Abstract
South Africa’s Cape Point (CPT) trace gas observatory, operated by the South African Weather Service (SAWS), has been monitoring mole fractions (mol/vol) of ambient greenhouse gases (GHGs), e.g. carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and selected halocarbons (CFCs and CCl4) since the late 1970s. In addition, the Cape Point trace gas observatory boasts the longest atmospheric carbon monoxide (CO) dataset continuously from 1977 in the Southern Hemisphere (SH). Instruments for the measurement of radiation and other selected gases, such as ozone (O3), have gradually been added since the inception of measurements. The year 1995 heralded a milestone when the Cape Point observatory became part of the World Meteorological Organization’s (WMO) Global Atmosphere Watch (GAW) programme. Besides supplying data to the World Data Centres, it also supports the local database, South African Air Quality Information System (SAAQIS). These affiliations, which require strict measurement protocols, make the Cape Point data records available within the global data centres. Due to Cape Point’s location in a mostly pristine marine environment and its proximity to the Southern Ocean, measurements are highly valued in the United Nations Environment Programme (UNEP)/WMO Ozone and IPCC Climate Assessments and serve as a bellwether for regional changes in southern African atmospheric composition. A review of selected climate change relevant trace gas measurements acquired at Cape Point is presented here.
ACKNOWLEDGEMENTS
The authors would like to thank the South African Council for Scientific and Industrial Research for the early contribution they provided; Department of Environmental Affairs for supplying core funding for Cape Point to ensure continuous operation; the late H.E. Scheel, Karlsruhe Institute of Technology, for his continued support and advice.
DISCLOSURE STATEMENT
No potential conflict of interest was reported by the authors.
List of Abbreviations and Acronyms
ANSTO | = | Australian Nuclear Science and Technology Organisation |
CPT | = | Cape Point |
CRDS | = | Cavity Ring Down Spectroscopy |
CSIR | = | Council for Scientific and Industrial Research |
ECD | = | Electron Capture Detector |
EMPA | = | Swiss Federal Laboratories for Material Science |
ENSO | = | El Niño Southern Oscillation |
ESRL | = | GMD Earth System Research Laboratory Global Monitoring Division (of NOAA) |
FID | = | Flame Ionization Detector |
GAW | = | Global Atmosphere Watch |
GAWSIS | = | Global Atmosphere Watch Station Information System |
GC | = | Gas Chromatograph |
GHGs | = | Greenhouse Gases |
ICP | = | InterComParison |
IMK-IFU | = | Institute of Meteorology and Climate Research-Atmospheric Environmental Research (part of KIT) |
IPCC | = | Intergovernmental Panel on Climate Change |
KIT | = | Karlsruhe Institute of Technology |
NDIR | = | Non-dispersive infrared |
NOAA | = | National Oceanic and Atmospheric Administration |
SAWS | = | South African Weather Service |
UNFCCC | = | United Nations Framework Convention for Climate Change |
UV | = | Ultraviolet |
WDCGG | = | World Data Centre for Greenhouse Gases |
WMO | = | World Meteorological Organization |