The dataset of in-situ measurements of chemically and radiatively important atmospheric gases from the Advanced Global Atmospheric Gas Experiment (AGAGE) and affiliated stations (2024R1)

In the ALE/GAGE/AGAGE global network program, continuous high frequency
gas chromatographic measurements of four biogenic/anthropogenic gases
(methane, CH4; nitrous oxide, N2O; hydrogen, H2; and carbon monoxide,
CO) and several anthropogenic gases that contribute to stratospheric
ozone destruction and/or to the greenhouse effect have been carried out
at five globally distributed sites for several years. The program, which
began in 1978, is divided into three parts associated with three
changes in instrumentation: the Atmospheric Lifetime Experiment (ALE),
which used Hewlett Packard HP5840 gas chromatographs; the Global
Atmospheric Gases Experiment (GAGE), which used HP5880 gas
chromatographs; and the present Advanced GAGE (AGAGE). AGAGE uses two
types of instruments: a gas chromatograph with multiple detectors
(GC-MD), and a gas chromatograph with mass spectrometric analysis
(GC-MS). Beginning in January 2004, an improved cryogenic
preconcentration system (Medusa) replaced the absorption-desorption
module in the GC-MS systems at Mace Head and Cape Grim; this provided
improved capability to measure a broader range of volatile
perfluorocarbons with high global warming potentials. The Medusa GC-MS
systems were subsequently used at other AGAGE stations (Trinidad Head,
Barbados, American Samoa, Zeppelin, Jungfraujoch, and Goan) after the
initial setup at Mace Head and Cape Grim. More information may be found
on the AGAGE home page: https://agage.mit.edu/instruments. <br>Data from
the AGAGE and affiliated stations (total of 10 sites) between August
1993 and June 2023 are provided in
“Agage_gcmd_gcms_data_2024_07_11.tar.gz” (compressed tar file). The
metadata file has information on each station and currently released
species. The standard scales used in archived species are listed in
"AGAGE_scale_2024_v1.pdf". Additional information can be found on the
AGAGE website (https://agage.mit.edu). <br>Update: Dec. 4, 2024 <br>1. The
Cape Grim H2_PDD data are updated in this release ((H2_PDD values in
previous release are wrong due to coding error). All other data in this
release are the same as previous version
("Agage_gcmd_gcms.data.2024_07_11.tar.gz") <br>2. The latest data are
saved in "Agage_gcmd_gcms.data.2024_12_04.tar.gz"