1 / 29

Gianluca Volpe 1 , Rosalia Santoleri 1 , Salvatore Marullo 2 , Simone Colella 1

The colour of the Mediterranean Sea: global versus regional bio-optical algorithm evaluation and development of regional chlorophyll dataset in the framework of MERSEA. Gianluca Volpe 1 , Rosalia Santoleri 1 , Salvatore Marullo 2 , Simone Colella 1.

lelia
Download Presentation

Gianluca Volpe 1 , Rosalia Santoleri 1 , Salvatore Marullo 2 , Simone Colella 1

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The colour of the Mediterranean Sea: global versus regional bio-optical algorithm evaluation and development of regional chlorophyll dataset in the framework of MERSEA Gianluca Volpe1, Rosalia Santoleri1, Salvatore Marullo2,Simone Colella1 1 Istituto di Scienze dell’Atmosfera e del Clima – sezione di Roma 2 Ente per le Nuove tecnologie l’Energia e l’Ambiente – Centro Ricerche Frascati r.santoleri@isac.cnr.it; http://gos.ifa.rm.cnr.it;

  2. The aims are: • to identify and develop of an optimal algorithm for the Mediterranean sea to produce high quality ocean colour datasets for the region. • to provide an accurate and consistent stream of ocean colour data at a resolution and format compatible with operational forecasting of the Mediterranean Marine Environment. • To setup the Mediterranean Forecasting System (MFS) core products: satellite and model structure A new regional algorithm for Chlorophyll retrieval NRT MODIS and the SeaWiFS reanalysis from 1997 to 2005 Impact of OC regional product in models

  3. Mediterranean Ocean Color CAL/VAL DATA SETS 28 Mediterranean cruises: from 1997 up to now were organized by ISAC in the framework of Italian National Projects + 2 permanent stations Bio-optical measurements: 155 chl/opt measurements to define the Mediterranean regional algorithm (red points) Optical measurements: 938 SIMBADA for Rrs validation (blue points) In situ chlorophyll-a data: 1144 chlorophyll profiles for satellite data validation

  4. CAL/VAL cruise in the Eastern Mediterranean CNR-JRC joint cruise in Sep 2006

  5. THE NEW MEDITERRANEAN ALGORITHM (Volpe et al. RSE, 2006 in press) MEDOC4 : R is log10 of either the 443/560 or the 490/555 or the 510/555 band reflectance ratios. The switch from one band ratio to another one is based on the chlorophyll concentration itself (the Maximum is Chosen)

  6. MED_OC4 In situ Satellite

  7. Validation of MBR A SIMBADA-SeaWiFS RRS matchup dataset was build to test the accuracy of the satellite band ratios over the Mediterranean Sea.

  8. SeaBAM N=1174 Mediterranean N=156 Optical characteristics:Mediterranean vs Global • Low Chlorophyll: Med Band Ration < Global Band Ratio • Max Ratio choice similar for Med and Global • Is the Med Sea Greener or less Blue then the Global Ocean?

  9. Is the Med Sea Greener or less Blue then the Global Ocean? -blue (30%); +Green (15%) -blue (35%); +Green (18%) -blue (32%); Green similar Med and Global tend to converge +blue (23%); - Green (35%)

  10. MODIS & MERIS Algorithm Validation

  11. MODIS vs SeaWiFS regional global

  12. MERIS vs SeaWiFS regional global

  13. MBR validation against in situ measurements: Examined period: 2003-2004

  14. The SeaWiFS reanalysis from 1997 to 2005: reprocessing of the entire Mediterranean Sea L1A archive using MedOC4 Algorithm Available at the MERSEA web site

  15. WN:Node01.. ….Node16 SeaWiFS Re-PROCESSING ON ESA-CNR GRID infrastructure 1) Globus-job-submit UI CE 2) Globus-job-status Gridtest03.esrin.esa.int Grid0007.esrin.esa.int 3) Globus-job-get-output Globus-url-copy Globus-url-copy SE UI=User Interface SE=Storage element CE=Computer Element WN=Worker node Se0.artov.rm.cnr.it N° SeaWiFS pass= 6127 Total processing time ~ 4 days

  16. The GRID products output Previous algorithm NEW algorithm Difference OLD-NEW 2 July 2004 0.01 5 0.01 5 0 -0.1 0.2 OC4.V4 Med OC4 (OC4.V4) – (Med OC4)

  17. 1999 yearly average OC4.V4 Med OC4 (OC4.V4) – (Med OC4)

  18. Impact on Primary Productivity Global Model + Chl(OC4) Global Model + Chl(BRIC02) Global Model + Chl(MedOC4) The use of MedOC4 chlorophyll in PP Models reduces the annual PP estimate by about 40% and 10% respect to corresponding estimate made using OC4 and BRIC02

  19. Ctot Csat Ze Ctot Other MED Optical characteristic Antoine and Morel, 1996 (yellow) Morel and Berthon, 1989 (red) Uitz et al., 2006 (green) Colella 2006 (blue) Morel and Berthon, 1989 (red) Morel and Maritorena, 2001 (green) Colella 2006 (blue)

  20. Impact on Primary Productivity: global vs regional PP model (a) Global Model + Chl(OC4) (b) Global Model + Chl(BRIC02) (c) Global Model + Chl(MedOC4) (d) Regional Model + Chl(BRIC02) (e) Regional Model + Chl(MedOC4) MAX PP in SPRING

  21. Mediterranean biogeochemical coupled model for future Short term Forecasting: Model sensitivity to a longitudinal variable extinction coefficient Monthly chlorophyll climatology maps derived from SeaWiFS data, processed by GOS-ISAC-CNR, for the year 1997-2004. Monthly chlorophyll concentration maps obtained from OGS/OPA transport model after 10y spin-up. Crise et al, 2006

  22. Chl Anomaly Map [Chl(data)-Chl(model)]/Chl(data)) • relative error lower in late-Autumn Winter • error bias constant throughout the basin (positive anomaly in the W.Med in Spring) • Overall overestimation of surface • Chlorophyll • underestimates spring bloom • in NW • Relative error is below 0.8 Basin averaged relative anomaly

  23. Concluding remarks • The analysis demonstrate that OC overestimation chlorophyll in the Med is due to its peculiar optical characteristics. • the use of regional algorithm is mandatory to produce high quality OC products for ecosystem model assessment and assimilation • The MFS requirement for the GlobColour Project is to give access to the L2/L3 products (single sensors collocated Rrs data) from which we can produced specific regional L4 products taking into account the model community needs. • Regional OC products should be produced in the TAC

  24. The Mediterranean L4 products using L2P Medspiration data MF AVHRR acquisition Atlantic buffer zone + west Med ISAC AVHRR acquisition Entire Mediterranean Night-time SST using MF algorithm Cloud detection Night-time SST using Pathfinder algorithm Cloud detection SST daily composite binning on model grid (1/16x1/16) SST daily composite binning on model grid (1/16x1/16) Data merging ISAC L2P Medspiration Products Data quality controll Optimal Interpolation Data delivery on the GOS-ISAC web-site

  25. Conclusions To save the Mediterranean Sea from environmental problem look at the combination of satellites and ocean forecast!!

More Related