Questions on Validating Atmospheric Profiles

Tony, John,

In the latest TT5 report, NPROVS (NOAA Products Validation System) as well as SASBE (Site Atmospheric State Best Estimate) are mentioned as elements of TT5 activities. I have three questions  (I am yet to get fully familiar with discussions on ancillary measurements and the topic ‘GRUAN for satellite product validation’, so forgive me my ignorance):

  1. Am I correct in assuming that NPROVS is a tool which allows simultaneous analysis of profiles derived from different measurement techniques, and you have recently incorporated GRUAN data into that environment?
  2. What, if any, relationship exists between NPROVS and SASBE? I understand from Tobin et al. (JGR, 2006) the methodology of validating AIRS profiles using profiles obtained at ARM sites, where the term ‘site atmospheric state best estimate’ has been coined.
  3. How do the existing validation methods for AIRS profiles compare with the work published recently by Calbet et al. (AMT, 2011) on intercomparing IASI with radiosonde soundings at Sodankylä (Finland)?


One Response to Questions on Validating Atmospheric Profiles

  1. Tony reale says:

    Hi Stephan

    1) NOAA PROducts validation System (NPROVS) provides near real-time validation of satellite derived prodcut systems (currently about 10 different systems) against conventional radiosondes. You can go to web site: … download applets (PDISP) and collocation datasets (weekly), and see what you can do. Long-term collocation datasets are also availble for user access. We have recently set up an inetrface to begin comparing special GRUAN sondes from sites (via NCDC) that are also WMO conventional sites. GRUAN sondes also include uncertainties and at this time we are working to include them in NPROVS display and analysis tool, tbd.

    2) At this time no relationship. SASBE is “coined” from Dave Tobin (2006) and AIRS validation exercises at ARM sites. Ultimately we (NPROVS via TT5) would like to determine (feasibility of) a SASBE at GRUAN sites at times of NPP overpass. As you know, former validations for AIRS included dual sonde launches, ancillary ground measures, GOES etc. Not likely to get dual launches, so question is whether remaining ancillary and planned launches provide a suitable encvironment at resepctive GRUANs, tbd. Also, we hope to exapnd NPROVS interface / analysis tool in conjunction with planned NPP CrIMSS sounding product intensive validations at ARM sites that would incorporate uncertainty estimates for sat sounding, sondes, ancillary measures, SASBE etc… again tdb.

    3) I have not read in detail but one main difference is that Calbet et al compare calculated, interpolated spectra from “SASBE” to observed IASI spectra at overpass time and location; NPROVS would compare SASBE (or given sonde) to IASI soundings (plus uncertainties0. NPROVS does include several NWP and climate re-analysis forecast (but not ECMWF), utlizes drift time /location of sondes etc. It appears that methods for assigning SASBE at sat overpass time are similar to Tobin 2006 ….

    Hopefully this helps I will check back later


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