Regional gradients in Carbon Dioxide and Carbon Monoxide Concentrations across the Amazon Basin
James
William
Munger, Dept of Earth and Planetary Sciences, Harvard University, Cambridge, MA USA, jwm@io.harvard.edu
Scott
R.
Saleska, Dept of Earth and Planetary Sciences, Harvard University, Cambridge, MA USA, saleska@fas.harvard.edu
Bruce
C.
Daube, Climate Monitoring and Diagnostics Laboratory, NOAA, Boulder, CO USA, bruce.daube@noaa.gov
Steven
C.
Wofsy, Dept of Earth and Planetary Sciences, Harvard University, Cambridge, MA USA, scw@io.harvard.edu
Volker
W.J.H.
Kirchhoff, INPE, Sao Jose dos Campos, SP, Brazil, kir@dge.inpe.br
(Presenting)
Carbon dioxide and Carbon monoxide concentration measurements have been made at the km 67 tower site in the Tapajos Forest since April 2001. A coastal site at the INPE atmospheric observatory in Maxaranguape north of Natal was added in December 2002. The Maxaranguape measurements supersede the measurements operated by Kirchhoff et al [2003] and supplement the weekly whole-air samples that are collected at the site and analyzed at the S. José dos Campos central lab facility. Carbon dioxide sampled from onshore air flow at Maxaranguape measures 375 ± 3 ppmv in February 2004. The corresponding CO concentrations are 40-60 ppbv. Occasional offshore flows at Maxaranguape are easily detected by CO2 concentrations that increase to near 400 ppmv. The marine air mass does not have a significant diel cycle. Concentrations of CO during the well mixed mid-day period at Tapajos are near 70 ppbv during the wet season and increase to near 300 ppbv during the dry season as burning influence increases. CO2 concentrations above the forest vary by up to 50 ppmv from day to night. The seasonal variation of mid-day mean concentration is roughly only 5 ppmv. Mid-day mean concentrations for the end of February 2004 are 380 ppmv, a 5 ppmv increase over the coastal concentration seen at Maxaranguape. The regional gradients that are measured provide an important constraint on continental-scale net exchanges of CO2 and production of CO by urban activity, industry, biomass burning and oxidation of biogenic hydrocarbons. When these data are coupled to a meteorological transport model we can associate the CO2 and CO enhancements to specific areas of influence.
Submetido por Volker W. J. H. Kirchhoff em 17-MAR-2004