Comparison of SMMR and SSM/I passive microwave data collected over Antarctica

Spaceborne data are becoming sufficiently extensive spatially and sufficiently lengthy over time to provide important gauges of global change. There is a potentially long record of microwave brightness temperature from NASA's Scanning Multichannel Microwave Radiometer (SMMR), followed by the Navy's Special Sensor Microwave Imager (SSM/I). Thus it is natural to combine data from successive satellite programs into a single, long record. To do this, we compare brightness temperature data collected during the brief overlap period (7 July-20 August 1987) of SMMR and SSM/I. Only data collected over the Antarctic ice sheet are used to limit spatial and temporal complications associated with the open ocean and sea ice. Linear regressions are computed from scatter plots of complementary pairs of channels from each sensor revealing highly correlated data sets, supporting the argument that there are important relative calibration differences between the two instruments. The calibration scheme was applied to a set of average monthly brightness temperatures for a sector of East Antarctica.

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Characterization of a hoar-development episode using SSM/I brightness temperatures in the vicinity of the GISP2 site, Greenland

Annals of Glaciology ◽

10.3189/s0260305500012817 ◽

1993 ◽

Vol 17 ◽

pp. 183-188 ◽

Cited By ~ 11

Author(s):

Christopher A. Shuman ◽

Richard B. Alley ◽

Sridhar Anandakrishnan

Keyword(s):

Brightness Temperature ◽

Surface Density ◽

Temperature Data ◽

Gradual Decline ◽

Near Surface ◽

Microwave Brightness Temperature ◽

Brightness Temperatures ◽

Microwave Imager ◽

High Winds

Formation of a surface-hoar/depth-hoar complex at the GISP2 site in central Greenland was correlated with large changes in Special Sensor Microwave/Imager (SSM/I) brightness-temperature data. Pass-averaged SSM/I brightness-temperature data over a 1/2° latitude by 1° longitude cell for the 19 and 37 GHz, vertically (V) and horizontally (Η) polarized bands were manipulated to yield differential (V-Η) trends which clearly show a gradual decline as the hoar formation caused a progressively rougher surface with progressively lower density. The hoar episode ended as snowfall, and high winds buried and destroyed the surface-hoar layer and caused rapid V-Η increases in ≈ 1 day. Comparison of the different trends with changes in the field-monitored variables and theoretical values suggest that the V-Η trends are sensitive primarily to changes in surface roughness, and secondarily to near-surface density changes. Consistent expression of trends in microwave brightness temperature over 35 adjacent study cells indicates that this technique may provide a remote-sensing signature capable of defining the timing and spatial extent of surface- and depth-hoar formation in central Greenland.

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The Utilization of Spaceborne Microwave Radiometers for Monitoring Snowpack Properties

Hydrology Research ◽

10.2166/nh.1979.0003 ◽

1979 ◽

Vol 10 (1) ◽

pp. 25-40 ◽

Cited By ~ 90

Author(s):

A. Rango ◽

A. T. C. Chang ◽

J. L. Foster

Keyword(s):

Brightness Temperature ◽

Microwave Radiometer ◽

Snow Accumulation ◽

High Plains ◽

Snow Hydrology ◽

Microwave Brightness Temperature ◽

Brightness Temperatures ◽

Snow Properties ◽

Snow Conditions ◽

Snowpack Properties

Snow accumulation and depletion at specific locations can be monitored from space by observing related variations in microwave brightness temperatures. Using vertically and horizontally polarized brightness temperatures from the Nimbus 6 Electrically Scanning Microwave Radiometer, a discriminant function can be used to separate snow from no snow areas and map snowcovered area on a continental basis. For dry snow conditions on the Canadian high plains significant relationships between snow depth or water equivalent and microwave brightness temperature were developed which could permit remote determination of these snow properties after acquisition of a wider range of data. The presence of melt water in the snowpack causes a marked increase in brightness temperature which can be used to predict snowpack priming and timing of runoff. As the resolutions of satellite microwave sensors improve the application of these results to snow hydrology problems should increase.

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Characterization of a hoar-development episode using SSM/I brightness temperatures in the vicinity of the GISP2 site, Greenland

Annals of Glaciology ◽

10.1017/s0260305500012817 ◽

1993 ◽

Vol 17 ◽

pp. 183-188 ◽

Cited By ~ 23

Author(s):

Christopher A. Shuman ◽

Richard B. Alley ◽

Sridhar Anandakrishnan

Keyword(s):

Brightness Temperature ◽

Surface Density ◽

Temperature Data ◽

Gradual Decline ◽

Near Surface ◽

Microwave Brightness Temperature ◽

Brightness Temperatures ◽

Microwave Imager ◽

High Winds

Formation of a surface-hoar/depth-hoar complex at the GISP2 site in central Greenland was correlated with large changes in Special Sensor Microwave/Imager (SSM/I) brightness-temperature data. Pass-averaged SSM/I brightness-temperature data over a 1/2° latitude by 1° longitude cell for the 19 and 37 GHz, vertically (V) and horizontally (Η) polarized bands were manipulated to yield differential (V-Η) trends which clearly show a gradual decline as the hoar formation caused a progressively rougher surface with progressively lower density. The hoar episode ended as snowfall, and high winds buried and destroyed the surface-hoar layer and caused rapid V-Η increases in ≈ 1 day. Comparison of the different trends with changes in the field-monitored variables and theoretical values suggest that the V-Η trends are sensitive primarily to changes in surface roughness, and secondarily to near-surface density changes. Consistent expression of trends in microwave brightness temperature over 35 adjacent study cells indicates that this technique may provide a remote-sensing signature capable of defining the timing and spatial extent of surface- and depth-hoar formation in central Greenland.

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THIN ICE AREA EXTRACTION IN THE SEASONAL SEA ICE ZONES OF THE NORTHERN HEMISPHERE USING ASMR2 DATA

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences ◽

10.5194/isprs-archives-xlii-3-w7-5-2019 ◽

2019 ◽

Vol XLII-3/W7 ◽

pp. 5-9

Author(s):

K. Cho ◽

K. Miyao ◽

K. Naoki

Keyword(s):

Sea Ice ◽

Brightness Temperature ◽

Bering Sea ◽

Microwave Radiometer ◽

Ice Thickness ◽

Horizontal Polarization ◽

Brightness Temperatures ◽

Extraction Algorithm ◽

Scatter Plots ◽

The Bering Sea

<p><strong>Abstract.</strong> Sea ice has an important role of reflecting the solar radiation back into space. In addition, the heat flux of ice in thin ice areas is strongly affected by the ice thickness difference. Therefore, ice thickness is one of the most important parameters of sea ice. In our previous study, the authors have developed a thin ice area extraction algorithm using passive microwave radiometer AMSR2 for the Sea of Okhotsk. The basic idea of the algorithm is to use the brightness temperature scatter plots of AMSR2 19&thinsp;GHz polarization on difference (V-H) vs 19&thinsp;GHz&thinsp;V polarization. The algorithm was also applicable to the Bering Sea, and could extract most of the thin n ice areas. However, two problems have become clear. One was that some of the thin ice areas were not well extracted, and the other was that some of the consolidated ice were mis-extracted as thin ice areas. In this study, the authors have improved the thin ice area extraction algorithm to solve these problems. By adjusting the parameters of the algorithm applied to the brightness temperature scatter plots of AMSR2 19&thinsp;GHz polarization difference (V-H) vs 19&thinsp;GHz&thinsp;V polarization, most of the thin ice areas were also well extracted in the Bering Sea. The authors also introduced an equation using the brightness temperatures difference of 89GHz vertical and horizontal polarization to reject the thin ice area misextracted over consolidated ice. By applying the above two methods to AMSR2 data, most of the thin ice areas in the Bering Sea were well extracted. The algorithm was also applied to the Gulf of St. Lawrence with good result. The thin ice area extracted data are planed to be approved by JAXA as a AMSR2 research product.</p>

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INFLUENCE OF REGULARITY OF SATELLITE MICROWAVE RADIOMETER MEASUREMENTS ON THE ACCURACY OF BRIGHTNESS TEMPERATURE REPRODUCTION IN AREAS OF THE TROPICAL CYCLONES

Meteorologiya i Gidrologiya ◽

10.52002/0130-2906-2021-4-78-85 ◽

2021 ◽

pp. 78-85

Author(s):

А. G. Grankov ◽

◽

А. А. Milshin ◽

Keyword(s):

Brightness Temperature ◽

Tropical Cyclones ◽

Microwave Radiometer ◽

Measurement Data ◽

Hurricane Wilma ◽

Brightness Temperatures ◽

Atmosphere System ◽

Ocean Atmosphere ◽

The Caribbean ◽

Satellite Microwave

An accuracy of reproduction of daily variations in the ocean–atmosphere system brightness temperature in the areas of development and movement of tropical hurricanes in the Caribbean Sea and Gulf of Mexico is analyzed. The analysis is based on the data of single and group satellite microwave radiometer measurements. The results are obtained using archival measurement data of SSM/I radiometers from the F11, F13, F14, and F15 DMSP satellites during the period of existence of tropical hurricanes Bret and Wilma. An example is given to demonstrate the use of daily brightness temperatures obtained from DMSP satellites for monitoring the development and propagation of hurricane Wilma.

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Microwave Brightness Temperature Pattern Over the Indian Subcontinent and the Surrounding Oceans as Observed by the Satellite Microwave Radiometer (SAMIR) Onboard Bhaskara

10.1109/euma.1980.332877 ◽

1980 ◽

Cited By ~ 3

Author(s):

Opn Calla ◽

G Raju ◽

Ss Rana ◽

S Balasubramanian

Keyword(s):

Brightness Temperature ◽

Indian Subcontinent ◽

Microwave Radiometer ◽

Temperature Pattern ◽

Microwave Brightness Temperature ◽

Satellite Microwave

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Rain Retrieval from TMI Brightness Temperature Measurements Using a TRMM PR–Based Database

Journal of Applied Meteorology and Climatology ◽

10.1175/jam2346.1 ◽

2006 ◽

Vol 45 (3) ◽

pp. 455-466 ◽

Cited By ~ 61

Author(s):

Nicolas Viltard ◽

Corinne Burlaud ◽

Christian D. Kummerow

Keyword(s):

Brightness Temperature ◽

Rain Rate ◽

Tropical Rainfall Measuring Mission ◽

High Standard ◽

Brightness Temperatures ◽

Trmm Pr ◽

Microwave Imager ◽

Point To Point ◽

Trmm Microwave Imager ◽

Test Database

Abstract This study focuses on improving the retrieval of rain from measured microwave brightness temperatures and the capability of the retrieved field to represent the mesoscale structure of a small intense hurricane. For this study, a database is constructed from collocated Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and the TRMM Microwave Imager (TMI) data resulting in about 50 000 brightness temperature vectors associated with their corresponding rain-rate profiles. The database is then divided in two: a retrieval database of about 35 000 rain profiles and a test database of about 25 000 rain profiles. Although in principle this approach is used to build a database over both land and ocean, the results presented here are only given for ocean surfaces, for which the conditions for the retrieval are optimal. An algorithm is built using the retrieval database. This algorithm is then used on the test database, and results show that the error can be constrained to reasonable levels for most of the observed rain ranges. The relative error is nonetheless sensitive to the rain rate, with maximum errors at the low and high ends of the rain intensities (+60% and −30%, respectively) and a minimum error between 1 and 7 mm h−1. The retrieval method is optimized to exhibit a low total bias for climatological purposes and thus shows a high standard deviation on point-to-point comparisons. The algorithm is applied to the case of Hurricane Bret (1999). The retrieved rain field is analyzed in terms of structure and intensity and is then compared with the TRMM PR original rain field. The results show that the mesoscale structures are indeed well reproduced even if the retrieved rain misses the highest peaks of precipitation. Nevertheless, the mesoscale asymmetries are well reproduced and the maximum rain is found in the correct quadrant. Once again, the total bias is low, which allows for future calculation of the heat sources/sinks associated with precipitation production and evaporation.

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Modeling time series of microwave brightness temperature at Dome C, Antarctica, using vertically resolved snow temperature and microstructure measurements

Journal of Glaciology ◽

10.3189/002214311795306736 ◽

2011 ◽

Vol 57 (201) ◽

pp. 171-182 ◽

Cited By ~ 46

Author(s):

Ludovic Brucker ◽

Ghislain Picard ◽

Laurent Arnaud ◽

Jean-Marc Barnola ◽

Martin Schneebeli ◽

...

Keyword(s):

Time Series ◽

Grain Size ◽

Brightness Temperature ◽

Near Infrared ◽

Microwave Emission ◽

Dense Medium ◽

Emission Model ◽

Microwave Brightness Temperature ◽

Brightness Temperatures ◽

Size Profile

AbstractTime series of observed microwave brightness temperatures at Dome C, East Antarctic plateau, were modeled over 27 months with a multilayer microwave emission model based on dense-medium radiative transfer theory. The modeled time series of brightness temperature at 18.7 and 36.5 GHz were compared with Advanced Microwave Scanning Radiometer–EOS observations. The model uses in situ high-resolution vertical profiles of temperature, snow density and grain size. The snow grain-size profile was derived from near-infrared (NIR) reflectance photography of a snow pit wall in the range 850–1100 nm. To establish the snow grain-size profile, from the NIR reflectance and the specific surface area of snow, two empirical relationships and a theoretical relationship were considered. In all cases, the modeled brightness temperatures were overestimated, and the grain-size profile had to be scaled to increase the scattering by snow grains. Using a scaling factor and a constant snow grain size below 3 m depth (i.e. below the image-derived snow pit grain-size profile), brightness temperatures were explained with a root-mean-square error close to 1 K. Most of this error is due to an overestimation of the predicted brightness temperature in summer at 36.5 GHz.

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Temperature variability at Siple Dome, West Antarctica, derived from ECMWF re-analyses, SSM/I and SMMR brightness temperatures and AWS records

Annals of Glaciology ◽

10.3189/172756402781817699 ◽

2002 ◽

Vol 34 ◽

pp. 106-112 ◽

Cited By ~ 10

Author(s):

Sarah B. Das ◽

Richard B. Alley ◽

David B. Reusch ◽

Christopher A. Shuman

Keyword(s):

Southern Oscillation ◽

Microwave Radiometer ◽

Temperature Variability ◽

West Antarctica ◽

Weather Forecasts ◽

Brightness Temperatures ◽

Siple Dome ◽

Temperature Records ◽

Microwave Imager ◽

Temperature Time

AbstractWe produced four independent temperature time series derived from different sensors for the Siple Dome region of West Antarctica to investigate seasonal to interannual temperature variability over the last 20 years. We use data from automatic weather station air-temperature records (1997–99), European Centre for Medium-range Weather Forecasts surface temperature from the 15 year re-analyses (ERA-15, 1979–93), and emissivity-corrected brightness temperatures from the Special Sensor Microwave/Imager (1987–99) and the Scanning Multichannel Microwave Radiometer (1978–87). Each technique has limitations and errors, but all respond to temperature, and all agree in the large patterns of temperature variability over time. Our results show that there is high seasonal to interannual variability in both mean temperature and variance in the Siple Dome region during the study period. In particular, fluctuations in seasonal to interannual temperature variance occur on an approximately 5 year cycle and correlate with variations in the Southern Oscillation Index.

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