Entity

Time filter

Source Type

East Missoula, MT, United States

Jones L.A.,University of Montana | Jones L.A.,Numerical Terradynamic Simulation Group | Ferguson C.R.,Princeton University | Kimball J.S.,University of Montana | And 7 more authors.
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2010

We present an approach to retrieve daily minimum and maximum 2-m height air temperatures from 18.7, and 23.8 GHzH and V polarized brightness temperature from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) during the snow free season. The approach accounts, with minimal ancillary data, for vertically integrated atmospheric water vapor, and variable surface emissivity due to open water and vegetation. Retrieved temperatures were evaluated using Northern Hemisphere weather stations and independent satellite-based air temperatures from the Atmosphere Infrared Sounder and Advanced Microwave Sounding Unit (AIRS/AMSU; hereafter AIRS) sensors on Aqua. The retrieved temperatures are within 1.0 3.5 K of surface weather station measurements for vegetated locations, but uncertainty can exceed 4 K for desert and sparsely vegetated regions, mainly due to site to site biases. The AIRS and AMSR-E temperature retrievals generally agree more closely with one another than with weather stations and are generally within 1.02.8 K over vegetated regions, but with less agreement ( > 4 K ) over desert and mountainous regions. Additional useful information produced by our approach includes open water fraction, vegetation optical depth and atmospheric water vapor. The results of this study provide inputs for land surface models and a new approach for monitoring of land surface air temperatures with well quantified accuracy and precision. © 2008 IEEE. Source


Du J.,University of Montana | Du J.,Numerical Terradynamic Simulation Group | Kimball J.S.,University of Montana | Kimball J.S.,Numerical Terradynamic Simulation Group | And 2 more authors.
IEEE Transactions on Geoscience and Remote Sensing | Year: 2015

An approach for deriving atmosphere total precipitable water vapor (PWV) and surface air temperature over land using satellite passive microwave radiometry from the Advanced Microwave Scanning Radiometer 2 (AMSR2) was developed in this study. The PWV algorithm is based on theoretical analysis and comparisons against similar retrievals from the Atmospheric Infrared Sounder (AIRS). The AMSR2 PWV retrievals compare favorably with AIRS operational PWV products ( R^{2}\geqslant 0.80 and rmse: 4.4-5.6 mm) and independent PWV observations from the SuomiNet North American Global Positioning System station network, with an overall mean rmse of 4.7 mm and more than 78% of absolute retrieval errors below 5 mm. The PWV retrievals were then applied within an AMSR2 multifrequency brightness temperature algorithm for deriving atmosphere-corrected surface air temperatures. The estimated temperatures agree favorably ( R^{2}>0.80 and \hbox{rmse}<3.5\ \hbox{K}) with independent weather station daily air temperature measurements spanning global climate and land cover variability. The resulting PWV estimates increase surface air temperature retrieval accuracy in our algorithm scheme. The AMSR2 algorithm is readily applied to similar microwave sensors including the AMSR for EOS and provides suitable performance and accuracy to support hydrologic, ecosystem, and climate change studies. © 1980-2012 IEEE. Source

Discover hidden collaborations