Climate Variability

• Main Author: Malcolm Haylock
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2004
• Subjects: North Atlantic; North Atlantic oscillation
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.586.7076; http://www.vsamp.com/resume/publications/IPCC_Europe.pdf

North Atlantic climate variability has received much attention since the IPCC third assessment report. A selection of what has been published is presented here. North Atlantic Oscillation (NAO) Marshall et al. (2001) present a comprehensive review of the state of knowledge of Atlantic variability, including the NAO, tropical variability and meridional overturning circulation. Another review of the NAO is given by Wanner et al. (2001). Cassou et al. (2004) examined the stationarity of the NAO and highlight the differences between its two phases. Eastward displacement of the centres of action during the NAO+ phase (Jung et al. (2003) raises questions about the relevance of a station-based index. The role of SSTs is examined. Both tropical and extra tropical SST anomalies alter the frequency distribution of the North Atlantic regimes. Evidence for a northeast shift in the Icelandic low and Azores high centres under enhanced greenhouse conditions is presented by Hu and Wu (2004) who examined the NAO in a climate change GCM experiment. They propose an alternative index that accounts for this shift. Still, recent work has been done by Vinther et al. (2003) to update the Gibraltar/Reykjavik NAO index using recently digitised Spanish pressure data. The eastward shift of the NAO is examined further by Peterson et al. (2003). Their results reveal the nonlinear dependence of the spatial pattern of the NAO on the NAO index, the pattern being shifted to the east (west) for high (low) NAO index. They suggest that the eastward shift is a consequence of the trend towards higher NAO index during the last several decades of the 20th century. A new NAO index based on zonally averaged MSLP is proposed by Li and Wang (2003). Bojariu and Gimeno (2003) review recent work on predictability and methods of numerical modelling of the North Atlantic Oscillation. The SST forcing of the NAO is examined by Paeth et al. (2003). They conclude that while the observed year-to-year NAO fluctuations are barely influenced by the SST, decadal scale ...