tag:blogger.com,1999:blog-2220966763638300672.post903724999855418271..comments2023-07-29T05:11:23.558-04:00Comments on Climate Observations: An Introduction To ENSO, AMO, and PDO -- Part 3Bob Tisdalehttp://www.blogger.com/profile/15462377647970214137noreply@blogger.comBlogger21125tag:blogger.com,1999:blog-2220966763638300672.post-36996012290496539082010-11-21T17:48:30.057-05:002010-11-21T17:48:30.057-05:00Rob de Vos: Please feel free to translate the post...Rob de Vos: Please feel free to translate the post to Dutch.<br /><br />RegardsBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-7369739125532117102010-11-21T06:49:52.038-05:002010-11-21T06:49:52.038-05:00Very well-wrought explanation of ENSO , AMO and P...Very well-wrought explanation of ENSO , AMO and PDO, Bob! I would like to use your posts on this subject and translate them into Dutch on purpose of my climate site www.klimaatgek.nl . Of course with quotation of sources.Rob de Voshttp://www.klimaatgek.nlnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-49728719196795932502010-09-13T08:55:02.803-04:002010-09-13T08:55:02.803-04:00TallBloke: Not sure where your comment went. But ...TallBloke: Not sure where your comment went. But based on it I'm writing a post about the inverse relationship between North Pacific SST Residuals and the PDO.<br /><br />Thanks. I will give you credit for the find, of course.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-5903496503061173742010-09-09T23:41:56.378-04:002010-09-09T23:41:56.378-04:00Thanks so much Bob.
It always fascinates me that ...Thanks so much Bob.<br /><br />It always fascinates me that they quote tiny anomalies over large stretches of the world (land and ocean) in the middle of the 19th century.Johnnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-14113765115219755452010-09-09T20:47:43.910-04:002010-09-09T20:47:43.910-04:00John: Here's the ERSSST.v3b version:
http://i5...John: Here's the ERSSST.v3b version:<br />http://i55.tinypic.com/oi4nsj.jpg<br />Keep in mind that most of the early data in the North Pacific is make believe. I'll try to get you Kaplan SST tomorrow.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-28057374251476421962010-09-09T11:18:21.685-04:002010-09-09T11:18:21.685-04:00Hi Bob -
In reference to the last graph, do the m...Hi Bob -<br /><br />In reference to the last graph, do the multi-decadal PDO and AMO oscillations exist in all data sets?Johnnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-32873587484100382002010-09-07T15:07:20.528-04:002010-09-07T15:07:20.528-04:00I dare to say that while PDO has local climatic ef...I dare to say that while PDO has local climatic effect on US (cold or warm water near the west coast), the global climate effect (warming, cooling) comes from bulk SST changes. Therefore AMO, being the /detrended/ SST record, is much better representation of global datasets than PDO, which is a synthetic number.Unknownhttps://www.blogger.com/profile/01284441733104541252noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-76692163901642393232010-09-06T15:56:46.620-04:002010-09-06T15:56:46.620-04:00Sorry, John. I haven't looked into the respon...Sorry, John. I haven't looked into the response of Arctic Ice to the sign of the PDO.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-23687143134053243242010-09-06T10:36:54.341-04:002010-09-06T10:36:54.341-04:00Hi Bob -
Based on the map at the top, would you t...Hi Bob -<br /><br />Based on the map at the top, would you think that a time of positive PDO would be associated with a higher Artic ice melt around Alaska vs a time of negative PDO? Am I looking at the maps correctly?<br /><br />Thanks!Johnnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-81818550759135557472010-09-05T04:23:53.601-04:002010-09-05T04:23:53.601-04:00"Comparing the North Pacific Residual to the ..."Comparing the North Pacific Residual to the PDO, Figure 13, the two datasets have no relationship with one another. "<br /><br />Actually Bob, they look like they are in anti-correlation to my eye.<br /><br />Very interesting post - thanksRog Tallblokehttp://tallbloke.wordpress.comnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-9791534755624496682010-09-04T17:31:17.228-04:002010-09-04T17:31:17.228-04:00Pascvaks said, "Precisely my point. So a 241 ...Pascvaks said, "Precisely my point. So a 241 month filter wouldn't say anything significant about the actual overall trend? Thought it would have been closer to the mark for the true 'longterm' significance."<br /><br />The linear trend of NINO3.4 SST anomalies smoothed with a 241-month filter drops to 0.07 deg C per Century, and with a with a 361-month filter drops further to 0.03 deg C per Century. They’re basically flat like the raw data. The changes in the curves are interesting to see, though.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-4408700746831150442010-09-04T11:13:11.696-04:002010-09-04T11:13:11.696-04:00Precisely my point. So a 241 month filter wouldn&#...Precisely my point. So a 241 month filter wouldn't say anything significant about the actual overall trend? Thought it would have been closer to the mark for the true 'longterm' significance. People are like bacteria and sometimes don't appreciate the scale of time to larger scale events. Thanks Bob. Although I usually only follow about 50 percent of what you're saying, I am much appreciative of your blog and all your hard work. I've learned a lot (believe it or not:-).Pascvaksnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-23529897732194481712010-09-04T10:48:30.061-04:002010-09-04T10:48:30.061-04:00Pascvaks: The linear trend on the HADISST NINO3.4...Pascvaks: The linear trend on the HADISST NINO3.4 SST anomalies (1900 to present) smoothed with 121-month filter is only 0.09 deg C per century!!Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-10843822025352237092010-09-04T10:08:15.392-04:002010-09-04T10:08:15.392-04:00Appears that the larger the filter the more signif...Appears that the larger the filter the more significant the graphic. Perhaps the overall, longterm trend is obscured by a little too much short term detail?Pascvaksnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-58646303594831780602010-09-04T05:01:02.167-04:002010-09-04T05:01:02.167-04:00John says: "...does the PDO matter for the gl...John says: "...does the PDO matter for the global warming discussion?"<br /><br />I can't see how. There really is no mechanism for the PDO, in and of itself, to raise and lower global temperatures.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-38784350906228565102010-09-04T04:59:03.052-04:002010-09-04T04:59:03.052-04:00Bill Illis says: "Lots of people rely on the ...Bill Illis says: "Lots of people rely on the PDO as (one of) the source(s) for the 60 year cycle in the climate."<br /><br />Most of the 60-year cycle is explained by the AMO. If the North Atlantic SST anomalies are removed from global SST anomalies, the global SST flatten considerably.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-54131659858202625872010-09-04T04:46:27.797-04:002010-09-04T04:46:27.797-04:00Bill Illis says: "In that scenario, the north...Bill Illis says: "In that scenario, the north Pacific and the PDO pattern should be thought of as an after-impact of the ENSO."<br /><br />And that was the conclusion of Newman et al: "The PDO is dependent upon ENSO on all timescales."<br /><br />And to confirm your discussion on currents, Bill, Miller et al suggested an improvment to Newman's model to account for the ocean currents carrying the effects of ENSO up into the Kuroshio extension. They wrote, "Adding a lagged KOE response pattern, mimicking the gyre-scale spin-up delay, may improve the fit of the Newman et al. (2003) simple model. Alternatively, midlatitude ocean-atmosphere, or oceanatmosphere-ecosystem, feedbacks may be important."<br />http://horizon.ucsd.edu/miller/download/jgofs/JO_60-1-11.pdfBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-63190793288052161942010-09-03T22:05:57.356-04:002010-09-03T22:05:57.356-04:00Hi Bob -
So for purposes of the issue of global w...Hi Bob -<br /><br />So for purposes of the issue of global warming, does the PDO carry any significance? I can see it mattering for regional weather forecasting, but, given what you've shown in this post, does the PDO matter for the global warming discussion?Johnnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-61763994768591642662010-09-03T20:37:29.785-04:002010-09-03T20:37:29.785-04:00Good post Bob.
Lots of people rely on the PDO as ...Good post Bob.<br /><br />Lots of people rely on the PDO as (one of) the source(s) for the 60 year cycle in the climate.<br /><br />But Bob demonstrates here that we should probably develop some other measure for the north Pacific's impact on the climate. Nobody really understands what the PDO is measuring and that it doesn't actually correlate very well with the climate in any event.<br /><br />One problem is that the whole north Pacific starts to represent a significant fraction of the total global temperature measurement. It might just measure the climate itself rather than being an independent variable impacting it.<br /><br />I think the ENSO does well enough on its own (and can represent whatever the PDO is assumed to do) so we should just use it instead.<br /><br />There is a question of whether there should be longer ENSO lag periods or two different lags periods or 3 even. <br /><br />There is certainly a 3 month lag from the ENSO but maybe there is also a 5 month PDO-impact lag and then an 8 month AMO-impact lag for example. In that case, they should be developed as three separate lag impacts.<br /><br />The Ocean current measurements from the US Navy shows that some of the ENSO warm/or/cool waters do flow upwards from Indonesia to Japan and then enter the Kuroshio current where it starts to leave its signal in the PDO patterns. <br /><br />http://www7320.nrlssc.navy.mil/global_nlom32/navo/WHOSP1_nlomw12930doper.gif<br /><br />http://www7320.nrlssc.navy.mil/global_nlom32/navo/EQSP1_nlomw12930doper.gif<br /><br />http://www7320.nrlssc.navy.mil/global_nlom32/navo/ITFSP1_nlomw12930doper.gif<br /><br />http://www7320.nrlssc.navy.mil/global_nlom32/navo/TAWSP1_nlomw12930doper.gif<br /><br />http://www7320.nrlssc.navy.mil/global_nlom32/navo/KURSP1_nlomw12930doper.gif<br /><br />In that scenario, the north Pacific and the PDO pattern should be thought of as an after-impact of the ENSO. These waters can then re-circulate all the way around the north Pacific and then re-enter the ENSO region near the Galapagos Islands eventually, so there is also a weak PDO recycled-influence on the ENSO though.Bill Illisnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-81262164119604006142010-09-03T18:02:37.419-04:002010-09-03T18:02:37.419-04:00Anonymous: I also have emailed with Nate Mantua. ...Anonymous: I also have emailed with Nate Mantua. I included his reply in the earlier post. <br />http://bobtisdale.blogspot.com/2009/04/misunderstandings-about-pdo-revised.html<br /><br />Nate Mantua's more-detailed description is right after Figure 2. Hope it helps.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-59817661908851351912010-09-03T17:27:55.814-04:002010-09-03T17:27:55.814-04:00(Bob, I originally posted this comment for the wro...(Bob, I originally posted this comment for the wrong topic, sorry)<br /><br />I am a member of a weather forum for the Pacific Northwest, and one of our members has emailed Nate Mantura about how he calculates PDO, and here is what he said:<br /><br />"I don't know if this helps, and I admit this science is beyond my education, but I am part of a weather forum for the Pacific Northwest, and one of our members is in communication with Nate Mantua. He emailed our member and gave the following definition of how he calculates PDO.<br /><br />"Steve,<br /><br />The formal method for updating the PDO index involves subtracting the latest month's global average SST anomaly from each grid-point in the North Pacific (from 20-65N latitude), subtracting the long-term climatology for that month from each grid- point, and then projecting this "residual SST anomaly" pattern onto the pattern of SST anomalies developed from an EOF analysis of historical SSTs from 1900-93. This is all rather complicated, but the answer turns out to be very similar to simply taking the observed SST anomaly in the central North Pacific Ocean (from 30-50N, 150W to 150E), and multiplying that number by -1. As I noted in that earlier message to you, the core region of PDO SST anomalies is not off the west coast, although that is also a part of the PDO pattern of SST variations. The PDO SST pattern in full is the part of the attached figure from 20-65N latitude in the North Pacific."Anonymousnoreply@blogger.com