01427naa a2200229 a 450000100080000000500110000800800410001910000180006024500640007826000090014252008210015165000110097265000140098365300240099765300150102165300150103665300170105170000270106870000190109570000190111477300640113318104192017-03-13       1999    bl ---       0--  u    #d1 aALVALA, P. C.  aAtmospheric methane observations in BrazilbScar-B mission.  c1999  aMethane (CH4) concentrations have been measured in the lower troposphere using in situ grab sampling, analysed a posteriori by gas chromatography. data collected in the period 1993/1994/1995 in areas near Natal (6 S, 35 W), at the Atlantic coast and Cuiaba (16 S, 56 W), in the middle of the South American continent, show large differences in the  mari- me/continental environments. Aircraft observations have produced vertical profiles in the biomass burning affected areas of central Brazil, in opposite seasons (wet and dry). Verti- cal profiles taken randomly in the affected area generally are well mixed, except if sources are nearby. The difference in the mixed average concentrations between wet and dry se- asons is small but consistent, being of the order of tens of pppbv (parts per billion by volu- me).  aBrazil  aAtmosfera  aAtmospheric methane  aGas metano  aObservacao  aObservations1 aKIRCHHOFF, V. W. J. H.1 aZAMORANO B. F.1 aCASICCIA S. C.  tJournal of Geophysical Researchgv.103, n.D24, p.1-4, 1999.