Edinburgh in space race against global warming

In a bid to help curb global warming, researchers at the University of Edinburgh are to analyse data from two new satellites built by NASA and the Japan Aerospace Exploration Agency, JAXA.

The American and Japanese-built crafts, The Orbiting Carbon Observatory (OCO) and the Greenhouse Gases Observing Satellite (GOSAT) respectively, are designed to analyse the levels of CO2 in the earth's lower atmosphere.

At present, scientists are able to calculate emissions for large areas such as cities or whole oceans. The data from OCO and GOSAT would enable researches to monitor the range of regions in between, such as entire countries or remote areas where data collection has previously proved impossible.

Edinburgh University researcher Paul Palmer and his team have been involved with research groups from both OCO and GOSAT by analysing some of the data produced as a result of measurements taken by the two satellites. Working at the university's school of geosciences, they aim to infer relevant physical, chemical and biological processes on land, ocean and in the atmosphere from the mass of data.

Speaking to The Journal, Dr Palmer said: “My analysis starts in a few months when measurements start to be produced and we can start looking at the real atmosphere.”

The immediate implications of such data are numerous. Monitoring the CO2 output of individual countries could enable scientists to pinpoint the worst polluting areas.

In turn this would furnish the international community with valuable information in terms of where political pressure ought to be applied to force polluters to cut emissions. This is the primary goal of the Japanese GOSAT craft (locally know as IBUKI), which was launched into orbit last week. Built in association with Mitsubishi, Japan’s Space Agency JAXA hope it will “contribute to the international effort toward prevention of (global) warming."

America’s OCO satellite is NASA’s first spacecraft specifically dedicated to mapping CO2 and, in contrast to the Japanese project, is concerned with areas which are absorbing as opposed to emitting greenhouse gases.

Such regions, known as "carbon sinks", are thought to absorb over 50 per cent of all carbon emitted into the atmosphere. Oceanic and densely wooded areas are known examples of these. However, quite which areas absorb the most, and are therefore of greatest importance and in need of greatest protection, is unclear.

Furthermore, knowing the properties of a good carbon sink could lead to the development of further natural or artificial sinks to boost CO2 absorption.

Both OCO and GOSAT are to measure the quantity of CO2 in the atmosphere by breaking up the sunlight reflected off the Earth’s surface into its construct colours and analyzing the resulting spectrum.

The two craft, however, employ different approaches and harbor substantially different onboard instrumentation to do the job. GOSAT uses a spectrometer and imager in tandem to obtain its data while OCO contains an alternative spectrometer which provides greater spatial resolution.

The two different methods, it is hoped, will provide complementary results. “Comparisons of CO2 retrievals from these two measurement techniques could help to identify and correct subtle measurement biases that might otherwise be missed,” explains Dr Palmer.

When in orbit the two satellites will join a larger array of satellites concerned with monitoring and analyzing the atmosphere known as the "The A Train".

GOSAT was successfully launched from the Tanegashima Space Center on Friday morning GMT. The launch of OCO is scheduled for 23 February, should weather conditions prove suitable.