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Scientific projects


Extreme value theory applied to environmental science

Extreme value theory is a branch of statistics dedicated to the analysis of outliers and rare events. In environmental science, extremes are sometimes more important than measures of central tendency: for example, bridge builders care more about the maximum height of a river than its mean height. I've used extreme value theory to link winter meteorology in Beijing to severe smog events, which can shut down the city and are a major threat to public health. If you are interested in using this methodology in your own research, send me an email (drew@drewpendergrass.com) and we can collaborate.

GRL EVT plot

Figure: Probability (given in colored contours) for PM2.5 in Beijing to exceed 300 μg m-3 given relative humidity and 850-hPa meridional winds. Actual observations are overlaid on top: green dots represent days that exceeded 300 μg m-3, and black dots represent the rest.

Associated publications and presentations

Pendergrass, D. C., Shen, L., Jacob, D. J., & Mickley, L. J. (2019). Predicting the Impact of Climate Change on Severe Wintertime Particulate Pollution Events in Beijing Using Extreme Value Theory. Geophysical Research Letters, 46(3), 1824–1830. Publisher's version. PDF.

Pendergrass, D. C., L. Shen, D. J. Jacob, and L. J. Mickley. Predicting the impact of climate change on severe winter haze pollution events in Beijing using extreme value theory. American Geophysical Union Fall Meeting, Washington D.C., December 11, 2018. Talk. Slides.


Emissions and concentrations of pollutants in China

Pollutants like tropospheric ozone and fine particulate matter (PM2.5) cause serious public health burdens, especially in eastern China. In response to the severe smog problems, the Chinese government implemented the Action Plan on Air Pollution Prevention and Control in 2013. The plan led to rapid reductions in emissions of ozone precursors like NOx and aerosol precursors like SO2. However, observations show that while PM2.5 has decreased, surface ozone has increased, even though emissions have fallen. This project seeks to understand the PM2.5/ozone tradeoff both in the present day and under various models of the future.

China air quality map

Figure: Air quality changes due to strong NTCF emission reductions in China by midcentury (2045-54); PM2.5 is projected to improve due to modeled emissions mitigation while ozone is projected to worsen.

Associated publications and presentations

Pendergrass, D. C., L.W. Horowitz, and V. Naik. (in prep) Modeling the impact of strong regulation of near-term climate forcers in China on mid-21st century air quality and climate using a coupled Earth system model.

Pendergrass, D. C., L.W. Horowitz, and V. Naik. Modeling impact of strong regulation of near-term climate forcers in China on mid-21st century air quality and climate using the GFDL-ESM4 coupled model. American Geophysical Union Fall Meeting, San Francisco, Calif., December 13, 2019. Talk. Slides.


Other projects


Newsletter


Log on wheels

A hot new startup that sells logs on wheels for personal transporation.

Half-Earth Socialism

A pamphlet from Verso Books, co-authored with environmental historian Troy Vettese, on how we can get out of our current ecological mess. Due out April 2021.

Half-earth socialism cover

Musical Composition

I am a composer of modern and experimental music. You can learn more about my compositions on my music website and you can listen to my works on my SoundCloud.

Writing

I am on the staff of Harvard Magazine, and I freelance for a variety of outlets, including Harper's and Current Affairs. Some of my articles are linked here.

Commonplace Book

John Locke advised that his readers keep a commonplace book, a document where quotes, proverbs, and ideas would be gathered in an unrestricted way. This is my commonplace book. It is full of quotes and ideas that I find compelling and continue to return to.

Alchemy

Alchemy is a single-player military strategy game written in Java. It makes liberal use of statistical analysis of maps and resource distributions to make the goal of world domination as fair as possible. Alchemy is highly efficient and is designed to run on virtually any modern computer - more is on the game's website here.

Alchemy box cover

Intonation, Harmonics and Timbre notes

This is a resource on the physics of sound and musical instruments, which I wrote as I was researching the science behind my tuning software. You can read more on the IHT homepage.

Radcliffe Research Partner for Anthony Tan

For the 2016-17 academic year, I wrote code, processed and edited recordings, and typeset music for Anthony Tan at the Radcliffe Institute for Advanced Study. This culminated in a May 2017 concert, where I was a performer.