[gradsusr] Confirmation of TCORR command
James T. Potemra
jimp at hawaii.edu
Wed Sep 23 22:45:21 EDT 2015
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
> > > > 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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> > 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
>
>
> _______________________________________________
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> gradsusr at gradsusr.org <mailto:gradsusr at gradsusr.org>
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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
> 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
> Email: abdus.sattar at pstu.ac.bd <mailto:abdus.sattar at pstu.ac.bd>
>
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
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