To: various friends and work colleagues

This is to inform you that I plan to bring most of my work activities to a close later this year. Beginning in July I will be on 100% extended sick leave, though I prefer to view it as the equivalent of an early retirement.

Four years ago I was diagnosed with multiple sclerosis. The effects (in my case) are difficulty walking, fatigue, and back and hip pain. For several years I have also been aware that my work output was declining, both in quantity and quality. At this point I have decided to take advantage of Michigan's generous extended sick leave and disability insurance (and the credit I accumulated through 24 years here) and am bringing most of my work activities to a close.

I expect to continue to keep up with research, though at a reduced scale, and hope in particular to continue my involvement with topics in which I have special expertise: tropospheric ozone and mercury, especially in polluted regions, and their relation to precursor emissions. Please feel free to contact me if issues come up that I might contribute to.

I also expect to continue ongoing projects with colleagues at Michigan, including (among others) Guangxing Lin's Ph.D. dissertation and modeling projects that involve code I have helped develop.

About my situation: I expect to continue to have a good life. My form of MS is not life-threatening; so it’s more of an inconvenience than anything else. I walk with difficulty and have some chronic pain, and am ‘slowing down’ at a younger age than I might otherwise. But life is good, and I hope to keep involved with atmospheric science and with various other things.

Lastly, a personal note: Looking backwards, I find it most satisfying to think that some of my research helped to bring about an improvement in air quality over the eastern U.S. When I started out (in 1988) ozone air quality violations were common, and there was little change during the 1990’s. But during the 2000s there was a significant improvement – attributed in large part to reductions in nitrogen oxide emissions. There are still air quality violations today, but mostly because standards have become stricter and cleanup goals more ambitious. Since I (along with many others) published on this and occasionally pushed for it, I find this outcome especially satisfying.

(For documentation: Fiore et al., JGR, 1997; Butler et al., Atmos Environ., 2011; and Bloomer et al., GRL, 2009).

I'm not really a "cause scientist" in that I've been concerned mainly with getting the scientific content right rather than environmental policy. I've been a bit of an advocate (and made a fool of myself in the process) in cases where I thought that the science-based results strongly and convincingly pointed in a specific policy direction. The focus of a lot of my work was to take what I saw as a central policy-relevant finding and ask: is there a test that can prove that the current understanding is correct, or refute it, rather than just taking it for granted? That approach (if not the exact results) is something I'll always push for.

I've been fortunate to be able to work on topics that relate directly to issues of energy and the environment - not least because I've been able to work with people who have a touch of idealism (in addition to being really good scientists). I've been even more fortunate that some of my work seemed to have some positive real-world impact. (Brief aside - being in a very applied area, I also look with awe and admiration on abstract research that addresses fundamental topics - climate models or quantum chemistry come to mind immediately.) As people in my field tackle the much more difficult and dangerous problems posed by climate change, it may be good to remember that efforts sometimes do pay off in terms of policy. Plus, it is always important to get the science right.

Thanks, all.

Sandy Sillman

PS. To contact me: sillman@umich.edu and 734-769-0359.