気象衛星 ひまわり9号 画像の事例: 2022年12月の大雪
千葉大 CEReS では、ひまわり 8, 9号の観測データを、
リアルタイムに緯度経度格子に変換してアーカイブし、FTPサーバー から公開している。
気象衛星のシステム、インターネット基盤にくわえて、千葉大のサーバーのシステムが
頑丈につくられているおかげで、災害時であってもデータを見ることができる。
(ただし、立正大学内の計算機では、FTPで外とデータをやりとりすることがむずかしい。
わたしは自宅のパソコンでダウンロードした。)
事例
2022年12月下旬に、
高知で積雪、北海道で鉄道や道路交通が止まるような大雪があった。
これをくわしく見ることができるようにするために、
赤外と可視の画像データを取得し、bzip2 圧縮を展開し、
日本付近の緯度経度領域を切り出し、物理量に変換し、その空間分布を作図した。
- 赤外 TIR 01 (気象庁のいう Band 13):
2022年 12月21日 00 UTC (09 JST) から 12月 25日 23 UTC (08 JST) まで 1時間に1回。
- 高空間分解能 可視 EXT 01 (気象庁のいう Band 03):
赤外と同じ期間のうち、23 UTC (08 JST) と 00 UTC (09 JST) から 07 UTC (16 JST) までの 1時間に1回。
正時の画像が欠損のばあいは、10分後の画像で代用している (該当は 22日 1910 UTC、23日 0710 UTC)。
赤外画像は、北緯 20~50度、東経 120~150度の領域 (ファイル名にふくめる略号 「japan」) を切り出し、
物理量 (輝度温度) に変換した。
そのうち、北緯 30~50度、東経 125~145度の領域 (略号 「sjapan」) の空間分布を地図上に作図した。
可視画像は、北緯 30~50度、東経 125~145度の領域 (略号 「sjapan」) の領域を切り出し、
物理量 (規格化された反射) に変換した。
【赤外と可視で、作図した領域は同じだが、切り出した領域はちがうことに注意。
赤外については周辺に視野をひろげる便宜、可視についてはデータ量の節約を優先したからである。】
色は、数値を区別するためにとりあえずつけたものであり、
値が大きいところを赤系、小さいところを青系、中間の狭い範囲を薄い黄色にしている。
対象となる量にあわせてもっとくふうしたほうがよい。
切り出しと物理量への変換をするプログラム
物理量への変換表データ
千葉大学 CEReS による count2tbb_v103.tgz [2023-01-19 ダウンロードした] にふくまれているファイル。
作図をするプログラム
画像 (物理量の空間分布)
UTC | JST | 赤外画像 (輝度温度 K) | 可視画像 (反射 %) |
2022-12-21 00:00 | 2022-12-21 09:00 |  |
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2022-12-21 01:00 | 2022-12-21 10:00 |  |
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2022-12-21 02:00 | 2022-12-21 11:00 |  |
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2022-12-21 03:00 | 2022-12-21 12:00 |  |
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2022-12-21 04:00 | 2022-12-21 13:00 |  |
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2022-12-21 05:00 | 2022-12-21 14:00 |  |
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2022-12-21 06:00 | 2022-12-21 15:00 |  |
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2022-12-21 07:00 | 2022-12-21 16:00 |  |
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2022-12-21 08:00 | 2022-12-21 17:00 |  |
2022-12-21 09:00 | 2022-12-21 18:00 |  |
2022-12-21 10:00 | 2022-12-21 19:00 |  |
2022-12-21 11:00 | 2022-12-21 20:00 |  |
2022-12-21 12:00 | 2022-12-21 21:00 |  |
2022-12-21 13:00 | 2022-12-21 22:00 |  |
2022-12-21 14:00 | 2022-12-21 23:00 |  |
2022-12-21 15:00 | 2022-12-22 00:00 |  |
2022-12-21 16:00 | 2022-12-22 01:00 |  |
2022-12-21 17:00 | 2022-12-22 02:00 |  |
2022-12-21 18:00 | 2022-12-22 03:00 |  |
2022-12-21 19:00 | 2022-12-22 04:00 |  |
2022-12-21 20:00 | 2022-12-22 05:00 |  |
2022-12-21 21:00 | 2022-12-22 06:00 |  |
2022-12-21 22:00 | 2022-12-22 07:00 |  |
2022-12-21 23:00 | 2022-12-22 08:00 |  |
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UTC | JST | 赤外画像 (輝度温度 K) | 可視画像 (反射 %) |
2022-12-22 00:00 | 2022-12-22 09:00 |  |
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2022-12-22 01:00 | 2022-12-22 10:00 |  |
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2022-12-22 02:00 | 2022-12-22 11:00 |  |
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2022-12-22 03:00 | 2022-12-22 12:00 |  |
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2022-12-22 04:00 | 2022-12-22 13:00 |  |
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2022-12-22 05:00 | 2022-12-22 14:00 |  |
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2022-12-22 06:00 | 2022-12-22 15:00 |  |
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2022-12-22 07:00 | 2022-12-22 16:00 |  |
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2022-12-22 08:00 | 2022-12-22 17:00 |  |
2022-12-22 09:00 | 2022-12-22 18:00 |  |
2022-12-22 10:00 | 2022-12-22 19:00 |  |
2022-12-22 11:00 | 2022-12-22 20:00 |  |
2022-12-22 12:00 | 2022-12-22 21:00 |  |
2022-12-22 13:00 | 2022-12-22 22:00 |  |
2022-12-22 14:00 | 2022-12-22 23:00 |  |
2022-12-22 15:00 | 2022-12-23 00:00 |  |
2022-12-22 16:00 | 2022-12-23 01:00 |  |
2022-12-22 17:00 | 2022-12-23 02:00 |  |
2022-12-22 18:00 | 2022-12-23 03:00 |  |
2022-12-22 19:10 | 2022-12-23 04:10 |  |
2022-12-22 20:00 | 2022-12-23 05:00 |  |
2022-12-22 21:00 | 2022-12-23 06:00 |  |
2022-12-22 22:00 | 2022-12-23 07:00 |  |
2022-12-22 23:00 | 2022-12-23 08:00 |  |
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UTC | JST | 赤外画像 (輝度温度 K) | 可視画像 (反射 %) |
2022-12-23 00:00 | 2022-12-23 09:00 |  |
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2022-12-23 01:00 | 2022-12-23 10:00 |  |
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2022-12-23 02:00 | 2022-12-23 11:00 |  |
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2022-12-23 03:00 | 2022-12-23 12:00 |  |
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2022-12-23 04:00 | 2022-12-23 13:00 |  |
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2022-12-23 05:00 | 2022-12-23 14:00 |  |
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2022-12-23 06:00 | 2022-12-23 15:00 |  |
 |
2022-12-23 07:10 | 2022-12-23 16:10 |  |
 |
2022-12-23 08:00 | 2022-12-23 17:00 |  |
2022-12-23 09:00 | 2022-12-23 18:00 |  |
2022-12-23 10:00 | 2022-12-23 19:00 |  |
2022-12-23 11:00 | 2022-12-23 20:00 |  |
2022-12-23 12:00 | 2022-12-23 21:00 |  |
2022-12-23 13:00 | 2022-12-23 22:00 |  |
2022-12-23 14:00 | 2022-12-23 23:00 |  |
2022-12-23 15:00 | 2022-12-24 00:00 |  |
2022-12-23 16:00 | 2022-12-24 01:00 |  |
2022-12-23 17:00 | 2022-12-24 02:00 |  |
2022-12-23 18:00 | 2022-12-24 03:00 |  |
2022-12-23 19:00 | 2022-12-24 04:00 |  |
2022-12-23 20:00 | 2022-12-24 05:00 |  |
2022-12-23 21:00 | 2022-12-24 06:00 |  |
2022-12-23 22:00 | 2022-12-24 07:00 |  |
2022-12-23 23:00 | 2022-12-24 08:00 |  |
 |
UTC | JST | 赤外画像 (輝度温度 K) | 可視画像 (反射 %) |
2022-12-24 00:00 | 2022-12-24 09:00 |  |
 |
2022-12-24 01:00 | 2022-12-24 10:00 |  |
 |
2022-12-24 02:00 | 2022-12-24 11:00 |  |
 |
2022-12-24 03:00 | 2022-12-24 12:00 |  |
 |
2022-12-24 04:00 | 2022-12-24 13:00 |  |
 |
2022-12-24 05:00 | 2022-12-24 14:00 |  |
 |
2022-12-24 06:00 | 2022-12-24 15:00 |  |
 |
2022-12-24 07:00 | 2022-12-24 16:00 |  |
 |
2022-12-24 08:00 | 2022-12-24 17:00 |  |
2022-12-24 09:00 | 2022-12-24 18:00 |  |
2022-12-24 10:00 | 2022-12-24 19:00 |  |
2022-12-24 11:00 | 2022-12-24 20:00 |  |
2022-12-24 12:00 | 2022-12-24 21:00 |  |
2022-12-24 13:00 | 2022-12-24 22:00 |  |
2022-12-24 14:00 | 2022-12-24 23:00 |  |
2022-12-24 15:00 | 2022-12-25 00:00 |  |
2022-12-24 16:00 | 2022-12-25 01:00 |  |
2022-12-24 17:00 | 2022-12-25 02:00 |  |
2022-12-24 18:00 | 2022-12-25 03:00 |  |
2022-12-24 19:00 | 2022-12-25 04:00 |  |
2022-12-24 20:00 | 2022-12-25 05:00 |  |
2022-12-24 21:00 | 2022-12-25 06:00 |  |
2022-12-24 22:00 | 2022-12-25 07:00 |  |
2022-12-24 23:00 | 2022-12-25 08:00 |  |
 |
UTC | JST | 赤外画像 (輝度温度 K) | 可視画像 (反射 %) |
2022-12-25 00:00 | 2022-12-25 09:00 |  |
 |
2022-12-25 01:00 | 2022-12-25 10:00 |  |
 |
2022-12-25 02:00 | 2022-12-25 11:00 |  |
 |
2022-12-25 03:00 | 2022-12-25 12:00 |  |
 |
2022-12-25 04:00 | 2022-12-25 13:00 |  |
 |
2022-12-25 05:00 | 2022-12-25 14:00 |  |
 |
2022-12-25 06:00 | 2022-12-25 15:00 |  |
 |
2022-12-25 07:00 | 2022-12-25 16:00 |  |
 |
2022-12-25 08:00 | 2022-12-25 17:00 |  |
2022-12-25 09:00 | 2022-12-25 18:00 |  |
2022-12-25 10:00 | 2022-12-25 19:00 |  |
2022-12-25 11:00 | 2022-12-25 20:00 |  |
2022-12-25 12:00 | 2022-12-25 21:00 |  |
2022-12-25 13:00 | 2022-12-25 22:00 |  |
2022-12-25 14:00 | 2022-12-25 23:00 |  |
2022-12-25 15:00 | 2022-12-26 00:00 |  |
2022-12-25 16:00 | 2022-12-26 01:00 |  |
2022-12-25 17:00 | 2022-12-26 02:00 |  |
2022-12-25 18:00 | 2022-12-26 03:00 |  |
2022-12-25 19:00 | 2022-12-26 04:00 |  |
2022-12-25 20:00 | 2022-12-26 05:00 |  |
2022-12-25 21:00 | 2022-12-26 06:00 |  |
2022-12-25 22:00 | 2022-12-26 07:00 |  |
2022-12-25 23:00 | 2022-12-26 08:00 |  |
 |
2023-01-21, 2023-01-22
増田 耕一 (MASUDA Kooiti)