10th anniversary for Cape Verde Observatory

Posted on Thursday 10 November 2016

Funded in the UK by the National Centre for Atmospheric Science (NCAS), the CVO delivers crucial information about atmospheric pollution and greenhouse gas levels in the northern hemisphere, and contributes to improved predictions of climate change through provision of data to global climate models.

The Observatory is one of 31 global stations within the World Meteorological Organisation's Global Atmospheric Watch (GAW) programme, established by the United Nations to monitor trends in the Earth's atmosphere, and one of the few centres in the tropics.

Notable discoveries

Notable discoveries from the CVO over the past decade include:

• The finding that large amounts of ozone – around 50 per cent more than predicted – were being destroyed over the tropical Atlantic Ocean, caused by emissions of the natural halogens bromine and iodine from sea spray and ocean surface chemistry. This discovery was significant because ozone in the lower atmosphere acts as a greenhouse gas and air pollutant, and the results indicated that these processes were ubiquitous over the ocean. This study therefore established a link between ocean emissions and the catalytic destruction of ozone in the lower atmosphere, initiating a new research field for the atmospheric community.
• An international study identified increasing concentrations of ethane and propane gas over much of the Northern Hemisphere, likely due to increasing North American oil and natural gas production. Observing the largest increases over the central and eastern USA, ethane emissions were found to have risen by nearly 50 per cent since 2007. This trend represented a hemispheric-wide reversal of the overall global steady decline in ethane that began in the 1970s, which was primarily due to stricter air quality emission controls.

Global impact

Professor Lucy Carpenter, who leads the CVO team at York, said: “The Cape Verde Atmospheric Observatory has gained a reputation as a high quality international facility, providing vital data to the UK and global atmospheric communities. It provides a powerful tool for characterising transport and transformations of greenhouse and reactive gases, aerosols and dust from the US, Europe, and Africa to the tropical Atlantic.

Professor Ally Lewis, Director of Atmospheric Composition at the National Centre for Atmospheric Science and a lead CVO scientist, said “Measurements at the observatory have led to around 40 scientific publications to date, and many significant discoveries which have made large impacts on our understanding of the global atmosphere.”

Scientists from York visited the CVO from 26 – 28 October to conduct a series of workshops to mark the anniversary, reflect on the data and discuss a vision for the next decade.