Search NASA⌕ Search

SEARCH · Search NASA

Results for “cloud top temperature”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1990

Convective and stratiform components of a Winter Monsoon Cloud Cluster determined from geosynchronous infrared satellite data

The horizontal precipitation structure of cloud clusters observed over the South China Sea during the Winter Monsoon Experiment (WMONEX) is analyzed using a convective-stratiform technique (CST) developed by Adler and Negri (1988). The technique was modified by altering the method for identifying convective cells in the satellite data, accounting for the extremely cold cloud tops characteristic of the WMONEX region, and modifying the threshold infrared temperature for the boundary of the stratiform rain area. The precipitation analysis was extended to the entire history of the cloud cluster by applying the modified CST to IR imagery from geosynchronous-satellite observations. The ship and aircraft data from the later period of the cluster's lifetime make it possible to check the locations of convective and stratiform precipitation identified by the CST using in situ observations. The extended CST is considered to be effective for determining the climatology of the convective-stratiform structure of tropical cloud clusters.

Goldenberg, Stanley B.↗
NASA NTRSDate not supplied

A Long-Term GOES Satellite Overshooting Cloud Top and Anvil Cloud Climatology Over South America

The modern-era GOES satellite series began in 1994 with the GOES-8 satellite, and was augmented in 2018 with higher spatial resolution and more frequent imaging when GOES-16 became operational. GOES imagery has provided forecasters and researchers new perspectives into cloud top patterns associated with severe convection, and the ability to better forecast convection in regions without adequate ground-based weather radar coverage. While much attention has been given to convection over North America, convection over South America can be equally, if not more, intense and frequent. Recent studies have demonstrated that overshooting cloud tops (OT) and surrounding anvil clouds can be detected within infrared satellite imagery. Relative storm updraft intensity metrics such as the tropopause-relative infrared brightness temperature, the prominence of an OT relative to its surrounding anvil, and cloud top height can also be derived using automated methods combined with reanalysis data. These automated OT detection and intensity estimation methods have recently been applied to all GOES images collected over South America, in combination with the MERRA-2 reanalysis, from 1995 to 2022 at NASA Langley within a project supported by the NASA Applied Sciences Disasters program. Innovative aggregation methods have merged these products into daily, monthly, annual, and multi-annual composites, with hourly time bins, at ~4 km pixel spacing to enable researchers a new opportunity to study South American convective processes throughout the diurnal cycle. These products have recently become publicly available from NASA. This presentation will overview this new dataset, and novel insights into South American convection depicted by the data.

Kristopher Bedka↗
NASA NTRSDate not supplied

Surface Radiation Budget

The Surface Radiation Budget (SRB) data sets contain global 3-hourly, daily and monthly averages of surface longwave and shortwave radiative properties, cloud amount, and meteorological properties computed using models. The main input data for these models include cloud information, top-of-atmosphere radiances and profiles of atmospheric water vapor and temperature. Some of the input data include Earth Radiation Budget Energy (ERBE) top-of-atmosphere clear-sky albedo and International Satellite Cloud Climatology Project (ISCCP) radiances and cloud amount. SRB parameters derived for the renewable energy community are also available from the Surface meteorology and Solar Energy (SSE) data set. Other SRB data are available from Clouds and the Earth's Radiant Energy System (CERES) and Multi-angle Imaging SpectroRadiometer (MISR). [Mission Objectives] The objective of the SRB Project is to produce and archive a global data set of shortwave (SW) and longwave (LW) surface and top of the atmosphere parameters. The data generated in the SRB project may be used in conjunction with other data sets to facilitate the development of renewable energy resources and increase understanding of radiative properties within the meteorological community. [Temporal_Coverage: Start_Date=1983-07-01; Stop_Date=2005-06-30] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180].

Stackhouse, Paul W.↗
NASA NTRS1999

Re-evaluation of Dust Absorption and Radiative Forcing of Climate Using Satellite and Ground Based Remote Sensing

Simultaneous spaceborne and ground based measurements of the scattered solar radiation, create a powerful tool for determination of dust absorption and scattering properties. Absorption of solar radiation is a key component in understanding dust impact on radiative forcing at the top of the atmosphere, on the temperature profile and on cloud formation. We use Landsat spaceborne measurements at seven spectral channels in the range of 0.47 to 2.2 microns over Senegal with corresponding measurements of the aerosol spectral optical thickness by ground based sunphotometers, to find that Saharan dust absorption of solar radiation is two to four times smaller than measured in situ and represented in models. Though dust was found to absorb in the blue (single scattering albedo w = 0.88), almost no absorption, w = 0.98, was found for wavelengths > 0.6 microns. The new finding increases by 50% recently estimated solar radiative forcing by dust at the top of the atmosphere and decreases the estimated dust heating of the lower troposphere due to absorption of solar radiation. Dust transported from Asia shows slightly higher absorption for wavelengths under 1 micron, that can be explained by the presence of black carbon from urban/industrial pollution associated with the submicron size mode. In the talk I shall also discuss recent observation of the impact of dust shape on the dust scattering properties.

Kaufman, Yoram↗
NASA NTRS1999

Evaluation of Dust Absorption and Radiative Forcing of Climate Using Satellite and Ground Based Remote Sensing

Simultaneous spaceborne and ground based measurements of the scattered solar radiation, create a powerful tool for determination of dust absorption. Absorption of solar radiation is a key component in understanding dust impact on radiative forcing at the top of the atmosphere, on the temperature profile and on cloud formation. We use Landsat spaceborne measurements at seven spectral channels in the range of 0.47 to 2.2 microns over Senegal with corresponding measurements of the aerosol spectral optical thickness by ground based sunphotometers, to find that Saharan dust absorption of solar radiation is two to four times smaller than measured in situ and represented in models. Though dust was found to absorb in the blue (single scattering albedo wo = 0.88), almost no absorption, wo = 0.98, was found for 1 greater than 0.6 microns. The results are in agreement with dust radiative measurements reported in the literature, and explain some previously reported but unexplained dust radiative properties. Therefore, the new finding should be of general relevance. The new finding increases by 50% recently estimated solar radiative forcing by dust at the top of the atmosphere and decreases the estimated dust heating of the lower troposphere due to absorption of solar radiation. Dust transported from Asia shows slightly higher absorption for wavelengths under 1 @im, that can be explained by the presence of black carbon from urban/industrial pollution associated with the submicron size mode.

Kaufman, Yoram J.↗
NASA NTRS1982

Applications of stereoscopic height computations from dual geosynchronous satellite data/joint NASA-Japan stereo project

Stereoscopic heights of the top of an Oklahoma thunderstorm were computed, finding that high cloud tops are not always characterized by very cold IR temperature. The identical method was also applied to the computation of stereo heights based on GOES West and GMS stereo pairs obtained under the NASA-JAPAN cooperative program. It was found that stereo techniques are extremely useful in understanding the structure of thunderstorms in the United States, as well as that of hurricanes over the South Pacific.

Fujita, T. T.↗
NASA NTRS2004

Comparison of Satellite and Aircraft Measurements of Cloud Microphysical Properties in Icing Conditions During ATREC/AIRS-II

Satellites are ideal for continuous monitoring of aircraft icing conditions in many situations over extensive areas. The satellite imager data are used to diagnose a number of cloud properties that can be used to develop icing intensity indices. Developing and validating these indices requires comparison with objective "cloud truth" data in addition to conventional pilot reports (PIREPS) of icing conditions. Minnis et al. examined the relationships between PIREPS icing and satellite-derived cloud properties. The Atlantic-THORPEX Regional Campaign (ATReC) and the second Alliance Icing Research Study (AIRS-II) field programs were conducted over the northeastern USA and southeastern Canada during late 2003 and early 2004. The aircraft and surface measurements are concerned primarily with the icing characteristics of clouds and, thus, are ideal for providing some validation information for the satellite remote sensing product. This paper starts the process of comparing cloud properties and icing indices derived from the Geostationary Operational Environmental Satellite (GOES) with the aircraft in situ measurements of several cloud properties during campaigns and some of the The comparisons include cloud phase, particle size, icing intensity, base and top altitudes, temperatures, and liquid water path. The results of this study are crucial for developing a more reliable and objective icing product from satellite data. This icing product, currently being derived from GOES data over the USA, is an important complement to more conventional products based on forecasts, and PIREPS.

Nguyen, Louis↗
NASA NTRS1985

Effects of stratospheric lapse rate on numerically simulated thunderstorm cloud top structure

The three-dimensional anelastic model of Schlesinger (1975, 1978, 1984) is utilized to study the effects of stratospheric stability on thunderstorm cloud top structure. Three experiments were conducted; in the first the stratosphere is assumed isothermal, in the second test there is a temperature lapse of 3 K/km, and in the third case there is a 3 K/km inversion. Time variations of vertical velocity, mature storm structure, and cloud top are examined. It is observed that the cloud summit height is lowered as stratospheric stability increases, a cloud-top thermal couplet occurs in all cases, the cold region has a U or V shape, and there is a height minimum in the warm regions.

Schlesinger, Robert E.↗
NASA NTRS2000

Performance and Results from a Space Borne, Uncooled Microbolometer Array Spectral Radiometric Imager

The Infrared Spectral Imaging Radiometer experiment was flown on a space shuttle mission as a shuttle hitchhiker experiment in August of 1997. The goals of the experiment were to test uncooled array detectors for infrared spectral imaging from space and to apply for the first time retrieval from space of brightness temperatures of cloud, land and sea along with direct laser measurements of cloud top height. The instrument operates in 3 narrow and one broad spectral band, all between 7 and 13 microns in either stare or time-delay and integration mode. The nominal spatial resolution was 1/4 kilometer. Using onboard calibrations along with periodic views of deep space, radiometric calibration of imagery was carried out and performance analyzed. The noise equivalent temperature difference and absolute accuracy reported here varied with operating mode, spectral band and scene temperature but were within requirements. This paper provides a description of the instrument, its operating modes, the method of brightness temperature retrieval, the method of spectral registration and results from the flight.

Spinhirne, James M↗
NASA NTRS1990

Structural analysis of stratocumulus convection

The 1 and 20 Hz data are examined from the Electra flights made on July 5, 1987. The flight legs consisted of seven horizontal turbulent legs at the inversion, midcloud, and below clouds, plus 4 soundings made within the same period. The Rosemont temperature sensor and the top and bottom dewpoint sensors were used to measure temperature and humidity at 1 Hz. Inversion structure and entrainment; local dynamics and large scale forcing; convective elements; and decoupling of cloud and subcloud are discussed in relationship to the results of the Electra flight.

Siems, S. T.↗
NASA NTRS2007

Cloudy Sounding and Cloud-Top Height Retrieval From AIRS Alone Single Field-of-View Radiance Measurements

High-spectral resolution measurements from the Atmospheric Infrared Sounder (AIRS) onboard the EOS (Earth Observing System) Aqua satellite provide unique information about atmospheric state, surface and cloud properties. This paper presents an AIRS alone single field-of-view (SFOV) retrieval algorithm to simultaneously retrieve temperature, humidity and ozone profiles under all weather conditions, as well as cloud top pressure (CTP) and cloud optical thickness (COT) under cloudy skies. For optically thick cloud conditions the above-cloud soundings are derived, whereas for clear skies and optically thin cloud conditions the profiles are retrieved from 0.005 hPa down to the earth's surface. Initial validation has been conducted by using the operational MODIS (Moderate Resolution Imaging Spectroradiometer) product, ECMWF (European Center of Medium range Weather Forecasts) analysis fields and radiosonde observations (RAOBs). These inter-comparisons clearly demonstrate the potential of this algorithm to process data from 38 high-spectral infrared (IR) sounder instruments.

Weisz, Elisabeth↗
NASA NTRS2003

Dynamic Turbulence Modelling in Large-eddy Simulations of the Cloud-topped Atmospheric Boundary Layer

The use of large eddy simulation, or LES, to study the atmospheric boundary layer dates back to the early 1970s when Deardor (1972) used a three-dimensional simulation to determine velocity and temperature scales in the convective boundary layer. In 1974 he applied LES to the problem of mixing layer entrainment (Deardor 1974) and in 1980 to the cloud-topped boundary layer (Deardor 1980b). Since that time the LES approach has been applied to atmospheric boundary layer problems by numerous authors. While LES has been shown to be relatively robust for simple cases such as a clear, convective boundary layer (Mason 1989), simulation of the cloud-topped boundary layer has proved more of a challenge. The combination of small length scales and anisotropic turbulence coupled with cloud microphysics and radiation effects places a heavy burden on the turbulence model, especially in the cloud-top region. Consequently, over the past few decades considerable effort has been devoted to developing turbulence models that are better able to parameterize these processes. Much of this work has involved taking parameterizations developed for neutral boundary layers and deriving corrections to account for buoyancy effects associated with the background stratification and local buoyancy sources due to radiative and latent heat transfer within the cloud (see Lilly 1962; Deardor 1980a; Mason 1989; MacVean & Mason 1990, for example). In this paper we hope to contribute to this effort by presenting a number of turbulence models in which the model coefficients are calculated dynamically during the simulation rather than being prescribed a priori.

Kirkpatrick, M. P.↗
NASA NTRS2010

Cassini/CIRS Observations of Saturn's "Storm Alley"

In the Voyager era storms on Saturn were observed predominantly in the northern hemisphere, however, in recent years storm activity has been confined to a narrow range of latitudes referred to as "storm alley" (approx.40degS planetographic latitude). Throughout Cassini's prime mission storms have been detected by two independent instruments: ISS through dayside images and RPWS using radio emissions from Saturn Electrostatic Discharges (SED's) (Dyudina et al. 2007). Analysis of these storms indicates that the cloud tops are in the 200 - 500rnbar altitude range. During Saturn's Equinox, in August 2009, lSS imaged lightning on the night side in storm alley when ring-shine was at a minimum (Dyudina et al. 2010). This study indicates that lightning may have originated as deep as the water cloud. Decently, Cassini/CIRS was targeted at storm alley while a storm, originally detected by amateurs, was ongoing (March 2010). Phosphine can be used as a tracer of vertical transport because it is a disequilibrium species that falls off with altitude in the upper troposphere. CIRS can measure temperature and phosphine abundance independently in the altitude range where these cloud tops occur. Early analysis of these data shows stronger phosphine absorption at storm longitudes. This is an indication that powerful updrafts were dredging material upward into the upper troposphere. The results of the analysis of the March 2010 CIRS observations of storm alley will be presented.

Hesman, Brigette E.↗
NASA NTRS2019

Evaluating Models' Response of Tropical Low Clouds to SST Forcings Using CALIPSO Observations

Recent studies have shown that, in response to a surface warming, the marine tropical low-cloud cover (LCC) as observed by passive-sensor satellites substantially decreases, therefore generating a smaller negative value of the top-of-the-atmosphere (TOA) cloud radiative effect (CRE). Here we study the LCC and CRE interannual changes in response to sea surface temperature (SST) forcings in the GISS model E2 climate model, a developmental version of the GISS model E3 climate model, and in 12 other climate models, as a function of their ability to represent the vertical structure of the cloud response to SST change against 10 years of CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) observations. The more realistic models (those that satisfy the observational constraint) capture the observed interannual LCC change quite well ([delta]LCC]/[delta]SST= -3.49±1.01%K [negative 1 superscript] vs. [delta]LCC/[delta]SST[subscript obs]= -3.59±0.28%K[negative 1 superscript]) while the others largely underestimate it ([delta]LCC/[delta]SST= -1.32±1.28%K[negative 1 superscript]). Consequently, the more realistic models simulate more positive shortwave (SW) feedback ([delta]CRE/[delta]SST=2.60±1.13Wm[negative 2 superscript] K[negative 1 superscript]) than the less realistic models (CRE/SST=0.87±2.63Wm2K1), in better agreement with the observations ([delta]CRE/[delta]SST[subscript obs]=3±0.26Wm[negative 2 superscript] K[negative 1 superscript] ), although slightly underestimated. The ability of the models to represent moist processes within the planetary boundary layer (PBL) and produce persistent stratocumulus (Sc) decks appears crucial to replicating the observed relationship between clouds, radiation and surface temperature. This relationship is different depending on the type of low clouds in the observations. Over stratocumulus regions, cloud-top height increases slightly with SST, accompanied by a large decrease in cloud fraction, whereas over trade cumulus (Cu) regions, cloud fraction decreases everywhere, to a smaller extent.

low clouds↗
DOE OSTI2026

E3SMv3 ‘Nephele’ Perturbed Parameter Ensemble Value-Added Product for ENA, SGP, NSA, and Global Means

Processed output from the E3SMv3 Nephele perturbed parameter ensemble (PPE). This product contains global means of present-day (using 2010 aerosol forcings) and preindustrial (using 1850 aerosol forcings) monthly and daily global-mean quantities, as well as hourly mean quantities at the E3SMv3 model grid cell closest to the ENA, SGP, and NSA ARM sites. In this PPE, the E3SMv3 model was run for 27 months in an atmosphere-only configuration with free tropospheric winds nudged to reanalysis. Each ensemble member represents a unique combination of 25 model parameter values (in the microphysics, convective microphysics, and aerosol schemes) that were perturbed randomly and simultaneously. The E3SMv3 default configuration is included as member 0. See https://doi.org/10.22541/essoar.174907165.57104591/v1 (in review) for more information on the Nephele PPE and the perturbed parameters.

Model atmospheric temperature↗
NASA NTRS2018

Constraining the Models' Response of Tropical Clouds to SST Forcings Using CALIPSO Observations

Here we present preliminary results from the analysis of the low cloud cover (LCC) and cloud radiative effect (CRE) interannual changes in response to sea surface temperature (SST) forcings in two GISS climate models, and 12 other climate models. We further classify them as a function of their ability to reproduce the vertical structure of the cloud response to SST change against 10 years of CALIPSO observations: “the constrained models, which match the observation constraint, and the unconstrained models”. The constrained models replicate the observed interannual LCC change particularly well (ΔLCC(sub con)=-3.49 ±1.01 %/K vs. ΔLCC(sub obs)=-3.59 ±0.28 %/K) as opposed to the unconstrained models, which largely underestimate it (ΔLCC(sub unc) = -1.32 ± 1.28 %/K). As a result, the amount of short-wave warming simulated by the constrained models (ΔCRE(sub con)=2.60 ±1.13 W/m2/K) is in better agreement with the observations (ΔCRE(sub obs)=3.05 ±0.28 W/m2/K) than the unconstrained models (ΔCRE(sub con)=0.87 ±2.63 W/m2/K). Depending on the type of low cloud, the observed relationship between cloud/radiation and surface temperature varies. Over the stratocumulus regions, increasing SSTs generate higher cloud top height along with a large decrease of the cloud fraction below as opposed to a slight decrease of the cloud fraction at each level over the trade cumulus regions. Our results suggest that the models must generate sustainable stratocumulus decks and moist processes in the planetary boundary layer to reproduce these observed features. Future work will focus on defining a method to objectively discriminate these cloud types that can be applied consistently in both the observations and the models.

Cesana, Gregory↗
NASA NTRS1988

Satellite-observed characteristics of midwest severe thunderstorm anvils

The cloud top and anvil structure of severe thunderstorms observed by the GOES satellite are analyzed for five SESAME cases in 1979 and four non-SESAME cases in 1980-1982. The data is compared with previous models and hypotheses, paying particular attention to the V feature and thermal couplets in the IR observations. The characteristics of the cases are examined and related to the upper-level temperature and wind conditions. It is found that the warm points downwind of the cloud top are due to subsidence. The anaylsis suggests the presence of subsidence due to mountainlike waves. A model in which the close-in warm point is produced by both internal cloud air motions and stratospheric flow around and over the cloud top. It is suggested that the distant warm point is due to either a wave perturbation from air flowing over the cloud top, or air flowing horizonatlly around the elevated portion of the cloud top and anvil.

Heymsfield, Gerald M.↗
NASA NTRS2005

North Pacific Cloud Feedbacks Inferred from Synoptic-Scale Dynamic and Thermodynamic Relationships

This study analyzed daily satellite cloud observations and reanalysis dynamical parameters to determine how mid-tropospheric vertical velocity and advection over the sea surface temperature gradient control midlatitude North Pacific cloud properties. Optically thick clouds with high tops are generated by synoptic ascent, but two different cloud regimes occur under synoptic descent. When vertical motion is downward during summer, extensive stratocumulus cloudiness is associated with near surface northerly wind, while frequent cloudless pixels occur with southerly wind. Examinations of ship-reported cloud types indicates that midlatitude stratocumulus breaks up as the the boundary level decouples when it is advected equatorward over warmer water. Cumulus is prevalent under conditions of synoptic descent and cold advection during winter. Poleward advection of subtropical air over colder water causes stratification of the near-surface layer that inhibits upward mixing of moisture and suppresses cloudiness until a fog eventually forms. Averaging of cloud and radiation data into intervals of 500-hPa vertical velocity and advection over the SST gradient enables the cloud response to changes in temperature and the stratification of the lower troposphere to be investigated independent of the dynamics.

Norris, Joel R.↗