今年櫻花何時開放？原來日本是這樣預測櫻花花期的

日本櫻花今年將在何時盛開？想去日本旅遊的你，是不是也在琢磨根據這個時間安排行程？在如今的信息時代，櫻花花期的預測也緊跟潮流，除了人員觀測，大數據、算法、甚至人工智能齊上陣。只要密切關注相關的預測平臺信息發佈，保準錯不了。

As spring approaches in Japan, the country's weather forecasters face one of their biggest missions of the year: predicting exactly when the cherry blossoms will bloom.

隨着春天的臨近，日本的天氣預報員們將面臨着每年最重要的一項任務：預測櫻花開放的準確日期。

Japan's Sakura or cherry blossom season is feverishly anticipated by locals and visitors alike. Many tourists plan their entire trips around the blooms, and Japanese flock to parks in their millions to enjoy the seasonal spectacle.

當地人和遊客都非常期待日本的櫻花季。很多遊客按照櫻花季的時間規劃整個行程，還有數百萬日本人會在櫻花季涌入公園飽覽盛景。

"People pay more attention to the cherry blossom season than any other flower in Japan," Ryo Dojo, an official of the statistics unit at the Japan Meteorological Agency, told AFP.

日本氣象廳統計部門官員道焦亮告訴法新社記者說：“在日本，人們對櫻花的關注遠多於其他花。”

The most basic element of predicting when the delicate pink and white petals will begin to unfurl is a large data set of temperatures.

要預測嬌美的粉白色櫻花何時盛開，最基本的是要基於大規模的氣溫數據集合。

unfurl [ʌn'fɜːl]：vt.展開；使…臨風招展

That's because the flowers will come earlier if temperatures rise quickly in spring.

因爲如果氣溫在春季快速上升，櫻花就會提早盛開。

Conversely, if temperatures in the autumn and winter period are higher than usual, the blooms can end up being delayed.

相反，如果此前的秋冬兩季氣溫比平時高，櫻花的開放時間會推遲。

Extreme weather can affect the trees too, with unusual patterns in 2018 prompting some blossoms to appear in October, well before the usual season.

極端天氣也會影響櫻樹。2018年不尋常的氣候類型導致一些櫻花在10月開放，比平時提早太多。

In general, blooms begin as early as March in southern Kyushu and appear as late as May in northernmost Hokkaido.

一般來講，日本南部九州的櫻花早在三月就開放了，而在最北部的北海道，櫻花要到五月纔開放。

In a bid to improve its forecasts, some outfits have started crowdsourcing data, including Weathernews, a firm in Chiba near Tokyo.

爲提高預測準確性，一些機構開始通過衆包的方式收集數據，比如，東京附近千葉市的天氣新聞公司。

It relies on photos of buds sent in regularly by 10,000 citizens across the country who are registered on the company's website and app.

這家公司的數據來源於1萬名日本各地的市民定期發送的櫻花花蕾照片。這些市民都在該公司的網站和應用程序上進行了註冊。

"Cherry blossom forecasting is impossible for us without this system," a spokeswoman said.

公司一位女發言人說：“如果沒有這個系統，我們就無法預測櫻花盛開的時間。”

200萬份報告

The company launched what they call the "Sakura project" in 2004, signing up members who choose their own cherry tree and send pictures of its buds to the firm at regular intervals.

這家公司在2004年推出了“櫻花項目”，與民衆簽約。民衆選擇所要觀測的櫻花樹，並定期將花蕾照片發送給公司。

Just observing the bud can give surprisingly accurate information about how far the flower is from full bloom.

只需觀察花蕾，就能給出櫻花盛開時間的準確信息，着實出人意料。

A sakura bud still a month from blossoming will be small and firm, but after 10 days, the tip turns slightly yellow-green, and then a darker green part emerges.

還有一個月纔開花的櫻花花蕾小而緊實，但在10天之後，花蕾的頂部有些許變爲黃綠色，之後會呈現出深綠色。

When the tip of the bud turns a faint pink, it's just a week until bloom-time.

花蕾的頂部變爲淡粉色時，距離花開就只有一週了。

Thanks to the project, Weathernews has accumulated data from two million reports on cherry flower buds in the past 15 years, which it uses to increase the accuracy of its forecasting.

由於有了這個項目，天氣新聞公司在過去15年間已經收集了櫻花花蕾的200萬份報告，公司以此提高了預測的準確性。

It also incorporates weather data collected from its own observation devices across Japan－13,000 locations in total, 10 times more than the official weather agency has.

公司還整合了用自己的觀測設備收集的天氣數據，這些設備遍佈日本1.3萬處觀測場所，比日本氣象廳的觀測場所多10倍。

Weathernews employees also call around 700 parks regularly to check the growth of cherry flower buds.

公司職員還會定期給700個公園打電話，覈對櫻花花蕾的生長情況。

The company and other forecasters also employ mathematical models and algorithms.

該公司和其他預測機構還使用了數字模型和算法。

Otenki Japan, a forecaster run by a subsidiary of precision-equipment manufacturer Shimadzu, even began using artificial intelligence to predict cherry blossoms in 2018.

精密儀器製造商日本島津公司的子公司運營的預測機構Otenki Japan去年甚至開始使用人工智能預測花期。

subsidiary [səb'sɪdɪərɪ]：n.子公司

櫻花季蘊藏大商機

The forecasts are not only for flower fans but reflect the fact that Sakura season is big business in Japan.

這些預測並不只針對賞花者，還說明賞櫻在日本是個大生意。

Cherry blossoms symbolize the fragility of life in Japanese culture as full blooms only last about a week before the petals start falling off trees.

櫻花盛開在日本文化中象徵着生命的脆弱，因爲花朵全部盛開的時間僅有一週左右，之後花瓣凋零落下。

And in that period and the preceding weeks, shops will pack their shelves with sakura-themed merchandise. Pink and white blossoms seem to decorate everything from beer cans to sakura-flavored chips and flower-themed candy.

在花期及之前數週，商店會囤滿櫻花主題商品。啤酒罐、櫻花味薯條、櫻花主題糖果……粉白色的櫻花裝點着各種商品。

Japan's Meteorological Agency stopped forecasting cherry blossoms in 2010, after more than five decades, saying other organizations were now making predictions with sufficient accuracy.

日本氣象廳在2010年終止了其持續50多年的櫻花花期預測工作，稱其他機構目前的預測準確率已足夠高。

The agency does however still declare the official start of cherry blossom season by monitoring 58 so-called barometer trees.

不過，日本氣象廳還是會通過監測58棵“晴雨樹”來正式宣佈櫻花季的開始。

The trees are at locations across the country, and the precise locations are considered a closely-guarded secret.

這些“晴雨樹”遍佈日本各地，但其準確地點祕而不宣。

From the beginning of March, inspectors visit the barometer trees once a day, with the trips increasing to twice daily as blossoming nears.

從3月初起，監測員每天去觀察一次“晴雨樹”。隨着花期的臨近，他們會改爲每天去兩次。