Isoprene and Biomass Burning Emissions from Satellite Observations: Synergistic Use of HCHO and NO2 Trace Gas Measurements
Thierry Marbach(1), Steffen Beirle(1), Ulrich Platt(1) and Thomas Wagner(1)
(1) Environmental Physics Heidelberg, INF 229, 69120 Heidelberg, Germany
We present case studies for combined HCHO and NO2 satellite observations, derived from GOME measurements. Launched on the ERS-2 satellite in April 1995, GOME has already performed continuous operations over 8 years providing global observations of the different trace gases. In this way, satellite observations provide unique opportunities for the identifications of trace gas sources. The satellite HCHO observations provide information concerning the localization of biogenic isoprene emissions and biomass burning (intense source of HCHO over the Amazon basin region and in central Africa). The HCHO data can be compared with NO2 results to identify more precisely the tropospheric sources (biogenic isoprene emissions, biomass burning events, human activities). For example the HCHO emissions situated in the northern part of the Amazon basin region are not correlated with forest fires. Only the southern part of the HCHO emissions correlates with the measured forest fires and also with the NO2 concentrations. The northern part of the Amazon basin HCHO concentrations can be attributed to biogenic isoprene emissions over the rain forest. In this case study the NO2 emissions are mostly due to the biomass burning. We propose to use this NO2-fires correlation through NO2/HCHO ratios to discriminate the HCHO due to biogenic isoprene emissions from the HCHO due to biomass burning. Biomass burning are important tropospheric sources for both HCHO and NO2.
There seems also to be a dependence between the NO2 emissions during biomass burning and the vegetation type: NO2 correlate with HCHO over Africa (grassland fires) but not over Indonesia (forest fires). In south America, an augmentation of the NO2 concentrations can be observed with the fire shift from the forest to grassland vegetation.
Keywords: ESA European
Space Agency - Agence spatiale europeenne,
observation de la terre, earth observation,
satellite remote sensing,
teledetection, geophysique, altimetrie, radar,
chimique atmospherique, geophysics, altimetry, radar,