<div dir="ltr"><div>FYI: You might find the following WWW URL of interest:<br> NOAA: Earth System Research Laboratory: Physical Sciences Division produces<br><br></div><div> <a href="https://www.esrl.noaa.gov/psd/map/clim/olr.shtml" target="_blank">https://www.esrl.noaa.gov/psd/<wbr>map/clim/olr.shtml</a><br><br></div><div> These may be adequate for your needs.<br></div><div>==============<br><br>"My input daily OLR data file contains data from 1-1-2002 to 14-7-2018"<br> "I am trying to make time-longitude (Hovmueller) plot for the period 10 June 2018 to 25 June 2018."<br>"I am using NCL script ”mjoclivar_5.ncl” from “MJO clivar."<br><br></div><div>[1] <br>If you want the values for 25 June 2018 to be included in the Hovmueller and your data ends in 14 July 2018, you have a only <b>19 days after</b> 25 June 2018. As noted in the <br><br> <a href="http://www.ncl.ucar.edu/Document/Functions/Diagnostics/band_pass_hovmueller.shtml">http://www.ncl.ucar.edu/Document/Functions/Diagnostics/band_pass_hovmueller.shtml</a><br><br>documentation, a <b>Lanczos band-pass</b> filter is used to filter the values :<br><br> <a href="http://www.ncl.ucar.edu/Document/Functions/Built-in/filwgts_lanczos.shtml">http://www.ncl.ucar.edu/Document/Functions/Built-in/filwgts_lanczos.shtml</a><br><br></div><div>The MJO-Clivar committee suggested using a Lanczos filter of 20-100 days with the half-power points at 20 and 100 days <br><pre> spd = 1 ; sample per day
bpf = (/20,100,201/) ; 20 is the low cutoff and 100 is the high cutoff<br></pre></div><div>bpf(2)=201 weights are used. So, after the Lanczos filter is performed, 100 days at the beginning and 100 days at the end are returned as missing (_FillValue). You do not have enogh data after 25 June 2018 to uses these settings.<br><br></div><div>[2] <br></div><div>What band-pass period do you want: bpf(0) and bpf(1) ? The maximum number of weights would be <b>bpf(2)=37</b>. Hence, it can not be a sharp band-pass period.<br><br></div><div>[3] As a matter of implementation, I suggest passing the filter over the entire time span, then plot the 10 June 2018 to 25 June 2018 period.<br><br></div><div>[4] My suggestion is that you play with the lanczos function.<br></div><div><br></div><div>Good luck<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jul 23, 2018 at 6:30 AM, Sujata Mandke <span dir="ltr"><<a href="mailto:amin@tropmet.res.in" target="_blank">amin@tropmet.res.in</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><br>
Dear NCL community,<br>
Greetings!<br>
<br>
I am using NCL script ”mjoclivar_5.ncl” from “MJO clivar”<br>
application examples on NCL website. <br>
<br>
I am trying to make time-longitude (Hovmueller) plot for the<br>
period 10 June 2018 to 25 June 2018. <br>
<br>
My input daily OLR data file contains data from <br>
1-1-2002 to 14-7-2018. <br>
I have question on time setting (for buffer) in this NCL script<br>
<br>
<br>
(i) In the sample script -”mjoclivar_5.ncl” enough buffer<br>
(1 year buffer) is included by setting <br>
twStrt = 19950101 and twLast = 19981231 <br>
and Hovmueller start and end time are set as follows <br>
thStrt = 19960101 ; Hov start time<br>
thLast = 19971231 ; Hov last time<br>
<br>
(ii)Last day in the daily OLR data file (which i am using)<br>
is 14-7-2018. In order to set enough buffer what should<br>
be set for “twLast”?<br>
As ip data ends on 14-7-2018, buffer time of<br>
1 year in case of “twLast” is not possible.<br>
<br>
I am using NCL version 6.4.0 on linux machine.<br>
Please help in this regard. <br>
Any suggestion would be of great help.<br>
Many thanks in advance.<br>
With best regards<br>
Sujata<br>
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