Strategic Considerations Regarding the Quantification of Climate Forcing by Anthropogenic Aerosols

The Atmospheric Sciences Division of Brookhaven Labs on Long Island, New York, presents a great sounding seminar:

Friday, January 26, 2007, 11:00 AM

Brookhaven National Labs
Bldg 815E Conference Room
William Floyd Parkway, County Road 46, 1 1/2 miles north of Exit 68 of the Long Island Expressway.

Stay the Course' or 'Cut and Run'? Strategic Considerations Regarding the Quantification of Climate Forcing by Anthropogenic Aerosols

Dr. Tad Anderson
University of Washington

This Seminar is Open to the Public...all are welcome to attend. Please bring a photo ID with you for entrance onto the Brookhaven National Labs site.

Overview:

Since the second year of the Ford Administration when Junge outlined the problem, atmospheric scientists have been engaged in a mission to beat down the uncertainties in Aerosol Climate Forcing. The intervening years have seen exponential increases in the number of scientist attacking this problem, the power of their instrumental and computational weaponry, and, of course, the overall cost of the mission. Publications have also increased exponentially, and yet, five Presidents and four party switches later, any semblance of victory remains elusive. Even our weakest enemy (the "direct forcing" problem), though targeted in well-armed field campaigns, has managed to stage repeated comebacks via such unanticipated tactics as the insertion of absorbing aerosol above boundary layer clouds, where its effects may be great and yet are almost impossible to measure. Meanwhile, the hydra-headed monster known as "indirect forcing", while surrendering tiny slivers of territory, has only grown in overall strength and incomprehensibility. Our great nation stands this very day at a turning point - a moment of decision. Shall we battle on with our bottom-up techniques, as the mad-dogs of the Red Party advocate? Shall we abandon the field to top-down (or inverse) methods, wherein we merely pick the forcing value that allows a climate model to fit the temperature record, as called for by the cowards of the Blue Party? Should we listen to those queer Third Party voices, urging, for example, approaches based on monitoring the heat content of the ocean or the albedo of the entire planet? These are trying and confusing times, and yet the choice is upon us. My goal in this presentation and the discussion to follow is not to recommend any particular course of action, but to help equip us to choose wisely. Specific topics will include: What do recent, so-called "observation-based" estimates of direct forcing tell us about the state of the science? What do we know about the accuracy of AERONET retrievals of absorption optical depth and fine-mode fraction? How does the notion of an aerosol/cloud continuum affect our observational and modeling strategies? Even though they cannot vote today, non-U.S. citizens are encouraged to come and participate - we need all the help we can get!