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| Study on the concentration variation of CO2 in the background area of Yangtze River Delta |
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Abstract Atmospheric CO2 concentration was continuously measured from January 2009 to December 2010 to study the effects of surface wind direction, surface wind speed and air mass transport on CO2 concentration at Lin’an regional atmospheric background station. The results revealed that the diurnal variation of atmospheric CO2 concentration showed the single-peak pattern at Lin'an regional background station. The diurnal concentration of CO2 varied from 9.5×10-6 (V/V) to 44.3×10-6 (V/V), with the lowest value observed in the afternoon and the highest at dawn. The difference between maximum and minimum monthly mean CO2 concentrations was 10.1×10-6 (V/V), with the highest concentration observed in winter and spring and the lowest in summer. Study on the effects of surface wind direction, surface wind speed and air mass transport on CO2 concentration showed the dominant wind directions were NW~NNE in summer and NNE~ESE in winter, which could bring on higher CO2 concentration. The CO2 concentration turned lower with higher surface wind speed. The impact of long-range transport of air masses on CO2 concentration depended on the source strength of CO2 in the pathway.
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Received: 29 September 2011
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