CLIVAR A16 N 2013 (GO-SHIP/CO2 Repeat Hydrography Cruise)

June 4 to August 11, 2003: The A16N cruise took place aboard the NOAA ship Ronald H. Brown under the auspices of the National Oceanic and Atmospheric Administration (NOAA). The first hydrographic leg (June 19 - July 10) was from Reykjavik to Funchal, Madeira along the 20°W meridian and the second leg (July 15 - August 11) continued operations from Funchal to Natal, Brazil on a track southward and ending at 6°S, 25°W. The research was the first in a decadal series of repeat hydrography sections jointly funded by NOAA-OGP and NSF-OCE as part of the CLIVAR/CO2/hydrography/tracer program (http://www.pmel.noaa.gov/co2/story/A16N)

Ten years later... : August 3, 2013: The NOAA research vessel, Ronald H. Brown, leaves Reykjavik, Iceland to embark on a voyage that will reoccupy the same cruise track as it did 10 years ago. On board are scientists from fourteen universities/institutions, including two from EOAS/FSU (Bill landing and Rachel Shelley). In fact, many of the same scientists (and many new ones) are on board, excited to see differences and/or similarities in their comparison with their earlier data from line A16N. To see the range of parameters that we will be measuring during A16N, take a look at this link: http://www.aoml.noaa.gov/ocd/gcc/A16N/.

What's the point?

The aim of this cruise is to investigate how much anthropogenic (generated by human activity) carbon dioxide has been taken up by the ocean. Atmospheric CO₂ concentrations have increased rapidly since the start of the industrial revolution (circa 1850). Although there are a number of well-studied natural processes that release CO₂to the atmosphere (e.g. volcanic eruptions), models can only capture the current rapid increase in atmospheric CO₂ concentrations if they factor in human activities (i.e. fossil fuel burning). In order to do this, scientists are measuring tracers that inform us of carbon cycling. For example, one such tracer is CFCs (chlorofluorocarbons - a group of very stable, and persistent, organic compounds that were used as refrigerants and aerosol propellants). In the late 1980s CFC use was regulated and their use has been phased out, after it was found that their use contributed significantly to ozone depletion in the upper atmosphere ('the ozone hole'). As the ocean is in contact with the atmosphere, gas exchange across the ocean-atmosphere interface results in the ocean absorbing an atmospheric 'signature' that can be accurately dated. This information then identifies the water mass which can be traced on its flow path around the global ocean, which in turn provides data on how other gases (such as CO₂ ) are cycled by the ocean.

The ocean is the major global sink for CO₂. What that means is that more CO₂is absorbed by the ocean than by any other sink (the next most important sink is terrestrial plants). If the ocean did not absorb as much anthropogenic CO₂ as it does, the global average temperature would be much higher than it is currently. One of the many things that people are trying to establish is just how much excess CO₂ the ocean can absorb, and what the implications for less (or more storage) would be. For that, they need data!

Over the next few weeks, I will introduce you to the scientists behind the instruments, but for now, here's some photos...





Global map of the hydrographic sections with carbon system measurements

 




The RV Ronald H. Brown in port in Reykjavik, Iceland




The cabins on the Ron Brown. Two people share a cabin (or stateroom). I have the top bunk (not much headroom!).
The bathroom (or head) is shared between four people.