1. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD and first preliminary results of the aerosol measurements campaign. RMI December 6 th 2006. Validation of the method to retrieve the Aerosol Optical Depth from the Brewer Ozone measurements First preliminary results of the aerosol measurements campaign at Uccle

2. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Validation of the method to retrieve the Aerosol Optical Depth from the Brewer Ozone measurements Anne Cheymol, Hugo De Backer, Weine Josefsson and René Stübi anne.cheymol@oma.be Cheymol et al., jgr, 2006

3. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Overview 1. Introduction 2. The Brewer spectrophotometer instrument 3. Description of the method 4. Results  Impact of the neutral density filter on AOD and Validation of the AOD between a Brewer and a sunphotometer  Comparisons between different Brewer at the same place 5. Conclusions and perspectives

4. Role of aerosol particles Most aerosol particles’s knowledge is in VIS and IR and not in UV Important role in climate forcing  UV-B irradiance reduction by about 5-35%  Indirect effect on clouds Impact on Human health Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006.

5. Anthropogenic origin Polluted day on January 28 th 2006 Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Photo by A. Delcloo and A. Mangold smoke Clear day on November 9 th 2006

6. Natural origin Sea salt ejected from the sea in the air Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Photo by Plisson

7. Natural origin Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Clean roof Photo from the web Pollen

8. Seasonal cycle of AOD at Uccle Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006.

9. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Overview 1. Introduction 2. The Brewer spectrophotometer instrument 3. Description of the method 4. Results  Impact of the neutral density filter on AOD and Validation of the AOD between a Brewer and a sunphotometer  Comparisons between Brewer at the same place 5. Conclusions and perspectives

10. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006 Over 100 Brewer stations (blue points)

11. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006 280-363 nm 306-320 nm

12. Validation of the method to retrieve the AOD. RMI December 6 th 2006 Royal Meteorological Institute of Belgium Zenith angle = z a sunset Rotation of the instrument during the day 12H AfternoonMorning

13. Royal Meteorological Institute of Belgium Summary of the Brewer measurements 5 Direct Sun measurements/3mns every 30mns Automatic rotation during the day to follow the sun No cloud  direct sun measurement 25°  z a  70 ° for one day at Uccle Validation of the method to retrieve the AOD. RMI December 6 th 2006

14. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Aerosol Optical Depth = attenuation of solar radiation by aerosol particles Direct Sun radiation at 306, 310, 313, 316 and 320 nm

15. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Overview 1. Introduction 2. The Brewer spectrophotometer instrument 3. Description of the method 4. Results  Impact of the neutral density filter on AOD and Validation of the AOD between a Brewer and a sunphotometer  Comparisons between Brewer at the same place 5. Conclusions and perspectives

16. Attenuation of solar radiation Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006.

17. Royal Meteorological Institute of Belgium Beer’s law equation S( ) = K( ) I o ( ) exp[ D o3 ( ) + D ray ( ) + D aer (  sec(z a ) ) ] Validation of the method to retrieve the AOD. RMI December 6 th 2006 Aerosol particlesMoleculeOzone Signal received by the Brewer Brewer’s sensitivity to I o ( )

18. Royal Meteorological Institute of Belgium ln[ S( ) ]-D o3 - D ray = ln[ K( ) I o ( ) ]-  ( ) * sec(z a ) + Y = A * X + B Langley plot method Validation of the method to retrieve the AOD. RMI December 6 th 2006 Y axisX axisSlopeIntercept

19. Royal Meteorological Institute of Belgium Langley plot method 19/06/05 for 320 nm Y = ln[S( )] - D o3 - D ray A = -  ( ) *X = sec(za) +B = ln[K( )I o ( )] Validation of the method to retrieve the AOD. RMI December 6 th 2006

20. Selection of clear days for the Langley Plot Method 1.Ozone stdev for individual DS measurements < 2.5 DU  z a per day  20° 3.Number of good data per day  50 4.Distance between each point and the regression line < 4 (Y unit) 5.Daily mean absolute deviation from the regression line < 0.055 (Y units) Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006

21. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Calibration factor Average of these 65 calibration factors with error of about 0.2% 65 Calibration factors at Uccle

22. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Summary of the method

23. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Overview 1. Introduction 2. The Brewer spectrophotometer instrument 3. Description of the method 4. Results  Impact of the neutral density filter on AOD and Validation of the AOD between a Brewer and a sunphotometer  Comparisons between Brewer at the same place 5. Conclusions and perspectives

24. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Where?

25. Validation of the method to retrieve the AOD. RMI December 6 th 2006 Royal Meteorological Institute of Belgium If solar intensity too high Brewer instrument Filter I1I1 I2I2 If not Brewer instrument I1I1 I 2 < I 1 What is a Brewer’s filter?

26. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. 320 nm 368 nm sunphotometer Time difference max = 3 min

27. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Filters impact on AOD c = 0.87 b = 0.80 ± 0.011 a = -0.08 ± 0.004 c = 0.98 b= 0.85 ± 0.004 a= 0.02 ± 0.0014 N = 1718 Standard filters N = 1934 Real filters Errors

28. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Where?

29. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Arosa

30. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. 320 nm 368 nm Hourly mean AOD compared for 2002 Brewer spectrophotometer Sunphotometer

31. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Comparison Arosa/Davos c = 0.62 b = 0.56 ± 0.04 a = 0.02 ± 0.0006 N = 335

32. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Overview 1. Introduction 2. The Brewer instrument 3. Description of the method  Physical equation  Langley plot method 4. Results  Impact of the neutral density filter on AOD and Validation of the AOD between a Brewer and a sunphotometer  Comparisons between different Brewer at the same place 5. Conclusions and perspectives

33. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Where?

34. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Uccle 2002-2005 N = 5781 c = 0.98 b= 1.02 ± 0.003 a= 0.06 ± 0.001

35. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Arosa 2004 N = 2771 c = 0.94 b= 0.98 ± 0.006 a= 0.03 ± 0.002

36. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Summary of the comparisons Brewer016040072 178 0.98 1.02 0.06 156 0.94 0.98 0.03 0.98 0.98 -0.04 072 0.99 0.98 -0.02

37. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Overview 1. Introduction 2. The Brewer spectrophotometer instrument 3. Description of the method  Physical equation  Langley plot method 4. Results  Impact of the neutral density filter on AOD and Validation of the AOD between a Brewer and a sunphotometer  Comparisons between Brewer at the same place 5. Conclusions and perspectives

38. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Conclusions 1. Important role of the filter values of the Brewer spectrophotometer on the accuracy of AOD 2. High level of confidence of the method used to retrieve the AOD:  correlation coefficient > 0.94  slope ~ 1  Intercept is negligible 3. Validation of the Langley plot method with a comparison between Brewer spectrophotometer and a sunphotometer

39. Royal Meteorological Institute of Belgium Validation of the method to retrieve the AOD. RMI December 6 th 2006. Perspectives 1. Application of the method at different Brewer stations 2. Determination of relation between different aerosol parameters: AOD, ssa, type, size and air mass origin

40. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. First preliminary results of the aerosol measurements campaign at Uccle RMI team: Anne Cheymol, Alexander Mangold, Hugo De Backer, Andy Delcloo, René Lemoine and Roeland Van Malderen Ghent university team: Pr. Willy Maenhaut, Wan Wang, Nico Raes, Xuguang Chi and Jan Cafmeyer Thanks to the weather forecasters of RMI

41. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Overview 1. Objectives of the campaign 2. The instruments and the first preliminary results 3. Perspectives

42. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Objectives Aerosol campaign from January 4 th to 30 th November 2006 at Uccle Determination of the relations between AOD, size and type of aerosol particles and air mass origin  Observations in parallel from Brewer spectrophotometer (AOD) and the other aerosol instruments (sampling and monitoring)

43. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Sampling by Delcloo and Mangold PM10 Mineral Aerosol Organic Aerosol PM2.5 Mineral Aerosol Organic Aerosol

44. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Sampling Filter by Delcloo and Mangold Inlet PM10 PM2.5

45. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Ratio PM2.5/PM10

46. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Coarse particle PM10-PM2.5 Fine particles PM2.5 20% anthropogenic source 61% anthropogenic source

47. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. TEOM inlet

48. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Mass concentration of PM2.5 01/02 Mean = 15.4 ug/m3 03/01

49. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. 1 February 2006 03/01 01/02 50 ug/m3

50. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Photo by A. Delcloo and A. Mangold smoke 28/0109/11 50 ug/m3 20 ug/m3 50 ug/m3

51. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Aethalometer Mass of Black Carbon

52. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Perspectives 1 1. Determination of the relation between AOD, mass, size and type of the particles and the air mass origin 2. Aerosol studies is foreseen within the Antarctic project with BIRA and Ghent University

53. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. Most important perspectives snoepjes

54. Royal Meteorological Institute of Belgium Aerosol Measurements Campaign at Uccle. RMI December 6 th 2006. The END

55. Royal Meteorological Institute of Belgium Antarctic project. RMI December 6 th 2006. The antarctic project

56. Royal Meteorological Institute of Belgium Antarctic project. RMI December 6 th 2006. RMI Ozone/UV/aerosol group BIRA M. Van Roozendael, M. De Mazière, C. Hermans, D. Gillotay, C. Depiesse, C. Muller,D. Bolsee Ugent W. Maenhaut and J. Cafmeyer Members of the project