Stereo Height Research Articles

A GEO-GEO Stereo Observation of Diurnal Cloud Variations over the Eastern Pacific

Fast atmospheric processes such as deep convection and severe storms are challenging to observe and understand without adequate spatiotemporal sampling. Geostationary (GEO) imaging has the advantage of tracking these fast processes continuously at a cadence of the 10 min global and 1 min mesoscale from thermal infrared (TIR) channels. More importantly, the newly-available GEO-GEO stereo observations from our 3D-Wind algorithm provide more accurate height assignment for atmospheric motion vectors (AMVs) than those from conventional TIR methods. Unlike the radiometric methods, the stereo height is insensitive to radiometric TIR calibration of satellite sensors and can assign the feature height correctly under complex situation (e.g., multi-layer clouds and atmospheric inversion). This paper shows a case study from continuous GEO-GEO stereo observations over the Eastern Pacific during 1–5 February 2023, to highlight diurnal variations of clouds and dynamics in the planetary boundary layer (PBL), altocumulus/congestus, convective outflow and tropical tropopause layer (TTL). Because of their good vertical resolution, the stereo observations often show a wind shear in these cloud layers. As an example, the stereo winds reveal the classic Ekman spiral in marine PBL dynamics with a clockwise (counterclockwise) wind direction change with height in the Northern (Southern) Hemisphere subtropics. Over the Southeastern Pacific, the stereo cloud observations show a clear diurnal variation in the closed-to-open cell transition in the PBL and evidence of precipitation at a lower level from broken stratocumulus clouds.

Stereo Plume Height and Motion Retrievals for the Record‐Setting Hunga Tonga‐Hunga Ha'apai Eruption of 15 January 2022

AbstractStereo methods using GOES‐17 and Himawari‐8 applied to the Hunga Tonga‐Hunga Ha'apai volcanic plume on 15 January 2022 show overshooting tops reaching 50–55 km altitude, a record in the satellite era. Plume height is important to understand dispersal and transport in the stratosphere and climate impacts. Stereo methods, using geostationary satellite pairs, offer the ability to accurately capture the evolution of plume top morphology quasi‐continuously over long periods. Manual photogrammetry estimates plume height during the most dynamic early phase of the eruption and a fully automated algorithm retrieves both plume height and advection every 10 min during a more frequently sampled and stable phase beginning 3 hr after the eruption. Stereo heights are confirmed with Global Navigation Satellite System Radio Occultation bending angles, showing that much of the plume was lofted 30–40 km into the atmosphere. Cold bubbles are observed in the stratosphere with brightness temperature of ∼173 K.

Constraining the relationships between aerosol height, aerosol optical depth and total column trace gas measurements using remote sensing and models

Abstract. Proper quantification of the aerosol vertical height is essential to constrain the atmospheric distribution and lifetime of aerosols, as well as their impact on the environment. We use globally distributed, daily averaged measurements of aerosol stereo heights of fire aerosols from the Multi-angle Imaging SpectroRadiometer (MISR) to understand the aerosol distribution. We also connect these results with a simple plume rise model and a new multi-linear regression model approach based on daily measurements of NO2 from OMI and CO from MOPITT to understand and model the global aerosol vertical height profile over biomass burning regions. First, plumes associated with the local dry-burning season at midlatitudes to high latitudes frequently have a substantial fraction lofted into the free troposphere and in some cases even the stratosphere. Second, plumes mainly associated with less-polluted regions in developing countries and heavily forested areas tend to stay closer to the ground, although they are not always uniformly distributed throughout the boundary layer. Third, plumes associated with more serious loadings of pollution (such as in Africa, Southeast Asia and northeast China) tend to have a substantial amount of smoke transported uniformly through the planetary boundary layer and up to around 3 km. Fourth, the regression model approach yields a better ability to reproduce the measured heights compared to the plume rise model approach. This improvement is based on a removal of the negative bias observed from the plume model approach, as well as a better ability to work under more heavily polluted conditions. However, over many regions, both approaches fail, requiring deeper work to understand the physical, chemical and dynamical reasons underlying the failure over these regions.

Fano-Enhanced Circular Dichroism in Deformable Stereo Metasurfaces.

2D metasurfaces have emerged as a paradigm-shifting platform for light management with considerable miniaturization and alleviated fabrication challenges than their 3D counterparts. However, the appearance of in-plane mirror symmetry and reduced dimensions impose fundamental restraints to advanced chiroptical responses and reconfiguration capabilities. Here, a new concept of Fano-enhanced circular dichroism by introducing a reconfigurable stereo metasurface, which possesses deformable out-of-plane twists that are readily achieved by a simple nano-kirigami fabrication method, is demonstrated. The stereo height and twisting geometries can be reproducibly controlled, providing a facile and automated fashion to tailor the distinct profiles of Fano resonances under circularly polarized incidence. As a result, a recorded high efficiency of circular dichroism generation per unit sample thickness is achieved with Fano resonances in opposite lineshapes. Leveraging this feature, large-range reconfiguration of circular dichroism at optical wavelengths is demonstrated through reversible compression of the stereo metasurfaces with a fiber tip. The studied stereo metasurface unfolds a new degree of freedom for advanced photonic applications in a quasi-flat optical platform, and the proposed concept of Fano-enhanced circular dichroism opens new venues to explore interesting fundamental phenomena of chiral optics.

Using stereo SAR and InSAR by combining the COSMO-SkyMed and the TanDEM-X mission satellites for estimation of absolute height

The objective of this work is to estimate absolute height in synthetic aperture radar (SAR) interferograms. Since height in interferograms is relative, we use stereo SAR with several satellites to achieve absolute height references of natural or man-made reflectors. We study the performance of stereo height estimation and geographic positioning using the satellites TerraSAR-X (TSX) and COSMO-SkyMed (CSK), both individually and in combination. Corner reflectors positioned by global positioning system (GPS) are used as reference. The accuracy obtained with corner reflectors may be the best we can expect using SAR for height estimation and geolocation. The location errors in this study were less than 0.6 m for TSX alone, and 1.5 m for CSK alone or combined with TSX. By combining TSX and CSK, stereo SAR is applied to estimate absolute height in bistatic interferograms generated from TSX and TanDEM-X (TDX). This method seems to yield absolute height accuracy in interferograms better than 1–2 m.

Improvements to MISR stereo motion vectors

[1] This study evaluated the effects of recent major modifications to the Multiangle Imaging SpectroRadiometer (MISR) wind retrieval algorithm by repeating an earlier yearlong comparison with Meteosat-9 cloud motion vectors. Algorithm upgrades included an area-based stereo matcher, enhanced quality control, georegistration corrections to focal plane distortions, and increased retrieval resolution. The new winds had better quality at all levels, yielding a particularly large increase in coverage at middle and high levels. The upgrades had an overall neutral impact on the E-W wind comparison statistics, which were already quite good in the preceding MISR data set. The comparison statistics for the more error-prone N-S wind, however, improved significantly on all scales—global, zonal, and regional—and throughout the entire atmosphere. Both the negative N-S wind bias and root mean square difference decreased, and correlation increased substantially, with middle and high levels, and tropics and subtropics experiencing the largest improvements. Subpixel georegistration corrections reduced cross-swath variations in N-S wind and height by half. As the net effect of these improvements, the error characteristics of the previously more uncertain N-S wind component became comparable to those of the E-W wind component at low and middle levels. Despite the substantial reductions in N-S wind errors, which are highly correlated with stereo height errors, the MISR – Meteosat-9 height comparison did not generally improve, strongly suggesting Meteosat-9 height assignment errors as the primary driver of discrepancy.

A multi-sensor plume height analysis of the 2009 Redoubt eruption

During an explosive volcanic eruption, accurately determining the height of a volcanic plume or cloud is essential to accurately forecast its motion because volcanic ash transport and dispersion models require the initial plume height as an input parameter. The direct use of satellite infrared temperatures for height determination, one of the most commonly employed methods at the Alaska Volcano Observatory, often does not yield unique solutions for height. This result is documented here for the 2009 eruption of Redoubt Volcano. Satellite temperature heights consistently underestimated the height of ash plumes in comparison to other methods such as ground-based radar and Multi-angle Imaging SpectroRadiometer (MISR) stereo heights. For ash plumes below the tropopause, increasing transparency of a plume begins to affect the accuracy of simple temperature height retrievals soon after eruption. With decreasing opacity, plume temperature heights become increasingly inaccurate. Comparison with dispersion models and aircraft gas flight data confirms that radar and MISR stereo heights are more accurate than basic satellite temperature heights. Even in the cases in which satellite temperature results appeared to be relatively accurate (e.g., for plumes below the tropopause), a mixed signal of plume and ground radiation still presented an issue for almost every event studied. This was true regardless of the fact that a band differencing method was used to remove presumably translucent pixels. The data presented here make a strong case for the use of data fusion in volcano monitoring, as there is a need to confirm satellite temperature heights with other height data. If only basic satellite temperature heights are available for a given eruption, then these heights must be considered with a significant margin of error.

A review of cloud top height and optical depth histograms from MISR, ISCCP, and MODIS

There are notable differences in the joint histograms of cloud top height and optical depth being produced from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multiangle Imaging Spectro‐Radiometer (MISR) and by the International Satellite Cloud Climatology Project (ISCCP). These differences have their roots in the different retrieval approaches used by the three projects and are driven largely by responses of the retrievals to (1) stratocumulus (or more broadly low‐level clouds under temperature inversions), (2) small (subpixel) or broken low‐level clouds, and (3) multilayer clouds. Because each data set has different strengths and weakness, the combination tells us more about the observed cloud fields than any of the three by itself. In particular, the MISR stereo height retrieval provides a calibration insensitive approach to determining cloud height that is especially valuable in combination with ISCCP or MODIS because the combination provides a means to estimate the amount of multilayer cloud, where the upper cloud is optically thin. In this article we present a review of the three data sets using case studies and comparisons of annually averaged joint histograms on global and regional scales. Recommendations for using these data in climate model evaluations are provided.

MISR Stereo Heights of Grassland Fire Smoke Plumes in Australia

Plume heights from wildfires are used in climate modeling to predict and understand trends in aerosol transport. This paper examines whether smoke from grassland fires in the desert regions of western and central Australia ever rises above the atmospheric boundary layer. Three methods for deriving plume heights from the Multi-angle Imaging SpectroRadiometer (MISR) instrument were utilized: (1) the MISR standard stereo-height algorithm; (2) the MISR enhanced stereo product; and (3) the MISR INteractive eXplorer (MINX) v.1 tool. To provide context and to search for correlative factors, stereo heights were combined with fire radiant energy flux from the Moderate Resolution Imaging Spectroradiometer instrument, atmospheric structure information from the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis project model, surface cover from the Australia National Vegetation Information System, and forward and backward trajectories from the National Oceanic and Atmospheric Administration Hybrid Single-Particle Lagrangian Integrated Trajectory model. Although most smoke plumes concentrate in the near-surface boundary layer as expected, some appear to rise higher. Smoke that gets above the boundary layer will travel farther, remain in the atmosphere longer, and therefore have a larger environmental impact. It was previously thought unlikely for grassland fires to inject smoke above the boundary layer. Our findings suggest that climate modelers should reevaluate common assumptions about the heights of smoke plumes when producing aerosol transport models involving grassland fires. A closer examination of grassland fire energetics may also be warranted.

Stereo observations of polar stratospheric clouds

We present the first observations of polar stratospheric clouds (PSCs) within near‐infrared (NIR) satellite images by using the Multi‐angle Imaging SpectroRadiometer (MISR) to stereoscopically identify clouds with altitudes above the tropopause. Rather than using the operational MISR stereo product, a tailored stereo height algorithm operating upon MISR's most oblique viewing cameras is employed to identify PSC. Cloud top heights retrieved by this algorithm for scenes observed during the 2003 Antarctic Spring exhibit bias relative to the satellite‐borne lidar, GLAS, of −0.60 ± 1.71 km for low (1–5 km altitude) tropospheric clouds, −0.35 ± 1.48 km for high (>5 km altitude) tropospheric clouds, and 0.77 ± 1.86 km for low (<18 km altitude) stratospheric clouds. During this period, MISR captured a Sep. 30th intensification of PSC spanning over 1 million sq. km and occurring as the apparent result of synoptic scale isentropic uplift associated with a potential vorticity anomaly tied to planetary waves, but likely also strengthened by a nearby tropospheric depression.

Multiview Cloud-Top Height and Wind Retrieval with Photogrammetric Methods: Application to Meteosat-8 HRV Observations

Abstract The European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT) currently operates three geostationary satellites: Meteosat-5, Meteosat-7, and Meteosat-8. Observations by Meteosat-5 can be combined with observations from either Meteosat-7 or Meteosat-8 to allow geostationary stereo height retrievals within the overlap area over the Indian Ocean and east Africa. This paper aims to demonstrate the capabilities of the geostationary stereophotogrammetric cloud-top height retrieval—in particular, with the new high-resolution visible channel (HRV) of Meteosat-8. Conceived as a proof-of-concept study, the retrieval was limited to four distinct cloud areas in northeast Africa. The effects of the geolocation, spatial resolution, satellite position, and acquisition time on the cloud-top height accuracy were studied. It is demonstrated that the matching accuracy is sensitive to the acquisition-time difference and spatial resolution. As a result, there is only a marginal benefit from the good spatial resolution offered by the Meteosat-8 HRV channel because of the low spatial resolution of Meteosat-5 and the poor time synchronization between the observations of the two satellites. On the contrary, the good time synchronization between Meteosat-5 and Meteosat-7 observations offsets the errors in the height assignment resulting from the relatively coarse spatial resolution, if the geolocation accuracy is locally enhanced with additional landmarks from higher-resolution images. With the geolocation correction and the newly implemented time information in the Meteosat-5 and -7 header information, the stereo cloud-top height assignment for the Meteosat-5/-7 and Meteosat-5/-8 HRV combination resulted in about the same accuracy of approximately ±1 km. For the Meteosat-5/-8 HRV combination, the time differences of up to 7.5 min preclude higher accuracy. To validate the cloud-top heights, observations by the Multiangle Imaging Spectroradiometer (MISR) and Moderate Resolution Imaging Spectroradiometer (MODIS) were used.

Comparison between ATSR‐2 stereo, MOS O2‐A band and ground‐based cloud top heights

A new method to retrieve cloud top heights stereoscopically using the dual‐view facility of the Along Track Scanning Radiometer 2 (ATSR‐2) instrument is assessed. This assessment is performed through a comparison of the cloud top heights obtained from ATSR‐2 stereo and those derived from a 94‐GHz radar, radiosonde profiles and independently from the Modular Optoelectronic Scanner (MOS) using the O2‐A band. The data for this study were collected over the United Kingdom from September 1998–March 1999. The results show that the accuracy of the ATSR‐2 stereo heights is generally as predicted on theoretical grounds, with the errors in the 1.6 µm and 0.65 µm stereo heights rarely exceeding 2 km. Case study periods with disagreements between the ATSR‐2 heights and the ground‐based retrievals are often due to the lack of precise match‐ups between the ground‐based and satellite scenes, while the MOS O2‐A band is shown sometimes to miss the tops of high clouds. Evidence that the 11 µm channel is more sensitive to high clouds than originally thought is given and a future application of multi‐spectral stereo cloud top heights is proposed.

Cloud top height comparisons from ASTER, MISR, and MODIS for trade wind cumuli

ASTER stereo and ASTER infrared (IR) retrieved cloud top heights (CTHs) at 90 m spatial resolution are compared to operational Multi-Angle Imaging SpectroRadiometer (MISR) stereo and MODerate Resolution Imaging Spectroradiometer (MODIS) thermal IR techniques at 1100 m and 5000 m spatial resolution, respectively. ASTER data availability limits this study to trade wind cumulus clouds only. ASTER IR, MISR stereo and MODIS IR cloud height frequency distributions were derived for 41 trade wind cumulus cloud scenes with no cirrus contamination. All three retrievals produce a bimodal CTH distribution with maxima at 650 and 1500 m. Several scenes are investigated in further details utilizing the ASTER stereo heights. The ASTER stereo-derived CTH frequency distribution is also bimodal and coincides best with a surface-based ceilometer-derived cloud base height distribution, in the sense that it produces the fewest CTH retrievals below the typical lidar-observed cloud base height. Sensitivity to spatial resolution was investigated by degrading ASTER stereo and IR CTH retrievals to the MISR spatial resolution, and also by deriving ASTER stereo heights from degraded radiances. The degraded ASTER stereo CTH retrievals remain bimodal, but showed less high clouds and more lower clouds, whereas the ASTER stereo heights from degraded radiances lose the bimodal structure similarly to the ASTER degraded resolution IR technique. Overall, the stereo technique appears more suitable for retrieving CTH for trade wind cumulus clouds than IR techniques, because it shows less sensitivity to resolution. With either technique CTHs should be produced at the high spatial resolution (finer than 1 km) and with subsampling preferred over spatial averaging, if necessary. Nonetheless, even at a spatial resolution of 1 km (which often exceeds the horizontal size of many trade wind cumulus clouds) both stereo and IR techniques reflect the CTH bimodality characterizing the scenes we studied.

Stereo Cloud Heights From Multispectral IR Imagery via Region-of-Interest Segmentation

Multispectral thermal imagery acquired from low Earth orbit was used to develop a method of cloud-height determination that applies image brightness temperature histograms and region-of-interest (ROI) image segmentation as a processing step prior to stereo-height retrieval. The National Aeronautics and Space Administration's Infrared Spectral Imaging Radiometer (ISIR) acquired all imagery during the August 1997 STS-85 mission of the Space Shuttle Discovery. ISIR, the first Earth-observing spectroradiometer to employ an uncooled large-format microbolometer-array focal plane, provided continuous coverage in four spectral bands along track in an 80-km-wide swath. ROI segmentation created binary cloud masks ranging over brightness temperatures in the imagery for which the parallax was determined by a two-dimensional correlation method, allowing stereo heights to be determined using the standard parallax equations. A subpixel parallax algorithm allowed stereo heights to be determined with a precision of roughly plusmn0.39 km for clouds in the observed altitude range of 0.5-10 km

Assessment of multispectral ATSR2 stereo cloud-top height retrievals

The Along-Track Scanning Radiometer 2 (ATSR2) instrument has a dual view capability that allows for stereo height retrievals. Stereo heights were retrieved for selected scenes over the United Kingdom Chilbolton Facility for Atmospheric and Radio Research and the United States Atmospheric Radiation Measurement program Southern Great Plains site from 1997 to 2000. Stereo cloud-top heights obtained with the 11 μm and 1.6 μm channels of ATSR2 were compared with ground-based millimeter-wave cloud radar measurements at both sites. On average ATSR2 11 μm channel cloud-top height retrievals were 350 m higher than those from radar with a standard deviation of 1 km. This difference increased with decreasing cloud-top height. One major problem found in the 11 μm channel cloud-top height retrievals was poor delineation between surface (i.e., clear) and low-altitude cloud pixels, though this tends to lower cloud-top heights rather than raise them. The ATSR2 1.6 μm channel stereo cloud-top heights had large discrepancies compared to radar because of the 1.6 μm channel sensitivity to a lower layer in the case of multilayer clouds or the terrain in the case of optically thin single-layer clouds. For single-layer clouds, the agreement between the ATSR2 1.6 μm channel and the radar cloud-top heights was similar to that between ATSR2 11 μm channel and radar cloud-top heights.

Mariner 10 stereo image coverage of Mercury

A computer search was performed on all useable Mariner 10 images of Mercury for which refined camera positions and orientations are available. Over 2000 valid stereo pairs have been found. The results of this search allowed us to construct a map illustrating the available stereo coverage and the corresponding stereo height accuracy across the surface of Mercury. Examples are given to illustrate the quality of the available stereo pairs and the resulting digital elevation models.

Improved Cloud Motion Wind Vector and Altitude Assignment Using VAS

Abstract A CO2 cloud tracking technique to determine simultaneous heights and velocities of cloud motion winds is presented. Using animated CO2 channel imagery from VAS, multi-level cloud situations are separated into high, middle and low level cloud motion wind vectors by the CO2 slicing method. The VAS CO2 channel radiometric values are used in the CO2 absorption method to assign quantitative heights to the cloud vectors; cloud top pressures are determined from the ratio of the deviations in cloud produced radiances and the corresponding clear air values for three CO2 channels in a radiative transfer equation formulation. Two case studies are presented that show CO2 cloud-motion wind vectors to be in good agreement with radiosonde wind observations and CO2 cloud heights to be within a 50 mb rms deviation of radiosonde, bispectral and stereo height determinations.

Stereoscopic observations from meteorological satellites

The capability of making stereoscopic observations of clouds from meteorological satellites is a new basic analysis tool with a broad spectrum of applications. Stereoscopic observations from satellites were first made using the early vidicon tube weather satellites (e.g., Ondrejka and Conover [1]). However, the only high quality meteorological stereoscopy from low orbit has been done from Apollo and Skylab, (e.g., Shenk et al. [2] and Black [3], [4]). Stereoscopy from geosynchronous satellites was proposed by Shenk [5] and Bristor and Pichel [6] in 1974 which allowed Minzner et al. [7] to demonstrate the first quantitative cloud height analysis. In 1978 Bryson [8] and desJardins [9] independently developed digital processing techniques to remap stereo images which made possible precision height measurement and spectacular display of stereograms (Hasler et al. [10], and Hasler [11]). In 1980 the Japanese Geosynchronous Satellite (GMS) and the U.S. GOES-West satellite were synchronized to obtain stereo over the central Pacific as described by Fujita and Dodge [12] and in this paper. Recently the authors have remapped images from a Low Earth Orbiter (LEO) to the coordinate system of a Geosynchronous Earth Orbiter (GEO) and obtained stereoscopic cloud height measurements which promise to have quality comparable to previous all GEO stereo. It has also been determined that the north-south imaging scan rate of some GEOs can be slowed or reversed. Therefore the feasibility of obtaining stereoscopic observations world wide from combinations of operational GEO and LEO satellites has been demonstrated.Stereoscopy from satellites has many advantages over infrared techniques for the observation of cloud structure because it depends only on basic geometric relationships. Digital remapping of GEO and LEO satellite images is imperative for precision stereo height measurement and high quality displays because of the curvature of the earth and the large angular separation of the two satellites. A general solution for accurate height computation depends on precise navigation of the two satellites. Validation of the geosynchronous satellite stereo using high altitude mountain lakes and vertically pointing aircraft lidar leads to a height accuracy estimate of ± 500 m for typical clouds which have been studied. Applications of the satellite stereo include: 1) cloud top and base height measurements, 2) cloud-wind height assignment, 3) vertical motion estimates for convective clouds (Mack et al. [13], [14]), 4) temperature vs. height measurements when stereo is used together with infrared observations and 5) cloud emissivity measurements when stereo, infrared and temperature sounding are used together (see Szejwach et al. [15]).When true satellite stereo image pairs are not available, synthetic stereo may be generated. The combination of multispectral satellite data using computer produced stereo image pairs is a dramatic example of synthetic stereoscopic display. The classic case uses the combination of infrared and visible data as first demonstrated by Pichel et al. [16]. Hasler et at. [17], Mosher and Young [18] and Lorenz [19], have expanded this concept to display many channels of data from various radiometers as well as real and simulated data fields.A future system of stereoscopic satellites would be comprised of both low orbiters (as suggested by Lorenz and Schmidt [20], [19]) and a global system of geosynchronous satellites. The low earth orbiters would provide stereo coverage day and night and include the poles. An optimum global system of stereoscopic geosynchronous satellites would require international standarization of scan rate and direction, and scan times (synchronization) and resolution of at least 1 km in all imaging channels. A stereoscopic satellite system as suggested here would make an extremely important contribution to the understanding and prediction of the atmosphere.

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.

Cloud-top Structure of Tornadic Storms on 10 April 1979 from Rapid Scan and Stereo Satellite Observations1

The cloud top structure of the Wichita Falls tornadic storm of 10 April 1979 (and other severe storms on this day) is studied using remotely-sensed observations from radar and satellite. A comprehensive data set included 3 min interval visible (0.6 μm) and infrared (11 μm) radiances from the eastern GOES and similar 30 min interval data from the western GOES. The near synchronization of these two satellites allowed for the stereoscopic determination of cloud top heights. In addition, at 2048 GMT, TIROS-N scanned the storms within one minute of the geosynchronous stereo and provided 1 km resolution infrared blackbody temperatures. Because internal storm dynamics are hidden from the view of the satellite, storm updraft intensity must be inferred from cloud-top minimum temperature and its rate of change. The Wichita Falls, Tex. tornadic storm could be defined in the satellite data by a point of minimum temperature which displayed temporal continuity and achieved a temperature of 208 K. A cloud-top cooling rate above the tropopause of 7 K/21 min preceded tornadogenesis. An adjacent warm area (221 K) developed downwind and was surrounded by a “V”-shaped pattern of lower temperatures. The warm area is postulated as due to subsidence in the lee of an ascending tower. The measured stereo height of the Wichita Falls storm was 15.6 km at 2349 GMT, 1.5 km higher than severe storms 150 km downwind, although its minimum blackbody temperature was 9 K higher than that of these downwind storms. In addition, unrealistic fluctuations in the time sequence of temperature 30 min prior to the Wichita Falls tornado indicate that the IR measurements are affected by sensor response and/or field of view limitations, at least close to the anvil edge. Cross sections of stereo heights, IR temperature, and radar reflectivity at 2349 GMT demonstrate that while there is, in general, a co-location of high tops, low temperatures, and high low-level radar reflectivity, significant variations can exist in height/rainfall relationships. A comparison of data sets at 2048 GMT between stereo height measurements and IR temperatures from GOES-East and TIROS-N revealed that anvil top features can be up to 10 K warmer in the GOES field of view (100 km2) than from TIROS-N (1 km2), and that this difference can reach 20 K for young thunderstorms, with perhaps 4 K explained by calibration differences. The lapse rate for tops penetrating the tropopause was substantially closer to the adiabatic lapse rate when TIROS-N temperature minima, rather than GOES minima, were plotted as a function of stereo determined height.