Diurnal cycle of greenhouse gases and biogenic hydrocarbons during summer near Cool, CA
Abstract
Photosynthesis by forests is a large sink for atmospheric carbon dioxide (CO2) and also a large source of biogenic volatile organics (VOCs) that produce aerosols, nucleate clouds, and interact with nitrogen oxides (NOx) to produce ozone. To elucidate these complex biogeochemical mechanisms, we performed continuous high temporal resolution measurements of CO2, VOC, trace gases, and aerosol in June 2010 at the T1 site, 70 km from Sacramento, CA, during the Carbonaceous Aerosol and Radiative Effects Study (CARES) in June 2010. Throughout the month we find that diurnal profiles exhibit minima in CO2 and maxima in isoprene during daytime. Both their amplitudes are modulated strongly by cloud cover consistent with a common photosynthetic mechanism. In contrast, we find that diurnal monoterpene profiles peak at night while CO2 is at its maxima. Their amplitudes are modulated by temperature and boundary layer height. The monoterpenes and CO2 cycle show larger increases at warmer temperatures, suggesting respiration as a common driver. Additional measurements of CH4, CO, benzene, toluene, NO, NOy and O3 are used to define biogeochemical cycling of greenhouse gases and are demonstrated as a baseline for separating anthropogenic and biogenic emissions and observing transport of greenhouse gases and air pollution.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2010
- Bibcode:
- 2010AGUFM.A21C0077F
- Keywords:
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- 0315 ATMOSPHERIC COMPOSITION AND STRUCTURE / Biosphere/atmosphere interactions;
- 0345 ATMOSPHERIC COMPOSITION AND STRUCTURE / Pollution: urban and regional