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Interannual variations and trends in surface air temperature in Finland in relation to atmospheric circulation patterns, 1961-2011

Irannezhad, M.; Chen, Deliang and Kløve, B. (2014) In International Journal of Climatology Epub ahead of print.
Abstract
Annual and seasonal variations in surface air temperature (SAT) during the period 1961–2011 were analysed using daily mean temperature data sets from regular grid points (10?×?10?km2) throughout Finland. The Mann–Kendall nonparametric test was used to detect significant historical trends in SAT and Spearman's correlation coefficient (?) to test the relationships between SAT patterns and various atmospheric circulation patterns over the northern hemisphere. The results showed that mean annual SAT in Finland increased (p?<?0.05) by 0.4?±?0.2?°C per decade during the study period and that the SAT was significantly (??=?0.58, p?<?0.05) positively correlated with the Arctic Oscillation (AO) index. However, there were spatial differences... (More)
Annual and seasonal variations in surface air temperature (SAT) during the period 1961–2011 were analysed using daily mean temperature data sets from regular grid points (10?×?10?km2) throughout Finland. The Mann–Kendall nonparametric test was used to detect significant historical trends in SAT and Spearman's correlation coefficient (?) to test the relationships between SAT patterns and various atmospheric circulation patterns over the northern hemisphere. The results showed that mean annual SAT in Finland increased (p?<?0.05) by 0.4?±?0.2?°C per decade during the study period and that the SAT was significantly (??=?0.58, p?<?0.05) positively correlated with the Arctic Oscillation (AO) index. However, there were spatial differences within Finland for both the trends and relationships with the atmospheric circulation. Analysis of seasonal mean SAT identified significant (p?<?0.05) warming trends for both spring (by 0.4?±?0.2?°C per decade) and summer (by 0.3?±?0.2?°C per decade). Winter and spring mean SATs were most strongly (p?<?0.05) correlated with the AO index (??=?0.72 and 0.42, respectively), while the most significant teleconnection pattern for mean SAT in summer was the East Atlantic (EA) pattern (??=?0.43, p?<?0.05); and in autumn the EA/West Russia (WR) pattern (??=??0.59, p?<?0.05). These results provide a detailed spatial picture of climate warming in Finland in recent decades and reveal that interannual variation of the SAT in Finland is closely linked with a number of atmospheric circulation patterns, not just the AO and North Atlantic Oscillation (NAO). Annual and cold-season SAT are mainly influenced by the AO and NAO, whereas the EA, EA/WR, Scandinavia (SCA) and West Pacific (WP) patterns play an important role for warm-season SAT. (Less)
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author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Finland, atmospheric circulation patterns, surface air temperature, trend analysis, interannual variability
in
International Journal of Climatology
volume
Epub ahead of print
publisher
John Wiley & Sons
external identifiers
  • scopus:84938889423
ISSN
1097-0088
DOI
10.1002/joc.4193
project
MERGE
language
English
LU publication?
no
id
e603b816-aafb-4160-a92a-4398f6c0eed7 (old id 7515355)
date added to LUP
2015-07-08 14:55:44
date last changed
2017-10-01 04:59:55
@article{e603b816-aafb-4160-a92a-4398f6c0eed7,
  abstract     = {Annual and seasonal variations in surface air temperature (SAT) during the period 1961–2011 were analysed using daily mean temperature data sets from regular grid points (10?×?10?km2) throughout Finland. The Mann–Kendall nonparametric test was used to detect significant historical trends in SAT and Spearman's correlation coefficient (?) to test the relationships between SAT patterns and various atmospheric circulation patterns over the northern hemisphere. The results showed that mean annual SAT in Finland increased (p?&lt;?0.05) by 0.4?±?0.2?°C per decade during the study period and that the SAT was significantly (??=?0.58, p?&lt;?0.05) positively correlated with the Arctic Oscillation (AO) index. However, there were spatial differences within Finland for both the trends and relationships with the atmospheric circulation. Analysis of seasonal mean SAT identified significant (p?&lt;?0.05) warming trends for both spring (by 0.4?±?0.2?°C per decade) and summer (by 0.3?±?0.2?°C per decade). Winter and spring mean SATs were most strongly (p?&lt;?0.05) correlated with the AO index (??=?0.72 and 0.42, respectively), while the most significant teleconnection pattern for mean SAT in summer was the East Atlantic (EA) pattern (??=?0.43, p?&lt;?0.05); and in autumn the EA/West Russia (WR) pattern (??=??0.59, p?&lt;?0.05). These results provide a detailed spatial picture of climate warming in Finland in recent decades and reveal that interannual variation of the SAT in Finland is closely linked with a number of atmospheric circulation patterns, not just the AO and North Atlantic Oscillation (NAO). Annual and cold-season SAT are mainly influenced by the AO and NAO, whereas the EA, EA/WR, Scandinavia (SCA) and West Pacific (WP) patterns play an important role for warm-season SAT.},
  author       = {Irannezhad, M. and Chen, Deliang and Kløve, B.},
  issn         = {1097-0088},
  keyword      = {Finland,atmospheric circulation patterns,surface air temperature,trend analysis,interannual variability},
  language     = {eng},
  publisher    = {John Wiley & Sons},
  series       = {International Journal of Climatology},
  title        = {Interannual variations and trends in surface air temperature in Finland in relation to atmospheric circulation patterns, 1961-2011},
  url          = {http://dx.doi.org/10.1002/joc.4193},
  volume       = {Epub ahead of print},
  year         = {2014},
}