[gradsusr] Defining Nino Regions
James T. Potemra
jimp at hawaii.edu
Sun Sep 27 17:14:39 EDT 2015
Abdus,
Your data are defined 0 to 360, so stick with the Nino box defined 160
to 210. The other option was if your data were defined -180 to 180.
Jim
On 9/27/15 4:52 AM, MD ABDUS SATTAR wrote:
> 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
> <mailto: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
> <mailto: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 <mailto:andfried at gmail.com>> wrote:
>
> Thank you, Jim.
> -Andrew
>
>
>
> On Sep 24, 2015, at 9:10 PM, James T. Potemra
> <jimp at hawaii.edu <mailto: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 <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
>>>> > > gradsusr at gradsusr.org
>>>> <mailto: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 <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
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>>>
>>>
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> _______________________________________________
> 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
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>
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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
> <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
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