Stanley Q. Kidder

Satellite Analysis of Tropical Cyclones Using the Advanced Microwave Sounding Unit (AMSU)

The first Advanced Microwave Sounding Unit (AMSU) was launched aboard the NOAA-15 satellite on 13 May 1998. The AMSU is well suited for the observation of tropical cyclones because its measurements are not significantly affected by the ice clouds that cover tropical storms. In this paper, the following are presented: 1) upper-tropospheric thermal anomalies in tropical cyclones retrieved from AMSU data, 2) the correlation of maximum temperature anomalies with maximum wind speed and central pressure, 3) winds calculated from the temperature anomaly field, 4) comparison of AMSU data with GOES and AVHRR imagery, and 5) tropical cyclone rainfall potential. The AMSU data appear to offer substantial opportunities for improvement in tropical cyclone analysis and forecasting.

Urban Heat Island Modeling in Conjunction with Satellite-Derived Surface/Soil Parameters

Although it has been studied for over 160 years, the urban heat island (UHI) effect is still not completely understood, yet it is increasingly important. The main purpose of this work is to improve UHI modeling by using AVHRR (Advanced Very High Resolution Radiometer) satellite data to retrieve the surface parameters (albedo, as well as soil thermal and moisture properties). In this study, a hydrostatic three-dimensional mesoscale model was used to perform the numerical modeling. The Carlson technique was applied to retrieve the thermal inertia and moisture availability using the thermal AVHRR channels 4 and 5. The net urban effect was determined as the difference between urban and nonurban simulations, in which urban parameters were replaced by rural parameters. Two winter days were each used for two numerical simulations: a control and an urban-to-rural replacement run. Moisture availability values on the less windy day showed generally a south to north gradient downwind of the city and urban values less than rural values (the urban dry island day). Moisture availability was higher on the windy day, with uniform values in the rural and urban areas (uniform soil moisture day). The only exceptions were variations in the rural hills north of the city and the low rural values under the polluted urban plume downwind of the city. While thermal inertia values showed no urban‐rural differences on the uniform soil moisture day, they exhibited larger values over Atlanta than in surrounding rural area on the (less moist) dry island day. Two puzzling facts exist in the data: 1) lack of a north‐south thermal inertia gradient on the dry soil day to correspond to its abovementioned moisture availability gradient and 2) rural thermal inertia values do not change between both days in spite of their large difference in soil moisture. The observed lack of corresponding urban change is expected, as its thermal inertia values depend more on urban building materials than on moisture of soil. In both cases both the 2-m and surface skin UHIs showed positive values at night and negative values (an urban cool island, UCI) during the day. The larger nighttime 2-m UHI was on the dry day (0.88 vs 0.68C), while the larger daytime 2-m UCI was on the moist soil day (20.38 vs 20.58C). Note that the surface differences were almost always greater than the 2-m differences. These day‐night differences imply a rural thermal inertia lower than its urban values on both days, which is in conflict with the observations on the wet uniform soil moisture day. On the uniform thermal inertia day (wet day), both the UHI and UCI amplitudes should be less than on the other day, but this is not the case. A possible explanation for both of these conflicts is the improper influence of the urban plume on this day on lowering the thermal inertia and moisture availability values used in the replacement urban simulation.

First-Light Imagery from Suomi NPP VIIRS

The Suomi National Polar-Orbiting Partnership (NPP) satellite was launched on 28 October 2011, heralding the next generation of operational U.S. polar-orbiting satellites. It carries the Visible– Infrared Imaging Radiometer Suite (VIIRS), a 22-band visible/infrared sensor that combines many of the best aspects of the NOAA Advanced Very High Resolution Radiometer (AVHRR), the Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS), and the National Aeronautics and Space Administration (NASA) Moderate Resolution Imaging Spectroradiometer (MODIS) sensors. VIIRS has nearly all the capabilities of MODIS, but offers a wider swath width (3,000 versus 2,330 km) and much higher spatial resolution at swath edge. VIIRS also has a day/night band (DNB) that is sensitive to very low levels of visible light at night such as those produced by moonlight reflecting off low clouds, fog, dust, ash plumes, and snow cover. In addition, VIIRS detects light emissions from cities, ships, oil flares, and ...

Estimating Tropical Cyclone Central Pressure and Outer Winds from Satellite Microwave Data

Abstract A technique is proposed for estimating tropical cyclone central pressure and surface wind speeds outside of the radius of maximum wind speed from the 55.45 GHz channel of the Scanning Microwave Spectrometer on board the Nimbus 6 satellite. The method was developed using measurements over eight typhoons and five hurricanes during 1975.

A multispectral study of the St. Louis area under snow-covered conditions using NOAA-7 AVHRR data

Abstract Albedos and equivalent blackbody temperatures from the 5-channel Advanced Very High Resolution Radiometer (AVHRR) on board the NOAA-7 satellite have been examined for two consecutive passes of the satellite over the St. Louis area when snow was on the ground. The albedo difference for channel 1 (visible) between St. Louis and a typical rural area was − 16%, much larger than urban-rural albedo differences found in previous studies under snow-free conditions. The albedo difference between channel 1 and channel 2 (near-infrared) appears to be a better indicator of the snow boundary than either channel alone. The channel 4 (11 μm) equivalent blackbody temperature difference between the warmest part of St. Louis and a typical rural area was 3 K during the day and 2.5 K at night, about the same as urban-rural temperature differences found under snow-free conditions. Day-night temperature differences were nearly the same in urban as in rural areas. Largest day-night differences were found in forested portions of the snow-covered area. Slightly larger (about 0.5 K) day-night differences were observed in the commercial-industrial area of St. Louis than in the residential area. This may be caused by residential heating. Finally, hot industrial targets were easily observed in 3.7 μm images. These targets may be useful for accurate registration of AVHRR images.

The Tropical Rainfall Potential (TRaP) Technique. Part I: Description and Examples

Abstract Inland flooding caused by heavy rainfall from landfalling tropical cyclones is a significant threat to life and property. The tropical rainfall potential (TRaP) technique, which couples satellite estimates of rain rate in tropical cyclones with track forecasts to produce a forecast of 24-h rainfall from a storm, was developed to better estimate the magnitude of this threat. This paper outlines the history of the TRaP technique, details its current algorithms, and offers examples of its use in forecasting. Part II of this paper covers verification of the technique.

A Blended Satellite Total Precipitable Water Product for Operational Forecasting

Abstract Total precipitable water (TPW), the amount of water vapor in a column from the surface of the earth to space, is used by forecasters to predict heavy precipitation. In this paper, a process for blending TPW values retrieved from two satellite sources is detailed: the Advanced Microwave Sounding Unit (AMSU) instruments on three NOAA satellites, and the Special Sensor Microwave Imager (SSM/I) instruments on three Defense Meteorological Satellite Program (DMSP) satellites. The process starts with a blending algorithm, which matches the cumulative probability distribution functions of TPW retrievals from the two instruments to lessen their differences. The data are then mapped to a map projection useful to forecasters and composited for 12 h to make a global map. These maps are produced hourly using Data Processing and Error Analysis System (DPEAS) software and made available to forecasters online.

On the Use of Satellites in Molniya Orbits for Meteorological Observation of Middle and High Latitudes

Abstract Time and space sampling is an increasingly critical aspect of Earth observation satellites. The highly eccentric orbit used by Soviet Molniya satellites functions much like a high-latitude geostationary orbit. Meteorological instruments placed on a satellite in a Molniya orbit would improve the temporal frequency of observation of high-latitude phenomena such as polar lows. Consideration of this new sampling strategy is suggested for future systems such as the “Earth Probe” satellites in the Mission to Planet Earth program as well as for operational meteorological satellite programs.

Tropical Cyclone Outer Surface Winds Derived from Satellite Microwave Sounder Data

Abstract Upper tropospheric temperature anomalies are detected in brightness temperature data from the Nimbus 6 Scanning Microwave Spectrometer (SCAMS). Brightness temperature anomalies are related to surface pressure anomalies through the radiative transfer and hydrostatic equation. Surface wind speeds at outer radii are then estimated using the gradient wind equation and a shearing parameter. The method is first tested using simulated satellite data constructed from temperature, pressure and height data recorded by aircraft reconnaissance of four hurricanes. Wind speeds in the 80–95 kPa region are estimated with 2–3 m s−1 accuracy, Next, 55.45 GHz SCAMS data over eight typhoons during 1975 are used to estimate the radii of 15.4 m s−1 (30 kt) and 27.5 m a−1 (50 kt) winds. Accuracies of about ±80 and ±70 km, respectively, are found. It is suggested that the technique be further tested using data from the Microwave Sounding Unit (MSU) on board the TIROS-N and NOAA 6 satellites.

Assessing Moonlight Availability for Nighttime Environmental Applications by Low-Light Visible Polar-Orbiting Satellite Sensors

AbstractThe next-generation U.S. polar-orbiting environmental satellite program, the Joint Polar Satellite System (JPSS), promises unprecedented capabilities for nighttime remote sensing by way of the day/night band (DNB) low-light visible sensor. The DNB will use moonlight illumination to characterize properties of the atmosphere and surface that conventionally have been limited to daytime observations. Since the moon is a highly variable source of visible light, an important question is where and when various levels of lunar illumination will be available. Here, nighttime moonlight availability was examined based on simulations done in the context of Visible/Infrared Imager Radiometer Suite (VIIRS)/DNB coverage and sensitivity. Results indicate that roughly 45% of all JPSS-orbit [sun-synchronous, 1330 local equatorial crossing time on the ascending node (LTAN)] nighttime observations in the tropics and midlatitudes would provide levels of moonlight at crescent moon or greater. Two other orbits, 1730 and...