GLOBALVIEW-CO, 2009 is the 4th annual update of this product. Since October 2006, GLOBALVIEW-CO has been accessed more than 540 times by users from over 25 countries. The GLOBALVIEW-CO FTP server averages 15 product requests monthly. This update includes 145 extended records derived from ESRL observations. Data updates through 2008 have been used to derive GLOBALVIEW-CO, 2009. The data product includes extended records from January 1, 1991 to January 1, 2009.
GLOBALVIEW-CO is a product of the Cooperative Atmospheric Data Integration Project for Carbon Monoxide. The project is coordinated and maintained by the Carbon Cycle Greenhouse Gases Group of the National Oceanic and Atmospheric Administration (NOAA), Earth System Research Laboratory (ESRL), Global Monitoring Division (GMD).
Unlike GLOBALVIEW-CO2 and GLOBALVIEW-CH4, this product is currently derived using NOAA ESRL measurements only. At the moment, inconsistencies among observations made by different laboratories may be large [e.g., Masarie et al., 2001; Levin et al., 2005] often exceeding the level of agreement required to address current scientific objectives. In the northern hemisphere consistency of 2-3 nmol -1 is suitable for most studies. In the southern hemisphere where signals are smaller, agreement better than 1 nmol -1 is required. Once laboratories are able to demonstrate and maintain the desired level of agreement and if there is interest within the CO modeling community, we can develop a cooperative data product that utilizes high precision CO measurements made by other laboratories.
GLOBALVIEW-CO is derived from measurements but contains no actual data. To facilitate use with carbon cycle modeling studies, the measurements have been processed (smoothed, interpolated, and extrapolated) resulting in extended records that are evenly incremented in time. Be aware that information contained in the actual data may be lost in this process. Users are encouraged to review the actual data in the literature, in data archives (CDIAC, WDCGG), or by contacting the participating laboratories.
GLOBALVIEW-CO is derived using the data extension and data integration techniques described by Masarie and Tans, [1995]. These techniques were developed using CO2 measurements from the NOAA ESRL cooperative air sampling network.
The impetus for the work done by the many cooperating organizations and institutions is to make atmospheric measurements of trace gas species that will facilitate a better understanding of the processes controlling their abundance. These and other measurements have been widely used to constrain atmospheric models that derive plausible source/sink scenarios. Serious obstacles to this approach are the paucity of sampling sites and the lack of temporal continuity among observations from different locations. Consequently, there is the potential for models to misinterpret these spatial and temporal gaps resulting in derived source/sink scenarios that are unduly influenced by the sampling distribution. GLOBALVIEW-CO is an attempt to address these issues of temporal discontinuity and data sparseness and is a tool intended for use in carbon cycle modeling.