tag:blogger.com,1999:blog-2220966763638300672.post381673136666739364..comments2023-07-29T05:11:23.558-04:00Comments on Climate Observations: Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The WorldBob Tisdalehttp://www.blogger.com/profile/15462377647970214137noreply@blogger.comBlogger26125tag:blogger.com,1999:blog-2220966763638300672.post-22539572209844622692011-03-07T09:11:10.181-05:002011-03-07T09:11:10.181-05:00Bob, thanks for reminding me of your chart showing...Bob, thanks for reminding me of your chart showing that a property of the NINO3.4 SST Anomalies since 1900 is that their linear trend is flat.<br /><br />But the property of the NINO3.4 SST Anomalies of most interest to me is that their running total bears a striking correlation to global temperature changes for the same 110-year period.<br /><br />Another way of displaying the correlation which you have so well highlighted is the step-structure in the sequence of ENSO events, where we observe three main multi-decadal periods (approx 1910-1944, 1945-1975, and 1976-present).<br /><br />So an important question is whether the sequential structure of ENSO is itself an independent, natural cause of the observed extent and pattern of global warming over the past century?<br /><br />Or, because ENSO events originate in the complex fluid dynamics of the ocean-atmosphere system, is their sequential structure a co-dependent result of other long-running forces, perhaps not as yet well understood? Maybe even of the smooth increase of CO2 in the atmosphere?<br /><br />Why doesn’t the academic climate research community address the sequential structure of ENSO and its correlation to climate change, which you have so aptly demonstrated?Bill Hudsonhttp://bill@proexporter.comnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-55516181505074494002011-03-07T07:59:51.820-05:002011-03-07T07:59:51.820-05:00dh7fb: In the Pacific, the leftover warm water fr...dh7fb: In the Pacific, the leftover warm water from a significant El Nino is returned to the Western Pacific during the La Nina. Does the shape of the landmass in the Western tropical Pacific cause more of the leftover warm water to be spun up into the KOE, than into the South Pacific Convergence Zone?<br /><br />In the Atlantic, we might come to that conclusion, but creating animations that actually show this has proven elusive for me. The tropical Atlantic warms during an El Niño due to the weakening of the trade winds. During the La Niña, the trade winds resume. Where does the warm water go that was created by the El Niño? The South Equatorial Current in the Atlantic splits at the Brazilian coast, with some heading into the Northern Hemisphere. Does the El Niño-warmed water from the Southern Hemisphere merge with the El Niño-warmed water in the Northern Hemisphere and get swept up into the Gulf Stream, to appear higher latitudes at what I’ll call the Gulf Stream Extension?<br /> <br />And to answer your question, “So we should look for the reason of this behaviour in the northern extratropic oceans 80 W...180 0, the western northpacific and atlanic ocean?,” you should find the behavior is most prevalent in the Kuroshio-Oyashio Extension…<br />http://bobtisdale.blogspot.com/2010/12/enso-related-variations-in-kuroshio.html<br />…and in the Gulf Stream Extension.<br /><br />RegardsBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-31215503305654481382011-03-07T05:52:56.678-05:002011-03-07T05:52:56.678-05:00Bob, the ElNino triggered "step up" sign...Bob, the ElNino triggered "step up" signal in the global SST's is very interesting. I took a look to the areas, where we can identify this signal very clear. It can't be found in the southern hemisphere: http://climexp.knmi.nl/data/ihadisst1_-80-180E_-90-0N_n_su_1980:2011_6month_low-pass_box_6month_low-pass_boxa.png , much better in the northern: http://climexp.knmi.nl/data/ihadisst1_-80-180E_0-90N_n_su_1980:2011_6month_low-pass_boxa.png. <br />It seems 2 b very clear in the SST's of northern extratropics: http://climexp.knmi.nl/data/ihadisst1_-80-180E_25-60N_n_su_1980:2011_6month_low-pass_boxa.png.<br />So we should look for the reason of this behaviour in the northern extratropic oceans 80 W...180 0, the western northpacific and atlanic ocean?dh7fbnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-86194607527923064262011-03-07T05:40:33.945-05:002011-03-07T05:40:33.945-05:00data grinder: I can remove the volcanic adjustmen...data grinder: I can remove the volcanic adjustment. The upward steps remain. So your argument doesn’t ring true. <br />http://i56.tinypic.com/icl6jp.jpg<br /><br />By adjusting for the volcanic aerosols the graph doesn’t require the note about the periods impacted by volcanic eruptions. In other words, it’s a cleaner graph in the post.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-31482699369462464562011-03-06T22:43:21.249-05:002011-03-06T22:43:21.249-05:00"What processes could cause anthropogenic glo..."What processes could cause anthropogenic global warming to work only during the significant El Niño events of 1986/87/88, 1997/98 and 2009/10?"<br /><br />In my point about normalization, I was intending to address the above quote. As normalization is a back door to introducting researcher bias, and normalization is needed to handle large events like El Niño, thus the "process" that "could cause" the AGW to ratchet up during the El Niños could be nothing more than the researchers' methodology. This is a general point hailing from what I've seen elsewhere, where researchers publish graphs of their results, not conscious that their graphs are actually showing only their own misapprehension of their source data.data grindernoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-36888332789873091522011-03-06T21:51:55.702-05:002011-03-06T21:51:55.702-05:00Bill Hudson:
PS: Let me attempt to address you...Bill Hudson: <br /><br />PS: Let me attempt to address your concerns in another way. If there was a known anthropogenic component to ENSO, climate studies wouldn't attempt to treat it simply noise and remove it using linear regression.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-89485246202534931022011-03-06T21:33:10.664-05:002011-03-06T21:33:10.664-05:00data grinder: Thanks for the thoughts, but the co...data grinder: Thanks for the thoughts, but the coefficients I've presented are toward the low end of the ranges of past research studies. Cutting them in half would put them well outside the range. <br /><br />Also, with respect to normalization, right or wrong, it is very common for the data to remain in its raw (not normalized) form for basic research like this. Example:<br /> http://www.atmos.colostate.edu/ao/ThompsonPapers/ThompsonWallaceJonesKennedy_JClimate2009.pdf<br /><br />RegardsBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-29297058819588013522011-03-06T21:24:37.613-05:002011-03-06T21:24:37.613-05:00Bill Hudson asked, "But how do we know that t...Bill Hudson asked, "But how do we know that this entire 10-decade pattern is independent of the smooth increase of CO2 during the same period of time?"<br /><br />No one has proven anything in either direction, but what I can show you is that the linear trend of NINO3.4 SST anomalies is flat since 1900:<br />http://i56.tinypic.com/2ag0u2u.jpgBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-8963357922581787872011-03-06T20:57:36.355-05:002011-03-06T20:57:36.355-05:00"What processes could cause anthropogenic glo..."What processes could cause anthropogenic global warming to work only during the significant El Niño events of 1986/87/88, 1997/98 and 2009/10?"<br /><br />I work with large data myself, and typically one needs to normalize the data -- and normalization is a wide-open back door for introducing experimenter-driven bias, because one builds one's assumptions into the grand average -- as you are doing in your volcano adjustment. I recommend you halve your adjustment in this and everything -- else your models will dominate the data -- exactly what you don't want.data grindernoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-41778744239788450102011-03-06T18:15:15.704-05:002011-03-06T18:15:15.704-05:00Thanks, Bob, I recall these charts from your previ...Thanks, Bob, I recall these charts from your previous posts, and it’s good to have them all together in one file.<br /><br />But my basic question remains, I can’t shake it. Let’s take your last chart, the period average NINO3.4 SST anomalies from 1910 to 2010. There are three multidecadal components, the plus 0.15, the minus 0.06, and the plus 0.20 degree C. These three steps fit the SST curve.<br /><br />But how do we know that this entire 10-decade pattern is independent of the smooth increase of CO2 during the same period of time? Is ENSO perhaps some kind of “chaotic rhythm” in the fluid dynamics of the ocean-atmospheric system? Does ENSO simply do its own cosmic thing? Is an unfettered ENSO the underlying causal “drum beat” for multi-decadal SST, with no feedback loop from changes to the atmosphere—either solar-induced or anthropogenic?<br /><br />To me, if we cannot establish ENSO firmly as a mulitdecadal independent variable, then modeling arithmetic almost automatically makes it a dependent noise. In other words, despite your clearly charted “step structure,” the trend over 100 years is up.Bill Hudsonhttp://bill@proexporter.comnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-55366742096786317002011-03-06T16:44:18.657-05:002011-03-06T16:44:18.657-05:00Bill: You asked, “…what is it that accounts for t...Bill: You asked, “…what is it that accounts for the fact that in the period since the late 1970s, the ENSO episodes have been predominantly El Ninos whose strength and duration seems to 'outweigh' the LaNinas during the same period?”<br /><br />There is a multidecadal component to ENSO. This can be seen if you smooth NINO3.4 SST anomalies with a 121-month running-average filter:<br />http://oi43.tinypic.com/33agh3c.jpg<br /><br />When I first used the running total of NINO3.4 SST anomalies, I was trying to determine if there were periods when El Niño events outweighed La Niña events, and vice versa.<br /><br />BTW, the running total of scaled NINO3.4 SST anomalies reproduces the basic shape of global land plus sea surface temperature anomaly curve not only since the 1950s. It does a good job of it since the early 1900s, including the two warming periods and the 1940s to 1970s cooling period:<br />http://i42.tinypic.com/2zqufzp.jpg<br /><br />The above graph is from this post:<br />http://bobtisdale.blogspot.com/2009/01/reproducing-global-temperature.html<br /><br />Or if you like, you could use global sea surface temperatures for the comparison:<br />http://i53.tinypic.com/29fcjl2.jpg<br /><br />And that graph is from this post:<br />http://bobtisdale.blogspot.com/2010/11/multidecadal-changes-in-sea-surface_17.html<br /><br />Back to the frequency and magnitude of El Niño events: as illustrated above, they outweighed those of La Niña events during the early warming period also. We can use period average NINO3.4 SST anomalies to show the same thing:<br />http://i56.tinypic.com/zxmsg8.jpg<br /><br />Personally, I like the looks of a graph that compares period average NINO3.4 SST anomalies (from the above graph) to global SST anomalies:<br />http://i55.tinypic.com/33cwt4j.jpgBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-16929885440509064102011-03-06T14:52:57.345-05:002011-03-06T14:52:57.345-05:00In previous posts, you have shown how the running ...In previous posts, you have shown how the running total of the montlhy ENSO since say 1950 produces a curve that closely correlates with SST, or in fact with aggregate world temperature. So my question is not exactly what forces initiate an episode of El Nino, but what is it that accounts for the fact that in the period since the late 1970s, the ENSO episodes have been predominantly El Ninos whose strength and duration seems to "outweigh" the LaNinas during the same period? If this question cannot be answered, then don't AGW modelers simply "answer" it with the steady upslope of CO2 increase?Bill Hudsonhttp://bill@proexporter.comnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-35758646580234528542011-03-05T20:41:36.353-05:002011-03-05T20:41:36.353-05:00Bob:
"Roger: Your question was whether there...Bob:<br /><br />"Roger: Your question was whether there was a detectable lag between the trade winds relaxing and an El Niño, so I’m not sure why you ran correlations at different lags of the full terms of the datasets. The additional data that has nothing to do with the evolution of the El Niño would skew your results."<br /><br />It doesn't skew the results in the slightest. The lag between West Pacific winds and the Niño 3.4 index stays reasonably constant at about 2 months whether there's an El Niño or not. The implication is that West Pacific winds aren't correlated just with the evolution of El Niños. They're correlated with the entire Niño Index.<br /><br />The reason I ran the correlations in the first place was simply that if one is going to postulate that A causes B then it's a good idea to make sure that A starts before B, or at least no later. I have now satisfied myself that this is the case.Roger Andrewsnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-51210692719751735522011-03-05T19:51:14.575-05:002011-03-05T19:51:14.575-05:00Roger: Your question was whether there was a dete...Roger: Your question was whether there was a detectable lag between the trade winds relaxing and an El Niño, so I’m not sure why you ran correlations at different lags of the full terms of the datasets. The additional data that has nothing to do with the evolution of the El Niño would skew your results. Comparing the two…<br />http://i52.tinypic.com/3129zk3.jpg<br />…they appear to be in lockstep during El Niño development.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-11909497313346069672011-03-05T12:35:48.766-05:002011-03-05T12:35:48.766-05:00Hi Bob:
Sorry about the delay in replying but I&#...Hi Bob:<br /><br />Sorry about the delay in replying but I've been running some checks.<br /><br />I cross-correlated the monthly Niño 3.4 Index with the monthly NOAA 850mb Trade Wind Indices (http://www.cpc.ncep.noaa.gov/data/indices/) for the West, Central and East Pacific. The correlations were all negative (i.e. less wind = higher Niño 3.4), which fits your hypothesis. I also got the following lags in Niño 3.4 relative to changes in the wind indices: <br /><br />W. Pacific: 2 months (R=0.61)<br />C. Pacific: 0-1 month (R=0.77)<br />E. Pacific: no lag (R=0.48)<br /><br />These results suggest that El Niños are in fact preceded by a reduction in trade wind strength that begins in the W Pacific and works its way eastwards.<br /><br />Regards<br /><br />RogerRoger Andrewsnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-25725640969732339252011-03-05T12:34:13.487-05:002011-03-05T12:34:13.487-05:00Reference the relaxation in Trade Wind "press...Reference the relaxation in Trade Wind "pressure" that holds the 'pile' of warm water in place in the Pacific Warm Pool, would imagine that a corresponding "pressure" cell (or two?) at (an)other position(s) on the globe is/are responsible for this hold/release phenom. Since, next to ENSO, the Monsoons are the next biggest observable weather pattern, a close connection would be found in their pattern shifts. (-;Still of a mind that variation in temp/salinity within the global conveyor are #3 in the big picture.) Your work is so interesting. Thank you again!Pascvaksnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-26456849779734088802011-03-04T18:24:45.796-05:002011-03-04T18:24:45.796-05:00Roger: The trade winds are in effect holding the ...Roger: The trade winds are in effect holding the "pile" of warm water in place in the Pacific Warm Pool. As soon as the trade winds relax, gravity dictates the response.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-74606597844513049112011-03-04T18:10:27.762-05:002011-03-04T18:10:27.762-05:00Bob
"A relaxation of the trade winds starts ...Bob<br /><br />"A relaxation of the trade winds starts an El Nino." You've probably dealt with this question somewhere else, but is there in fact a detectable time lapse between the two?Roger Andrewsnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-24930271322341095802011-03-04T15:23:41.730-05:002011-03-04T15:23:41.730-05:00Roger: A relaxation of the trade winds starts an E...Roger: A relaxation of the trade winds starts an El Nino. The next question is, what initiates the relaxation of the trade winds? And the answer to that is unknown. There are many hypotheses, but none stand up to scrutiny. In other words, there are probably many factors that can initiate an El Nino. <br /><br />The El Nino is the truly anomalous phase, while a La Nina is an exaggeration of "normal" conditions. In fact, there are hypotheses that there only two phases of ENSO (El Nino and other) not the three phases that are usually discussed (El Nino, La Nina, ENSO neutral). <br /><br />Some researchers consider the formation of a Rossby wave in the far eastern tropical Pacific (at about 10N) as the start of the La Nina. Refer to the westward moving band of elevated sea level at about 10N in the following: <br />http://www.youtube.com/watch?v=MF5vZErQ6HM<br />That's the video that started me looking at the SST anomalies of the East Indian and West Pacific Oceans, and at the processes that could cause the upward steps there after an El Nino.<br /><br />RegardsBob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-85277634154068424582011-03-04T14:59:00.064-05:002011-03-04T14:59:00.064-05:00Howard: The fuel (warm water) for an El Nino come...Howard: The fuel (warm water) for an El Nino comes from below the surface (and the surface) of the Western tropical Pacific, an area known as the Pacific Warm Pool. <br /><br />There doesn't need to be a build-up over years. The warm water for the 1997/98 El Nino built up during the 1995/96 La Nina, resulting from unusually high trade winds in the tropical Pacific. Higher trade wind strength yields less cloud cover, which yields more downward shortwave radiation (visible light) warming the ocean.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-67354840212058740352011-03-04T12:22:54.098-05:002011-03-04T12:22:54.098-05:00Bob
Thanks for your answers.
Another question is...Bob<br /><br />Thanks for your answers.<br /><br />Another question is what causes the Niño and Niña events. FWIW I've been messing around superimposing sine curves with the dominant ENSO frequency (+/-7 years) on the sunspot record. Adding the two together gives a plot that doesn't of course match the ENSO Index, but it doesn't look all that different either.Roger Andrewsnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-50165042675310299862011-03-04T11:13:25.804-05:002011-03-04T11:13:25.804-05:00Hi Bob
Thanks, I get that. It was clear from you...Hi Bob<br /><br />Thanks, I get that. It was clear from your most excellent post.<br /><br />However, where does the warmth come from that causes the El Nino events resulting in the step up in world-wide SST and Air temps?<br /><br />Conceptually, for the step model to work, heat needs to build up over time somewhere not evident in SST or Air temps, then be released to SST via El Nino to cause the step up.<br /><br />I'm probably all wet, thanks for you interesting blog.Howardhttps://www.blogger.com/profile/01048255624944551506noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-21005861608042142732011-03-04T10:28:47.171-05:002011-03-04T10:28:47.171-05:00Roger: Sorry I can’t provide more specific answer...Roger: Sorry I can’t provide more specific answers to your questions:<br /><br />1)Every El Niño event does not cause the upward steps, as far as I can tell. The lesser El Niño events that are not followed by a La Niña event do not appear to have the same effect. <br /><br />The 1939-1942 El Niño lasted a long time but it wasn’t too strong:<br />http://i56.tinypic.com/i3850k.jpg<br /><br />2)If there is a threshold I haven’t identified it. The 1972/73 El Niño was stronger than the 2009/10 El Niño, yet the 1972/73 El Niño did not cause an upward step while the 2009/10 El Niño appears to be doing so. <br /><br />And while we’re discussing this, both El Niño Modoki and “traditional” El Niño events can cause them.<br /><br />3)I have been hoping the AMO would “make a turn”, or that there would be a Pacific Climate shift in the other direction, so that we could see if they’re providing feedback of some kind.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-43138539691311565062011-03-04T09:30:51.680-05:002011-03-04T09:30:51.680-05:00Hi Bob:
I have a few questions connected with som...Hi Bob:<br /><br />I have a few questions connected with some work I am doing. <br /><br />1. Do El Niños always cause a step-function increase in SST? As I recollect there was a large El Niño in 1941 or thereabouts that was followed by a temperature decrease, at least in SAT.<br /><br />2. Do the El Niños/La Niñas have to exceed some kind of a threshold value before the effect occurs?<br /><br />3. How might the effect work in the opposite sense, i.e. cause cooling?<br /><br />Apologies if you've already dealt with these questions and I missed it. <br /><br />RogerRoger Andrewsnoreply@blogger.comtag:blogger.com,1999:blog-2220966763638300672.post-78470625973506866132011-03-04T03:57:02.903-05:002011-03-04T03:57:02.903-05:00Howard: The following animation disagrees with yo...Howard: The following animation disagrees with your thought that the "step changes are the result of warming that has occurred several decades in the past." <br />http://i51.tinypic.com/2qiwscz.jpg<br /><br />The upward steps are caused by the respective El Nino events.Bob Tisdalehttps://www.blogger.com/profile/15462377647970214137noreply@blogger.com