The monitoring of pollutants and greenhouse gases is crucial to support efforts by the State of California to improve air quality and combat climate change. Two remote sensing methods, a multi-axis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument and a Fourier Transform Spectrometer (CLARS-FTS) to monitor pollutants and greenhouse gases, were developed and deployed at JPL's California Laboratory for Atmospheric Remote Sensing (CLARS) on Mt. Wilson (1673 meters asl) to scan the Los Angeles Basin. A version of the regional air quality model WRF-Chem for the LA basin was developed and validated for the 2010 CalNex Study.
Vertical profiles of NO2 concentrations and aerosol extinction were retrieved from the MAX-DOAS observations. MAX-DOAS HCHO/NO2 ratios show a decreased VOC sensitivity during the weekends compared to weekdays due to lower NO2 levels on the weekends, in agreement with WRF-Chem results. Elevated CH4:CO2 ratios were observed in west Pasadena and in the eastern LA basin by the CLARS-FTS. The annual basin total top-down CH4 emissions was derived to be 0.39±0.06 Tg CH4 per year, significantly larger than the bottom-up emissions. The preliminary annual top-down CO2 emissions of 211±12 Tg CO2/year in 2011, 230±12 Tg CO2/year in 2012, 212±11 Tg CO2/year in 2013, and 204±10 Tg CO2/year in 2014, were about 10-15% greater than the CARB bottom-up CO2 emissions in 2012.
For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753
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