Artículo de referencia: Florenci Rey y la conexión de la ola de frío con el cambio climático
- Jihong Cole-Dai et al (2009) – Cold decade (AD 1810-1819) caused by Tambora (1815) and another (1809) stratospheric volcanic eruption – Geophysical Research Letters 36 L22703 doi:10.1029/2009GL040882 – Published online: 01/01/2009 – Department of Chemistry and Biochemistry – http://imag.academia.edu/AlysonLanciki/Papers/138569/Cold_Decade_AD_1810-1819_Caused_by_Tambora_1815_and_Another_1809_Stratospheric_Volcanic_Eruption – 6 authors – Peer-reviewed
“Climate records indicate that the decade of AD 1810–1819 including “the year without a summer” (1816) is probably the coldest during the past 500 years or longer, and the cause of the climatic extreme has been attributed primarily to the 1815 cataclysmic Tambora eruption in Indonesia.” - Florenci Rey – Siberia se deja la puerta abierta – El País – Published online: 02/02/2012 – – http://www.elpais.com/articulo/internacional/Siberia/deja/puerta/abierta/elpepiint/20120202elpepiint_2/Tes
“¿Son estas situaciones adversas consecuencia del cambio climático? Rotundamente no: es un fenómeno excepcional aunque no insólito y que se enmarca en la normalidad climática del continente. Ahora bien, hasta hace diez días calificábamos este 2012 como «el año sin invierno». Estas bruscas discontinuidades en un corto espacio de tiempo, una alta variabilidad meteorológica, pueden ser un buen indicio de la traducción del cambio climático global en la región europea.” - Simon L. Lewis et al (2011) – The 2010 Amazon Drought – Science 331:554 DOI:10.1126/science.1200807 – Published online: 04/02/2011 – School of Geography, University of Leeds – 5 authors – Peer-reviewed
“In 2005, a major Atlantic SST–associated drought occurred, identified as a 1-in-100-year event (2). Here,we report on a second drought in 2010, when Atlantic SSTs were again high.” - Martin Wild et al (2007) – Impact of global dimming and brightening on global warming – Geophysical Research Letters 34, L04702doi:10.1029/2006GL028031 – Published online: 20/02/2007 – Institute for Atmospheric and Climate Science, ETH Zurich – http://www.iac.ethz.ch/people/wild/2006GL028031.pdf – 3 authors
“To disentangle surface solar and greenhouse influences on global warming, trends in diurnal temperature range are analyzed. They suggest that solar dimming was effective in masking greenhouse warming, but only up to the 1980s, when dimming gradually transformed into brightening. Since then, the uncovered greenhouse effect has revealed its full dimension, as manifested in a rapid temperature rise (+0.38 ºC/decade over land since mid-1980s). Recent solar brightening cannot supersede the greenhouse effect as main cause of global warming, since land temperatures increased by 0.8 ºC from 1960 to 2000, even though solar brightening did not fully outweigh solar dimming within this period.” - Simon K. Allen et al (2011) – IPCC Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) – Fact Sheet – Intergovernmental Panel on Climate Change (IPCC) – Published online: 18/11/2011 – http://ipcc.ch/news_and_events/docs/srex/SREX_fact_sheet.pdf – 29 authors – Peer-reviewed
“There is evidence from observations gathered since 1950 of change in some extremes … It is very likely that there has been an overall decrease in the number of cold days and nights [ref] and an overall increase in the number of warm days and nights,3 at the global scale, that is, for most land areas with sufficient data. It is likely that these changes have also occurred at the continental scale in North America, Europe, and Australia.” - John Petter Reinertsen – More cold and snowy winters to come – Oslo Science Conference – Published online: 11/06/2010 – http://ipy-osc.no/article/2010/1276176306.8
“»Cold and snowy winters will be the rule, rather than the exception,» says Dr James Overland of the NOAA/Pacific Marine Environmental Laboratory in the United States. Dr Overland is at the International Polar Year Oslo Science Conference (IPY-OSC) to chair a session on polar climate feedbacks, amplification and teleconnections, including impacts on mid-latitudes.” - Warm Arctic, Cold Continents – National Oceanic and Atmospheric Administration – Published online: 28/02/2011 – http://www.noaa.gov/features/02_monitoring/warmarctic.html
“Extremely cold winds have swept down through the Northern Hemisphere recently, reaching as far south as the state of Florida and causing record low temperatures in January.” - Andrew Freedman – Warming Arctic May Be Causing Cooler Winters in Eastern U.S., Europe – Climate Central – Published online: 13/01/2012 – – http://www.climatecentral.org/blogs/warming-arctic-may-be-causing-cooler-winters-in-us-europe/
“I called the «Arctic Paradox.» In short, it holds that as the Arctic warms up — it’s generally warming twice as fast as the rest of the globe — the loss of sea ice and changes in how heat moves between the ocean and the atmosphere is rearranging weather patterns. The result, paradoxically, favors colder and snowier conditions outside the Arctic. In other words, the Arctic gets warmer, while winters in Boston, London, and Paris turn colder and snowier.” - Dagmar Budikova (2009) – Role of Arctic sea ice in global atmospheric circulation: A review – Global and Planetary Change 68:149–163 doi: – Published online: 08/04/2009 – Department of Geography-Geology, Illinois State University – http://www.arctic.noaa.gov/future/docs/ArcticAND_Globe.pdf
“Addressed also are the theoretical, methodological, and logistical challenges facing the current observational and modeling studies that aim to improve our awareness of the role that Arctic sea ice plays in the definition of global climate. Moving towards an improved understanding of the role that polar sea ice plays in shaping the global climate is a subject of timely importance as the Arctic environment is currently undergoing rapid change with little slowing down forecasted for the future. ” - Jennifer A. Francis et al (2009) – Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent – Geophysical Research Letters 36, L07503, doi:10.1029/2009GL037274 – Published online: 11/04/2009 – Institute of Marine and Coastal Sciences, Rutgers University – http://www.colorado.edu/geography/class_homepages/geog_4271_f10/readings/week_12_13_francis_et_al_2009GL037274.pdf – 5 authors – Peer-reviewed
“By combining satellite measurements of sea-ice extent and conventional atmospheric observations, we find that varying summer ice conditions are associated with large-scale atmospheric features during the following autumn and winter well beyond the Arctic’s boundary. Mechanisms by which the atmosphere ‘‘remembers’’ a reduction in summer ice cover include warming and destabilization of the lower troposphere, increased cloudiness, and slackening of the poleward thickness gradient that weakens the polar jet stream. This ice-atmosphere relationship suggests a potential long-range outlook for weather patterns in the northern hemisphere.” - Meiji Honda et al (2009) – Influence of low Arctic sea-ice minima on anomalously cold Eurasian winters – Geophysical Research Letters 36, L08707doi:10.1029/2008GL037079 – Published online: 28/04/2009 – Research Institute for Global Change, Japan Agency for Marine‐Earth Science and Technology – http://media.cigionline.org/geoeng/2008—Honda-et-al—Influence-of-low-Arctic-sea%E2%80%90ice-minima-on-anomalously-cold-Eurasian-winters.pdf – 3 authors – Peer-reviewed
“The late‐winter cold anomalies over Eurasia are also reproduced in our experiment, which is associated with the negative phase of the North Atlantic Oscillation.” - James E. Overland et al (2011) – Arctic Report Card 2011 – Atmosphere – National Oceanic and Atmospheric Administration – Published online: 07/03/2011 – http://www.arctic.noaa.gov/report10/atmosphere.html – 3 authors “Models suggest that loss of sea ice in fall favors higher geopotential heights over the Arctic. With future loss of sea ice, such conditions as winter 2009-2010 could happen more often. Thus we have a potential climate change paradox. Rather than a general warming everywhere, the loss of sea ice and a warmer Arctic can increase the impact of the Arctic on lower latitudes, bringing colder weather to southern locations.”
- James Hansen et al (2009) – If It’s That Warm, How Come It’s So Damned Cold? – NASA – Published online: 01/12/2009 – NASA Goddard Institute for Space Studies and Columbia University Earth Institute – http://www.columbia.edu/~jeh1/mailings/2010/20100115_Temperature2009.pdf – 4 authors
“The degree to which Arctic air penetrates into middle latitudes is related to the Arctic Oscillation (AO) index, which is defined by surface atmospheric pressure patterns and is plotted in Figure 6. When the AO index is positive surface pressure is high in the polar region. This helps the middle latitude jet stream to blow strongly and consistently from west to east, thus keeping cold Arctic air locked in the polar region. When the AO index is negative there tends to be low pressure in the polar region, weaker zonal winds, and greater movement of frigid polar air into middle latitudes.” - Global Patterns – Arctic & North Atlantic Oscillations (AO & NAO) – North Carolina State University – http://www.nc-climate.ncsu.edu/climate/patterns/NAO.html
“The Arctic Oscillation (AO) is a climate index of the state of the atmospheric circulation over the Arctic. It consists of a negative phase, featuring below average geopotential heights , which are also referred to as negative geopotential height anomalies , and a positive phase in which the opposite is true. In the negative phase, the polar low pressure system (also known as the polar vortex) over the Arctic is weaker, which results in weaker upper level winds (the westerlies). The result of the weaker westerlies is that cold, Arctic air is able to push farther south into the U.S., while the storm track also remains farther south. The opposite is true when the AO is positive.” - Judah Cohen et al (2010) – Winter 2009-2010: A case study of an extreme Arctic Oscillation event – Geophysical Research Letters 37, L17707, doi:10.1029/2010GL044256 – Published online: 11/09/2010 – Atmospheric and Environmental Research, Inc. – http://web.mit.edu/jlcohen/www/papers/Cohenetal_GRL10.pdf – 5 authors – Peer-reviewed “Further, and somewhat counterintuitively, the severe cold winter weather may be attributed to boundary forcing changes consistent with an overall warming planet. A warmer atmosphere can hold more moisture and as the interior of the NH continents cool in fall, this can lead to increased snowfall. And as argued here, more extensive fall snow cover contributed to the extreme negative AO observed during the winter of 2009–2010. This hypothesis is being further investigated.”
- Judah Cohen and Justin Jones (2011) – A new index for more accurate winter predictions – Geophysical Research Letters 38, L21701, doi:10.1029/2011GL049626 – Published online: 05/11/2011 – Atmospheric and Environmental Research, Inc. – Peer-reviewed “Here we develop a snow advance index (SAI) derived from antecedent observed snow cover that explains a large fraction of the variance of the winter AO. The high correlation between the SAI and the winter AO demonstrates that the AO is most likely predictable and that this index can be exploited for skillful seasonal climate predictions.”
- Judah L Cohen et al (2012) – Arctic warming, increasing snow cover and widespread boreal winter cooling – Environment Research Letters 7 014007 doi:10.1088/1748-9326/7/1/014007 – Published online: 12/01/2012 – Atmospheric and Environmental Research, Inc. – http://iopscience.iop.org/1748-9326/7/1/014007/pdf/1748-9326_7_1_014007.pdf – 8 authors – Peer-reviewed
“Though we cannot conclude definitively that warming in the summer and autumn is forcing winter regional cooling, analysis of the most recent observational and modelling data supports links between strong regional cooling trends in the winter and warming trends in the prior seasons. A warmer, more moisture-laden Arctic atmosphere in the autumn contributes to an increase in Eurasian snow cover during that season. This change in snow cover dynamically forces negative AO conditions the following winter. We deduce that one main reason for models failing to capture the observed wintertime cooling is probably their poor representation of snow cover variability and the associated dynamical relationships with atmospheric circulation trends (Hardiman et al 2008, Jeong et al 2011).” - James E. Overland and Muyin Wang (2010) – Large-scale atmospheric circulation changes are associated with the recent loss of Arctic sea ice – Tellus A 62:1-9 doi:10.1111/j.1600-0870.2009.00421.x – Published online: 28/10/2009 – NOAA/Pacific Marine Environmental Laboratory; JISAO/University of Washington – http://bit.ly/wJj9FS – 2 authors – Peer-reviewed
“Thus, while the magnitude of the direct effect of anthropogenic forcing to climate change is still emerging, it may already have shifted the normal chaotic patterns of natural climate variability in the sub-Arctic through sea ice/ocean feedbacks and contributed to an accelerated arctic amplification of temperature.” - Vladimir Petoukhov and Vladimir A. Semenov (2010) – A link between reduced Barents-Kara sea ice and cold winter extremes over northern continents – Journal of Geophysical Research 115 D21111 doi:10.1029/2009JD013568 – Published online: 05/11/2010 – Potsdam Institute for Climate Impact Research; Leibniz Institute of Marine Sciences at the University of Kiel + A.M. Obukhov Institute of Atmospheric Physics RAS – http://eprints.ifm-geomar.de/8738/1/2009JD013568-pip.pdf – 2 authors – Peer-reviewed
“Furthermore, our results suggest that high-latitude atmospheric circulation response to the B-K sea ice decrease is highly nonlinear and characterized by transition from anomalous cyclonic circulation to anticyclonic one and then back again to cyclonic type of circulation as the B-K sea ice concentration gradually reduces from 100% to ice free conditions. We present a conceptual model that may explain the nonlinear local atmospheric response in the B-K seas region by counter play between convection over the surface heat source and baroclinic effect due to modified temperature gradients in the vicinity of the heating area.” - Steve Connor – Science behind the big freeze: is climate change bringing the Arctic to Europe? – The Independent – Published online: 04/02/2012 – – http://www.independent.co.uk/news/science/science-behind-the-big-freeze-is-climate-change-bringing-the-arctic-to-europe-6358928.html
“»Whoever thinks that the shrinking of some far-away sea ice won’t bother him could be wrong. There are complex interconnections in the climate system, and in the Barents-Kara Sea we might have discovered a powerful feedback mechanism,» Dr Petoukhov said.” - Positively Arctic: Arctic Oscillation switches phase – National Snow and Ice Data Center – Published online: 05/02/2012 – – http://nsidc.org/arcticseaicenews/2012/01/positively-arctic-arctic-oscillation-switches-phase/
“Arctic sea ice extent fell to its seasonal minimum on September 9, 2011, falling just short of the record low set in September 2007, when summer weather conditions were extremely favorable for ice loss. This summer, the weather was not as extreme as 2007, so it was surprising that ice extent dropped so low. The low ice extent, along with data on ice age, suggests that the Arctic ice cover remains thin and vulnerable to summer melt.” - Positively Arctic: Arctic Oscillation switches phase – National Snow and Ice Data Center – Published online: 05/02/2012 – http://nsidc.org/arcticseaicenews/2012/01/positively-arctic-arctic-oscillation-switches-phase/ “Arctic sea ice extent remained unusually low through December, especially in the Barents and Kara seas. In sharp contrast to the past two winters, the winter of 2011 has so far seen a generally positive phase of the Arctic Oscillation, a weather pattern that helps to explain low snow cover extent and warmer than average conditions over much of the United States and Eastern Europe. In Antarctica, where summer is beginning, sea ice extent is presently above average.”
- Peter Wadhams (2012) – Arctic Ice Cover, Ice Thickness and Tipping Points – AMBIO: A Journal of the Human Environment 41: – Published online: 01/02/2012 – Peer-reviewed
“Thickness has been falling at a more rapid rate (43% in the 25 years from the early 1970s to late 1990s) with a specially rapid loss of mass from pressure ridges. The summer 2007 event may have arisen from an interaction between the long-term retreat and more rapid thinning rates. We review thickness monitoring techniques that show the greatest promise on different spatial and temporal scales, and for different purposes. We show results from some recent work from submarines, and speculate that the trends towards retreat and thinning will inevitably lead to an eventual loss of all ice in summer, which can be described as a ‘tipping point’ in that the former situation, of an Arctic covered with mainly multi-year ice, cannot be retrieved.” - Climate Prediction Center – Daily AO index – National Snow and Ice Data Center – http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao_index.html
- Greg Postel – Don’t blame the Arctic oscillation – The Washington Post – Published online: 10/02/2011 – http://voices.washingtonpost.com/capitalweathergang/2011/02/dont_blame_the_arctic_oscillat.html
“In this example of circular reasoning, the positive AO and the temperature pattern are manifestations of each other. But the fact that they are identified with one another does not imply causality … Rather, the AO is a response to, or a byproduct of, the interaction among a group of fundamental atmospheric mechanisms. On more technical terms, it can be understood without appealing to fluid dynamics, and it is not a solution to any governing mathematical equation.” - James Hansen et al (2012) – Global Temperature in 2011, Trends, and Prospects – Columbia University – Published online: 19/01/2012 – Peer-reviewed http://www.columbia.edu/~jeh1/mailings/2012/20120119_Temperature.pdf – 4 authors
“Although there has been speculation about possible effects of reduced Arctic sea ice on outbreaks of Arctic air, Figure 6 provides little support for that hypothesis. Several years had low sea ice cover in the past decade, yet most of those years were warm at middle latitude winters by 1951-1980 standards. Given the fact that winters are much «noisier» (greater natural variability) than summers, the past two unusually cool winters in the United States and Europe do not alter the expectation that middle latitude winters will tend to become warmer as global warming continues.” - Yohai Kaspi and Tapio Schneider (2011) – Winter cold of eastern continental boundaries induced by warm ocean waters – Nature 471:621–624 doi:10.1038/nature09924 – Published online: 31/03/2011 – California Institute of Technology – http://www.gps.caltech.edu/~tapio/papers/kaspi11a.pdf – 2 authors – Peer-reviewed
“Here we show that this anomalous winter cold can result in part from westward radiation of large-scale atmospheric waves—nearly stationary Rossby waves—generated by heating of the atmosphere over warm ocean waters. We demonstrate this mechanism using simulations with an idealized general circulation model [refs], with which we show that the extent of the cold region is controlled by properties of Rossby waves, such as their group velocity and its dependence on the planetary rotation rate. Our results show that warm ocean waters contribute to the contrast in mid-latitude winter temperatures between eastern and western continental boundaries not only by warming western boundaries, but also by cooling eastern boundaries.” - Rasmus Benestad – Cold winter in a world of warming? – Real Climate – Published online: 14/12/2010 – http://www.realclimate.org/index.php/archives/2010/12/cold-winter-in-a-world-of-warming/
“I think that the scientific community will need some time to confirm this link.” - C. Wissel (1984) – A universal law of the characteristic return time near thresholds – Oecologia 65:101-107doi:10.1007/BF00384470 – Peer-reviewed
“Dramatic changes at thresholds in multiple stable ecosystems may be irreversible if caused by man. The characteristic return time to an equilibrium increases when a threshold is approached. A universal law for this increase is found, which may be used to forecast the position of a threshold by extrapolation of empirical data. Harvesting experiments on populations are proposed that can be used to verify the method. Preliminary harvesting experiments on rotifer populations display a good agreement with the theory.” - Vasilis Dakos et al (2008) – Slowing down as an early warning signal for abrupt climate change – Proceedings of the National Academy of Sciences PNAS 105:14308-14312 – Published online: 23/09/2008 – Max Planck Institute for Meteorology – http://www.pnas.org/content/105/38/14308 – 6 authors – Peer-reviewed
“We analyze eight ancient abrupt climate shifts and show that they were all preceded by a characteristic slowing down of the fluctuations starting well before the actual shift. Such slowing down, measured as increased autocorrelation, can be mathematically shown to be a hallmark of tipping points.” - Marten Scheffer et al (2009) – Early-warning signals for critical transitions – Nature 461:53-59 doi:10.1038/nature08227 doi: 10.1073/pnas.0802430105 – Published online: 03/09/2009 – Department of Environmental Sciences, Wageningen University, The Netherlands – http://ieg.ebd.csic.es/JordiBascompte/Publications/Nature_09b.pdf – 10 authors – Peer-reviewed
“The dynamics of systems near a critical point have generic properties, regardless of differences in the details of each system … Critical slowing down (recovery rate); Increased variance; Skewness and flickering … The principles discussed so far apply to systems that may be stochastically forced but have an underlying attractor that corresponds to a stable point … Critical transitions in cyclic and chaotic systems are less well studied from the point of view of early-warning signals. Such transitions are associated with different classes of bifurcation.” - S. R. Carpenter et al (2011) – Early Warnings of Regime Shifts: A Whole-Ecosystem Experiment – Science doi:10.1126/science.1203672 – Published online: 28/04/2011 – Center for Limnology, University of Wisconsin – 12 authors
“Catastrophic ecological regime shifts may be announced in advance by statistical early-warning signals such as slowing return rates from perturbation and rising variance … We tested the hypothesis that these statistics would be early-warning signals for an experimentally induced regime shift in an aquatic food web … An adjacent lake was monitored simultaneously as a reference ecosystem. Warning signals of a regime shift were evident in the manipulated lake during reorganization of the food web more than a year before the food web transition was complete, corroborating theory for leading indicators of ecological regime shifts.” - Timothy M. Lenton (2011) – Early warning of climate tipping points – Nature Climate Change 1:201–209 doi:10.1038/nclimate1143 – Published online: 19/06/2011 – College of Life and Environmental Sciences, University of Exeter + UK and School of Environmental Sciences, University of East Anglia – http://www.slideshare.net/Stepscentre/tim-lenton-early-warning-of-climate-tipping-points – Peer-reviewed
“Conclusion: 1) Tipping elements in the climate system could be triggered this century by anthropogenic forcing; 2) The Greenland and West Antarctic ice sheets probably represent the largest risks; 3) Some tipping points can be anticipated in principle, but sufficiently high-resolution, long records are often lacking; 4) A change in the number of climate states can be detected, in a noisy climate system that is moving between states; 5) Improved understanding is needed to help policy makers “avoid the unmanageable and manage the unavoidable.” - Peter Ditlevsen (2010) – Tipping points: Early warning and wishful thinking – Geophysical Research Letters doi:10.1029/2010GL044486 – Published online: 24/08/2010 – University of Copenhagen, Niels Bohr Institute, Centre for Ice and Climate – http://www.leif.org/EOS/2010GL044486.pdf – Peer-reviewed
“The conclusions drawn is that these most probably are not generated by bifurcations: They are noise induced transitions without early warning signals. This means that it is necessary to understand the full non-linear structure of the climate system, including assessing the influence by an external perturbation (such as increased greenhouse gas concentrations) on the short time scale fluctuations (noise), which might push the system into a different (quasi-)stationary state.” - Doug McNeall et al (2011) – Analyzing abrupt and nonlinear climate changes and their impacts – WIREs Climate Change 2:I663–686 doi:10.1002/wcc.130 – Published online: 29/06/2011 – Met Office Hadley Centre – 4 authors – Peer-reviewed
“Although such signs show promise as early warnings of oncoming abrupt changes, they do not yet provide accurate predictions of exactly when a transition will occur. In addition, shifts that are due to fast changes in external forcing (such as is the case with recent anthropogenic forcing of the climate) cannot be predicted from such early warning signals.” - Peter Ashwin et al (2011) – Tipping points in open systems: bifurcation, noise-induced and rate-dependent examples in the climate system – Proceedings of the Royal Society A – Published online: 13/07/2011 – Mathematics Research Institute, University of Exeter- 4 authors – Peer-reviewed
“Tipping points associated with bifurcations (B-tipping) or induced by noise (N-tipping) are recognized mechanisms that may potentially lead to sudden climate change. We focus here a novel class of tipping points, where a sufficiently rapid change to an input or parameter of a system may cause the system to «tip» or move away from a branch of attractors. Such rate-dependent tipping, or R-tipping, need not be associated with either bifurcations or noise. We present an example of all three types of tipping in a simple global energy balance model of the climate system, illustrating the possibility of dangerous rates of change even in the absence of noise and of bifurcations in the underlying quasi-static system.” - Grant Foster and Stefan Rahmstorf (2011) – Global temperature evolution 1979–2010 – Environmental Research Letters 6 044022 doi:10.1088/1748-9326/6/4/044022 – Published online: 06/12/2011 – Tempo Analytics; Potsdam Institute for Climate Impact Research – http://sciences.blogs.liberation.fr/files/rahmstorf-vraies-temp%C3%A9ratures.pdf – Peer-reviewed
“When the data are adjusted to remove the estimated impact of known factors on short-term temperature variations (El Niño/southern oscillation, volcanic aerosols and solar variability), the global warming signal becomes even more evident as noise is reduced. Lower-troposphere temperature responds more strongly to El Niño/southern oscillation and to volcanic forcing than surface temperature data. The adjusted data show warming at very similar rates to the unadjusted data, with smaller probable errors, and the warming rate is steady over the whole time interval. In all adjusted series, the two hottest years are 2009 and 2010.” - James Hansen et al (2010) – Yes, Cold Weather in Europe STILL Means Global Warming – Red, Green and Blue – Published online: 12/12/2010 – NASA Goddard Institute for Space Studies and Columbia University Earth Institute
“Figure 3, from our paper in press, shows that 7 of the last 10 European winters were warmer than the 1951-1980 average winter, and 10 of the past 10 summers were warmer than climatology.” - James Hansen et al (2010) – Global Surface Temperature Change – Reviews of Geophysics 48, RG4004 doi:10.1029/2010RG000345 – Published online: 14/12/2010 – NASA Goddard Institute for Space Studies – http://data.giss.nasa.gov/gistemp/paper/gistemp2010_draft0601.pdf – 4 authors – Peer-reviewed
Referencias complementarias
Xiangdong Zhang et al (2008) – Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system – Geophysical Research Letters 35, L22701, doi:10.1029/2008GL035607 – Published online: 18/09/2008 – International Arctic Research Center, University of Alaska Fairbanks – 5 authors – Peer-reviewed
“We report on drastic, systematic spatial changes in atmospheric circulations, showing a sudden jump from the conventional tri-polar AO/NAO to an unprecedented dipolar leading pattern, following accelerated northeastward shifts of the AO/NAO centers of action. These shifts provide an accelerating impetus for the recent rapid Arctic climate system changes, perhaps shedding light on recent arguments about a tipping point of global-warming-forced climate change in the Arctic. The radical spatial shift is a precursor to the observed extreme change event, demonstrating skilful information for future prediction.”
R. Seager et al (2010) – Northern Hemisphere winter snow anomalies: ENSO, NAO and the winter of 2009/10 – Geophysical Research Letters 37, L14703, doi:10.1029/2010GL043830 – Published online: 24/07/2010 – Lamont Doherty Earth Observatory, Earth Institute at Columbia University – http://bit.ly/wBiXGC – 5 authors – Peer-reviewed
“It is argued that increased snowfall in the southern U.S. is contributed to by a southward displaced storm track but further north, in the eastern U.S. and northern Europe, positive snow anomalies arise from the cold temperature anomalies of a negative NAO. These relations are used with observed values of NINO3 and the NAO to conclude that the negative NAO and El Niño event were responsible for the northern hemisphere snow anomalies of winter 2009/10.”
Julienne C. Stroeve et al (2011) – The Arctic’s rapidly shrinking sea ice cover: a research synthesis – Climatic Change DOI:10.1007/s10584-011-0101-1 – Published online: 08/06/2011 – National Snow and Ice Data Center, Cooperative Institute for Research in Environmental Sciences, University of Colorado – 6 authors – Peer-reviewed
“Because of the extensive open water in recent Septembers, ice cover in the following spring is increasingly dominated by thin, first-year ice (ice formed during the previous autumn and winter) that is vulnerable to melting out in summer. Thinner ice in spring in turn fosters a stronger summer ice-albedo feedback through earlier formation of open water areas. A thin ice cover is also more vulnerable to strong summer retreat under anomalous atmospheric forcing. Finally, general warming of the Arctic has reduced the likelihood of cold years that could bring about temporary recovery of the ice cover. Events leading to the September ice extent minima of recent years exemplify these processes.”
R. Jaiser et al (2012) – Impact of sea ice cover changes on the Northern Hemisphere atmospheric winter circulation – Tellus A 64:11595 doi:10.3402/tellusa.v64i0.11595 – Published online: 02/01/2012 – Alfred Wegener Institute for Polar and Marine Research, Research Unit Potsdam – http://web.mit.edu/jlcohen/www/papers/Jaiseretal_Tellus12.pdf – 4 authors – Peer-reviewed
“Our analysis suggests that Arctic sea ice concentration changes exert a remote impact on the large-scale atmospheric circulation during winter, exhibiting a barotropic structure with similar patterns of pressure anomalies at the surface and in the mid-troposphere. These are connected to pronounced planetary wave train changes notably over the North Pacific.”
Steve Connor – Science behind the big freeze: is climate change bringing the Arctic to Europe? – The Independent – Published online: 04/02/2012 – http://www.independent.co.uk/news/science/science-behind-the-big-freeze-is-climate-change-bringing-the-arctic-to-europe-6358928.html
“A growing number of experts believe complex wind patterns are being changed because melting Arctic sea ice has exposed huge swaths of normally frozen ocean to the atmosphere above. In particular, the loss of Arctic sea ice could be influencing the development of high-pressure weather systems over northern Russia, which bring very cold winds from the Arctic and Siberia to Western Europe and the British Isles, the scientists believe. An intense anticyclone over north-west Russia is behind the bitterly cold easterly winds that have swept across Europe and some climate scientists say the lack of Arctic sea ice brought about by global warming is responsible.”
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