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The use of synoptic climatology with general circulation model output over New Zealand
Author(s) -
Parsons Simon,
McDonald Adrian J.,
Renwick James A.
Publication year - 2014
Publication title -
international journal of climatology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.58
H-Index - 166
eISSN - 1097-0088
pISSN - 0899-8418
DOI - 10.1002/joc.3919
Subject(s) - climatology , gcm transcription factors , context (archaeology) , general circulation model , environmental science , atmospheric circulation , coupled model intercomparison project , meteorology , climate change , geography , geology , oceanography , archaeology
ABSTRACT A cluster analysis‐based synoptic classification scheme, known as the Kidson types, was applied to reanalyses and Coupled Model Inter‐comparison Project phase 3 ( CMIP3 ) general circulation model ( GCM ) output over New Zealand to identify the potential for future changes in regional circulation. Results indicate that a number of GCM 20th century control runs reproduce the type frequencies observed in reanalysis data. Application to future scenario runs for the periods 2046–2065 and 2081–2100 displays little variation in the annual frequency of the synoptic types relative to the 20th century, especially when uncertainty associated with the model ensemble is considered. This is surprising in the context of previous work on possible future movements in jet position and subsequent impacts on weather patterns. A sensitivity analysis that mimics the movement of the jet position was performed, revealing that the annual type frequencies are relatively insensitive to change. To determine whether this is a problem with the synoptic typing scheme, a correlation‐based classification technique was also used, but showed similar results. This work highlights issues with applying synoptic classification schemes to GCM output and indicates that if such schemes are to be used they should be designed and tested with this application in mind.