[gradsusr] Confirmation of TCORR command

James T. Potemra jimp at hawaii.edu
Thu Sep 24 15:10:55 EDT 2015


Hi Andrew,

Actually, if you can redefine the longitudes in your control file from 
(-180:180) to (0:360)
that would solve the dateline issue.  In this case you could have 
aave(sstanom,lon=160,lon=210....
to resolve to 160E to 150W.

In order to go beyond 360 (e.g., lon=340,lon=390), your data set has to 
be continuous in
the sense that 361 (or whatever) is a legitimate extension.  For 
example, if you start at 0
and go to 359 increment by 1, the next point would be 360 (0), then 361 
(1), etc.  To check
you can try make a global plot of some variable, and set the longitude 
range from 0 to 720;
in this case you should either see a twice-global plot.

Jim

On 9/24/15 12:24 AM, Andrew Friedman wrote:
> Thank you for these clarifications, Jim.
>
> To follow up:
> To use your suggested option (2), "define nino4 = 
> aave(sstanom,lon=340,lon=390,lat=-5,lat=5)"
>
> Would I first need to redefine the longitude values
> 'set lon 0 360' ?
>
> Best,
> Andrew
>
> On Thu, Sep 24, 2015 at 4:45 AM, James T. Potemra <jimp at hawaii.edu 
> <mailto:jimp at hawaii.edu>> wrote:
>
>     Hi Abdus/Andrew,
>
>     I'd be cautious of your nino4 as defined.  I presume your data are
>     defined -180 to 180, where eastern longitudes are 0 to 180 and
>     western longitudes are -180 to 0.  In your line:
>
>     "define nino4=aave(sstanom,lon=-150,lon=160,lat=-5,lat=5)”
>
>     the longitudes are in fact ascending (-150 is less than 160),
>     however I believe this will create a mean from 150W eastward all
>     the way around to 160E (again, assuming your longitudes are
>     defined -180 to 180), a mean over 310 longitudes.  Instead you
>     want 160E to 150E, or a mean over 50 longitudes.  I further think
>     Andrew's suggestion
>
>     "define nino4=aave(sstanom,lon=160,lon=-150,lat=-5,lat=5)”
>
>     will give an operation error (min lon > max lon).
>
>     Instead you could try either:
>
>     1.  define two different boxes across the dateline:
>     define nino4a = aave(sstanom,lon=160,lon=180,lat=-5,lat=5)
>     define nino4b = aave(sstanom,lon=-180,lon=-150,lat=-5,lat=5)
>     define nino4 = ( 20 * nino4a + 30 * nino4b ) / 50.0
>
>     2.  if the file is global and continuous, you might be able to use
>     define nino4 = aave(sstanom,lon=340,lon=390,lat=-5,lat=5)
>
>     Jim
>
>
>     On 9/22/15 4:41 PM, MD ABDUS SATTAR wrote:
>>     Hi Andrew
>>     Thanks!
>>
>>     On Wed, Sep 23, 2015 at 5:58 AM, Andrew Friedman
>>     <andfried at gmail.com <mailto:andfried at gmail.com>> wrote:
>>
>>         Hi Abdus,
>>
>>         I think that you are setting up the anomalies correctly.
>>         However, you may have a problem with your NINO4 domain:
>>         > "define nino4=aave(sstanom,lon=-150,lon=160,lat=-5,lat=5)”
>>
>>         https://climatedataguide.ucar.edu/climate-data/nino-sst-indices
>>
>>         In GrADS, longitudes need to be ascending.
>>
>>         I think that you want to reverse your longitudes so you have
>>
>>         "define nino4=aave(sstanom,lon=160,lon=-150,lat=-5,lat=5)” OR
>>         "define nino4=aave(sstanom,lon=160,lon=210,lat=-5,lat=5)”
>>
>>         Best, Andrew
>>
>>         > On Sep 22, 2015, at 7:57 AM, MD ABDUS SATTAR
>>         <md-abdus.sattar at students.mq.edu.au
>>         <mailto:md-abdus.sattar at students.mq.edu.au>> wrote:
>>         >
>>         > Dear Andrew
>>         > Thank you very much for your previous suggestion. Now, I
>>         can prepare El Nino series as well as temporal correlation.
>>         However, I am not confident enough whether I am right or
>>         wrong. I use the following script for correlating El Nino 4
>>         index with sea level pressure (Jan 1979 to Dec2014). Please
>>         confirm me the following command.
>>         > "reinit"
>>         > "sdfopen \Temp\sst7914.mnmean.v4.nc
>>         <http://sst7914.mnmean.v4.nc>"
>>         > "set t 1 12"
>>         > "define avesst=ave(sst1,t+0,t=432,12)"
>>         > "modify avesst seasonal"
>>         > "set t 1 432"
>>         > "define sstanom=sst1-avesst"
>>         >
>>         > "define nino4=aave(sstanom,lon=-150,lon=160,lat=-5,lat=5)"
>>         >
>>         > "sdfopen \Users\mq43879691\documents\test2\mslp.mon.mean.nc
>>         <http://mslp.mon.mean.nc>"
>>         > "set lon 0 360"
>>         > "set lat -90 90"
>>         > "set t 1"
>>         > "d tcorr(nino4,mslp.2,t=1,t=432)"
>>         >
>>         > Output:
>>         > <image.png>
>>         >
>>         > How can perform lead or lag correlation?
>>         >
>>         > Best regards
>>         > Abdus
>>         >
>>         > On Tue, Sep 15, 2015 at 6:48 AM, Andrew Friedman
>>         <andfried at gmail.com <mailto:andfried at gmail.com>> wrote:
>>         > Hi Abdus,
>>         >
>>         > Your timeseries is static because your boundaries for ssta
>>         do not have a time-varying dimension.
>>         >
>>         > There are different commands, depending on what you’re
>>         trying to do.
>>         >
>>         > Are you trying to create a monthly ssta climatology? If so,
>>         check out the instructions for the command ‘modify’:
>>         http://www.iges.org/grads/gadoc/gradcomdmodify.html
>>         >
>>         > Or are you trying to create a running mean timeseries of
>>         ssta? In that case, try something like ssta=ave(sst,t-11,t+0).
>>         >
>>         > Best,
>>         > Andrew
>>         >
>>         >
>>         > On Sep 13, 2015, at 8:01 AM, MD ABDUS SATTAR
>>         <md-abdus.sattar at students.mq.edu.au
>>         <mailto:md-abdus.sattar at students.mq.edu.au>> wrote:
>>         >
>>         > > Hi Andrew
>>         > > I was trying to set tloop, but still facing difficulties.
>>         I prepared the script as:
>>         > > "reinit"
>>         > > "sdfopen
>>         \Users\mq43879691\documents\test2\sst.mnmean.v4.nc
>>         <http://sst.mnmean.v4.nc>"
>>         > > "set t 1 1937"
>>         > > "define ssta=ave(sst,t=1501,t=1933,12)"
>>         > >
>>         > > "set lat 25"
>>         > > "set lon 50"
>>         > > "set lev 0"
>>         > > "set t 1501 1933"
>>         > >
>>         > >
>>         > > "d tloop(aave(ssta,lon=100,lon=170,lat=-5,lat=5))"
>>         > >
>>         > > "d tloop(aave(sst,lon=100,lon=170,lat=-5,lat=5))"
>>         > >
>>         > > I can display time series of El Nino by using sst value
>>         ("d tloop(aave(sst,lon=100,lon=170,lat=-5,lat=5))"). However,
>>         I would like use to ssta ("d
>>         tloop(aave(ssta,lon=100,lon=170,lat=-5,lat=5))") and when I
>>         use this the following map is found. Could you please suggest
>>         me in this regards?
>>         > >
>>         > >
>>         > >
>>         > > <image.png>
>>         > >
>>         > >
>>         > > Thanking you
>>         > >
>>         > > Abdus
>>         > >
>>         > >
>>         > >
>>         > > On Fri, Sep 11, 2015 at 4:18 PM, Andrew Friedman
>>         <andfried at gmail.com <mailto:andfried at gmail.com>> wrote:
>>         > > Hi Abdus,
>>         > > You may need to use ‘tloop’ with aave:
>>         http://www.iges.org/grads/gadoc/gradfunctloop.html
>>         > > Andrew
>>         > >
>>         > > On Sep 11, 2015, at 7:05 AM, MD ABDUS SATTAR
>>         <md-abdus.sattar at students.mq.edu.au
>>         <mailto:md-abdus.sattar at students.mq.edu.au>> wrote:
>>         > >
>>         > > > Dear GrADS Team
>>         > > > I am trying to calculate time series of El Nino SST
>>         anomaly in January for a specific time period.
>>         > > >
>>         > > > I wrote my script as:
>>         > > >
>>         > > > "reinit"
>>         > > > "sdfopen
>>         \Users\mq43879691\documents\test2\sst.mnmean.v4.nc
>>         <http://sst.mnmean.v4.nc>"
>>         > > > "set lon 100"
>>         > > > "set lat 25"
>>         > > > "set z 1"
>>         > > > "set t 1 600"
>>         > > >
>>         > > > "define ssta=ave(sst,t=1,t=600,12)"
>>         > > >
>>         > > > "define elnino = aave(ssta,lon=100,lon=170,lat=-5,lat=5)"
>>         > > >
>>         > > > "d elnino"
>>         > > >
>>         > > > The GrADS did not know show anything by this script. On
>>         the other hand, when I display only ssta setting lon 50 100
>>         and lat 0 25; then it shows the ssta. Can anybody help me in
>>         this regards?
>>         > > >
>>         > > > I look forward to your suggestion.
>>         > > >
>>         > > > Regards
>>         > > > Abdus
>>         > > > --
>>         > > > Md. Abdus Sattar
>>         > > > PhD Student
>>         > > > Department of Environmental Sciences
>>         > > > Level 2, Australian Hearing Hub Building
>>         > > >
>>         > > > Faculty of Science and Engineering
>>         > > > Macquarie University
>>         > > > NSW 2109 Australia
>>         > > >
>>         > > >
>>         > > > Cell: +61404400401 <tel:%2B61404400401>
>>         > > > Email: md-abdus.sattar at students.mq.edu.au
>>         <mailto:md-abdus.sattar at students.mq.edu.au>
>>         > > >
>>         > > > AND
>>         > > >
>>         > > > Assistant Professor
>>         > > > Department of Disaster Risk Management (DRM)
>>         > > > Faculty of Disaster Management
>>         > > > Patuakhali Science and Technology University, Dumki,
>>         Patuakhali, Bangladesh
>>         > > >
>>         > > > Cell: +8801716851612 <tel:%2B8801716851612>
>>         > > > Email: abdus.sattar at pstu.ac.bd
>>         <mailto:abdus.sattar at pstu.ac.bd>
>>         > > > _______________________________________________
>>         > > > gradsusr mailing list
>>         > > > gradsusr at gradsusr.org <mailto:gradsusr at gradsusr.org>
>>         > > > http://gradsusr.org/mailman/listinfo/gradsusr
>>         > >
>>         > >
>>         > > _______________________________________________
>>         > > gradsusr mailing list
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>>         > > http://gradsusr.org/mailman/listinfo/gradsusr
>>         > >
>>         > >
>>         > >
>>         > > --
>>         > > Md. Abdus Sattar
>>         > > PhD Student
>>         > > Department of Environmental Sciences
>>         > > Level 2, Australian Hearing Hub Building
>>         > >
>>         > > Faculty of Science and Engineering
>>         > > Macquarie University
>>         > > NSW 2109 Australia
>>         > >
>>         > >
>>         > > Cell: +61404400401 <tel:%2B61404400401>
>>         > > Email: md-abdus.sattar at students.mq.edu.au
>>         <mailto:md-abdus.sattar at students.mq.edu.au>
>>         > >
>>         > > AND
>>         > >
>>         > > Assistant Professor
>>         > > Department of Disaster Risk Management (DRM)
>>         > > Faculty of Disaster Management
>>         > > Patuakhali Science and Technology University, Dumki,
>>         Patuakhali, Bangladesh
>>         > >
>>         > > Cell: +8801716851612 <tel:%2B8801716851612>
>>         > > Email: abdus.sattar at pstu.ac.bd
>>         <mailto:abdus.sattar at pstu.ac.bd>
>>         > > _______________________________________________
>>         > > gradsusr mailing list
>>         > > gradsusr at gradsusr.org <mailto:gradsusr at gradsusr.org>
>>         > > http://gradsusr.org/mailman/listinfo/gradsusr
>>         >
>>         >
>>         > _______________________________________________
>>         > gradsusr mailing list
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>>         >
>>         >
>>         >
>>         > --
>>         > Md. Abdus Sattar
>>         > PhD Student
>>         > Department of Environmental Sciences
>>         > Level 2, Australian Hearing Hub Building
>>         >
>>         > Faculty of Science and Engineering
>>         > Macquarie University
>>         > NSW 2109 Australia
>>         >
>>         >
>>         > Cell: +61404400401 <tel:%2B61404400401>
>>         > Email: md-abdus.sattar at students.mq.edu.au
>>         <mailto:md-abdus.sattar at students.mq.edu.au>
>>         >
>>         > AND
>>         >
>>         > Assistant Professor
>>         > Department of Disaster Risk Management (DRM)
>>         > Faculty of Disaster Management
>>         > Patuakhali Science and Technology University, Dumki,
>>         Patuakhali, Bangladesh
>>         >
>>         > Cell: +8801716851612 <tel:%2B8801716851612>
>>         > Email: abdus.sattar at pstu.ac.bd <mailto:abdus.sattar at pstu.ac.bd>
>>         > _______________________________________________
>>         > gradsusr mailing list
>>         > gradsusr at gradsusr.org <mailto:gradsusr at gradsusr.org>
>>         > http://gradsusr.org/mailman/listinfo/gradsusr
>>
>>
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>>
>>
>>
>>     -- 
>>     Md. Abdus Sattar
>>     PhD Student
>>     Department of Environmental Sciences
>>     Level 2, Australian Hearing Hub Building
>>
>>     Faculty of Science and Engineering
>>     Macquarie University
>>     NSW 2109 Australia
>>
>>
>>     Cell: +61404400401 <tel:%2B61404400401>
>>     Email: md-abdus.sattar at students.mq.edu.au
>>     <mailto:md-abdus.sattar at students.mq.edu.au>
>>
>>     *AND*
>>
>>     Assistant Professor
>>     Department of Disaster Risk Management (DRM)
>>     Faculty of Disaster Management
>>     Patuakhali Science and Technology University, Dumki, Patuakhali,
>>     Bangladesh
>>
>>     Cell: +8801716851612 <tel:%2B8801716851612>
>>     Email: abdus.sattar at pstu.ac.bd <mailto:abdus.sattar at pstu.ac.bd>
>>
>>
>>     _______________________________________________
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