模式中时间calendar的分类记录

一大碗年糕

在处理cmip和再分析数据的时候经常有采用不同的日历，对含润年的日历要格外小心，比如月平均求季节等应该注意润年2月天数变化所带来的权重变化
4.4.1. Calendar

In order to calculate a new date and time given a base date, base time and a time increment one must know what calendar to use. For this purpose we recommend that the calendar be specified by the attribute calendar which is assigned to the time coordinate variable. The values currently defined for calendar are:

gregorian or standardMixed Gregorian/Julian calendar as defined by Udunits. This is the default.
proleptic_gregorian A Gregorian calendar extended to dates before 1582-10-15. That is, a year is a leap year if either (i) it is divisible by 4 but not by 100 or (ii) it is divisible by 400.
noleap or 365_day Gregorian calendar without leap years, i.e., all years are 365 days long.
all_leap or 366_day Gregorian calendar with every year being a leap year, i.e., all years are 366 days long.
360_day All years are 360 days divided into 30 day months.
julian Julian calendar.
none No calendar.

The calendar attribute may be set to none in climate experiments that simulate a fixed time of year. The time of year is indicated by the date in the reference time of the units attribute. The time coordinate that might apply in a perpetual July experiment are given in the following example.

LeslieTse

请问，不同nc数据使用的不同日历，那在计算一年的总和时是不是应该乘以各个数据使用日历代表的每年时间？例如，两个数据单位都是g day-1，但是一个数据用的是360_day日历，另一个数据用的是365_day日历，那么计算年总和时是分别乘以360和365吗？

一大碗年糕

LeslieTse 发表于 2022-8-18 22:42
请问，不同nc数据使用的不同日历，那在计算一年的总和时是不是应该乘以各个数据使用日历代表的每年时间？例 ...

照道理来说是的，比较确实天数不一样，年平均肯定也不一样，可以看看值的差距大不大

LeslieTse

一大碗年糕 发表于 2022-8-19 00:29
照道理来说是的，比较确实天数不一样，年平均肯定也不一样，可以看看值的差距大不大

好的，谢谢！我感觉也是这样，但不是特别确定。不过相差5天对结果影响确实也很小，画出图来肉眼也是很难分辨的。