Aerosol optical properties measured from aircraft, satellites and the ground during ARCTAS - their relationship to CCN,

1. Aerosol optical properties measured from aircraft, satellites and the ground during ARCTAS - their relationship to CCN, aerosol chemistry and smoke type Yohei Shinozuka*, John Livingston, Jens Redemann, Phil Russell, Roy Johnson, S Ramachandran (NASA Ames), Tony Clarke, Cameron McNaughton, Steffen Freitag, Steve Howell, Volodia Kapustin, Vera Brekhovskikh (University of Hawai’i), Terry Lathem, ThanosNenes (Georgia Tech) Brent Holben, Norm O'Neill, Bruce McArthur and Alain Royer (AERONET) *yohei@hawaii.edu

2. In this talk… • Consistency check among the P-3 aircraft, ground and satellite observations of spectral aerosol optical depth (AOD) • Linking CCN and optical properties • Optical characterization of aerosol composition and smoke type

3. AATS-14 Consistency check

4. AOD above P-3 (measured with AATS-14): 0.033 An example of extinction profile See also HSRL talk. PRELIMINARY DATA Clarke, McNaughton, Freitag, Howell et al. Layer AOD over aircraft altitudes (500 – 6250 m GPS) : 0.201 at 550 nm AOD below P-3: 0.005 (150 m * 30.5 Mm-1) 500 350 (Surface)

5. HiGEAR layer AOD was typically within 10% + 0.02 of the AATS’s for the 35 spiral vertical profiles with altitude gain/loss greater than 1 km under clear sky with AATS and HiGEAR instruments running. PRELIMINARY +10% + 0.02 1:1 agreement -10% - 0.02

6. Camsell & Viking fires north of Lake Athabasca Time = 192.8937 Marker size proportional to dry scattering HiGEAR Dry Scattering 4000 Mm-1 at 550 nm, AATS AOD 2.5 at 519 nm in the smoke. The high spatial variability prevented agreement between AATS and HiGEAR.

7. P-3 and AERONET AODs Fort McMurray P-3 AERONET AERONET PIs: Holben, O'Neill, McArthur and Royer

8. PEARL at Eureka P-3 and AERONET AODs agreed within <0.01 (excellent!) – 0.02 (good) during 3 fly-over events, at all wavelengths but 1.6 um. AERONET PIs: Holben, O'Neill, McArthur and Royer Fort McMurray Saturn Island off Vancouver

9. Comparison of AATS with Satellites (OMI and MODIS) MODIS, OMI AOD (380 nm) OMAERUV MODIS OMAERO P-3

10. Comparison of AATS, OMI, and MODIS AOD spectra Preliminary J. Redemann, J. Livingston, Torres, Veihelmann, Veefkind

12. ARCTAS: 30 June 2008 P-3B Flight Track

13. MODIS % cloud MODIS OMAERUV MODIS AOD (470 nm) OMAERO ARCTAS: 30 June 2008 Note: Google Map from July 1, 1545 UT P-3B flight track color-coded by AATS AOD (451 nm) AATS: 19.65-19.95 UT Aqua: 19.83 UT Aura: 20.01 UT

14. OMAERUV and AATS AOD spectra OMAERO and AATS AOD spectra smoke weakly abs weakly abs smoke sulfate sulfate weakly abs smoke smoke smoke smoke smoke smoke smoke smoke sulfate sulfate smoke smoke smoke Cloud-clearing turned off for OMAERO retrievals Retrievals produced with cloud-clearing on ARCTAS: 30 June 2008 OMI retrievals in highlighted cells likely cloud-contaminated

15. ARCTAS: 30 June 2008 AATS MODIS OMAERUV OMAERO MODIS AOD (470 nm) MODIS OMI

16. The first half of the P-3 July 3 flight 220 km

17. The first half of the P-3 July 3 flight encountered a well-mixed local pollution layer up to ~2 km GPS altitude and a long-range transport air mass above, both homogenous over >200 km. 220 km HiGEAR TSI Neph. Dry Scat. Coeff. (Mm-1) at 550 nm

18. MODIS PRELINARY MODIS 3-km resolution product from Remer and Mattoo.

19. MODIS 660 550 470 nm +15% + 0.05 1:1 -15% - 0.05 (HiGEAR extinction * radar altitude) MODIS 3-km resolution product from Remer and Mattoo. MODIS underestimated the AOD in some pixels.

20. CCN and optical properties

21. CCN concentration at supersaturation 0.3 – 0.4% is related to the column AOD at 354 nm typically with a geometric standard deviation of 3 (vertical bar). (Shown are data taken at GPS Altitude < 1000 m during ARCTAS Summer over Canada only.) (Lathem and Nenes)

22. AOD does not tell near-surface extinction, particularly with high scattering. We need to use better assessment of extinction (e.g., HSRL). <1000 m GPS altitude

23. CCN concentration is related to in-situ dry extinction coefficient with a geometric standard deviation of ~2. (Lathem and Nenes)

24. aerosol composition and smoke type

25. White smoke from smoldering fires White smoldering and black flaming identified based on Tony Clarke’s flight report. Dark smoke from flaming fires

26. Smoke after evolution, or pollution from other sources? To be investigated. White smoke from smoldering fires Aerosol evolution in downwind transport? Characterization of smoke types and age with the wavelength dependence of scattering and SSA Dark smoke from flaming fires

27. Summary • AATS, HiGEAR and AERONET measurements of AOD agreed well, except for some profiles with high spatial variability associated with forest fire smoke. • Comparison with satellite observations is in progress. • CCN concentration is related to single wavelength light extinction typically with a geometric standard deviation of 2. • Smoke type and age may be characterized by the wavelength dependence of scattering, that of absorption and SSA . Thanks Ellen Baum from the Clean Air Task Force for supporting my travel.

29. Extra slides

30. The humidity response of aerosol scattering was often negligible in Canada’s forest fire smoke we sampled. Both gamma and ambient RH were almost always too low to matter (gamma< 0.53 and ambient RH <50% for two thirds of our samples).

31. CALIPSO profile, all adjacent pro-files yield no aerosol retrieval