Are Greenhouse Gas Signals of Northern Hemisphere winter extra-tropical cyclone activity dependent on the identification and tracking algorithm? ...

• Main Authors: Lionello, Piero, Grieger, Jens, Wernli, Heini, Reale, Marco, Rudeva, Irina, Simmonds, Ian, Schuster, Mareike, Wang, Xiaolan L., Gulev, Sergey, Ulbrich, Uwe, Bardin, Mikhail Yu., Trigo, Isabel F., Leckebusch, Gregor C., Neu, Urs, Tilinina, Natalia D., Ulbrich, Sven, Kew, Sarah F., Raible, Christoph, Liberato, Margarida L. R., Mokhov, Igor I., Feng, Yang, Keay, Kevin, Pinto, Joaquim G., Akperov, Mirseid G., Inatsu, Masaru
• Format: Article in Journal/Newspaper
• Language: English
• Published: Borntraeger 2013
• Subjects: 550 Earth sciences & geology; 530 Physics; Arctic; Greenland; Pacific; Climate change
• Online Access: https://dx.doi.org/10.7892/boris.47712; http://boris.unibe.ch/47712/

For Northern Hemisphere extra-tropical cyclone activity, the dependency of a potential anthropogenic climate change signal on the identification method applied is analysed. This study investigates the impact of the used algorithm on the changing signal, not the robustness of the climate change signal itself. Using one single transient AOGCM simulation as standard input for eleven state-of-the-art identification methods, the patterns of model simulated present day climatologies are found to be close to those computed from re-analysis, independent of the method applied. Although differences in the total number of cyclones identified exist, the climate change signals (IPCC SRES A1B) in the model run considered are largely similar between methods for all cyclones. Taking into account all tracks, decreasing numbers are found in the Mediterranean, the Arctic in the Barents and Greenland Seas, the mid-latitude Pacific and North America. Changing patterns are even more similar, if only the most severe systems are ...