Observed ocean and land CO2 data show both seasonal and spatial variations, where latitude is the most important in addition to the increase in time. A simple, approximative corrective procedure is proposed which will be of use when comparing contemporary CO2 data from land and ocean influenced stations, and for the validation of historical CO2 measurements. This could help to validate regional CO2 measurements against the Mauna Loa reference, or to analyse historical measurements done at different locations by applying common corrections.
The original paper has been finalized the 17 May 2007; except some editing for typing errors,
layout and links, no changes have been made in this version which should be seen as a tribute to the late Ernst-Georg Beck, (Francis Massen 2022)
1. The variations of global CO2 with latitude and time
Figure 1 shows the global distribution of CO2 1996-2005 as given by NOAA (NOAA, Globalview-CO2, gv files). Clearly CO2 varies with time (continuous increase), season (high and low) and latitude. The aim of this paper is to find an easy approximative procedure to validate CO2 measurements from different stations taken at the same time. The procedure should allow handling differences in latitude, in location-type as sea- or land-based, and in hemisphere. Thus, it should be considered as a first step, before the application of full-grown models like MATCH (CGD, Match model).