{"id":380269,"date":"2025-05-27T10:28:31","date_gmt":"2025-05-27T08:28:31","guid":{"rendered":"https:\/\/climatescience.press\/?p=380269"},"modified":"2025-05-27T10:28:33","modified_gmt":"2025-05-27T08:28:33","slug":"musings-on-the-amo","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=380269","title":{"rendered":"Musings on the AMO"},"content":{"rendered":"\n<figure class=\"wp-block-image size-large\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"723\" height=\"426\" data-attachment-id=\"353865\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=353865\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?fit=1236%2C728&amp;ssl=1\" data-orig-size=\"1236,728\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;Print&quot;,&quot;orientation&quot;:&quot;1&quot;}\" data-image-title=\"Print\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?fit=723%2C426&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?resize=723%2C426&#038;ssl=1\" alt=\"\" class=\"wp-image-353865\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?resize=1024%2C603&amp;ssl=1 1024w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?resize=300%2C177&amp;ssl=1 300w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?resize=768%2C452&amp;ssl=1 768w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?resize=1200%2C707&amp;ssl=1 1200w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?w=1236&amp;ssl=1 1236w\" sizes=\"auto, (max-width: 723px) 100vw, 723px\" \/><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">From <a href=\"https:\/\/wattsupwiththat.com\/2025\/05\/26\/musings-on-the-amo\/\">Watts Up With That?<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">By <a href=\"https:\/\/wattsupwiththat.com\/author\/andymay2014_69488455_3713736997\/\">Andy May<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We hear a lot about the AMO, or the Atlantic Multidecadal Oscillation. How much does it influence the global mean surface temperature or GMST? Exactly what is the AMO? These are the issues we will discuss. First let\u2019s look at various definitions of the AMO.<\/p>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/abs\/10.1029\/2000gl012745\">Enfield, et al.<\/a>: \u201cThe AMO index [is a] ten-year running mean of detrended Atlantic SSTA [sea surface temperature anomaly] north of the equator.\u201d<\/p>\n<\/blockquote>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/full\/10.1029\/2004GL019932\">Gray, et al.<\/a>: Uses detrended raw tree-ring measurements to demonstrate a strong and regular 60-100 year variability in basin-wide (0-70\u00b0N) North Atlantic sea surface temperatures (SSTs) that has been persistent for the past five centuries.<\/p>\n<\/blockquote>\n\n\n\n<blockquote class=\"wp-block-quote is-layout-flow wp-block-quote-is-layout-flow\">\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/full\/10.1029\/2006GL026894\">Trenberth &amp; Shea<\/a>: \u201cTo deal with purely Atlantic variability, it is highly desirable to remove the larger-scale global signal that is associated with global [anthropogenic] processes, and is thus related to global warming in recent decades \u2026 Accordingly, the global mean SST has been subtracted to derive a revised AMO index.\u201d<\/p>\n<\/blockquote>\n\n\n\n<p class=\"wp-block-paragraph\"><a href=\"https:\/\/climatedataguide.ucar.edu\/climate-data\/atlantic-multi-decadal-oscillation-amo\">NCAR<\/a>&nbsp;uses the Trenberth &amp; Shea method, but&nbsp;<a href=\"https:\/\/psl.noaa.gov\/data\/timeseries\/AMO\/\">NOAA<\/a>&nbsp;uses the original methodology and detrends the North Atlantic temperatures using a least squares linear trend. We will also use the original Enfield and Gray method in this post.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">The reason for the AMO SST 60-70-year pattern is unknown, but according to Gray et al. it extends back to 1567AD, so it is a natural oscillation of some kind. Some have speculated that it is a result of the&nbsp;<a href=\"https:\/\/climatedataguide.ucar.edu\/climate-data\/atlantic-multi-decadal-oscillation-amo\">thermohaline circulation<\/a>&nbsp;in the North Atlantic or a \u201ccombination of natural and anthropogenic forcing during the historical era.\u201d (Mann, Steinman, &amp; Miller, 2020). But while interesting these ideas are speculative. Further if the oscillation has existed since 1567, it seems unlikely that it is caused by human CO<sub>2<\/sub>&nbsp;and aerosol emissions.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">It is clear that \u201cglobal\u201d warming is mostly an extra-tropical Northern Hemisphere phenomenon. This is discussed&nbsp;<a href=\"https:\/\/andymaypetrophysicist.com\/2017\/06\/09\/a-holocene-temperature-reconstruction-part-4-the-global-reconstruction\/\">here<\/a>&nbsp;in figures 1A &amp; 1B and&nbsp;<a href=\"https:\/\/andymaypetrophysicist.com\/2023\/02\/24\/the-holocene-temperature-conundrum\/\">here<\/a>&nbsp;in the discussion around figure 1, which is also shown as figure 1 below. Regions outside the extratropical Northern Hemisphere don\u2019t change temperature as quickly or as drastically.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"723\" height=\"428\" data-attachment-id=\"380272\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=380272\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-494.png?fit=970%2C574&amp;ssl=1\" data-orig-size=\"970,574\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"image\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-494.png?fit=723%2C428&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-494.png?resize=723%2C428&#038;ssl=1\" alt=\"\" class=\"wp-image-380272\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-494.png?w=970&amp;ssl=1 970w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-494.png?resize=300%2C178&amp;ssl=1 300w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-494.png?resize=768%2C454&amp;ssl=1 768w\" sizes=\"auto, (max-width: 723px) 100vw, 723px\" \/><figcaption class=\"wp-element-caption\">Figure 1. Proxy temperature anomalies shown for 30-degree latitude slices. The Antarctic slice is 90S to 60S, the Southern Hemisphere is 60S to 30S, the tropics are from 30S to 30N, the Northern Hemisphere is 30N to 60N, and the Arctic is 60N to 90N. Most of the records are relatively flat, the Northern Hemisphere drives global temperature changes. \u201cMHT\u201d is the Mid-Holocene Transition. Source:\u00a0<a href=\"https:\/\/andymaypetrophysicist.com\/2023\/02\/24\/the-holocene-temperature-conundrum\/\">here<\/a>.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">A similar pattern can also be seen for the modern era in figure 2.11 in Chapter 2 of\u00a0<a href=\"https:\/\/www.ipcc.ch\/report\/ar6\/wg1\/\">AR6<\/a>\u00a0(page 316), part of which is shown as figure 2 below.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"526\" height=\"645\" data-attachment-id=\"380275\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=380275\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-496.png?fit=526%2C645&amp;ssl=1\" data-orig-size=\"526,645\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"image\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-496.png?fit=526%2C645&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-496.png?resize=526%2C645&#038;ssl=1\" alt=\"\" class=\"wp-image-380275\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-496.png?w=526&amp;ssl=1 526w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-496.png?resize=245%2C300&amp;ssl=1 245w\" sizes=\"auto, (max-width: 526px) 100vw, 526px\" \/><figcaption class=\"wp-element-caption\">Figure 2. A portion of figure 2.11 from AR6. Most of the warming since 1980 has occurred in the extra-tropical Northern Hemisphere. This pattern is also seen in longer-term proxy records as shown in figure 1. Source:\u00a0<a href=\"https:\/\/www.ipcc.ch\/report\/ar6\/wg1\/\">AR6<\/a>, page 316.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">Trenberth and Shea\u2019s method of detrending the AMO by first subtracting the global average surface temperature from it is an attempt to remove \u201cglobal anthropogenic changes\u201d from the AMO signal so it can be viewed as a natural phenomenon. This assumes that global warming has no natural component and is all anthropogenic. However, there is no evidence to support this assumption outside of global climate models. Thus, the Trenberth and Shea version of the AMO index can be discarded if our intent is to show the correlation between GMST and the AMO.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">We clearly have a chicken-and-egg problem here. The cause of the AMO pattern is unknown, but does the AMO influence global temperature patterns? Or does some sort of global 60-70-year pattern of warming and cooling affect or cause the AMO?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 3 shows the AMO pattern using HadSST and ERSST sea surface temperatures detrended with linear least-squares best-fit lines. Yearly averages are plotted, and the curves are not smoothed.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"720\" height=\"416\" data-attachment-id=\"380278\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=380278\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-498.png?fit=720%2C416&amp;ssl=1\" data-orig-size=\"720,416\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"image\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-498.png?fit=720%2C416&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-498.png?resize=720%2C416&#038;ssl=1\" alt=\"\" class=\"wp-image-380278\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-498.png?w=720&amp;ssl=1 720w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-498.png?resize=300%2C173&amp;ssl=1 300w\" sizes=\"auto, (max-width: 720px) 100vw, 720px\" \/><figcaption class=\"wp-element-caption\">Figure 3. North Atlantic AMO region ERSST and HadSST records detrended using linear trends. The recent anomaly that is probably due to the 2022 Hunga-Tonga volcanic eruption can be clearly seen at the end of both records. Plot of yearly averages, no smoothing.<\/figcaption><\/figure>\n<\/div>\n\n\n<p class=\"wp-block-paragraph\">In figure 3 we see that both the HadSST and the ERSST sea surface temperature records produce the same pattern and closely match each other. This is not surprising since they mostly use the&nbsp;<a href=\"https:\/\/andymaypetrophysicist.com\/2025\/04\/08\/what-is-the-global-average-sst\/\">same raw data from ICOADS v. 3<\/a>&nbsp;and&nbsp;<a href=\"https:\/\/andymaypetrophysicist.com\/2020\/12\/19\/sea-surface-temperature-anomalies\/\">similar processing methods<\/a>. Both the 1900-1910 and the early 1970s were colder across the Northern Hemisphere. The spike at the end of both records is probably due to the Hunga-Tonga volcanic eruption in January of 2022.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In figure 4 we plot the detrended HadSST 4.1 record shown in figure 3 with the HadCRUT 5 global surface temperature anomaly detrended in the same way.<\/p>\n\n\n\n<figure class=\"wp-block-image size-full\"><img data-recalc-dims=\"1\" loading=\"lazy\" decoding=\"async\" width=\"723\" height=\"418\" data-attachment-id=\"380280\" data-permalink=\"https:\/\/climatescience.press\/?attachment_id=380280\" data-orig-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-499.png?fit=871%2C503&amp;ssl=1\" data-orig-size=\"871,503\" data-comments-opened=\"1\" data-image-meta=\"{&quot;aperture&quot;:&quot;0&quot;,&quot;credit&quot;:&quot;&quot;,&quot;camera&quot;:&quot;&quot;,&quot;caption&quot;:&quot;&quot;,&quot;created_timestamp&quot;:&quot;0&quot;,&quot;copyright&quot;:&quot;&quot;,&quot;focal_length&quot;:&quot;0&quot;,&quot;iso&quot;:&quot;0&quot;,&quot;shutter_speed&quot;:&quot;0&quot;,&quot;title&quot;:&quot;&quot;,&quot;orientation&quot;:&quot;0&quot;}\" data-image-title=\"image\" data-image-description=\"\" data-image-caption=\"\" data-large-file=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-499.png?fit=723%2C418&amp;ssl=1\" src=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-499.png?resize=723%2C418&#038;ssl=1\" alt=\"\" class=\"wp-image-380280\" srcset=\"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-499.png?w=871&amp;ssl=1 871w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-499.png?resize=300%2C173&amp;ssl=1 300w, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/image-499.png?resize=768%2C444&amp;ssl=1 768w\" sizes=\"auto, (max-width: 723px) 100vw, 723px\" \/><figcaption class=\"wp-element-caption\">Figure 4. HadSST and HadCRUT detrended temperature anomalies plotted together. Both anomalies are from 1961-1990 originally but are from their respective linear least squares trends. This is updated from figure 2 in\u00a0<a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/abs\/10.1111\/ajes.12579\">(May &amp; Crok, 2024)<\/a>.<\/figcaption><\/figure>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 4 is very similar to figure 2 in May &amp; Crok, 2024, but it is extended through 2024 and HadCRUT 4 is replaced by the newer&nbsp;<a href=\"https:\/\/www.metoffice.gov.uk\/hadobs\/hadcrut5\/data\/HadCRUT.5.0.2.0\/download.html\">HadCRUT 5<\/a>. In addition, the detrended HadSST 4.1 AMO region record replaces the&nbsp;<a href=\"https:\/\/psl.noaa.gov\/data\/timeseries\/AMO\/\">NOAA unsmoothed record<\/a>&nbsp;used in&nbsp;<a href=\"https:\/\/onlinelibrary.wiley.com\/doi\/abs\/10.1111\/ajes.12579\">May &amp; Crok<\/a>.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 4 opens some possibilities. The AMO pattern may influence the global mean temperature anomaly, or the reverse may be true. The former idea is more attractive given the apparent influence that the Northern Hemisphere has on global climate as shown in figures 1 and 2. There is a very close correspondence between the two temperature anomalies and there is very little, if any, time lag between the two, at least in these plots of yearly averages. We can\u2019t be sure which record is driving the other, but they clearly correlate very well.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Figure 2 in May &amp; Crok was criticized because the AMO index plotted did not conform to the Trenberth &amp; Shea definition of the index, that is, the global mean temperature anomaly was not used to detrend the North Atlantic SSTs. But, if we are trying to show the correlation between the AMO and GMST, why would we do that? Even so, figure 3 in Trenberth and Shea shows that the AMO pattern can still be seen after subtracting the GMST, a testament to its strength. Removing the least squares linear trend has \u201cno physical meaning\u201d as Trenberth and Shea write in their paper, but detrending imposes no bias and does not attempt to hide the correlation.<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">In conclusion, I think it is very clear from the data presented in this post that Northern Hemispheric climatic changes drive global changes as shown in figures 1 and 2. It is also clear that the AMO and global average surface temperature patterns are closely related, with the AMO being the stronger pattern of the two. Gray, et al. show that the AMO 60-70-year AMO pattern extends into the past at least to 1567AD, which argues against any anthropogenic cause for the AMO or GMST patterns.<\/p>\n\n\n\n<h1 class=\"wp-block-heading\">Works Cited<\/h1>\n\n\n\n<p class=\"wp-block-paragraph\">Enfield, D., Mestas-Nunez, A. M., &amp; Trimble, P. (2001). The Atlantic multidecadal oscillation and its relation to rainfall and river flows in the continental U.S.&nbsp;<em>Geophysical Research Letters, 28<\/em>(10). Retrieved from <a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdfdirect\/10.1029\/2000GL012745\" rel=\"nofollow\">https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdfdirect\/10.1029\/2000GL012745<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Gray, S. T., Graumlich, L. J., Betancourt, J. L., &amp; Pederson, G. T. (2004). A tree-ring based reconstruction of the Atlantic Multidecadal Oscillation since 1567 A.D.&nbsp;<em>Geophys. Res. Lett., 31<\/em>. doi:10.1029\/2004GL019932<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Mann, M., Steinman, B., &amp; Miller, S. (2020). Absence of internal multidecadal and interdecadal oscillations in climate model simulations.&nbsp;<em>Nat Commun, 11<\/em>. doi:10.1038\/s41467-019-13823-w<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">May, A., &amp; Crok, M. (2024, May 29). Carbon dioxide and a warming climate are not problems.&nbsp;<em>American Journal of Economics and Sociology<\/em>, 1-15. doi:10.1111\/ajes.12579<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">Trenberth, K., &amp; Shea, D. (2006). Atlantic hurricanes and natural variability in 2005.&nbsp;<em>Geophysical Research Letters, 33<\/em>. Retrieved from <a href=\"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1029\/2006GL026894\" rel=\"nofollow\">https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1029\/2006GL026894<\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>We hear a lot about the AMO, or the Atlantic Multidecadal Oscillation. How much does it influence the global mean surface temperature or GMST? Exactly what is the AMO? These are the issues we will discuss. First let\u2019s look at various definitions of the AMO.<\/p>\n","protected":false},"author":121246920,"featured_media":353865,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_crdt_document":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[691828920,691831096,691818087,691835371,691835370,691835369],"class_list":{"0":"post-380269","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","8":"tag-atlantic-multidecadal-oscillation-amo","9":"tag-global-mean-surface-temperature-gmst","10":"tag-global-warming","11":"tag-hadsst-and-ersst","12":"tag-north-atlantic-temperatures","13":"tag-ssta-sea-surface-temperature-anomaly","15":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/0AMOC_Fig_1.jpg?fit=1236%2C728&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-1AVn","jetpack-related-posts":[{"id":380996,"url":"https:\/\/climatescience.press\/?p=380996","url_meta":{"origin":380269,"position":0},"title":"The Bray Solar Cycle and AMO","author":"uwe.roland.gross","date":"31\/05\/2025","format":false,"excerpt":"Trenberth and Shea further criticize the original AMO index as having no physical meaning. While this is true, it is also unbiased and not tainted with unwarranted assumptions about the cause of global warming. In this post we will show that the long-term trend evident in the raw North Atlantic\u2026","rel":"","context":"In \"AMO (Atlantic Multidecadal Oscillation)\"","block_context":{"text":"AMO (Atlantic Multidecadal Oscillation)","link":"https:\/\/climatescience.press\/?tag=amo-atlantic-multidecadal-oscillation"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/0ChatGPT-Image-31.-Mai-2025-12_10_50.png?fit=1024%2C1024&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/0ChatGPT-Image-31.-Mai-2025-12_10_50.png?fit=1024%2C1024&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/0ChatGPT-Image-31.-Mai-2025-12_10_50.png?fit=1024%2C1024&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/05\/0ChatGPT-Image-31.-Mai-2025-12_10_50.png?fit=1024%2C1024&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":354072,"url":"https:\/\/climatescience.press\/?p=354072","url_meta":{"origin":380269,"position":1},"title":"Michael Mann\u2019s Latest Attempts to Support the \u2018Hockey Stick\u2019 Graph Aren\u2019t Even Convincing Alarmists","author":"uwe.roland.gross","date":"12\/12\/2024","format":false,"excerpt":"The Atlantic hurricane season has come to an end, and the global warming believers have been looking for records to ascribe to global warming. According to a\u00a0NOAA\u00a0news report, the end-of-season flourish of cyclone activity was as predicted, and a record for the period. The\u00a0BBC Weather\u00a0commented that the activity corresponded with\u2026","rel":"","context":"In \"Atlantic Multidecadal Oscillation (AMO)\"","block_context":{"text":"Atlantic Multidecadal Oscillation (AMO)","link":"https:\/\/climatescience.press\/?tag=atlantic-multidecadal-oscillation-amo"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/02024-02-15-17_02_48-mann-thumb-clean.jpg-1800%C3%971013-1.jpeg?fit=1200%2C671&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/02024-02-15-17_02_48-mann-thumb-clean.jpg-1800%C3%971013-1.jpeg?fit=1200%2C671&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/02024-02-15-17_02_48-mann-thumb-clean.jpg-1800%C3%971013-1.jpeg?fit=1200%2C671&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/02024-02-15-17_02_48-mann-thumb-clean.jpg-1800%C3%971013-1.jpeg?fit=1200%2C671&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/12\/02024-02-15-17_02_48-mann-thumb-clean.jpg-1800%C3%971013-1.jpeg?fit=1200%2C671&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":384092,"url":"https:\/\/climatescience.press\/?p=384092","url_meta":{"origin":380269,"position":2},"title":"Climate Oscillations 2: The Western Hemisphere Warm Pool (WHWP)","author":"uwe.roland.gross","date":"21\/06\/2025","format":false,"excerpt":"The Western Hemisphere warm pool or the WHWP is an anomaly based on the area of the ocean warmer than 28.5\u00b0C (that is within the 28.5\u00b0C isotherm) and approximately within the rectangular region from 7\u00b0N \u2013 27\u00b0N and 110\u00b0W to 50\u00b0W. This area extends from the eastern North Pacific (west\u2026","rel":"","context":"In \"Atlantic Warm Pool (AWP)\"","block_context":{"text":"Atlantic Warm Pool (AWP)","link":"https:\/\/climatescience.press\/?tag=atlantic-warm-pool-awp"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0ChatGPT-Image-21.-Juni-2025-20_19_01.png?fit=800%2C1200&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0ChatGPT-Image-21.-Juni-2025-20_19_01.png?fit=800%2C1200&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0ChatGPT-Image-21.-Juni-2025-20_19_01.png?fit=800%2C1200&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/0ChatGPT-Image-21.-Juni-2025-20_19_01.png?fit=800%2C1200&ssl=1&resize=700%2C400 2x"},"classes":[]},{"id":393316,"url":"https:\/\/climatescience.press\/?p=393316","url_meta":{"origin":380269,"position":3},"title":"Climate Oscillations 12: The Causes &amp; Significance","author":"uwe.roland.gross","date":"06\/08\/2025","format":false,"excerpt":"While internal variability may play a role in our observed oscillations, it is possible that gravitational forces and changes in solar output provide the pacing of the oscillations. Since all climate oscillations clearly influence the others through a mechanism named \u201cteleconnections,\u201d if the pacing of a few of the oscillations\u2026","rel":"","context":"In \"astronomical periods\"","block_context":{"text":"astronomical periods","link":"https:\/\/climatescience.press\/?tag=astronomical-periods"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/08\/0AQNPLSWo_KzxXKVbW7IbL7_vsFYRwpeEDr7n4wOji7EYEkkB1n0lKGSzzfQRN21EEW2YTvQtJVQSWUfh7fwAwOb_zqmvvqK2jdNxixoG7mgswXaDvyZS-6qY2mUTFO5a-1.jpeg?fit=1200%2C1200&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/08\/0AQNPLSWo_KzxXKVbW7IbL7_vsFYRwpeEDr7n4wOji7EYEkkB1n0lKGSzzfQRN21EEW2YTvQtJVQSWUfh7fwAwOb_zqmvvqK2jdNxixoG7mgswXaDvyZS-6qY2mUTFO5a-1.jpeg?fit=1200%2C1200&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/08\/0AQNPLSWo_KzxXKVbW7IbL7_vsFYRwpeEDr7n4wOji7EYEkkB1n0lKGSzzfQRN21EEW2YTvQtJVQSWUfh7fwAwOb_zqmvvqK2jdNxixoG7mgswXaDvyZS-6qY2mUTFO5a-1.jpeg?fit=1200%2C1200&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/08\/0AQNPLSWo_KzxXKVbW7IbL7_vsFYRwpeEDr7n4wOji7EYEkkB1n0lKGSzzfQRN21EEW2YTvQtJVQSWUfh7fwAwOb_zqmvvqK2jdNxixoG7mgswXaDvyZS-6qY2mUTFO5a-1.jpeg?fit=1200%2C1200&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/08\/0AQNPLSWo_KzxXKVbW7IbL7_vsFYRwpeEDr7n4wOji7EYEkkB1n0lKGSzzfQRN21EEW2YTvQtJVQSWUfh7fwAwOb_zqmvvqK2jdNxixoG7mgswXaDvyZS-6qY2mUTFO5a-1.jpeg?fit=1200%2C1200&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":383684,"url":"https:\/\/climatescience.press\/?p=383684","url_meta":{"origin":380269,"position":4},"title":"Climate Oscillations 1: The Regression","author":"uwe.roland.gross","date":"19\/06\/2025","format":false,"excerpt":"I did a regression analysis to see how the twelve oscillations (14 in the 1978 regression) I looked at correlated to the HadCRUT5 global mean surface temperature (GMST). GMST is not a very good indicator of climate or climate change, but it is a commonly used yardstick of climate model\u2026","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/ChatGPT-Image-8.-Juni-2025-18_50_51-2.png?fit=1200%2C800&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/ChatGPT-Image-8.-Juni-2025-18_50_51-2.png?fit=1200%2C800&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/ChatGPT-Image-8.-Juni-2025-18_50_51-2.png?fit=1200%2C800&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/ChatGPT-Image-8.-Juni-2025-18_50_51-2.png?fit=1200%2C800&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2025\/06\/ChatGPT-Image-8.-Juni-2025-18_50_51-2.png?fit=1200%2C800&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":330851,"url":"https:\/\/climatescience.press\/?p=330851","url_meta":{"origin":380269,"position":5},"title":"Carbon Dioxide and a Warming Climate are not problems","author":"uwe.roland.gross","date":"01\/06\/2024","format":false,"excerpt":"The featured image for this post, also shown below, is part of figure 2 from the paper. It shows the Atlantic Multidecadal Oscillation (AMO) index compared to the detrended HadCRUT4 global average surface temperature record, the similarity is obvious. The AMO is the North Atlantic sea surface temperature record, detrended.\u2026","rel":"","context":"In \"Atlantic Multidecadal Oscillation (AMO)\"","block_context":{"text":"Atlantic Multidecadal Oscillation (AMO)","link":"https:\/\/climatescience.press\/?tag=atlantic-multidecadal-oscillation-amo"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0moc_diagram_f.jpg?fit=1200%2C491&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0moc_diagram_f.jpg?fit=1200%2C491&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0moc_diagram_f.jpg?fit=1200%2C491&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0moc_diagram_f.jpg?fit=1200%2C491&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2024\/06\/0moc_diagram_f.jpg?fit=1200%2C491&ssl=1&resize=1050%2C600 3x"},"classes":[]}],"_links":{"self":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/380269","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/users\/121246920"}],"replies":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=380269"}],"version-history":[{"count":7,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/380269\/revisions"}],"predecessor-version":[{"id":380282,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/posts\/380269\/revisions\/380282"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=\/wp\/v2\/media\/353865"}],"wp:attachment":[{"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=380269"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=380269"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/climatescience.press\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=380269"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}