著者

青野 靖之 谷 彩夏

出版者

日本農業気象学会

雑誌

生物と気象 (ISSN:13465368)

巻号頁・発行日

vol.14, pp.18-28, 2014 (Released:2014-03-27)

参考文献数

25

被引用文献数

1 7

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We investigated historical records (e.g. old diaries, historiography, and daily newspapers) and acquired phenological data series for autumn-tinted maple (Acer spp.) leaves in Kyoto, Japan. From the 10th to 21st centuries, we gathered 504 years of phenological data for maple leaves' autumn tints. A preliminary analysis suggested that the dates of the maple autumn tints were affected by the October mean temperature. Therefore, an attempt was made to reconstruct the October mean temperature in Kyoto by applying the phenological data for autumn tints of maple leaves. Autumn temperature series partially showed a pattern similar to springtime temperature series. A cooling trend over the 15th — 16th centuries and cool conditions in the late 17th and the early 19th centuries were detected in both the October and the March temperature series; however, October temperature change preceded March temperature change by about 10—20 years. This suggests that the time-lag of response of October temperatures in Kyoto to the solar variation may be smaller than that of March temperatures.

著者

青野 靖之 小元 敬男

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.49, no.4, pp.263-272, 1994-03-10 (Released:2010-02-25)

参考文献数

29

被引用文献数

11 18

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The change of the monthly mean temperature for March since the 11th century is estimated from the records of cherry blossom in old documents. The dates given as cherry blossom festivals in old diaries and chronicles are assumed as full flowering dates of Prunus jamasakura, one of the native cherry tree species of Japan. The temperatures are estimated by means of DTS method, which has been used to estimate flowering date from temperature data. It is shown that computations for the recent 40 years proved that the decadal average values of the March temperature may be obtained by the method for P. jamasakura with the accuracy of 0.1°C of the root mean square error.It is shown that the entire study period can be roughly divided into three subsections. In the first period (the 11-13th centuries), the March appeared to be generally very warm compared with other periods, however, accuracy of the estimated values are rather poor because decadal averages are computed from relatively small number of years due to missing of records.For the second period (the 14-16th centuries), there was a period of warming of 2°C from 1470's to 1610's, otherwise the decadal averages suggest large fluctuations, at least partly attributed to poor quality of full flowering data of P. jamasakura.For the third period (the 17-20th centuries), temperatures generally tend to be estimated in low values, especially estimations in 1690-1710's and 1810-30's continued to the present is noticeable. The rise amounts to 3.4°C seems due both to urban warming and larger scale warming over the central Japan roughly the same degree.

著者

青野 靖之

出版者

日本時間学会

雑誌

時間学研究 (ISSN:18820093)

巻号頁・発行日

vol.1, pp.17-29, 2011 (Released:2017-02-28)

著者

青野 靖之 村上 なつき

出版者

The Society of Agricultural Meteorology of Japan

雑誌

生物と気象 (ISSN:13465368)

巻号頁・発行日

vol.17, pp.25-33, 2017 (Released:2017-04-10)

参考文献数

32

被引用文献数

6 8

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We constructed a simplified method to estimate first flowering dates of cherry tree (Prunus×yedoensis), considering temperature conditions in endodormancy process. We adopted the DTS method, which is an accumulation model of forcing effect of temperatures during developing process, as an estimation model of cherry blossom phenology in this study. In our previous studies, DTS method with fixed (pre-determined) starting dates for each site showed high accuracies for cold regions, whereas low accuracies for warm regions. Such accuracy drop was attributed to the volatility in endodormancy completion in warmer region of Japan, affected by inter-annual variation in chilling temperature during winter season. In order to reduce such error, it had been necessary to calculate chilling hours from hourly temperature data and evaluate the progress in endodormancy releasing process, with complicated conventional procedures. In our new model, an annual discrepancy in starting date of forcing effect from the pre-determined dates, calculated from a simplified procedure in our previous model, were calculated as the product of the correction coefficient, Ci, for each year and a winter temperature normal value above a threshold of chilling effect for endodormancy release, (TDJ-1.5), for each site. Annual correlation coefficient Ci was calculated from averaged winter temperatures at 7 secular observatories in warm region in Japan. Estimated first flowering dates with and without correction of starting dates were compared each other. The estimations by new method kept under about 3.2 days of RMSE. The introduction of new method also reduced RMSE within 3 days into approximately half of stations, applied to verification of new method with relatively long (50-year) period.

著者

青野 靖之

出版者

The Association of Japanese Geographers

雑誌

日本地理学会発表要旨集

巻号頁・発行日

pp.17, 2013 (Released:2013-09-04)

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17世紀以降に江戸(東京)で書かれた古記録類から得られたサクラの植物季節データを用いて、3月平均気温の復元を試みた。西暦1636年から1905年までで判明した合計207年分のヤマザクラの満開日により、17世紀中盤以降の3月平均気温の推移が明らかになった。解析の結果、17世紀後半と19世紀初頭に寒冷な時代のあることがわかった。これらの低温期は、京都における3月の気温の復元推移にも共通して現れており、太陽活動のマウンダー極小期(17世紀後半)とドルトン極小期(19世紀初頭)に対応したものである。マウンダー極小期とドルトン極小期における江戸の3月平均気温はそれぞれ、およそ4℃、5℃とみられる。

著者

青野 靖之 小元 敬男

出版者

日本農業気象学会

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.45, no.4, pp.243-249, 1990-03-10 (Released:2010-02-25)

参考文献数

25

被引用文献数

19 22

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Blooming dates of Prunus yedoensis at 38 sites are estimated by using “the number of days transformed to standard temperature (hereafter referred as DTS)” for the 25 year period starting 1961. The sites are all located at or in the vicinity of the meteorological observatories of Japan Meteorological Agency. The standard temperature for DTS in this study is chosen 25°C, for the temperature characteristic Ea, a value [71.1kJ mol-1] is used for all stations. Both of these values are the same as those in our previous paper, although CGS unit was used before.It is shown that by this first estimation RMS errors of estimated blooming dates fell within a range 1-3 days except for stations in regions of southern coasts of Kyushu Is. and Izu Is. An attempt of reducing errors, in the first place, readjustment of accumulated DTS was made. This enable us to reduce RMS error up to 0.5 days from the previous computations. But this approach was not very effective at southern stations. Large RMS error in these warm regions seemed to be due to incomplete transition of rest break or large interannual variation of this process. An adjustment of estimation of blooming date at southern sites is made by applying the concept of chill-unit which is the weighted hour corresponding to the effectiveness of chilling to rest completion. It is shown that this procedure reduced RMS error of blooming dates to 2.32 days from 6.64 days at Hachijo Is., and at all stations in warm regions the error reduced to about 2 days.

著者

小元 敬男 青野 靖之

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.45, no.1, pp.25-31, 1989-06-10 (Released:2010-02-25)

参考文献数

21

被引用文献数

22 15

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An attempt is made to estimate blooming dates of Prunus yedoensis for 21 meteorological stations in Japan by using DTS (the number of days transformed to standard temperature). The starting date for computation at each station is determined by correlation analysis. At many stations the date lies between 40 and 55th day from January 1st.The number of days transformed to a standard temperature (in this study 25°C is used) at each station is computed by adding characteristic temperature of each day from a starting date to blooming date for various temperature characteristic (Ea). The estimated blooming date is the date when accumulated value of DTS reached at that of mean observed blooming date for the site.It is found that 17kcal mol-1 for Ea gives minimum error when averaged over all sites. Using this Ea and D2 which is the starting date determined from error analysis, computations are made to estimate blooming dates at each station between 1961 and 1985. It is shown that at stations in Hokkaido and Tohoku districts, RMS errors between the observed and the calculated blooming dates fall between 1 and 2 days. At stations in other areas, the errors range between 2 and 3, except for Hachijo where it becomes 6.7 days. The large error at this southernmost station seemed to be attributed to year to year change of degrees of rest completion of Prunus yedoensis, which affect effectiveness of temperature just before blooming.

著者

本間 幸治 青野 靖之 小元 敬男

出版者

The Society of Agricultural Meteorology of Japan

雑誌

農業気象 (ISSN:00218588)

巻号頁・発行日

vol.51, no.4, pp.321-327, 1995-12-10 (Released:2010-02-25)

参考文献数

17

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The relationship between temperature and the southern limits of temperate deciduous trees in Japan is discussed by using two indexes of temperature. One is the mean temperature of the warmest month to represent summer condition, and another is the chilling hours (accumulated hours below 7.2°C (45°F)) for winter. Eight species of deciduous trees (Zelkova serrata, Fagus crenata, Aesculus turbinata, Pterocarya rhoifolia, Betula ermanii, Quercus mongolica, Ulmus davidiana and Acer mono) were chosen for this purpose. It appeared that the chilling hours are effective in determining the southern limit of Zelkova serrata, suggesting at least thermal condition in winter is important in the warm side distribution for this species. For other species, the case in which winter condition may affect southern limits is found in the coastal areas and the relatively low latitude region of Japanese mainland.The impact of global warming on the potential probability of occurence for Fagus crenata in Osaka Prefecture and its vicinity is also examined. For a 1.5°C mean temperature rise, the potential probability becomes 0.02-0.21 from the present 0.13-0.68 in Mt. Izumi-Katsuragi and Mt. Koya area, and 0.24-0.70 from 0.65-0.76 in Mt. Kongo. For a 3.0°C rise, the probability decreases to 0.04-0.34 in Mt. Kongo. In the other two areas, it will become almost 0 suggesting the climatic condition becomes too warm for the occurence of this species.