Study Sheds New Light On Global Warming

The index of day-to-day (24-hour) atmospheric pressure variability, will help researchers study both natural and human-induced greenhouse gas climate variations on a global scale. An extended index will also give information on atmospheric pressure fluctuations across various scales of space and time from local through to global and from sub-hourly through to monthly. It will therefore provide a more complete and detailed contemporary long-term record of changes in storminess.

Current measures, including the North Atlantic Oscillation (NAO) index, are unable to provide adequate long-term perspectives and are often subject to uncertainties. For example, current research suggests that there are large natural variations in storminess in the North East Atlantic. However the North East Atlantic is no stormier now than it was around 100 years ago.

The research, which was carried out in collaboration with Dr. Trausti Jónsson from the Icelandic Meteorological Office, has so far been based mainly on Icelandic pressure data but Dr. Edward Hanna at the University of Sheffield´s Department of Geography is leading follow-up work to apply the new index more widely across North West Europe and the North Atlantic.

With the help of international partners, including the Hadley Centre and Danish Meteorological Institute, the project is currently being extended to provide a new global index of pressure variations and storminess.

Dr. Hanna said: "This index will enable us to place climatic phenomena, such as the North Atlantic Oscillation and El Nino Southern Oscillation (ENSO), in a broader perspective of global environmental change. It will also help assess the significance of recent variations in storminess over the UK for example."

"This index will give scientists a better understanding of the bigger picture facing climate change and global warming."

The research has been published in the Meteorologische Zeitschrift, the joint periodical of the meteorological societies of Austria, Germany and Switzerland.