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  1. Links Section In This Post, below the intro. I have been recently asked to start a thread, to talk about weather teleconnections and similar topics. This is often a topic not very well discussed on other weather places, and places like Twitter. We have a number of experts, enthusiasts, and meteorologists, who are knowledgeable in this area. So this is a thread for technical discussion about the teleconnections, etc, as well as a place for questions about these topics. We need to start talking about these climate drivers more, as they are the key to unlocking medium-long term forecasts. We are making a place for technical discussion about these factors away from the main thread/s. So this thread is born. Teleconnections that could be up for discussion are: MJO, AAM/GWO, NAO, RRWT, NP jet, Mountain & Frictional Torques, AO/AAO, ENSO, IOD, AMO, SSTs in general, SOI, QBO, the Stratosphere, etc. Feel free to talk about related topics, but stick to this general topic. I encourage all posters to discuss and pose questions relating to the topic, and keep it a relaxed atmosphere. Any questions, just PM me or comment here. Hope we can make this work Links Section ERSL Link, Up to 24 hours behind. GWO 90 day Victor Gensini Site. Features Total AAM, Bias Corrected Rel AAM GEFS, CFS GWO Forecast. He stated he is soon to add torque products. Nick Schraldi GWO Site Non-Bias Corrected GEFS GWO forecast. Michael Ventrice Hovmoller from MV, to help spot AAM trends and patterns. GEFS. Carl Schreck More Hovmollers and other tropical charts to spot trends in the AAM. CFS forecast. NPJ Phase Diagrams/Albany Shows a GEFS forecast and observation of NP jetstream, which is largely controlled by the AAM. MJO Composites:
  2. The Climate of the Antarctic Peninsula during the Twentieth Century: Evidence from Ice Cores Authors: Elizabeth R. Thomas and Dieter R. Tetzner Published online: 5th November, 2018 Abstract: The Antarctic Peninsula (AP) is a region of special climatological interest. The late twentieth century has been a period of warming surface temperatures, enhanced mass loss from melting glaciers and increased snowfall, which have a direct and measurable impact on global sea levels. However, the observational period for Antarctica is short. Observational records only began in the 1940s and much of our understanding of the wider spatial climate variability and glacial dynamics is limited to the satellite era (post 1979). Proxy records, such as those from ice cores, provide an invaluable tool to place these recent changes in context of the past few hundred years, allowing us to investigate climate variability over the entire twentieth century and beyond. In this chapter we review the climate of the AP during the twentieth century, as captured by the instrumental records, and extend our understanding of climate variability over the twentieth century based on climate proxies contained in ice cores. For this study we focus on stable water isotopes and snow accumulation and how they are influenced by changes in atmospheric circulation and sea ice conditions. Link to full paper:
  3. Decadal Variability of the ENSO Teleconnection to the High-Latitude South Pacific Governed by Coupling with the Southern Annular Mode Authors: Ryan L. Fogt and David H. Bromwich Published: 15th March, 2006 Abstract: Decadal variability of the El Niño–Southern Oscillation (ENSO) teleconnection to the high-latitude South Pacific is examined by correlating the European Centre for Medium-Range Weather Forecasts (ECMWF) 40-yr Re-Analysis (ERA-40) and observations with the Southern Oscillation index (SOI) over the last two decades. There is a distinct annual contrast between the 1980s and the 1990s, with the strong teleconnection in the 1990s being explained by an enhanced response during austral spring. Geopotential height anomaly composites constructed during the peak ENSO seasons also demonstrate the decadal variability. Empirical orthogonal function (EOF) analysis reveals that the 1980s September–November (SON) teleconnection is weak due to the interference between the Pacific–South American (PSA) pattern associated with ENSO and the Southern Annular Mode (SAM). An in-phase relationship between these two modes during SON in the 1990s amplifies the height and pressure anomalies in the South Pacific, producing the strong teleconnections seen in the correlation and composite analyses. The in-phase relationship between the tropical and high-latitude forcing also exists in December–February (DJF) during the 1980s and 1990s. These results suggest that natural climate variability plays an important role in the variability of SAM, in agreement with a growing body of literature. Additionally, the significantly positive correlation between ENSO and SAM only during times of strong teleconnection suggests that both the Tropics and the high latitudes need to work together in order for ENSO to strongly influence Antarctic climate. Link to full paper:
  4. Relationship of Multidecadal Global Temperatures to Multidecadal Oceanic Oscillations Authors: J.S. D'Aleo and D.J. Easterbrook Published: First edition 2011, revised second edition 2016. Abstract: Evidence shows that observed climate changes can be explained by natural factors, including secular changes in multidecadal cycles in the oceans and solar activity. The correlation of two decades of climate changes in the 1980 and 1990s to increasing CO2 is coincidental, as five of the last seven decades since the beginning of the boom following the end of World War II have actually seen temperature cool or remain steady even as CO2 increased. Multidecadal cycles in the ocean correlate with the frequency and strength of the shorter-term El Niño Southern Oscillation (ENSO) and North Atlantic Oscillation (NAO) phases and through them, U.S. temperatures. Total solar irradiance is shown to vary with both these multidecadal ocean cycles and thus the temperatures, suggesting that the sun is the ultimate driver. Link to full paper:
  5. Circulation Anomalies Associated with Tropical Convection during Northern Winter Authors: George N. Kiladis and Dr Klaus M. Weickmann Published: 24th October, 1991 Abstract: Lagged cross correlations between outgoing longwave radiation (OLR) and National Meteorological Center global analyses are utilized to isolate the preferred upper-level and surface circulation anomalies associated with tropical convection during northern winter. Three intraseasonal time scales are studied: 30–70, 14–30, and 6–14 days. In the 30–70-day band, the upper-level circulation signals are zonally elongated, with zonal wavenumbers 0–2 dominant. Higher-frequency signals are dominated by zonal wavenumbers 5 and 6. In the 14–30-day band, convection over the eastern hemisphere is associated with upper-level anticyclones in the subtropics and appears to be linked in some cases to midlatitude wave trains. The strongest signals are for convection over Africa, Australia, and the eastern Indian Ocean. Only weak signals are seen for convection over Indonesia. In these regions of upper-level easterlies, OLR anomalies peak prior to the maximum anomalies in wind, suggesting forcing of the circulation by tropical heating. In contrast, 14–30-day and 6–14-day convection over the eastern tropical Pacific, eastern South America, and central South Pacific is primarily associated with the intrusion of troughs in the westerlies originating in the extratropics. These are regions of mean upper level westerly flow, or where upper-westerlies lie adjacent to tropical convergence zones overlain by only weak easterly flow aloft. The large amplitude of these troughs prior to the OLR anomaly is indicative of the forcing of the convection by these disturbances. Link to full paper:<1900%3ACAAWTC>2.0.CO%3B2
  6. Time-Lagged Response of the Antarctic and High-Latitude Atmosphere to Tropical MJO Convection Authors: Gina R. Henderson, Bradford S. Barrett, Ashley Lois, and Haadi Elsaawy Published: 22nd February, 2018 (online: 18th April, 2018) Abstract: Intraseasonal tropical variability has important implications for the mid- and high-latitude atmosphere, and in recent studies has been shown to modulate a number of weather processes in the Northern Hemisphere, such as snow depth, sea ice concentration, precipitation, atmospheric rivers, and air temperature. In such studies, the extratropical atmosphere has tended to respond to the tropical convection of the leading mode of intraseasonal variability, the Madden–Julian oscillation (MJO), with a time lag of approximately 7 days. However, the time lag between the MJO and the Antarctic atmosphere has been found to vary between less than 7 and greater than 20 days. This study builds on previous work by further examining the time-lagged response of Southern Hemisphere tropospheric circulation to tropical MJO forcing, with specific focus on the latitude belt associated with the Antarctic Oscillation, during the months of June (austral winter) and December (austral summer) using NCEP–DOE Reanalysis 2 data for the years 1979–2016. Principal findings indicate that the time lag with the strongest height anomalies depends on both the location of the MJO convection (e.g., the MJO phase) and the season, and that the lagged height anomalies in the Antarctic atmosphere are fairly consistent across different vertical levels and latitudinal bands. In addition, certain MJO phases in December displayed lagged height anomalies indicative of blocking-type atmospheric patterns, with an approximate wavenumber of 4, whereas in June most phases were associated with more progressive height anomaly centers resembling a wavenumber-3-type pattern. Link to full paper:
  7. The Antarctic Centennial Oscillation: A Natural Paleoclimate Cycle in the Southern Hemisphere That Influences Global Temperature Authors: W. Jackson Davis, Peter J. Taylor W. Barton Davis Published: 8th January 2018 Abstract: We report a previously-unexplored natural temperature cycle recorded in ice cores from Antarctica—the Antarctic Centennial Oscillation (ACO)—that has oscillated for at least the last 226 millennia. Here we document the properties of the ACO and provide an initial assessment of its role in global climate. We analyzed open-source databases of stable isotopes of oxygen and hydrogen as proxies for paleo-temperatures. We find that centennial-scale spectral peaks from temperature-proxy records at Vostok over the last 10,000 years occur at the same frequencies (±2.4%) in three other paleoclimate records from drill sites distributed widely across the East Antarctic Plateau (EAP), and >98% of individual ACOs evaluated at Vostok match 1:1 with homologous cycles at the other three EAP drill sites and conversely. Identified ACOs summate with millennial periodicity to form the Antarctic Isotope Maxima (AIMs) known to precede Dansgaard-Oeschger (D-O) oscillations recorded in Greenland ice cores. Homologous ACOs recorded at the four EAP drill sites during the last glacial maximum appeared first at lower elevations nearest the ocean and centuries later on the high EAP, with latencies that exceed dating uncertainty >30-fold. ACO homologs at different drill sites became synchronous, however, during the warmer Holocene. Comparative spectral analysis suggests that the millennial-scale AIM cycle declined in period from 1500 to 800 years over the last 70 millennia. Similarly, over the last 226 millennia ACO repetition period (mean 352 years) declined by half while amplitude (mean 0.67 ◦C) approximately doubled. The period and amplitude of ACOs oscillate in phase with glacial cycles and related surface insolation associated with planetary orbital forces. We conclude that the ACO: encompasses at least the EAP; is the proximate source of D-O oscillations in the Northern Hemisphere; therefore affects global temperature; propagates with increased velocity as temperature increases; doubled in intensity over geologic time; is modulated by global temperature variations associated with planetary orbital cycles; and is the probable paleoclimate precursor of the contemporary Antarctic Oscillation (AAO). Properties of the ACO/AAO are capable of explaining the current global warming signal. Link to full paper: file:///C:/Users/David/Downloads/climate-06-00003-v2.pdf
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