era 数据下载需要注意的问题
程序员文章站
2022-06-20 10:41:51
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首先附上官网的解释,有兴趣可看:
https://confluence.ecmwf.int/pages/viewpage.action?pageId=56658233
这张图说的非常清楚:
对steps选择的疑问:
从 00:00 12:00 出发, 分别有:3, 6, 9, 12 这几个步长可选,例如选0,3,代表从0点开始,到三点的值。如果下载降水就是累积降水,下载温度就是3点的温度。(注意温度和降水的区别)
一共三种类型。瞬时(如风速),累积(如降水),最大最小(如tmax和tmin)。最不容易理解的是第三个。请看解释:
最后这一个time只能从0或者12开始选。代表这三小时之内的tmax or tmin。
如果要要求日最高最低温度,脚本如下,至于为什么这么写,抛砖引玉,暂时不赘述。
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer
server = ECMWFDataServer()
server.retrieve({
"class": "ei",
"dataset": "interim",
"stream": "oper",
"expver": "1",
"date": "2017-01-01/to/2017-01-31",
"type": "fc",
"levtype": "sfc",
"param": "201.128/202.128", # 'Maximum temperature at 2 metres since previous post-processing' and 'Minimum temperature at 2 metres since previous post-processing'
"step": "3/6/9/12", # 4 steps per forecast
"time": "00:00:00/12:00:00", # 2 forecasts per day
"grid": "0.75/0.75",
"target": "output", # change this to your output file name
})