EOS Validation Program

Institution: NOAA/ERL/CMD
                    325 Broadway, R/E/CG1
                    Boulder, CO 80303
Phone: (303) 497-6974
FAX: (303) 497-6290
E-mail: pnovelli@cmdl.noaa.gov

Edward J. Dlugokencky, NOAA/ERL/CMD
Douglas W. Guenther, CIRES/Univ. Colorado
Pieter P. Tans, NOAA/ERL/CMD

June 2001

The general distributions of the three most abundant carbon gases in the lower troposphere (carbon monoxide (CO), methane (CH4) and carbon dioxide (CO2)) are known, however their variations with altitude have been less well described. Few data are available which define both the temporal and vertical variation of carbon gases above the planetary boundary layer. Space-based instruments have begun to provide global measurements of CO in the troposphere, and these programs benefit from comparison of their derived products to aircraft-based correlative measurements. In support of the validation of the Measurement Of Pollution In The Troposphere experiment (MOPITT), we propose to conduct biweekly measurements of the vertical profiles of CO, CH4, and other trace gases at five sites in the National Oceanic and Atmospheric Administration/Climate Monitoring and Diagnostics Laboratory (NOAA/CMDL) cooperative air sampling network (Mauna Loa, Hawaii; Park Falls, Wisconsin; Carr, Colorado; American Samoa, and near Moscow, Russia). Air samples will be collected at predefined altitudes (approximately 500 m intervals over an altitude range of 0.3 to 8-9 km) using portable, automated equipment aboard small aircraft. Weekly measurements above Carr, Colorado during the past 3 years have proved the effectiveness of the sampling approach. All samples will be analyzed for CO, CH4, CO2, hydrogen, nitrous oxide and sulfur hexafloride at the NOAA/CMDL Carbon Cycle Group central laboratory in Boulder, Colorado, thus ensuring an internally consistent data set. Measurements will be referenced to the internationally-recognized standard scales maintained by this lab. The data obtained will be directly applicable to the MOPITT level 2 product validation (CO profiles, and CO and CH4 column abundances). Ancillary measurements (including other trace gas distributions, temperature and relative humidity) will provide data useful for comparison to the a priori profiles used in the MOPITT retrievals.