Endo, H. 2011. Long-term changes of seasonal progress in baiu rainfall using 109 years (1901-2009) daily station data. Scientific Online Letters on the Atmosphere (SOLA) 7: 5-8.
The author, who is with the Meteorological Research Institute of Japan, writes that "the rainy season in early summer over East Asia, which is generally called the Baiu season in Japan, is brought about by northward migration of a narrow rain band with a stationary frontal zone from May to July," while noting that "future projections with climate model studies indicate that global warming induced by increasing greenhouse gases will lead to increased Baiu rainfall," citing the studies of Kimoto (2005), Kitoh and Uchiyama (2006), Kusunoki et al. (2006) and Kusunoki and Mizuta (2008).
What was done
Using digitized historical daily precipitation data from 37 stations of the Japan Meteorological Agency -- which were spread across both Eastern and Western Japan and had been checked for uniformity by Fujibe et al. (2006) -- Endo analyzed the data for "long-term changes of the Baiu rainfall during the last 109 years," in order to see how close they would come to confirming or refuting state-of-the-art climate model predictions of increased rainfall in response to increasing concentrations of atmospheric greenhouse gases, over a period of time when the atmosphere's CO2 concentration rose by more than 30%.
What was learned
Endo reports that "in the early Baiu season (early to mid June), significant decreasing trends with a 90% confidence level are observed in Eastern and Western Japan," but he says that "in the late Baiu season (mid to late July), in contrast, significant increasing trends with a 95% confidence level are observed on the Japan Sea side of Eastern and Western Japan." In the mid Baiu season (late June to early July), however, he says that "no significant trends are recognized." And, most importantly of all, he adds that the same holds true, i.e., that no significant trends are recognized, "in the entire Baiu season (June to July) over all regions."
What it means
Endo's findings clearly indicate that climate model projections of increased Baiu rainfall in response to global warming induced by increasing concentrations of atmospheric greenhouse gases -- over a period of time when the world's climate alarmists claim the earth warmed at a rate and to a level that were both unprecedented over the past millennium or more -- are simply not correct.
Fujibe, F., Yamazaki, N. and Kobayashi, K. 2006. Long-term changes of heavy precipitation and dry weather in Japan (1901-2004). Journal of the Meteorological Society of Japan 84: 1033-1046.
Kimoto, M. 2005. Simulated change of the east Asian circulation under global warming scenario. Geophysical Research Letters 32: 10.1029/2005GL023383.
Kitoh, A. and Uchiyama, T. 2006. Changes in onset and withdrawal of the East Asian summer rainy season by multi-model global warming experiments. Journal of the Meteorological Society of Japan 84: 247-258.
Kusunoki, S. and Mizuta, R. 2008. Future changes in the Baiu rain band projected by a 20-km mesh global atmospheric model: Sea surface temperature dependence. Scientific Online Letters of the Atmosphere (SOLA) 4: 85-88.
Kusunoki, S., Yoshimura, J., Yoshimura, H., Noda, A., Oouchi, K. and Mizuta, R. 2006. Change of Baiu rain band in global warming projection by an atmospheric general circulation model with a 20-km grid size. Journal of the Meteorological Society of Japan 84: 581-611.Reviewed 30 March 2011