莱利亚N. 霍金斯的研究

研究 in 霍金斯 lab aims to address the general question, “How does air pollution affect climate 和 anthropogenic climate change?”

请听霍金斯教授最近的采访:

“冠状病毒关闭是否改善了空气质量?2020年5月15日，The Pulse-WHYY (PBS)
“大流行如何改变空气污染水平2020年4月29日，CBS周日早上
“Stay-At-首页 Order Reduces Air Pollution, Offers Clues in Climate Change Fightcapradio, 2020年4月14日

To address this question, students work in one of four major areas:

  1. 洛杉矶空气污染的实时环境测量，
  2. simulation of brown carbon compounds 和 their atmospheric changes in bulk samples,
  3. mapping local particulate matter with mobile sensors, 和
  4. simulation of brown carbon compounds in an atmospheric cloud chamber in Paris, 法国.

If you are an undergraduate student at any of the Claremont Colleges, 我们鼓励你给霍金斯教授发邮件 hawkins@g.lfkgw.com to set up an in-person conversation regarding research opportunities (including senior thesis) 和 to consider applying for chemistry research in the annual January department call.

There are sometimes opportunities for students outside the Claremont Colleges to participate in research in her program, 但这些都很罕见. 即便如此, you are welcome to contact Professor 霍金斯 about any possible opportunities 和 to apply for research in the January department call. Professor 霍金斯 is unable to accommodate requests for research from current high school students 和 graduate students looking for postdoctoral opportunities at this time.

积极的研究

(1) Measuring particulate matter composition 和 color in Los Angeles

We use an Aerodyne aerosol mass spectrometer to obtain continuous information about aerosol amount 和 composition for up to several months at a time. An optical spectrometer connected with a specialized particle sampler provides a measure of aerosol color 和 the intensity of absorbance. Particle sizing 和 counting instruments provide insight into the microphysical properties of aerosol particles. 在一起, these online instruments allow students to answer questions about the sources of air pollution 和 their relative importance using statistical analyses designed for time series. [Well-suited to chemistry, engineering, math, 和 computer science majors. 学年的工作主要是数据分析.]

(2) Laboratory simulations of chromophore formation in cloud water

Three vials with labels written on their st和ing surface. 下面的描述.

Light absorbing compounds in aerosol comes from a variety of sources. 有些是在野火中排放的, others are generated in atmospheric reactions from non-absorbing precursors. Projects in this category combine UV/visible absorbance spectroscopy with mass spectrometry to characterize the products 和 properties of key browning reactions under atmospherically relevant conditions like variable pH, 自由基氧化, 和蒸发的云/雾滴. 【太阳2注册平台】

(3) Intelligent air quality sampling with mobile sensor networks (a collaboration with Prof. 克里斯·克拉克(工程师)

我的空气有多干净? This question could be answered with greater spatial resolution in air quality measurements. And as online instruments for gas 和 aerosol phase air pollutants become more rapid, 敏感的, 和健壮, 人们对移动采样的兴趣急剧增加. Mobile platforms provide much richer 和 more useful datasets for addressing particulate mass (PM) 和 ozone exposure than stationary sites because they capture both spatial 和 temporal variability in air quality. Mobile sampling adds flexibility to campaigns through the use of both ad hoc 和 algorithm-based redirection.

然而, to our knowledge current mobile sampling studies are lacking two key features that this interdisciplinary 和 collaborative work addresses: path planning 和 extrapolation to non-sampled regions. 本项目涉及验证:

  1. the fixed rank filtering method’s ability to fuse particle count measurements,
  2. the multi-resolution planner’s ability to scale well with increased graph size 和 function even in real-time, 和
  3. the system’s applicability to a real vehicle deployment for real data collection. [Well-suited to engineering 和 computer science majors as well as chemists with additional coursework]

(4) Studying pollution chemistry in an atmospheric cloud chamber at the University of Paris, 完成, 法国

This project exp和s the bulk laboratory simulations of chromophore formation to droplet phase experiments in an atmospheric simulation chamber (CESAM)housed at the University of Paris, 在完成, 法国. Gases 和 particles are introduced into the chamber 和 clouds 和/or sunlight can be simulated to underst和 the role of atmospheric variables in brown carbon formation. This work is a collaboration with the University of San Diego 和 LISA at the University of Paris. 学生 working on this project spend one summer month living in Paris 和 working at the University of Paris lab 在完成. The remainder of the summer is spent at HMC on either preparation or data analysis.