[ncl-talk] NDVI from Advanced Very High-Resolution Radiometer (AVHRR)

[Setareh Rahimi]

Dear Dennis,
So many thanks for your advice. I run the script on a remote server with at
least *1 terabyte* of memory. I think this is not the case.
I used the below commands to check the files:
===========================================
fils = systemfunc("ls [1-2][8-9-0-1]*/*nc")
   print(fils)

   f   = addfiles (fils, "r")

   x   = short2flt(f[:]->NDVI)

   printVarSummary(x)
===========================================
, and attached the result. Please look at the image, and kindly help me
sort the issue out. I do not know what is wrong with the files I downloaded.
best regards,

On Sat, Jun 18, 2022 at 10:52 PM Dennis Shea <shea at ucar.edu> wrote:

> Based on the provided information, I have no idea why you would get
> "returned nothing to me"
>
> I know that NDVI files are 0.1 degree resolution (3600,7200). You have 36
> years (1986-2021) of daily data.
> So, 36*365=13140   [+ a few Leap Year days)
>
>    prc(13140,3600,7200)    => daily data
>
> A lot of memory is needed. Maybe your computer can not handle this?
>
> After the
>       xM = calculate_monthly_values (prc, "avg", 0,opt)
>       printVarSummary(xM)
>
>    xM(432,3600,7200)
>
>
>
> On Sat, Jun 18, 2022 at 5:01 AM Setareh Rahimi via ncl-talk <
> ncl-talk at mailman.ucar.edu> wrote:
>
>> Dear all,
>>
>> I need to calculate the monthly anomaly of the Normalized Difference
>> Vegetation Index (NDVI), from Advanced Very High-Resolution Radiometer
>> (AVHRR) sensor. I have downloaded AVHRR data (1986-2021) from the link
>> below:
>>
>> https://www.ncei.noaa.gov/metadata/geoportal/rest/metadata/item/gov.noaa.ncdc:C01558/html
>> I first tried to prepare a script to combine all the data, and then
>> calculate the monthly average from daily data ( the link provides daily
>> data). After having monthly data I tried to figure out anomalies (the
>> script has been attached). But NCL stopped and returned nothing to me. I
>> just wonder what is wrong. Please kindly advise me on this issue.
>> Best wishes,
>>
>>
>> --
>> S.Rahimi
>>
>> _______________________________________________
>> ncl-talk mailing list
>> ncl-talk at mailman.ucar.edu
>> List instructions, subscriber options, unsubscribe:
>> https://mailman.ucar.edu/mailman/listinfo/ncl-talk
>>
>

-- 
S.Rahimi
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://mailman.ucar.edu/pipermail/ncl-talk/attachments/20220621/79a31d5b/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Screen Shot 1401-03-31 at 3.47.26 PM.png
Type: image/png
Size: 387403 bytes
Desc: not available
URL: <https://mailman.ucar.edu/pipermail/ncl-talk/attachments/20220621/79a31d5b/attachment-0001.png>