Insight into the carbon cycle from continuous measurements of oxygen and carbon dioxide at Weybourne Atmospheric Observatory, UK

• Main Author: Wilson, Philip
• Format: Thesis
• Language: English
• Published: 2012
• Subjects: Arctic; North Atlantic
• Online Access: https://ueaeprints.uea.ac.uk/id/eprint/42961/; https://ueaeprints.uea.ac.uk/id/eprint/42961/1/2013WilsonPAPhD.pdf

Atmospheric measurements of carbon dioxide (CO2) and oxygen (O2) are a valuable tool to better understand the global carbon cycle. Technological improvements have resulted in near-real-time continuous measurements of both O2 and CO2 becoming viable. The increased time resolution of continuous measurements compared to discrete flask samples provides greater insight into atmospheric variations and short-term processes. These measurements will become even more relevant as the research focus shifts from the global to regional scale, for example anthropogenic emissions verification. This thesis presents a 4.5 year record of atmospheric CO2 and O2 measurements made at Weybourne Atmospheric Observatory (WAO) on the north Norfolk coast in the United Kingdom. In situ, continuous measurements cover the period October 2007 to April 2012. Data for the tracer ‘Atmospheric Potential Oxygen’ (APO) are also presented. The analytical methodology is described in detail and the data are examined on interannual, seasonal, synoptic and diurnal timescales. The precision of ambient air measurements is about ±0.03 ppm for CO2 and ±2.0 per meg for O2. The average amplitude of the WAO seasonal cycle is 14.9 ppm for CO2, 134.2 per meg for O2 and 59.0 per meg for APO, similar to other stations at similar latitudes. Interannual variability in the seasonal cycle amplitude is also investigated. Growth rates over the 4.5 year period are 2.4 ppm yr-1 for CO2, -25 per meg yr-1 for O2 and -13 per meg yr-1 for APO, also similar to other nearby stations. Short-term analyses reveal clear diurnal cycles in both CO2 and O2 that vary seasonally throughout the year. No diurnal cycle is observed in APO. A number of short-term events are explored and confirm that WAO experiences both clean marine air masses from the Arctic and North Atlantic, as well as fossil fuel pollution signals from the UK and continental Europe.