ARB Research Seminar

This page updated November 10, 2015

Determination of the Spatial Distribution of Ozone Precursor and Greenhouse Gas Concentrations and Emissions in the LA Basin

Photo of Jochen Stutz, Ph.D.

Jochen Stutz, Ph.D., Chair, Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles

December 10, 2015
Cal EPA Headquarters, 1001 "I" Street, Sacramento, CA

Research Project


Monitoring pollutants and greenhouse gases is crucial to support efforts by the State of California to improve air quality and combat climate change. Two new remote sensing methods, a multi-axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument and a Fourier Transform Spectrometer (CLARS-FTS), were developed and deployed at JPL's California Laboratory for Atmospheric Remote Sensing (CLARS) on Mt. Wilson (1673 meters ASL) to monitor pollutants and greenhouse gases in the Los Angeles Basin.

In this seminar we will discuss both instruments and present the results for multi-year (2010 - 2015) observations. Vertical profiles of nitrogen dioxide (NO₂) concentrations and aerosol extinction were retrieved from the MAX-DOAS observations. MAX-DOAS ratios of formaldehyde to NO₂ (HCHO/NO₂) show a decreased VOC sensitivity during the weekends compared to weekdays due to lower NO₂ levels on the weekends, in agreement with WRF-Chem model results. The CLARS-FTS mapped the seasonal spatial variability of the excess ratios of methane to carbon dioxide (CH₄/CO₂) in the Los Angeles basin. Using the monthly basin average CH₄/CO₂ ratios and CO₂ emissions, we derived the monthly total methane flux for the South Coast Air Basin. Derived methane emissions showed two peaks in late summer/early fall and winter repeatedly from 2011 to 2015.

Speaker Biography

Jochen Stutz, Ph.D., is the Chair of the Department of Atmospheric and Oceanic Sciences, University of California Los Angeles. Profesor Stutz' research group studies the chemical and meteorological processes controlling tropospheric composition, in particular the chemistry of reactive nitrogen and reactive halogen species, using observations and model calculations. Dr. Stutz' group also develops novel remote sensing methods to study air quality and quantify pollutant emissions, and participates in the organization of large field projects, such as CalNex. Dr. Stutz has published 100 scientific articles, and co-authored a book on Differential Optical Absorption Spectroscopy. Dr. Stutz won the National Science Foundation's young investigator (CAREER) award in 2004. His group has participated in multiple community field experiments, including most recently the CalNex (2010), the Uintah Ozone Experiments (2012, 2014), NASA ATTREX (2011, 2013, 2014), and the Benzene and other Toxics Exposure (BEE-TEX) Study (2015). Dr. Stutz received his PhD in physics from the University of Heidelberg in 1996 and worked as a postdoctoral researcher at University of California, Irvine and University of Heidelberg. Dr. Stutz joined the Department of Atmospheric and Oceanic Sciences at UCLA as a faculty member in 1999.

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