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krichard2011|2016-9-14 07:05
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Itbayat 實測 883.0 hPa
201609131800 AAXX 13181 98132 11460 83418 10268 49830 57000 60301 8657/
333 56599 86616 88356=
57000 Characteristic of pressure tendency during the three hours preceding the time of observation : Decreasing (steadily or unsteadily); atmospheric pressure now lower than three hours ago
57000 3 Hour Pressure tendency : -0.0 hPa (mb)
補充說明一下
Itbayat 就是被颱風眼正中的小島
前一小時氣壓 933 百帕
而然而後一小時氣壓急遽上升 但風速反降(不合理)
但經由 SYNOP 代碼可以發現一些溪俏
以下為3小時氣壓變化量代碼對照表
5appp -- Pressure tendency over 3 hours
a -- characteristics of pressure tendency
0 -- Increasing, then decreasing -- resultant pressure same or higher
1 -- Increasing, then steady -- resultant pressure higher
2 -- Increasing steadily -- resultant pressure higher
3 -- Decreasing or steady, then increasing -- resultant pressure higher
4 -- Steady -- resultant pressure same
5 -- Decreasing, then increasing -- resultant pressure lower
6 -- Decreasing, then steady -- resultant pressure lower
7 -- Decreasing steadily -- resultant pressure lower
8 -- Increasing or steady, then decreasing -- resultant pressure lower
ppp -- 3 hour pressure change in 0.1 mb
a的部分是氣壓變化正或負
而後面的 ppp 則是氣壓變化量
取到小數點以下第一位 例如 -12.3 則會顯示 57123
由於前三小時氣壓為983.0百帕
如果持平應該會是 54000持平 而非 57000減少
可能降壓為-100.0百帕導致系統溢位 只讀到後面的00.0
因此實際海平面氣壓很可能就是 883.0 百帕
實測:http://ogimet.com/cgi-bin/gsynre ... s=09&day=13&hora=18
代碼對照表:http://weather.unisys.com/wxp/Appendices/Formats/SYNOP.html#15 |
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