======  Surface Property Models  ======

 by [[../../../author/leannea|Leanne Avila]]   —  last modified  Oct 21, 2014 07:10 AM 

 

===== The surface property models task group =====

At the Beijing 2005 ITSC the RTSP working group endorsed the formation of a task group to co-ordinate surface radiative property modelling activities, proposed by Ben Ruston. It was agreed that, while the task group will address surface property modelling for all surface types, in the first instance the task group would focus on land surface emissivity atlas and model developments in the first instance.

Catherine Prigent (Meteo France) and Fuzhong Weng (NOAA/NESDIS) are the co-chairs of the surface property models task group.

The task group has completed a [[http://cimss.ssec.wisc.edu/itwg/groups/rtwg/surface_property/survey|survey of operational weather centres]] on the use of surface-sensitive ATOVS radiances, and is organising the [[http://cimss.ssec.wisc.edu/itwg/groups/rtwg/meetings/sfcem/|First Workshop on Remote Sensing and Modeling of Surface Properties]], to be held in Paris in June 2006.

===== Summary of operational surface emissivity models =====

These tables are an incomplete summary of current surface emissivity models. Please feel free to provide updated or additional information to the RTSP-WG co-chairs.
==== Infrared ====

|Emissivity model                              |Surface type|RT model|More info                                                                                                             |
|Sea Surface Infrared Emissivity Model (SSIREM)|sea         |RTTOV   |[[http://www.metoffice.com/research/interproj/nwpsaf/rtm/rtm_reports|Eumetsat NWP SAF Technical Report]]         |
|InfraRed Sea Surface Emissivity (IRSSE)       |sea         |CRTM    |[[http://www.ssec.wisc.edu/%7Epaulv/Fortran90/Emissivity/Sensor_Emissivity_Model/|Paul van Delst's web documentation]]|

==== Microwave ====

|Emissivity model              |Surface type       |RT model|More info                                                                                                    |
|FASTEM                        |sea                |RTTOV   |[[http://www.metoffice.com/research/interproj/nwpsaf/rtm/rtm_reports|Eumetsat NWP SAF Technical Report]]|
|Microwave Emission Model (MEM)|sea, land (various)|CRTM ?  |updated link needed                                                                                          |

===== Surface emissivity atlases =====

  * the [[http://snowdog.larc.nasa.gov/surf/|CERES surface property website]] provides maps of soil type, surface albedo, broadband IR emissivity, water fraction and surface elevation.
  * the University of Wisconsin have recently generated a [[http://cimss.ssec.wisc.edu/iremis/|global infrared land surface emissivity database]]
  * the MetOffice hosts the [[http://www.metoffice.gov.uk/research/interproj/nwpsaf/rtm/emissivity/index.htm|NWP-SAF Emissivity webpage]] that collects together emissivity information for use in radiative transfer modeling

===== Miscelleaneous Surface emissivity information =====

  * The temperature dependence of sea surface emissivity is discussed by [[http://onlinelibrary.wiley.com/doi/10.1256/qj.04.150/abstract|Newman et al. (2005)]]. For skin temperature T, the refractive index (real part n, imaginary part k)  of water is given by: n =no+cn * (T-273.15) , k=ko+ck * (T-273.15). The parameters no, cn, ko, and ck are available on request from [[mailto:james.hocking@metoffice.gov.uk|James Hocking]].\\

  * [[http://www.ngdc.noaa.gov/ecosys/cdroms/reynolds/reynolds/reynolds.htm|Soil type database]] for emissivity modeling
  * AIRS Science Team Meeting (07 March, 2006) presentations on emissivity retrieval and validations
    * [[http://airs.jpl.nasa.gov/Science/ResearcherResources/MeetingArchives/TeamMeeting20060307/2006_03_07/barnet_emis.pdf|Barnet, Chris - Emissivity Focus Group Report]]
    * [[http://airs.jpl.nasa.gov/Science/ResearcherResources/MeetingArchives/TeamMeeting20060307/2006_03_07/Fishbein_AfricaEmissivity.pdf|Fishbein, Evan - Retrieved Surface Emissivity Impact of New Cloud-Clearing Channel Set]]
    * [[http://airs.jpl.nasa.gov/Science/ResearcherResources/MeetingArchives/TeamMeeting20060307/2006_03_07/knuteson_AIRS_STM_Mar2006.pdf|Knuteson, Bob - AIRS Land Surface Temperature and Emissivity Validation]]

===== Publications =====

  * Yan,B., F.Weng, H.Meng, and N.Grody, Retrieval of Snow Surface Microwave Emissivity from Advanced Microwave Sounding Unit (AMSU), submitted to //J.Geophys.Res// (2008).