[gradsusr] Confirmation of TCORR command

Fri Sep 25 06:55:28 EDT 2015

Hi Abdus,

There are two issues here:

(1) Your nino index longitudes are still not defined correctly. I believe
that you want degrees west, but what you have written is for degrees east
(the convention is that positive longitude is east and negative longitude
is west). How you set up the averaging across the date line depends on how
your dataset is formatted. Please see Jim's recent emails for how to set
this up.

(2) For your climatology, I think that your original sequence should create
climatologies for each month:

"set t 1 12"
"define avesst=ave(sst1,t+0,t=432,12)"
"modify avesst seasonal"
"set t 1 432

In other words, I think that avesst at t=2 should be the February
climatology.

Best, Andrew

On Fri, Sep 25, 2015 at 6:31 AM, MD ABDUS SATTAR <
md-abdus.sattar at students.mq.edu.au> wrote:

> Dear Andrew and Jim
> I am still a bit confused for defining the El Nino regions. Shall I define
> as:
>
> "define nino34=aave(sstanom,lon=120,lon=170,lat=-5,lat=5)"
> "define nino3=aave(sstanom,lon=90,lon=150,lat=-5,lat=5)"
> "define ninocp (central
> pacific)=aave(sstanom,lon=120,lon=160,lat=-5,lat=5)"
>
> Andrew, I have time frame of my data monthly mean from 1979/Jan(1) to
> 2014/Dec(432) and set as follows:
> "set t 1 12"
> "define avesst=ave(sst1,t+0,t=432,12)"
> "modify avesst seasonal"
> "set t 1 432"
>
> Therefore, this command calculate only the Jan months average sst from
> 1979-2014 as our first time data is from 1979/Jan. Now I would like to
> create climatology for February month. I have just changed as "define
> avesst=ave(sst1,t=1,t=432,12)". But I think there is a mistake as the index
> is not comparable to other sources.
>
> Could you please clarify me in these regards?
>
> I am really highly appreciate to your cooperation.
>
> Regards
> Abdus
>
>
> On Fri, Sep 25, 2015 at 8:34 AM, Andrew Friedman <andfried at gmail.com>
> wrote:
>
>> Thank you, Jim.
>> -Andrew
>>
>>
>>
>> On Sep 24, 2015, at 9:10 PM, James T. Potemra <jimp at hawaii.edu> wrote:
>>
>> 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>
>> 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>
>>> 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> 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"
>>>> > "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"
>>>> > "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>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>
>>>> 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> 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"
>>>> > > "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>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> 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"
>>>> > > > "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>
>>>> 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>abdus.sattar at pstu.ac.bd
>>>> > > > _______________________________________________
>>>> > > > gradsusr mailing list
>>>> > > > gradsusr at gradsusr.org
>>>> > > > http://gradsusr.org/mailman/listinfo/gradsusr
>>>> > >
>>>> > >
>>>> > > _______________________________________________
>>>> > > gradsusr mailing list
>>>> > > 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>
>>>> 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>abdus.sattar at pstu.ac.bd
>>>> > > _______________________________________________
>>>> > > gradsusr mailing list
>>>> > > gradsusr at gradsusr.org
>>>> > > http://gradsusr.org/mailman/listinfo/gradsusr
>>>> >
>>>> >
>>>> > _______________________________________________
>>>> > gradsusr mailing list
>>>> > gradsusr at gradsusr.org
>>>> > 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
>>>> > Email: 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
>>>> > _______________________________________________
>>>> > gradsusr mailing list
>>>> > 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
>>> Email: <md-abdus.sattar at students.mq.edu.au>
>>> 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>abdus.sattar at pstu.ac.bd
>>>
>>>
>>> _______________________________________________
>>> gradsusr mailing listgradsusr at gradsusr.orghttp://gradsusr.org/mailman/listinfo/gradsusr
>>>
>>>
>>>
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>>>
>>
>>
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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
>
> *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
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr
>
>
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