1. AMFIC: Aerosol retrieval Gerrit de Leeuw, FMI/UHEL/TNO Pekka Kolmonen, FMI Anu-Maija Sundström, UHEL Larisa Sogacheva, UHEL Juha-Pekka Luntama, FMI Sini Merikallio, FMI

2. AMFIC KO, KNMI, 26 October 20072 Aerosol measurments: in situ Physical, optical and chemical properties difficult to measure (EUSAAR) In situ measurements, when well made, provide the highest possible accuracy, reproduceability, temporal resolution (EUSAAR) Sophisticated measurements provide information on processes How representative are measurements at a certain site for the surrounding area and beyond? Courtesy Mikael Ehn, UHEL

3. AMFIC KO, KNMI, 26 October 20073 Satellite: retrieval of aerosol properties Satellites provide a snapshot for a large area, with the same instrument, the same method and the same algorithm However: The satellite data is less accurate than in situ data Different instruments provide different results Different methods provide different results Different algorithms provide different results But: the good news is the good agreement between several instruments and algorithms

4. AMFIC KO, KNMI, 26 October 20074 Satellites need ground based measurements: Validation Evaluation Satellites may fill the gaps when properly used Satellite retrieval methods need further development: to reach maturity be useful for scientific and operational applications

5. AMFIC KO, KNMI, 26 October 20075 Satellite observations and ground based networks MODIS retrieved aerosol optical depth at 0.55 μm + AERONET sites (Sun Photometers) + Aerosol LIDAR networks EARLINET ADNET MPLNET IPCC, AR4, 2007

6. AMFIC KO, KNMI, 26 October 20076 Validation AERONET sun photometers Campaigns: in situ ground based / airborne

7. AMFIC KO, KNMI, 26 October 20077 Remote Sensing from satellites : Top of the Atmosphere Radiance atmosphere surface

8. AMFIC KO, KNMI, 26 October 20078 Radiative transfer T = direct transmittance (↑) upwards and (↓) downwards, t = diffuse transmittance ρ s,dir, ρ s,dif ↓, ρ s,dif ↑ and ρ s,iso = bi-directional surface reflectance terms. All terms depend on the wavelength and on the sun- satellite geometry.

9. AMFIC KO, KNMI, 26 October 20079 ATSR-2 (ERS-2): 1995 – 2002+ AATSR (ENVISAT): 2002 – 2007+ > 0.555, 0.659, 0.865, 1.6, 3.7, 11, 12 μm > 1 x 1 km 2 > 500 km swath (global in 3 days) > 0.555, 0.659, 0.865, 1.6, 3.7, 11, 12 μm > 1 x 1 km 2 > 500 km swath (global in 3 days) Aerosols/types; clouds High resolution Along Track Scanning Radiometer

10. AMFIC KO, KNMI, 26 October 200710 Along-track scanning with two viewing angles Two viewing angles allow to account for surface effects on TOA radiation Swath 500 km High resolution (1x1 km 2 ) Over water (SV) Over land (DV) Bright surfaces Near real time Two viewing angles allow to account for surface effects on TOA radiation Swath 500 km High resolution (1x1 km 2 ) Over water (SV) Over land (DV) Bright surfaces Near real time

11. AMFIC KO, KNMI, 26 October 200711 Dual View Algorithm

12. AMFIC KO, KNMI, 26 October 200712 Algorithms

13. AMFIC KO, KNMI, 26 October 200713 Satellite remote sensing of aerosol AOD over land: 1990’s ATSR-2 (Veefkind et al., 1998): First AOD retrieved over land! Polder-1 & 2 MODIS MISR

14. AMFIC KO, KNMI, 26 October 200714 ATSR-2 / AATSR: Examples Veefkind et al., 2000 Sulfate Concentration ECN, Petten, NL 0 5 10 15 25-Jul 00:0026-Jul 00:00 Date SO4 µg m -3

15. AMFIC KO, KNMI, 26 October 200715 ATSR-2 / AATSR: Examples Aerosol distribution over Europe for August 1997: See colour scale on the right: high concentrations are red low concentrations are blue Roblez-Gonzalez et al., 2000

16. AMFIC KO, KNMI, 26 October 200716 TEMIS progress: Validation vs AERONET Ispra, 12 June 2003Venice, 2003

17. AMFIC KO, KNMI, 26 October 200717 ATSR-2: INDOEX Mixture of aerosols produced over land (industrial, fossil fuel and biomass burning, dust) and over sea Minimizing error function to determine optimum mixture Provides: AOD Angstrom coefficient Mixture Over the ocean the mixture gradually changes from continental to sea salt Validation with campaign data Robles Gonzalez et al., 2006

18. AMFIC KO, KNMI, 26 October 200718

19. AMFIC KO, KNMI, 26 October 200719 ATSR-2: SAFARI August 2000 September 2000 Robles Gonzalez et al., 2007

20. AMFIC KO, KNMI, 26 October 200720 AATSR aerosol retrieval over bright surfaces: United Aerosol Experiment, United Arabic Emirates UAE 2, 7 Sep, 2004 (670 nm) Over water: R=0.78 (22 points) Over land: R=0.57 (53 points) Robin Schoemaker

21. AMFIC KO, KNMI, 26 October 200721 TEMIS Progress: NRT Data availability: ftp from Rolling Archive: automated using script RAID: data stored on 2 HD Regular update with new data Example: AOD(670), Po Valley, 2 August 2007

22. AMFIC KO, KNMI, 26 October 200722 TEMIS Progress: NRT Automated selection area of interest (Po valley) Inclusion data processing in script QC: manual (later automated?) Comparison with AERONET (Ispra, Venice) Spatial variation and statistics Data presentation on website FMI, link from TEMIS website TEMIS website – examples Data description and background info User feedback: Data presentation Data use and use-ability China

23. AMFIC KO, KNMI, 26 October 200723 TEMIS Progress Improvements: Aerosol models tuned to China conditions (a priori), using climatology, models and in situ data Cloud screening