[ncl-talk] ESMF regridding

[Dennis Shea]

Let variable:  R(time,latR,lonR)

If you input a variable with SOURCE dimensions HR(time, lat_source,
lon_source) and specify your destination as latR,lonR
via ESMF you will get LR (time, latR, lonR)

DIFF = LR-R    ; DIFF(time,latR,lonR)



On Wed, Mar 24, 2021 at 12:38 PM Chathurika via ncl-talk <
ncl-talk at mailman.ucar.edu> wrote:

> Dear Rashed
>
> Many thanks for you email. I know this way. But what I want is regrid both
> dataset into one grid without removing the time dimension from it. To get
> the differences of datasets (HR-LR), I need to regrid them into the same
> dimension. Using the method you mentioned, I can plot the map. But how
> can I get the difference (HR-LR)?
>
>
> Thanks once again and best,
>
> Chathu
>
> -----Original Messages-----
> *From:*"Rashed Mahmood" <rashidcomsis at gmail.com>
> *Sent Time:*2021-03-25 01:38:37 (Thursday)
> *To:* Chathurika <chatu at scsio.ac.cn>
> *Cc:* ncl-talk at mailman.ucar.edu
> *Subject:* Re: [ncl-talk] ESMF regridding
>
> Hi Chatu,
>
> ESMF regridding works fine for 3 dimensional data. What makes you think it
> does not?
>
> Likely you would need to attach the 2d coordinate arrays with the
> variables, e.g.:
>
> varb1 at lat2d  = infile1->latitude
> varb1 at lon2d = infile1->longitude
>
> varb2 at lat2d  = infile2->latitude
> varb2 at lon2d = infile2->longitude
>
> If this does not work, then share a full script (and any error messages
> you get).
>
> HTH
> Rashed
>
>
>
>
> On Wed, Mar 24, 2021 at 4:28 PM Chathurika via ncl-talk <
> ncl-talk at mailman.ucar.edu> wrote:
>
>> Dear All,
>>
>>
>> Thank you so much for reading my email and helping me out to solve this
>> issue.
>>
>>
>> I want to perform the significance test (ttest) over time dimension for
>> the differences of two datasets which have lat[:,:] and lon[:,:] (two
>> dimensional, like WRF).
>>
>>
>>  differences = (high resolution - low resolution).
>>
>>
>> However, the dimensions of lat and lon are not same. The variable summary
>> is;
>>
>>
>> Low resolution:
>>
>> Type: float
>>
>> Total Size: 54067200 bytes
>>
>>             13516800 values
>>
>> Number of Dimensions: 3
>>
>> Dimensions and sizes: [time | 240] x [j | 220] x [i | 256]
>>
>> Coordinates:
>>
>>             time: [52975.5..60249.5]
>>
>>             j: [0..219]
>>
>>             i: [0..255]
>>
>> Number Of Attributes: 11
>>
>>   standard_name : sea_surface_height_above_geoid
>>
>>   long_name : Sea Surface Height Above Geoid
>>
>>   comment : This is the dynamic sea level, so should have zero global
>> area mean. It should not include inverse barometer depressions from sea ice.
>>
>>   units : m
>>
>>   original_name : zos
>>
>>   cell_methods : area: mean where sea time: mean
>>
>>   cell_measures : area: areacello
>>
>>   history : 2019-09-04T15:31:31Z altered by CMOR: replaced missing value
>> flag (-9e+33) and corresponding data with standard missing value (1e+20).
>>
>>   missing_value : 1e+20
>>
>>   _FillValue : 1e+20
>>
>>   coordinates : latitude longitude
>>
>>
>> High resolution:
>>
>>
>> Type: float
>>
>> Total Size: 311047680 bytes
>>
>>             77761920 values
>>
>> Number of Dimensions: 3
>>
>> Dimensions and sizes: [time | 240] x [j | 404] x [i | 802]
>>
>> Coordinates:
>>
>>             time: [52975.5..60249.5]
>>
>>             j: [0..403]
>>
>>             i: [0..801]
>>
>> Number Of Attributes: 11
>>
>>   standard_name : sea_surface_height_above_geoid
>>
>>   long_name : Sea Surface Height Above Geoid
>>
>>   comment : This is the dynamic sea level, so should have zero global
>> area mean. It should not include inverse barometer depressions from sea ice.
>>
>>   units : m
>>
>>   original_name : zos
>>
>>   cell_methods : area: mean where sea time: mean
>>
>>   cell_measures : area: areacello
>>
>>   history : 2019-08-25T07:38:10Z altered by CMOR: replaced missing value
>> flag (-9e+33) and corresponding data with standard missing value (1e+20).
>>
>>   missing_value : 1e+20
>>
>>   _FillValue : 1e+20
>>
>>   coordinates : latitude longitude
>>
>>
>> *latitude and longitude have two dimensions.
>>
>>
>>
>> I cannot do ESMF regridding as per it is not allowed to use the all three
>> dimensions (time, lat, lon). I am little confused here, How can I use ESMF
>> regridding and keep the time dimension also. If so, after regridding, I can
>> perform the ttest for the resolution difference.
>>
>>
>> Please help me and Many many thanks.
>>
>>
>> Best regards,
>>
>> Chathu
>>
>> ------------------------------
>>
>>
>>
>> Wickramage Chathurika Hemamali
>> Msc in Physical Oceanography
>> State Key Laboratory of Tropical Oceanography
>> South China Sea Institute of Oceanology
>> University of Chinese Academy of Science
>> China
>>
>> *Specialized in Oceanography and Marine Geology (Bachelor)*
>> *University of Ruhuna*
>> *Matara*
>> *Sri Lanka*
>>
>> Email : wickramagechathurika at rocketmail.com
>> chatu at scsio.ac.cn
>>
>> _______________________________________________
>> ncl-talk mailing list
>> ncl-talk at mailman.ucar.edu
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>> https://mailman.ucar.edu/mailman/listinfo/ncl-talk
>
>
>
>
> ------------------------------
>
>
>
> Wickramage Chathurika Hemamali
> Msc in Physical Oceanography
> State Key Laboratory of Tropical Oceanography
> South China Sea Institute of Oceanology
> University of Chinese Academy of Science
> China
>
> *Specialized in Oceanography and Marine Geology (Bachelor)*
> *University of Ruhuna*
> *Matara*
> *Sri Lanka*
>
> Email : wickramagechathurika at rocketmail.com
> chatu at scsio.ac.cn
>
> _______________________________________________
> ncl-talk mailing list
> ncl-talk at mailman.ucar.edu
> List instructions, subscriber options, unsubscribe:
> https://mailman.ucar.edu/mailman/listinfo/ncl-talk
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