School of Natural and Environmental Sciences

Projects

RAGNARoCC

Deployment of a Conductivity-Temperature-Depth (CTD) Rosette
Deployment of a Conductivity-Temperature-Depth (CTD) Rosette during the RAGNARRoC project. Photo credit: Robyn Tuerena

Radiatively active gases from the North Atlantic Region and Climate Change (RAGNARoCC)

This project is a successful NERC consortium bid lead by the University of East Anglia and involving Newcastle University, The University of Southampton, The National Oceanography Centre and The Plymouth Marine Laboratory. It will run for 4 years from 2013 with the objecive of understanding how large, and how variable, are sources and sinks of atmospheric greenhouse gases in the North Atlantic.

We aim to describe how these have changed in the recent past and how they will change in the future under various climate scenarios. Most effort will concentrate on carbon dioxide; we will deliver comprehensive budgets of natural and anthropogenic components of the carbon cycle in the North Atlantic and evaluate why CO2 air-sea fluxes vary regionally, seasonally and multi-annually. We will additionally estimate regional fluxes of methane and nitrous oxide.

In collaboration with partners in Europe and the US, we will determine CO2 air-sea fluxes from networks of voluntary observing ships and at fixed sites. These will be synthesised with observations from hydrographic sections of ocean interior carbon content. We will thus obtain accurate estimates of the uptake, present storage, and net transport of anthropogenic carbon, and variability in the natural uptake and release of atmospheric CO2 by the N. Atlantic.

In parallel we will develop forward and inverse models (of both atmospheric and oceanic kinds) of these fluxes.

Hypotheses 
  1. Past N. Atlantic uptake and variability of CO2 can be quantified by examining the deep Atlantic carbon inventory;
  2. Currently observed variability in CO2 uptake reflects a combination of biological and physical processes driven by climatic variations, the main factors being captured by ocean carbon simulations embedded in climate models;
  3. These variations (past, present and future) are due to a combination of variability internal to the climate system and external anthropogenic forcing - in proportions we will determine.
Objectives
  1. A template for operational forecasting of the fluxes of GHGs into and out of the N. Atlantic, to be implemented as part of ICOS and in combination with ECMWF;
  2. An understanding of that sink that will improve projections of future changes in the ocean CO2 sink;
  3. A quantitative understanding of how and why Atlantic Ocean uptake of anthropogenic CO2 has changed as a result of climate change over the last 100 years.