Cherry blossom front

The cherry blossom front (桜さくら前線ぜんせん, sakura zensen) is the advance of the cherry blossoms across Japan. The Japan Meteorological Agency records the opening and full bloom of the blossoms from Kyūshū in late March to Hokkaidō in the middle of May. The advancing front is also the subject of regular reports by the major news agencies. The cherry blossom is of great public interest in Japan due to its symbolism and the custom of flower viewing known as hanami.

Forecasts

From 1951 the Japan Meteorological Agency produced forecasts for the Kantō region and from 1955 for the whole of Japan excepting Okinawa and the Amami Islands.^[1] From 2010, the Agency left forecasting to the private sector although it continues to observe and determine the impact of the climate upon the flowering of the cherry.^[2]^[3] The forecast is based on the Arrhenius equation, with the formula ${\text{DTS}}=\exp \left[9.5\times 10^{3}\cdot {\frac {T-288.2}{288.2\,T}}\right],$ where T is the mean day temperature in kelvins, and DTS represents the number of days transformed to standard temperature.^[4]^[5]^[6]

Blossoming

The day of opening^{[note 1]} is defined as the point at which at least five to six flowers have opened on the sample tree. The day of full bloom is when at least 80% of the flowers have opened. The Yoshino cherry is typically observed since, from the late Edo period, it has been planted across the archipelago.^[7] Sample trees also include the Higan cherry in the south and Prunus sargentii (Sargent's cherry) in the north.^[7]

In 2006 it was reported that the cherry blossoms might overtake the plum blossoms before reaching Hokkaidō.^[8]

Sample trees

In Tokyo the sample tree specified by the Meteorological Agency is within the precincts of Yasukuni Jinja^[3]^[9]

There are fifty-nine sample trees at any one time. Successor junior trees are selected from among prospective candidates when an incumbent becomes too old or is otherwise incapacitated.^[3] For instance, the sample tree in Mito collapsed under the weight of snow in 2005, while that at the southern tip of Ishigaki Island was felled by a typhoon a year later.^[3] The fifty-nine sample trees are located across Japan, corresponding to the sites of the Agency's principal weather stations:^[10]^[11]^[12]

Okinawa: Ishigaki, Miyako-jima, Naha, Minamidaitō
Kyūshū/Yamaguchi: Fukuoka, Shimonoseki, Ōita, Nagasaki, Saga, Kumamoto, Miyazaki, Kagoshima, Amami (formerly Naze)
Shikoku: Takamatsu, Tokushima, Matsuyama, Kōchi
Chūgoku: Hiroshima, Okayama, Matsue, Tottori
Kinki: Ōsaka, Hikone, Kyōto, Maizuru, Kobe, Nara, Wakayama
Tōkai: Nagoya, Shizuoka, Gifu, Tsu
Kantō: Tōkyō, Mito, Utsunomiya, Maebashi, Kumagaya, Chōshi, Yokohama, Nagano, Kōfu
Hokuriku: Niigata, Toyama, Kanazawa, Fukui
Tōhoku: Sendai, Aomori, Akita, Morioka, Yamagata, Fukushima
Hokkaidō: Sapporo, Wakkanai, Asahikawa, Abashiri, Obihiro, Kushiro, Muroran, Hakodate.

Notes

^ Japanese terms: day of opening (開花かいか日び, kaikabi); day of full bloom (満開まんかい日び, mankaibi); sample tree (標本ひょうほん木き, hyōhonboku); cherry blossom forecast (さくらの開花かいか予想よそう, sakura no kaikayosō)

References

^ "新あたらしいサクラの開花かいか予想よそう" (PDF). Japan Meteorological Agency. Archived from the original (PDF) on 6 January 2013. Retrieved 1 March 2012.
^ "気象庁きしょうちょうにおけるさくらの開花かいか予想よそうの発表はっぴょう終了しゅうりょうについて" (PDF). Japan Meteorological Agency. 25 December 2009. Retrieved 1 March 2012.
^ ^a ^b ^c ^d "桜さくらの標本ひょうほん木き、進すすむ代替だいがわり老齢ろうれい化かで後進こうしん育成いくせい急きゅうピッチ". Asahi Shimbun. 25 March 2011. Retrieved 1 March 2012.
^ "さくら開花かいか予想よそう方法ほうほうについて". Japan Meteorological Agency. Archived from the original on 6 May 2012. Retrieved 1 March 2012.
^ Aono Yasuyuki (1993). "Climatological Studies on Blooming of Cherry Tree (Prunus yedoensis) by Means of DTS Method". Bulletin of the University of Osaka Prefecture. Ser. B, Agriculture and Life Sciences (in Japanese and English). 45. Osaka Prefecture University: 155–92.
^ Dass, Vidhya; Brennan, Elizabeth. "Predicting Peak Bloom Date of Cherry Blossoms: Finding an Optimal Heuristic". Virginia Tech. Archived from the original on 18 June 2013. Retrieved 9 March 2012.
^ ^a ^b "さくらの開花かいか日びと満開まんかい日び" (PDF). Japan Meteorological Agency. Retrieved 1 March 2012.
^ Joyce, Colin (7 April 2006). "Cherries winning the blossom race". The Daily Telegraph. Retrieved 1 March 2012.
^ "境内けいだいの桜さくら（東京とうきょうの開花かいか標本ひょうほん木き）開花かいか状じょう況きょうの映像えいぞう". Yasukuni Jinja. Archived from the original on 5 May 2012. Retrieved 1 March 2012.
^ "Cherry blossoms 2012 - day of opening" (in Japanese). Japan Meteorological Agency. Archived from the original on 8 March 2012. Retrieved 1 March 2012.
^ "Agency Weather Stations (気象台きしょうだい, 測候所そっこうじょ)" (in Japanese). Japan Meteorological Agency. Retrieved 2 March 2012.
^ "2009 revised forecast (Note 4. 気象台きしょうだいや測候所そっこうじょの定さだめた標本ひょうほん木き)" (PDF) (in Japanese). Japan Meteorological Agency. Archived from the original (PDF) on 20 April 2012. Retrieved 2 March 2012.

External links

(in Japanese) 2012 day of opening (JMA record)
(in Japanese) 2012 day of full bloom (JMA record)
(in Japanese) 2011 day of opening (JMA record)
(in Japanese) 2011 day of full bloom (JMA record)
(in Japanese) JMA flowering data, 1953–2010

[7] Japanese terms: day of opening (開花かいか日び, kaikabi); day of full bloom (満開まんかい日び, mankaibi); sample tree (標本ひょうほん木き, hyōhonboku); cherry blossom forecast (さくらの開花かいか予想よそう, sakura no kaikayosō)

[method-1] "新あたらしいサクラの開花かいか予想よそう" (PDF). Japan Meteorological Agency. Archived from the original (PDF) on 6 January 2013. Retrieved 1 March 2012.

[2] "気象庁きしょうちょうにおけるさくらの開花かいか予想よそうの発表はっぴょう終了しゅうりょうについて" (PDF). Japan Meteorological Agency. 25 December 2009. Retrieved 1 March 2012.

[Asahi-3] "桜さくらの標本ひょうほん木き、進すすむ代替だいがわり老齢ろうれい化かで後進こうしん育成いくせい急きゅうピッチ". Asahi Shimbun. 25 March 2011. Retrieved 1 March 2012.

[4] "さくら開花かいか予想よそう方法ほうほうについて". Japan Meteorological Agency. Archived from the original on 6 May 2012. Retrieved 1 March 2012.

[5] Aono Yasuyuki (1993). "Climatological Studies on Blooming of Cherry Tree (Prunus yedoensis) by Means of DTS Method". Bulletin of the University of Osaka Prefecture. Ser. B, Agriculture and Life Sciences (in Japanese and English). 45. Osaka Prefecture University: 155–92.

[6] Dass, Vidhya; Brennan, Elizabeth. "Predicting Peak Bloom Date of Cherry Blossoms: Finding an Optimal Heuristic". Virginia Tech. Archived from the original on 18 June 2013. Retrieved 9 March 2012.

[Cherry-8] "さくらの開花かいか日びと満開まんかい日び" (PDF). Japan Meteorological Agency. Retrieved 1 March 2012.

[9] Joyce, Colin (7 April 2006). "Cherries winning the blossom race". The Daily Telegraph. Retrieved 1 March 2012.

[10] "境内けいだいの桜さくら（東京とうきょうの開花かいか標本ひょうほん木き）開花かいか状じょう況きょうの映像えいぞう". Yasukuni Jinja. Archived from the original on 5 May 2012. Retrieved 1 March 2012.

[11] "Cherry blossoms 2012 - day of opening" (in Japanese). Japan Meteorological Agency. Archived from the original on 8 March 2012. Retrieved 1 March 2012.

[12] "Agency Weather Stations (気象台きしょうだい, 測候所そっこうじょ)" (in Japanese). Japan Meteorological Agency. Retrieved 2 March 2012.

[13] "2009 revised forecast (Note 4. 気象台きしょうだいや測候所そっこうじょの定さだめた標本ひょうほん木き)" (PDF) (in Japanese). Japan Meteorological Agency. Archived from the original (PDF) on 20 April 2012. Retrieved 2 March 2012.

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