Seasonal and Latitudinal Variation of Atmospheric Methane: a Ground-based and Ship-borne Solar IR Spectroscopic Study

Column-averaged volume mixing ratios of CH4 were retrieved with a precision of better than 0.5% from infrared solar absorption spectra obtained at Ny-Alesund (Spitsbergen, 79°N) between 1997 and 2004 and during two ship cruises (54°N-34°S) on the Atlantic in 2003. The retrieval has been performed in a spectral region available to all operational FTIR (Fourier Transform InfraRed) spectrometers performing solar absorption measurements. The seasonality and the long-term increase of the tropospheric volume-mixing ratio, derived from the infrared measurements agree well with data from surface sampling at this site. The latitudinal variation of ship-borne measurements between 54°N and 34°S is in agreement with inverse model simulations which are optimized vs. the global NOAA/ESRL measurements.

WARNEKE Thorsten;  MEIRINK Jan Fokke;  BERGAMASCHI Peter;  GROOSS J.U.;  NOTHOLT Justus;  TOON G.C.;  VELAZCO V.;  GOEDE Albert;  SCHREMS O.; 

2006-09-15

JRC34076

https://publications.jrc.ec.europa.eu/repository/handle/JRC34076,   

10.1029/2006GL025874,