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[CF-metadata] Is there a convention defining day offsets to use for monthly average time series?

From: Upendra Dadi <Upendra.Dadi>
Date: Thu, 11 Aug 2011 12:14:11 -0400

Hi,
   I have a related question about "bounds" attribute. I often see
regularly gridded latitude-longitude data which do not have "bounds"
specified when probably they should. But they almost always have
regularly spaced latitude and longitude values which are at the middle
of each cell. CF checkers have no way to identify the problem since
files are valid both ways even though CF implementations might interpret
them differently (do they?). My question is what are the consequences of
not having "bounds" for analysis operations that are commonly used in
various models.

Upendra


On 8/10/2011 8:31 AM, John Caron wrote:
> On 8/8/2011 3:43 PM, Jim Biard wrote:
>> Hi.
>>
>> I have a time series of monthly averaged values. I have an
>> integer-valued time coordinate variable and an associated time_bounds
>> variable. Is it correct to use the 15th of February and the 16th of
>> all the other months for my time centers, or should I use the 16th of
>> every month?
>>
>> Also, should I do anything differently if my data are climatological
>> monthly averages (say, over 30 years of data)? And, in this case,
>> should the time coordinate values be day numbers from the beginning
>> of the 30-year time interval, the end of the time interval, or
>> something else entirely?
>>
>> Grace and peace,
>>
>> Jim Biard
>>
>
> At the moment, IMO the best that can be done in CF is to accurately
> record the date range (using the bounds attribute). The coordinate
> value should then be considered for labeling purposes only. Make a one
> line description and put into the long_name attribute. Make sure you
> have human readable documentation that explains whats going on in
> detail, and add a global attribute that references it. Set up a
> 24-hour hotline to answer questions, staffed by post-docs wearing
> beepers. Ok, maybe not the last ;^)
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Received on Thu Aug 11 2011 - 10:14:11 BST

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