• New SOLab AMSRE product

    One of the tasks of the laboratory is processing data received from japan passive microwave radiometer Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) onboard Aqua satellite, and the placement of the finished product for free.

    Dataset contains six geophysical parameters, retrieved from Japan passive microwave radiometer Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) onboard Aqua satellite. Time span covers 6 June 2002 - 4 October 2011. Spatial coverage is global, gridding is not done: data are in swath resolution and organized by ascending and descending paths of original AMSR-E georeferencing (totally about 14 ascending and 14 descending paths). Swath pixel sampling is about 10 km, though the actual spatial resolution is lower and depends on the channels used in the retrievals. The six geophysical parameters are retrieved only over open ocean areas, not covered by ice. They are the following: total atmospheric water vapor content, total cloud liquid water content, sea surface wind speed, based on using high frequency channels, sea surface wind speed, based on using low frequency channels, sea surface temperature and total atmospheric absorption at 10.65 GHz.

    The parameter valid ranges are:

    1. total atmospheric water vapor content: 0 – 70 kg/m2;
    2. total cloud liquid water content: 0 – 0.7 kg/m2;
    3. sea surface wind speeds (both products): 0 - 30 m/s, though this range cuts thehurricane areas where low frequency algorithm gives reasonable wind speeds higherthan 30 m/s;
    4. sea surface temperature: -1.8 – 32°C;
    5. total atmospheric absorption at 10.65 GHz: 0 – 0.08;

     

    References

    1. Mitnik L.M., M.L. Mitnik and E.V. Zabolotskikh. Microwave sensing of the atmosphere-oceansystem with ADEOS-II AMSR and Aqua AMSR-E. J. Rem. Sens. Soc. Japan, 2009, Vol. 29, N1, pp. 156-166
    2. Bobylev L. P.,E. V. Zabolotskikh, L. M. Mitnik, and M. L. Mitnik, Atmospheric water vapor andcloud liquid Water Retrieval over the Arctic Ocean Using Satellite PassiveMicrowave Sensing, IEEE Trans. Geosci. Remote Sensing, vol. 48, no. 1, pp. 283- 294, doi: 0.1109/TGRS.2009.2028018, 2010.
    3. Zabolotskikh,E.; Chapron, B.; Bobylev, L. New Satellite Passive Microwave Retrieval Algorithms and Their Application to Study Atmospheric Phenomena and Oceanic ParametersDOI: 10.1109/RSETE.2012.6260637, Proc. of 2nd International Conference on Remote Sensing, Environment and Transportation Engineering (RSETE), 1-3 June 2012, Nanjing, China, pp.1 - 4

     

    Comment

    Land mask is taken from the original AMSR-E data (different for different channels), optically thick atmospheres are masked basing on usage of the total atmospheric absorption at 10.65 GHz (current threshold value is 0.04). Ice masking is applied when the brightness temperature at 6.95 GHz, horizontal polarization, is greater than 130 K.

    Care should be taken when using the product near the coast line: it may contain wrong values since the original AMSR-E land masking is not perfect. Sea surface temperature is considered to be not reliable when the sea surface wind speed, retrieved with lower frequency algorithm, is greater than 12 m/s.