Search Results
Surface Emissivity at Microwaves to Millimeter Waves over Polar Regions: Parameterization and Evaluation with Aircraft Experimentsemissivities have also been calculated directly from satellite observations, removing the atmospheric contribution (gas and clouds) and the modulation by the land surface temperature. This technique has been applied to conical imagers such as the SSM/I, the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), and the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) (e.g., Prigent et al. 1997 , 2005 , 2006 ; Moncet et al. 2011 ) but also to cross-track sounders
emissivities have also been calculated directly from satellite observations, removing the atmospheric contribution (gas and clouds) and the modulation by the land surface temperature. This technique has been applied to conical imagers such as the SSM/I, the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), and the Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) (e.g., Prigent et al. 1997 , 2005 , 2006 ; Moncet et al. 2011 ) but also to cross-track sounders
. 2006 ; John et al. 2011 ; Yue et al. 2013 ). Some analyses yield to include low cloud scenes for the free-tropospheric humidity estimation; these clouds having a negligible impact on the 6.3- μ m radiances, which helps to increase the sampling ( Brogniez et al. 2006 ). Microwave (MW) observations around 183.31 GHz, on the other hand, are only affected by optically thick or precipitating clouds and thus allow for extension of studies of the water vapor distribution to a wider range of atmospheric
. 2006 ; John et al. 2011 ; Yue et al. 2013 ). Some analyses yield to include low cloud scenes for the free-tropospheric humidity estimation; these clouds having a negligible impact on the 6.3- μ m radiances, which helps to increase the sampling ( Brogniez et al. 2006 ). Microwave (MW) observations around 183.31 GHz, on the other hand, are only affected by optically thick or precipitating clouds and thus allow for extension of studies of the water vapor distribution to a wider range of atmospheric
the development of more advanced rain retrieval algorithms, despite obvious limitations associated with the low sampling frequency of orbiting platforms carrying PM sensors. The recent availability of detailed precipitation observations jointly obtained by the first spaceborne precipitation radar (PR) and a multifrequency passive microwave radiometer, the TRMM microwave imager (TMI), on National Aeronautics and Space Administration (NASA)–National Space Development Agency of Japan Tropical
the development of more advanced rain retrieval algorithms, despite obvious limitations associated with the low sampling frequency of orbiting platforms carrying PM sensors. The recent availability of detailed precipitation observations jointly obtained by the first spaceborne precipitation radar (PR) and a multifrequency passive microwave radiometer, the TRMM microwave imager (TMI), on National Aeronautics and Space Administration (NASA)–National Space Development Agency of Japan Tropical
; Levizzani and Cattani 2019 ). Levizzani and Cattani (2019) and Levizzani et al. (2011) highlight issues impeding accurate remote sensing of snowfall, but suggest there is a framework for future improvements. Spaceborne passive microwave (PMW) instruments are attractive from a global snow perspective because they interact directly with the snow crystals—whether in the air or on the ground, have the ability to make observations through clouds both day and night, and have relatively frequent revisit
; Levizzani and Cattani 2019 ). Levizzani and Cattani (2019) and Levizzani et al. (2011) highlight issues impeding accurate remote sensing of snowfall, but suggest there is a framework for future improvements. Spaceborne passive microwave (PMW) instruments are attractive from a global snow perspective because they interact directly with the snow crystals—whether in the air or on the ground, have the ability to make observations through clouds both day and night, and have relatively frequent revisit
ice concentration are missed when a 15% “cutoff” is applied ( Ozsoy-Cicek et al. 2009 ). In addition, passive microwave satellite data for a sea ice edge show poor agreement during the melting (summer) season, although passive microwave satellite data for a sea ice edge agree well with the ship observations for the ice growth (winter) season ( Worby and Comiso 2004 ). However, the trend of the averaged roughness and refractive index may not change because of the missing data because the missing
ice concentration are missed when a 15% “cutoff” is applied ( Ozsoy-Cicek et al. 2009 ). In addition, passive microwave satellite data for a sea ice edge show poor agreement during the melting (summer) season, although passive microwave satellite data for a sea ice edge agree well with the ship observations for the ice growth (winter) season ( Worby and Comiso 2004 ). However, the trend of the averaged roughness and refractive index may not change because of the missing data because the missing
JUNE1990 ADLER, MACK, PRASAD, YEH AND HAKKARINEN 377Aircraft Microwave Observations and Simulations of DeepConvection from 18 to 183 GHz. Part I: ObservationsROBERT F. ADLER,* ROBERT A. MACK,+ N. PRASAD,+ H.-Y. M. YEH@ AND IDA M. HAKKARINEN+ * Laboratory for Atmospheres, NASA/Goddard Space Flight Center, Greenbelt, Maryland *General Sciences Corporation, Laurel, Maryland ~Caelum Research
JUNE1990 ADLER, MACK, PRASAD, YEH AND HAKKARINEN 377Aircraft Microwave Observations and Simulations of DeepConvection from 18 to 183 GHz. Part I: ObservationsROBERT F. ADLER,* ROBERT A. MACK,+ N. PRASAD,+ H.-Y. M. YEH@ AND IDA M. HAKKARINEN+ * Laboratory for Atmospheres, NASA/Goddard Space Flight Center, Greenbelt, Maryland *General Sciences Corporation, Laurel, Maryland ~Caelum Research
1. Introduction In the last three decades, microwave radiance observations from polar-orbiting satellites have been exploited widely for operational numerical weather prediction (NWP) and for climate studies assessing long-term trends in atmospheric temperatures. Observations from discrete channels in the 50–58-GHz range of the microwave spectrum have been particularly valuable in providing altitude-resolved information on atmospheric temperature, albeit at relatively coarse vertical resolution
1. Introduction In the last three decades, microwave radiance observations from polar-orbiting satellites have been exploited widely for operational numerical weather prediction (NWP) and for climate studies assessing long-term trends in atmospheric temperatures. Observations from discrete channels in the 50–58-GHz range of the microwave spectrum have been particularly valuable in providing altitude-resolved information on atmospheric temperature, albeit at relatively coarse vertical resolution
the higher-altitude ice microphysical details ( Evans and Stephens 1995 ). This paper will describe how coincident wideband (10–220 GHz) passive microwave T B observations from radiometers on both the DC-8 aircraft (∼11-km altitude) and the ER-2 aircraft (∼20-km altitude) obtained during the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) were utilized to investigate the underlying microphysical cloud profiles. A nadir-viewed, dual
the higher-altitude ice microphysical details ( Evans and Stephens 1995 ). This paper will describe how coincident wideband (10–220 GHz) passive microwave T B observations from radiometers on both the DC-8 aircraft (∼11-km altitude) and the ER-2 aircraft (∼20-km altitude) obtained during the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE) were utilized to investigate the underlying microphysical cloud profiles. A nadir-viewed, dual
Rainfall Estimation Accuracy of a Nationwide Instantaneously Sampling Commercial Microwave Link Network: Error Dependency on Known Characteristics1. Introduction Rain gauge networks and weather radar are well-known and prevalent rainfall monitoring technologies. However, rainfall observations are sparse or lacking in large areas of the world. Sensors are costly to install and maintain. Especially developing countries and urban areas are likely to benefit from denser rainfall measurements than currently available ( Schilling 1991 ; Berne et al. 2004 ; Kidd et al. 2017 ). Microwave links consist of a transmitting and a receiving antenna
1. Introduction Rain gauge networks and weather radar are well-known and prevalent rainfall monitoring technologies. However, rainfall observations are sparse or lacking in large areas of the world. Sensors are costly to install and maintain. Especially developing countries and urban areas are likely to benefit from denser rainfall measurements than currently available ( Schilling 1991 ; Berne et al. 2004 ; Kidd et al. 2017 ). Microwave links consist of a transmitting and a receiving antenna
from the Special Sensor Microwave Imager (SSM/I) and the Advanced Microwave Sounding Unit (AMSU-B). Over land, radiosondes, ground-based stations, and AMSU-B observations dominate. In the upper troposphere, also infrared sounding channels from the High-Resolution Infrared Radiation Sounder (HIRS), the Atmospheric Infrared Sounder (AIRS), and radiometers on board geostationary satellites provide significant information on humidity to the atmospheric analysis. When rainfall observations from the
from the Special Sensor Microwave Imager (SSM/I) and the Advanced Microwave Sounding Unit (AMSU-B). Over land, radiosondes, ground-based stations, and AMSU-B observations dominate. In the upper troposphere, also infrared sounding channels from the High-Resolution Infrared Radiation Sounder (HIRS), the Atmospheric Infrared Sounder (AIRS), and radiometers on board geostationary satellites provide significant information on humidity to the atmospheric analysis. When rainfall observations from the
