[gradsusr] Defining Nino Regions

Sun Sep 27 04:52:16 EDT 2015

Dear Andrew and Jim
I am still fighting in defining different nino regions in GrADS. I am using
sst data from
http://www.esrl.noaa.gov/psd/data/gridded/data.noaa.ersst.v4.html in
where -Spatial
Coverage:

   - 2.0 degree latitude x 2.0 degree longitude global grid (89x180).
   - 88.0N - 88.0S, 0.0E - 358.0E

When I define nino4 = aave(sstanom,lon=160,lon=210,lat=-5,lat=5) then it
seems to working (see the attached file). However, when I used Jim's first
suggestion, then the GrADS says "Entire Grid Undefined" and output from his
2nd suggestion does not comparable to other sources (e.g.
http://www.esrl.noaa.gov/psd/data/climateindices/. I could not identify my
problems. If you could help me in defining Nino 4, 3.4, 3 and central
pacific Nino then it would be very helpful for me.

Thanking you

Abdus

On Fri, Sep 25, 2015 at 8:55 PM, Andrew Friedman <andfried at gmail.com> wrote:

> 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
>>>>> > > 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>
>>>>> 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
>>>>> 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>
>>>> 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
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> gradsusr mailing list
>>>> gradsusr at gradsusr.org
>>>> http://gradsusr.org/mailman/listinfo/gradsusr
>>>>
>>>>
>>>
>>>
>>> _______________________________________________
>>> gradsusr mailing listgradsusr at gradsusr.orghttp://gradsusr.org/mailman/listinfo/gradsusr
>>>
>>>
>>> _______________________________________________
>>> 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
> 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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://gradsusr.org/pipermail/gradsusr/attachments/20150927/344837ea/attachment-0001.html 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: Nino Time series.docx
Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
Size: 47497 bytes
Desc: not available
Url : http://gradsusr.org/pipermail/gradsusr/attachments/20150927/344837ea/attachment-0001.bin 