 25 mb for the 23 National Weather Service and 19 special stations participating in the experiment are presented. Soundings were taken at 3 hr intervals beginning at 1200 GMT on April 25, 1979, and ending at 1200 GMT on April 26, 1979 (nine sounding times). The method of processing is discussed briefly, estimates of the rms errors in the data presented, an example of contact data given, reasons given for the termination of soundings below 100 mb, and soundings listed which exhibit abnormal characteristics.

Williams, S. T.↗
NASA NTRS1979

NASA's participation in the AVE-SESAME '79 program

NASA's Marshall Space Flight Center participated with its AVE (Atmospheric Variability Experiment) in a large interagency mesoscale and severe storms experiment identified herein as AVE-SESAME '79 (Atmospheric Variability Experiment-Severe Environmental Storms and Mesoscale Experiment 1979). A primary objective of NASA was to support an effort to acquire carefully edited sets of rawinsonde data during selected severe weather events for use in correlative and diagnostic studies with satellite and radar data obtained at approximately the same times. Data were acquired during six individual 24-h experiments on both the regional and storm scales over a network in the central United States that utilized approximately 20 supplemental rawinsonde sites meshed among 23 standard National Weather Service sites. Included among the six experiments are data obtained between 1200 GMT on April 10 and 1200 GMT on April 11, encompassing the formation and development period for the tornado-producing systems that devastated Wichita Falls, Texas, and other sections of Oklahoma and Texas. The other dates for which data sets are available are April 19-20 and 25-26, May 9-10 and 20-21, and June 7-8, 1979.

Hill, K.↗
NASA NTRS1980

AVE-SESAME IV: 25 mb sounding data

The rawinsonde sounding program for the AVE-SESAME 4 experiment is descirbed and tabulated data at 25 mb for the 23 National Weather Service and 20 special stations participating in the experiment are presented. Soundings were taken at 3 hr intervals beginning at 1200 GMT on May 9, 1979, and ending at 1200 GMT on May 10, 1979 (nine sounding times). The method of processing is discussed, estimates of the rms errors in the data are presented, and an example of contact data is given. Reasons are given for the termination of soundings below 100 mb, and soundings are listed which exhibit abnormal characteristics.

Sienkiewicz, M. E.↗
NASA NTRS1981

AVE-SESAME 6: 25-MB sounding data

The rawinsonde sounding program for the AVE-SESAME 6 experiment is described and tabulated data at 25 mb intervals from the surface to 25 mb for the 23 National Weather Service and 15 special stations participating in the experiment are presented. Soundings were taken at 3 h intervals beginning at 1200 GMT on June 7, 1979, and ending at 1200 GMT on June 8, 1979 (nine sounding times). The method of processing is discussed briefly, estimates of the rms errors in the data presented, an example of contact data given, reasons given for the termination of soundings below 100 mb, and soundings are listed which exhibit abnormal characteristics.

Sienkiewicz, M. E.↗
NASA NTRS1981

A split explicit reformulation of the regional numerical weather prediction model of the Japan Meteorological Agency

The split explicit integration scheme for numerical weather prediction models is employed in a version of the regional numerical weather prediction model of the Japan Meteorological Agency. The finite-difference scheme of the model is designed in the manner proposed by Okamura (1975). The horizontal advection terms in the governing equations are integrated with a time step limited by the wind speed while the terms which describe inertial-gravity oscillations are integrated in a succession of shorter time steps. The physical processes included within the model are precipitation, small-scale convection, surface exchanges of sensible and latent heat, and radiative heating and cooling. An example of a surface pressure forecast over Europe is shown for initial data observed at 0000 GMT 29 December 1979. Quantitative precipitation forecasts over Europe and North America for the 24 h period beginning at 0000 GMT 30 December 1979 are also shown. It is concluded that the model is capable of realistically depicting the evolution of synoptic-scale systems.

Duffy, D. G.↗
NASA NTRS1982

Ageostrophic winds in the severe strom environment

The period from 1200 GMT 10 April to 0000 GMT 11 April 1979, during which time several major tornadoes and severe thunderstorms, including the Wichita Falls tornado occurred was studied. A time adjusted, isentropic data set was used to analyze key parameters. Fourth order centered finite differences were used to compute the isallobaric, inertial advective, tendency, inertial advective geostrophic and ageostrophic winds. Explicit isentropic trajectories were computed through the isentropic, inviscid equations of motion using a 15 minute time step. Ageostrophic, geostrophic and total vertical motion fields were computed to judge the relative importance of ageostrophy in enhancing the vertical motion field. It is found that ageostrophy is symptomatic of those mass adjustments which take place during upper level jet streak propagation and can, in a favorable environment, act to increase and release potential instability over meso alpha time periods.

Moore, J. T.↗
NASA NTRS1983

AVE/VAS 1: 25 mb sounding data

The rawinsonde sounding program for the AVE/VAS I (shakedown) experiment is described. Tabulated data at 25-mb intervals for the 13 special rawinsonde stations and 1 National Weather Service station participating in the experiment are presented. Soundings were taken at 1200 and 1800 GMT on February 6, 1982, and at 0000 GMT on February 7, 1982. The method of processing soundings is discussed briefly, estimates of the RMS errors in the data are presented, and an example of contact data is given. Termination pressures of soundings are tabulated, as are observations of ground temperature at a depth of 2 cm.

Sienkiewicz, M. E.↗
NASA NTRS1984

SASS wind forecast impact studies using the GLAS and NEPRF systems: Preliminary conclusions

For this project, a version of the GLAS Analysis/Forecast System was developed that includes an objective dealiasing scheme as an integral part of the analysis cycle. With this system the (100 sq km) binned SASS wind data generated by S. Peteherych of AER, Canada corresponding of the period 0000 GMT 7 September 1978 to 1200 GMT 13 September 1978 was objectively dealiased. The dealiased wind fields have been requested and received by JPL, NMC and the British Meteorological Office. The first 3.5 days of objectively dealiased fields were subjectively enhanced on the McIDAS system. Approximately 20% of the wind directions were modified, and of these, about 70% were changed by less than 90 deg. Two SASS forecast impact studies, were performed using the dealiased fields, with the GLAS and the NEPRF (Navy Environmental Prediction Research Facility) analysis/forecast systems.

Kalnay, E.↗
NASA NTRS1984

Strategy for the IRAS all-sky survey

IRAS (the Infrared Astronomical Satellite) was launched on January 25, 1983 (January 26 GMT) with the primary purpose of performing an infrared survey of the entire celestial sphere. To ensure completeness and reliability, every point of sky was to be covered by a minimum of four separate scans of the telescope field-of-view, and as much as possible with six, with certain added timing constraints on the elapsed interval between scans. These strong requirements for sky coverage, combined with a restricted, rotating viewing-window, made extensive planning for the survey strategy, both pre-launch and during operations, a necessity. The result was that on November 21 (November 22 GMT), when the liquid helium required for cooling was depleted, 96 percent of the sky was covered to the minimum depth of four and 71 percent was coverd to depth six or more.

Lundy, S. A.↗
NASA NTRS1986

Wind profiler data in a mesoscale experiment from a meteorological perspective

During May and June of 1985, the Oklahoma-Kansas Preliminary Regional Experiment of STORM-Central (OK PRE-STORM) was carried out, with the major objectives of learning more about mesoscale convective systems (MCSs) and gaining experience in the use of new sensing systems and measurement strategies that will improve the design of STORM-Central. Three 50-MHz wind profilers were employed in a triangular array with sides about 275 km. It is far too soon to report any results of this effort, for it has barely begun. The purpose here is to show some examples of the data, some of the surrounding conventional data, and to discuss some of the issues important to meteorologists in evaluating the contribution of the profiler data. The case of 10 to 11 June 1985, featuring a major squall line system which crossed the dense observing network from northwest to southeast, passing the Liberal site about 2230 GMT/10 June, the McPherson site about 0100 GMT/11 June, and Wichita about 0300 GMT/11 June is discussed. Radar and satellite data show that the system was growing rapidly when it passed Liberal, and was large and mature when it passed through McPherson and Wichita. The radar depiction of the system during this stage is given, with the McPherson site in the intense convective echoes near the leading edge at 01 GMT and in the stratiform precipitation at 03 GMT. The profiler wind data for a 9-hour period encompassing the squall line passage at each site are given.

Zipser, E. J.↗
NASA NTRS1990

A stratocumulus thermodynamic analysis: July 5 case study

On July 5 (NCAR Electra flight 4, Mission 186-G) the Electra flew a single aircraft mission which consisted of cross and along-wind legs at 6 different altitudes between 10:43 to 16:00 PDT (17:43 to 23:00 GMT). The leg length was kept short (8 to 10 minutes) to permit maximum vertical resolution, and there were 8 soundings. Observer notes report a thin, solid stratocumulus cloud deck which gradually became more broken in the afternoon. Winds were from the north at 10 to 13/ms throughout the night. Sea surface temperature measurements and conservative variable analyses for several of the July 5 legs are presented. These results are preliminary to a study of the thermodynamic budget on July 5; they indicate that: the sea surface temperature dropped more than 1 K (from 17.3 to 15.9 C) over the course of the flight (18:01 and at 21:51 GMT); mixing lines for each of the horizontal subcloud legs show the effect of a strong north-south gradient in SST; and there is a clear demarcation over a transition of 5 to 10 km between air to the south and cooler, moister air to the north. The FSSP measurements indicate there are small clouds/scud 250 m below cloud base on the cold northern side of this transition. The transition is seen in the saturation point diagrams at 984, 959, and 946 mb. There is no corresponding change in the horizontal wind across the transition regions.

Austin, Philip↗
NASA NTRS1990

Evidence for asymmetric inertial instability in the FIRE satellite dataset

One of the main goals of the First ISCCP Regional Experiment (FIRE) is obtaining the basic knowledge to better interpret satellite image of clouds on regional and smaller scales. An analysis of a mesoscale circulation phenomenon as observed in hourly FIRE satellite images is presented. Specifically, the phenomenon of interest appeared on satellite images as a group of propagating cloud wavelets located on the edge of a cirrus canopy on the anticylonic side of a strong, upper-level subtropical jet. These wavelets, which were observed between 1300 and 2200 GMT on 25 February 1987, are seen most distinctly in the GOES-West infrared satellite picture at 1800 GMT. The purpose is to document that these wavelets were a manifestation of asymmetric inertial instability. During their lifetime, the wavelets were located over the North American synoptic sounding network, so that the meteorological conditions surrounding their occurrence could be examined. A particular emphasis of the analysis is on the jet streak in which the wavelets were imbedded. The characteristics of the wavelets are examined using hourly satellite imagery. The hypothesis that inertial instability is the dynamical mechanism responsible for generating the observed cloud wavelets was examined. To further substantiate this contention, the observed characteristics of the wavelets are compared to, and found to be consistent with, a theoretical model of inertia instability by Stevens and Ciesielski.

Stevens, Duane E.↗
NASA NTRS1991

Diagnosing development. II - A study of rapid cyclone development using analyzed data fields

A diagnosis is presented of the explosive development phase of a cyclone that occurred over the southeastern U.S. during the 24 hour period 1200 GMT January 20 to 1200 GMT January 21, 1979. The Zwack-Osossi development equation is extended to incorporate geostrophic and ageostrophic forcing of the basic development parameter, geostrophic vorticity tendency. This equation yields reasonable comparability with observed geostrophic vorticity changes and shows positive vorticity advection, latent heat release and thermal advection to be the primary development mechanisms.

Smith, Phillip↗
NASA NTRS1992

Sea surface velocities from visible and infrared multispectral atmospheric mapping sensor imagery

High resolution (100 m), sequential Multispectral Atmospheric Mapping Sensor (MAMS) images were used in a study to calculate advective surface velocities using the Maximum Cross Correlation (MCC) technique. Radiance and brightness temperature gradient magnitude images were formed from visible (0.48 microns) and infrared (11.12 microns) image pairs, respectively, of Chandeleur Sound, which is a shallow body of water northeast of the Mississippi delta, at 145546 GMT and 170701 GMT on 30 Mar. 1989. The gradient magnitude images enhanced the surface water feature boundaries, and a lower cutoff on the gradient magnitudes calculated allowed the undesirable sunglare and backscatter gradients in the visible images, and the water vapor absorption gradients in the infrared images, to be reduced in strength. Requiring high (greater than 0.4) maximum cross correlation coefficients and spatial coherence of the vector field aided in the selection of an optimal template size of 10 x 10 pixels (first image) and search limit of 20 pixels (second image) to use in the MCC technique. Use of these optimum input parameters to the MCC algorithm, and high correlation and spatial coherence filtering of the resulting velocity field from the MCC calculation yielded a clustered velocity distribution over the visible and infrared gradient images. The velocity field calculated from the visible gradient image pair agreed well with a subjective analysis of the motion, but the velocity field from the infrared gradient image pair did not. This was attributed to the changing shapes of the gradient features, their nonuniqueness, and large displacements relative to the mean distance between them. These problems implied a lower repeat time for the imagery was needed in order to improve the velocity field derived from gradient imagery. Suggestions are given for optimizing the repeat time of sequential imagery when using the MCC method for motion studies. Applying the MCC method to the infrared brightness temperature imagery yielded a velocity field which did agree with the subjective analysis of the motion and that derived from the visible gradient imagery. Differences between the visible and infrared derived velocities were 14.9 cm/s in speed and 56.7 degrees in direction. Both of these velocity fields also agreed well with the motion expected from considerations of the ocean bottom topography and wind and tidal forcing in the study area during the 2.175 hour time interval.

Pope, P. A.↗
NASA NTRS2000

The Sulfur Dioxide Plume from the February 26, 2000 Eruption of Mt. Hekla, Iceland

The February 2000 fissure eruption of Mt. Hekla, Iceland was captured in sulfur dioxide data from the Earth Probe TOMS. A special algorithm is used to discriminate sulfur dioxide from ozone. The eruption began at 18:19 GMT on February 26, 2000 and was first viewed by TOMS at 09:55 GMT on February 27. The volcanic cloud at that time appeared as a very long and narrow arc extending west from the volcano in southern Iceland, then north across Greenland, and finally east towards Norway. The cloud altitude was reported from aircraft sightings and data to be above 10 km. The circulation of a ridge located north of Iceland produced the large arc shaped cloud. As the eruption is non-explosive the high altitude cloud contains little ash. Almost all the ash from the eruption fell out locally across Iceland. By February 29, the sulfur dioxide cloud had drifted eastward in a band along the Barents Sea coast of Norway and Russia. The analysis includes an assessment of the initial sulfur dioxide content and its rate of conversion to sulfate.

Krueger, Arlin J.↗
DOE OSTI2023

Utah FORGE: InSAR Data Best Pairs

This submission provides Interferometric Synthetic Aperture Radar (InSAR) data covering the Utah FORGE site via the TerraSAR-X and TanDEM-X satellite missions operated by the German Space Agency (DLR). Data was collected between 2019/01/01 and 2023/06/30. Interferometric pairs (interferograms) were created using generic mapping tool GMT-SAR processing software. The best 112 pairs were selected based on having short orbital separations (perpendicular baseline less than 5 meters in absolute value).

15 GEOTHERMAL ENERGY↗
DOE OSTI2024

Utah FORGE: Interferometric Synthetic Aperture Radar Data from 2023 and 2024

The dataset comprises Interferometric Synthetic Aperture Radar (InSAR) data from the TerraSAR-X and TanDEM-X satellite missions, covering the Utah FORGE site. This data includes interferometric pairs created using GMT-SAR processing software, chosen for their short orbital separations between May 1, 2023, and June 30, 2024. Included are various data and metadata, including Digital Elevation Models, unit vectors, and correlation coefficients. The dataset is packaged in several compressed tar files and formatted in NetCDF. To utilize this dataset, users will need software capable of handling NetCDF files and tools for decompressing tar files.

15 GEOTHERMAL ENERGY↗