Spring 2006

EAS 8802 Graduate Seminars:

"Clouds, Aerosols and Climate"


Instructor:
Professor Irina N. Sokolik
office 2258, ph.404-894-6180
email: isokolik@eas.gatech.edu

Location and meeting time:
Mondays 2:05-4:05 PM
ES&T L1116

Jan. 9 Lecture 1. What this course is about? Assignments for Lecture 2.

Jan.16 NO CLASS

Jan. 23 Lecture 2. The main processes in the climate system involving aerosols and clouds: introductory survey
Lecture notes
Discussion materials (student's assignment)

Jan.30 Lecture 3. Changes in planetary albedo. Is there a clear signal caused by aerosols and clouds?
Lecture notes
Papers for discussion:
Palle et al., Changes in Earth’s reflectance over the past two decades. Science, vol.304, pp.1299-1301, 28 May 2004 ( presentation by Anton Darmenov)
Wielicki et al., Changes in Earth’s albedo measured by satellite. Science, vol. 308, p. 825, 6 May 2005. (presentation by Yunsoo Choi)
Additional reading:
Palle et al., Can Earth's albedo and surface temperatures increase together? EOS, 87, pp. 37 and 43, 2006.

Feb.6 Lecture 4. Impact of aerosols and clouds on solar radiation at Earth's surface: dimming or brightening?
Lecture notes
Papers for discussion:
Wild, M., et al., From dimming to brightening: decadal changes in solar radiation at Earth's surface, Science, vol.38, pp. 847- 850, 6 May 2005. (presentation by Donifan Barahona)
Alpert P., P. Kishcha, Y. J. Kaufman, and R. Schwazbard, Global dimming or local dimming?: Effect of urbanization on sunlight availability. GEOPHYSICAL RESEARCH LETTERS, VOL. 32, L17802, doi:10.1029/2005GL023320, 2005. (presentation by Bryan Karpowicz)

Feb.13 Lecture 5. Are there trends in cirrus and contrail clouds?
Lecture notes
Papers for discussion:
Minnis, P., et al., Contrails, Cirrus Trends, and Climate, Journal of Climate 17 (8): 1671-1685,2004 (presentation by Matthew Widlansky)
Stordal F. et al., Is there a trend in cirrus cloud cover due to aircraft traffic? Atmos.Chem.Phys., 5, 2155-2162, 2005. (presentation by Lance Giles)
Additional reading: (focus on sections 3 and 4)
Lohmann U. and J. Fletcher, Global indirect aerosol effects: a review. Atmos. Chem. Phys, 5, 715-737, 2005.

Feb.20 NO CLASS

Feb.27 Lecture 6. The challenges in founding trends in global cloud cover from satellite and ground-based observations.
Lecture notes
Papers for discussion:
Wylie D., et al., Trends in global cloud cover in two decades of HIRS observations, Journal of Climate, 18, 3021-3031, 2005. (presentation by Drexel Waggoner)
Warren S.G. and Hahn C.J., Clouds/Climatology, in: Encyclopedia of Atmospheric Sciences (Eds. J.R. Holton, J.A. Curry, and J.A. Pyle), Academic Press, pp.476-483, 2002. (presentation by Gill-Ran Jeong)
Additional reading:
Hahn, C.J., W.B. Rossow, and S.G. Warren, 2001: ISCCP cloud properties associated with standard cloud types identified in individual surface observations. J. Climate., 14, 11-28.

March 6 Lecture 7. How many types of indirect aerosol effects are known?
Lecture notes
Papers for discussion:
Lohmann U. and J. Fletcher, Global indirect aerosol effects: a review. Atmos. Chem. Phys, 5, 715-737, 2005. ((presentation by Yanping He))
Additional reading:
McFiggans et al., The effect of physical and chemical aerosol properties on warm cloud droplet activation, Atmos. Chem. Phys. Disc., 5, 8507-8646, 2005.

March 13 Lecture 8. How aerosols can contribute to climate change in the Arctic?
Papers for discussion:
Rinke, A., K. Dethloff, and M. Fortmann, Regional climate effects of Arctic Haze, Geophys. Res. Lett., 31, L16202, doi:10.1029/2004GL020318, 2004. (presentation by Jun Jian)
Hansen, J., and L. Nazarenko, Soot climate forcing via snow and ice albedos. Proc. Natl. Acad. Sci. 101, 423-428, doi:10.1073/pnas.2237157100, 2004. (presentation by Xueyuan Deng)
Additional reading:
Koch, D., and J. Hansen, Distant origins of Arctic black carbon: A Goddard Institute for Space Studies ModelE experiment. J. Geophys. Res. 110, D04204, doi:10.1029/2004JD005296, 2005.

March 20 NO CLASS

March 27 Lecture 9. Does particulate air pollution cool or heat the climate system?
Lecture notes
Paper for discussion:
Andreae M.O., C.D. Jones, and P.M.Cox, Strong present-day aerosol cooling implies a hot future, Nature, v.435, pp.1187-1190, 2005. (presentation by Kremena Darmenova )

April 3 Lecture 10. How aerosols can affect clouds, precipitation and climate in Asia?
Lecture notes
Papers for discussion:
Menon, S., J.E. Hansen, L. Nazarenko, and Y. Luo, Climate effects of black carbon aerosols in China and India. Science 297, 2250-2253, doi:10.1126/science.1075159, 2002 (presentation by Donifan Barahona)

Qian, Y., D. P. Kaiser, L. R. Leung, and M. Xu, More frequent cloud-free sky and less surface solar radiation in China from 1955 to 2000, Geophys. Res. Lett., 33, L01812, doi:10.1029/2005GL024586, 2006. (presentation by Drexel Waggoner )

April 10 Lecture 11. Cloud feedbacks in the climate system: outstanding challenges
Lecture notes
Paper for discussion:
Stephens G.L., Cloud feedbacks in the climate system: A critical review, Journal of Climate, 18, 237-273, 2005
(Sections 4-6 will be presented by Anton Darmenov;
Sections 7-9 will be presented by Matthew Widlansky)

April 17 Lecture 12. Aerosol and cloud feedbacks in the climate system: Discussion
Lecture notes

April 24 Lecture 13. Observing strategies for improved understanding of impacts of aerosol and cloud on the climate system: Group proposal presentations
Group A: Choi (leader), Darmenov, Jian, Kwon
Group B: Darmenova (leader), Barahona, Deng
Group C: Jeong (leader), Widlansky, Giles
Group D: Karpowicz(leader), Waggoner, He

Recommended reading:
Diner et al., RARAGON: An integrated approach for characterizing aerosol climate impacts and environmental interactions. BAMS, 85, 1451-1501, 2004.
Anderson et al., An A-Train strategy for quantifying direct climate forcing by anthropogenic aerosols, BAMS, 86, 1795-1809, 2005.
Stephens e al., The CloudSat mission and A-train: A new dimension of space-based observations of clouds and precipitation, BAMS, 83, 1771-1790, 2002.
MacDonald, A.E., A global profiling system for improved weather and climate prediction, BAMS, 86, 1747-1764, 2005.

May 1 Lecture 14. Class Quiz


(404)894-6180
isokolik@eas.gatech.edu