Characteristics of wintertime daily and extreme minimum temperature over South Korea

Abstract In South Korea, consecutive positive temperature anomalies have been observed since the mid‐1980s. The objective of this study is to assess the recent trends in, and variability of, daily minimum temperature over South Korea with particular emphasis on its extremes. Temporal characteristics...

Full description

Bibliographic Details
Published in:International Journal of Climatology
Main Authors: Ryoo, Sang‐Boom, Kwon, Won‐Tae, Jhun, Jong‐Ghap
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2004
Subjects:
Online Access:http://dx.doi.org/10.1002/joc.990
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjoc.990
https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/joc.990
Description
Summary:Abstract In South Korea, consecutive positive temperature anomalies have been observed since the mid‐1980s. The objective of this study is to assess the recent trends in, and variability of, daily minimum temperature over South Korea with particular emphasis on its extremes. Temporal characteristics of wintertime daily and extreme minimum temperature‐related variables were analysed on a seasonal basis for the period of 1958–59 to 2000–01. The results show continually fewer days with extreme low minimum temperature since the mid‐1980s. However, no significant change in the 1 day temperature difference was observed during the same period, indicating little change in the frequency of cold surges. Also, during the period analysed, there is a significant positive trend in the seasonal mean temperature, a negative trend in the frequency of the extreme cold days, and no significant trend in the seasonal occurrence of cold surges. Northern Hemisphere geopotential height fields before and after 1986–87, i.e. the start of successive positive anomalies in the winter surface air temperature over South Korea, showed a substantial decrease throughout the troposphere over the polar region. In the upper levels the overall pattern becomes more wavelike, with eddies embedded between meanders. The differences in the lower troposphere are remarkably similar to the Arctic oscillation, although the centre in the North Atlantic is shifted toward western Europe and differences in the North Pacific are relatively weaker than those in the polar region. The recent positive phase of the Arctic oscillation may contribute to these abrupt changes in wintertime daily minimum temperatures over South Korea. El Niño–southern oscillation phenomena appear to contribute to the interannual variation of cold surge days in South Korea. Years with no cold surges were experienced during La Niña episodes. On the other hand, all years with more than four cases of cold surges were during El Niño episodes. Copyright © 2004 Royal Meteorological Society