1. About the status and outlook for OMI Surface UV product OMI Science Team Meeting Helsinki, June 24-27, 2008 Antti Arola

2. Aapo left FMI about three months ago. Since then, I have been responsible for the scientific development of OMUVB, while Simo Tukiainen has been responsible for the processing related issues.

3. Puijo tower measurements Finnish meteorological institute and Univ. of Kuopio

4. Current setup of measurements Ion spectrometerAIS Gas concentrations (NO-NO x, O 3, SO 2, CO)‏GAS         Total particle number concentrationCPC Aerosol absorptionMAAP Aerosol particle size distribution (0.25-32  m)‏ ADM Visibility, precipitationPWD Weather parameters (T, RH, p, wind 2D)‏WXT Aerosol scatteringNM Cloud condensation nucleus (CCN) concentrationCCNC Cloud drop size distribution (2-50  m)‏ CDP Aerosol particle size distribution (7-900 nm) * simultaneously in and out of cloud” DMPS DMPS = differential mobility particle sizer; ADM = ambient dust monitor; CPC = condensation particle counter; CDP = cloud droplet probe; CCNC = cloud condensation nuclei counter; NM = nephelometer; MAAP = multi-angle absorption photometer; WXT = weather transmitter; PWD = present weather detector; AIS = Air Ion Spectrometer  

5. AERONET station AERONET sites in Finland Hyytiälä Kuopio Pallas Helsinki_Lighthouse Sodankylä‏ Soon FMI campaign site in India, near Delhi Provide a long term data set to: Characterize aerosol optical properties Validate Satellite & model aerosol retrievals Synergism with Satellite obs., models sfc net

6. Satellite observations from A-train Aqua CALIPSO CloudSat PARASOL Aura

7. OMI Surface UV Algorithm and Surface UV Products Inherits from the TOMS UV algorithm based on look-up-tables made with various radiative transfer models. Calculate clear-sky surface UV irradiance Define cloud optical depth  that gives the measured TOA radiance Make cloud correction using the obtained  Absorbing aerosol correction to be added in the future Products: Erythemal dose rate both at overpass and at local solar noon (UV Index)‏ Erythemal daily dose Irradiances at 305, 310, 324 and 380 nm both at overpass and at local solar noon The OMI surface UV algorithm is implemented in two separate processing systems: OMI-VFD and Global OMUVB.

8. OMI Very-Fast-Delivery has been operational since March 2006 OMI data is received by Direct Broadcast in Sodankylä and is processed immediately after each overpass of the Aura satellite. Distribution plots for total column ozone, UV Index and Erythemal daily dose are published within 30 minutes after the overpass at http://omivfd.fmi.fi/index_eng.html

9. Global OMUVB product

10. Processing Status and Data Release OMUVB Level 2 V003 reprocessing is on-going. Years 2007 and 2008 are ready, earlier data is in progress. Level 2 HDF5-EOS data are available at GES DISC. http://disc.gsfc.nasa.gov/Aura/OMI/omuvb_v003.shtml AVDC provides OMUVB overpass data for over 100 sites that has been used for validation. New sites can be added (michael.m.yan@nasa.gov).

11. Tanskanen, A., et al. (2007), Validation of daily erythemal doses from Ozone Monitoring Instrument with ground-based UV measurement data, J. Geophys. Res., 112, D24S44, doi:10.1029/2007JD008830. Brewers in Jokioinen and Sodankylä SUV100 network data by National Science Foundation Canadian Brewer network data from Meteorological Service of Canada Spectral UV data from Lauder and Tokyo

13. Corr. coeff. = 0.76 Slope = 2.4 Arola, A., S. Kazadzis, N. Krotkov, A. Bais, J. Grobner, and J. R. Herman (2005), Assessment of TOMS UV bias due to absorbing aerosols, J. Geophys. Res., 110, D23211, doi:10.1029/2005JD005913.

14. Relationship suggests a correction for the absorbing aerosols:

15. Kinne, S.: Aerosol Direct Radiative Forcing with an AERONET touch, Atmos. Environ., submitted, 2007.

17. Parameterization allows post-correction of the TOMS operational UV data:

19. Conclusions Analog to the TOMS total column ozone time-series the surface UV time-series are continued with the OMI measurement data applying an algorithm that is similar to the TOMS UV algorithm. There is a need to introduce a correction for absorbing aerosols. First step is to include a monthly climatology based on global aerosol models, satellite data, and sunphotometer measurements. The validation effort continues, important particularly when changes to the algorithm are applied.