New Research

[knocker]

The paper referred to above (open Access)

Warmer and wetter winters: characteristics and implications of an extreme weather event in the High Arctic

http://iopscience.iop.org/1748-9326/9/11/114021?utm_content=bufferd5cac&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

[knocker]

Snowmelt onset over Arctic sea ice from passive microwave satellite data: 1979–2012

 

Abstract. An updated version (Version 3) of the Snow Melt Onset Over Arctic Sea Ice from SMMR (Scanning Multichannel Microwave Radiometer) and SSM/I-SSMIS (Special Sensor Microwave/Imager-Special Sensor Microwave Imager/Sounder) Brightness Temperatures data set is now available. The data record has been reprocessed and extended to cover the years 1979–2012. From this data set, a statistical summary of melt onset (MO) dates on Arctic sea ice is presented. The mean MO date for the Arctic Region is 13 May (132.5 DOY – day of year) with a standard deviation of ±7.3 days. Regionally, mean MO dates vary from 15 March (73.2 DOY) in the St. Lawrence Gulf to 10 June (160.9 DOY) in the Central Arctic. Statistically significant decadal trends indicate that MO is occurring 6.6 days decade^−1 earlier in the year for the Arctic Region. Regionally, MO trends are as great as −11.8 days decade^−1 in the East Siberian Sea. The Bering Sea is an outlier and MO is occurring 3.1 days decade^−1 later in the year.

http://www.the-cryosphere.net/8/2089/2014/tc-8-2089-2014.pdf

[knocker]

Permafrost soil: Possible source of abrupt rise in greenhouse gases at end of last Ice Age

 

Bremerhaven/Germany, 20 November 2014. Scientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have identified a possible source of carbon dioxide (CO2) and other greenhouse gases that were abruptly released to the atmosphere in large quantities around 14,600 years ago. According to this new interpretation, the CO2 - released during the onset of the Bølling/Allerød warm period - presumably had their origin in thawing Arctic permafrost soil and amplified the initial warming through positive feedback. The study now appears online in the journal Nature Communications.

http://www.eurekalert.org/pub_releases/2014-11/awih-psp111914.php

[Gray-Wolf]

So if the slow 'drip drip' melt of permafrost can lead to such emissions then what will our blasting of them lead to?? We also have the submerged permafrosts to factor into any calcs on just how much GHG's we are set to inherit.

[knocker]

Arctic temperature trends from the early nineteenth century to the present

 

Abstract

Temperatures were examined at 118 stations located in the Arctic and compared to observations at 50 European stations whose records averaged 200 years and in a few cases extend to the early 1700s. Nearly all stations exhibited warming trends. For each station, the temperature relative to the average value during 1961–1990 was found. The resulting temperature change averaged over the Arctic stations was plotted. For the period 1820–2014, trends were found for the January, July and annual temperatures of 1.0, 0.0 and 0.7 Â°C per century, respectively. Decadal variations are evident and much of the temperature increase occurred during the 1990s. Over the past century, Siberia, Alaska and Western Canada have experienced somewhat greater warming than Eastern Canada, Greenland and Northern Europe. The temperature change experienced by the Arctic stations during the last two centuries closely tracks that found for the European stations.

http://rd.springer.com/article/10.1007%2Fs00704-014-1311-z?utm_content=buffer6f311&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

[knocker]

HadISDH land surface multi-variable humidity and temperature record for climate monitoring

 

Abstract. HadISDH.2.0.0 is the first gridded, multi-variable humidity and temperature in situ observations-only climate-data product that is homogenised and annually updated. It provides physically consistent estimates for specific humidity, vapour pressure, relative humidity, dew point temperature, wet bulb temperature, dew point depression and temperature. It is a monthly mean gridded (5° by 5°) product with uncertainty estimates that account for spatio-temporal sampling, climatology calculation, homogenisation and irreducible random measurement effects. It provides a tool for the long-term monitoring of a variety of humidity-related variables which have different impacts and implications for society. It is also useful for climate model evaluation and reanalyses validation. HadISDH.2.0.0 is shown to be in good agreement both with other estimates and with theoretical understanding. The data set is available from 1973 to the present.

The theme common to all variables is of a warming world with more water vapour present in the atmosphere. The largest increases in water vapour are found over the tropics and the Mediterranean. Over the tropics and high northern latitudes the surface air over land is becoming more saturated. However, despite increasing water vapour over the mid-latitudes and Mediterranean, the surface air over land is becoming less saturated. These observed features may be due to atmospheric circulation changes, land–sea warming disparities and reduced water availability or changed land surface properties.

 

http://www.clim-past.net/10/1983/2014/cp-10-1983-2014.pdf

[knocker]

Robust Arctic sea-ice influence on the frequent Eurasian cold winters in past decades

 

Over the past decade, severe winters occurred frequently in mid-latitude Eurasia^{1, 2}, despite increasing global- and annual-mean surface air temperatures³. Observations suggest that these cold Eurasian winters could have been instigated by Arctic sea-ice decline^{2, 4}, through excitation of circulation anomalies similar to the Arctic Oscillation⁵. In climate simulations, however, a robust atmospheric response to sea-ice decline has not been found, perhaps owing to energetic internal fluctuations in the atmospheric circulation⁶. Here we use a 100-member ensemble of simulations with an atmospheric general circulation model driven by observation-based sea-ice concentration anomalies to show that as a result of sea-ice reduction in the Barents–Kara Sea, the probability of severe winters has more than doubled in central Eurasia. In our simulations, the atmospheric response to sea-ice decline is approximately independent of the Arctic Oscillation. Both reanalysis data and our simulations suggest that sea-ice decline leads to more frequent Eurasian blocking situations, which in turn favour cold-air advection to Eurasia and hence severe winters. Based on a further analysis of simulations from 22 climate models we conclude that the sea-ice-driven cold winters are unlikely to dominate in a warming future climate, although uncertainty remains, due in part to an insufficient ensemble size.

 

http://www.nature.com/ngeo/journal/v7/n12/abs/ngeo2277.html

[knocker]

Eastern Atlantic tropical cyclone frequency from 1851–1898 is comparable to satellite era frequency

 

Trend in North Atlantic tropical cyclone frequency is subject to uncertainties related mainly to observational deficiencies. These uncertainties make assessments of anthropogenic effects on present and future trends problematic. Here we document that, contrary to received opinion, ship numbers actually peaked in the mid-nineteenth century and reached a minimum in the early twentieth century. The greater opportunities for ship encounters with tropical cyclones is demonstrated in re-analysis of Eastern Atlantic tropical cyclones from 1851–1898. Our results suggest that nineteenth century frequency is comparable to that for the same area during the entire satellite era from 1965–2012.

 

http://iopscience.iop.org/1748-9326/9/11/114023/pdf/1748-9326_9_11_114023.pdf

[Nouska]

I found this interesting article in the Club Soleil listing of new, solar research papers.

 

Modulation of UK lightning by heliospheric magnetic field polarity

 

 

1.??Introduction

The electrification of thunderclouds is generally accepted to result from strong updrafts in the mixed-phase region (e.g., [4]), where the presence of both a downward flux of graupel and and upward flux of ice crystals can produce charge transfer and separation by collisions [24]. Indeed, parameterization of these processes [8] in numerical weather prediction models has led to successful forecasts of lightning flash rates [30]. A number of observational studies, however, suggest lightning flash rates may also be modulated to some degree by external factors such as solar magnetic activity [25], though the mechanism(s) and even sign of response are still under debate. On solar-cycle timescales, both positive [27] and negative [21] correlations have been found between sunspot number and thunderstorm activity. On shorter time scales, lightning over the USA has been found to decrease following impulsive reductions in galactic cosmic ray (GCR) flux by strong heliospheric magnetic field (HMF) enhancements [6]. Conversely, smaller, recurrent HMF structures appear to increase UK lightning and thunder rates, possibly via lower energy solar particles compensating for the GCR decrease [26]. These thunderstorm trends have all been linked with changes in energetic charged particle flux incident on Earth and hence changes in global atmospheric conductivity [9] and/or global lightning trigger rates [22].

 

 

 

http://iopscience.iop.org/1748-9326/9/11/115009/article

[knocker]

The emergence of modern sea ice cover in the Arctic Ocean

 

Arctic sea ice coverage is shrinking in response to global climate change and summer ice-free conditions in the Arctic Ocean are predicted by the end of the century. The validity of this prediction could potentially be tested through the reconstruction of the climate of the Pliocene epoch (5.33–2.58 million years ago), an analogue of a future warmer Earth. Here we show that, in the Eurasian sector of the Arctic Ocean, ice-free conditions prevailed in the early Pliocene until sea ice expanded from the central Arctic Ocean for the first time ca. 4 million years ago. Amplified by a rise in topography in several regions of the Arctic and enhanced freshening of the Arctic Ocean, sea ice expanded progressively in response to positive ice-albedo feedback mechanisms. Sea ice reached its even larger teapot maximum extension for the first time during the culmination of the Northern Hemisphere glaciation, ca. 2.6 million years ago.

 

http://www.nature.com/ncomms/2014/141128/ncomms6608/full/ncomms6608.html

 

Synopsis

 

http://m.phys.org/news/2014-11-emergence-modern-sea-ice-arctic.html

[Gray-Wolf]

Maybe some folk need to take note of the results of the influx of fresh water on sea ice formation esp. when looking at the Antarctic surface freshening due to land ice ablation and sea ice extension?

[knocker]

Do I hear a rustling in the hedgerows?

 

Research confirms how global warming links to carbon emissions

 

Research by the University of Liverpool has identified, for the first time, how global warming is related to the amount of carbon emitted.

Read more at: http://phys.org/news/2014-12-global-links-carbon-emissions.html#jCp

Edited December 1, 2014 by knocker

[knocker]

Seasonal cycle and long-term trend of solar energy fluxes through Arctic sea ice

 

Abstract. Arctic sea ice has not only decreased in volume during the last decades, but has also changed in its physical properties towards a thinner and more seasonal ice cover. These changes strongly impact the energy budget, and might affect the ice-associated ecosystems. In this study, we quantify solar shortwave fluxes through sea ice for the entire Arctic during all seasons. To focus on sea-ice-related processes, we exclude fluxes through open water, scaling linearly with sea ice concentration. We present a new parameterization of light transmittance through sea ice for all seasons as a function of variable sea ice properties. The maximum monthly mean solar heat flux under the ice of 30 × 10⁵ Jm^−2 occurs in June, enough heat to melt 0.3 m of sea ice. Furthermore, our results suggest that 96% of the annual solar heat input through sea ice occurs during only a 4-month period from May to August. Applying the new parameterization to remote sensing and reanalysis data from 1979 to 2011, we find an increase in transmitted light of 1.5% yr^−1 for all regions. This corresponds to an increase in potential sea ice bottom melt of 63% over the 33-year study period. Sensitivity studies reveal that the results depend strongly on the timing of melt onset and the correct classification of ice types. Assuming 2 weeks earlier melt onset, the annual transmitted solar radiation to the upper ocean increases by 20%. Continuing the observed transition from a mixed multi-year/first-year sea ice cover to a seasonal ice cover results in an increase in light transmittance by an additional 18%.

 

http://www.the-cryosphere.net/8/2219/2014/tc-8-2219-2014.pdf

[knocker]

New study explains the role of oceans in 'global warming hiatus'

 

New research shows that ocean heat uptake across three oceans is the likely cause of the ‘warming hiatus’ – the current decade-long slowdown in global surface warming. Using data from a range of state-of-the-art ocean and atmosphere models, the research shows that the increased oceanic heat drawdown in the equatorial Pacific, North Atlantic and Southern Ocean basins has played a significant role in the hiatus.

 

http://www.sciencedaily.com/releases/2014/12/141203083754.htm

 

Surface warming hiatus caused by increased heat uptake across multiple ocean basins

 

Abstract

The first decade of the 21st century was characterized by a hiatus in global surface warming. Using ocean model hindcasts and reanalyses we show that heat uptake between the 1990s and 2000s increased by 0.7 ± 0.3W m^−2. Approximately 30% of the increase is associated with colder sea surface temperatures in the eastern Pacific. Other basins contribute via reduced heat loss to the atmosphere, in particular, the Southern and subtropical Indian Oceans (30%) and the subpolar North Atlantic (40%). A different mechanism is important at longer timescales (1960s–present) over which the Southern Annular Mode trended upward. In this period, increased ocean heat uptake has largely arisen from reduced heat loss associated with reduced winds over the Agulhas Return Current and southward displacement of Southern Ocean westerlies.

 

http://onlinelibrary.wiley.com/doi/10.1002/2014GL061456/abstract;jsessionid=B75771C342CBE80AF1BACDA0F4162E5E.f04t01

Edited December 3, 2014 by knocker

[knocker]

Rapid dynamic activation of a marine-based Arctic ice cap

 

Abstract

We use satellite observations to document rapid acceleration and ice loss from a formerly slow-flowing, marine-based sector of Austfonna, the largest ice cap in the Eurasian Arctic. During the past two decades, the sector ice discharge has increased 45-fold, the velocity regime has switched from predominantly slow (~ 10¹â€‰m/yr) to fast (~ 10³â€‰ m/yr) flow, and rates of ice thinning have exceeded 25 m/yr. At the time of widespread dynamic activation, parts of the terminus may have been near floatation. Subsequently, the imbalance has propagated 50 km inland to within 8 km of the ice cap summit. Our observations demonstrate the ability of slow-flowing ice to mobilise, and quickly transmit the dynamic imbalance inland; a process that we show has initiated rapid ice loss to the ocean and redistribution of ice mass to locations more susceptible to melt, yet which remains poorly understood.

 

http://onlinelibrary.wiley.com/doi/10.1002/2014GL062255/abstract;jsessionid=26FADB111E1AE35EC0E95F2659165F11.f01t03

[knocker]

Interaction of ice sheets and climate during the past 800 000 years

 

Abstract. During the Cenozoic, land ice and climate interacted on many different timescales. On long timescales, the effect of land ice on global climate and sea level is mainly set by large ice sheets in North America, Eurasia, Greenland and Antarctica. The climatic forcing of these ice sheets is largely determined by the meridional temperature profile resulting from radiation and greenhouse gas (GHG) forcing. As a response, the ice sheets cause an increase in albedo and surface elevation, which operates as a feedback in the climate system. To quantify the importance of these climate–land ice processes, a zonally averaged energy balance climate model is coupled to five one-dimensional ice sheet models, representing the major ice sheets.

In this study, we focus on the transient simulation of the past 800 000 years, where a high-confidence CO₂ record from ice core samples is used as input in combination with Milankovitch radiation changes. We obtain simulations of atmospheric temperature, ice volume and sea level that are in good agreement with recent proxy-data reconstructions. We examine long-term climate–ice-sheet interactions by a comparison of simulations with uncoupled and coupled ice sheets. We show that these interactions amplify global temperature anomalies by up to a factor of 2.6, and that they increase polar amplification by 94%. We demonstrate that, on these long timescales, the ice-albedo feedback has a larger and more global influence on the meridional atmospheric temperature profile than the surface-height-temperature feedback. Furthermore, we assess the influence of CO₂ and insolation by performing runs with one or both of these variables held constant. We find that atmospheric temperature is controlled by a complex interaction of CO₂ and insolation, and both variables serve as thresholds for northern hemispheric glaciation.

 

http://www.clim-past.net/10/2135/2014/cp-10-2135-2014.pdf

[BornFromTheVoid]

Early warning signals of Atlantic Meridional Overturning Circulation collapse in a fully coupled climate model

 

The Atlantic Meridional Overturning Circulation (AMOC) exhibits two stable states in models of varying complexity. Shifts between alternative AMOC states are thought to have played a role in past abrupt climate changes, but the proximity of the climate system to a threshold for future AMOC collapse is unknown. Generic early warning signals of critical slowing down before AMOC collapse have been found in climate models of low and intermediate complexity. Here we show that early warning signals of AMOC collapse are present in a fully coupled atmosphere-ocean general circulation model, subject to a freshwater hosing experiment. The statistical significance of signals of increasing lag-1 autocorrelation and variance vary with latitude. They give up to 250 years warning before AMOC collapse, after ~550 years of monitoring. Future work is needed to clarify suggested dynamical mechanisms driving critical slowing down as the AMOC collapse is approached.

 

http://www.nature.com/ncomms/2014/141208/ncomms6752/full/ncomms6752.html

 

 

Overview of the article here http://phys.org/news/2014-12-early-abrupt-climate.html

Edited December 8, 2014 by BornFromTheVoid

[knocker]

The Oslo temperature series 1837–2012: homogeneity testing and temperature analysis

 

ABSTRACT

A 175 years long homogenized composite record of monthly mean temperatures is presented for Oslo, the capital of Norway. The early raw data have been digitised and quality controlled, and monthly means have been calculated. Some early original observations carried out in a Wild screen (1877–1936) were found to be spuriously high because of inappropriate sheltering from sunlight. These spurious temperatures were not used in the composite record, but alternative temperatures measured (1837–1933) by thermometers placed outside windows at the Astronomical Observatory were used instead. No inhomogeneity was detected in the latter series after adding an instrument correction of +0.3 °C, but the start year of the correction remains uncertain. The more recent part of the composite record used the long-term series (1937 to present) from Blindern in Oslo, the premises of The Norwegian Meteorological Institute. Two small inhomogeneities were detected in the Blindern series, possibly caused by a weak urban heat island effect or growing/cutting of trees. The study revealed that the annual mean temperature has increased by 1.5 °C in the period 1838–2012. The most pronounced increase in annual temperature occurred during the last 50 years, and in the early 20th century that ended with a local maximum in the 1930s. The temperature has increased significantly in all seasons; however, the temperature increase in summer was less than a half of that in winter and spring, which were the seasons with largest increase. In addition the monthly mean temperature of the coldest month in each year has increased two times faster than the warmest one. The most significant temperature variations were associated to ∼ 5-year time scales in its early part, but since 1930 and up to present, the dominant time scales were 10–20 years.

 

http://onlinelibrary.wiley.com/doi/10.1002/joc.4223/abstract?utm_content=buffer5caea&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

[knocker]

Early warning signals of Atlantic Meridional Overturning Circulation collapse in a fully coupled climate model

 

The Atlantic Meridional Overturning Circulation (AMOC) exhibits two stable states in models of varying complexity. Shifts between alternative AMOC states are thought to have played a role in past abrupt climate changes, but the proximity of the climate system to a threshold for future AMOC collapse is unknown. Generic early warning signals of critical slowing down before AMOC collapse have been found in climate models of low and intermediate complexity. Here we show that early warning signals of AMOC collapse are present in a fully coupled atmosphere-ocean general circulation model, subject to a freshwater hosing experiment. The statistical significance of signals of increasing lag-1 autocorrelation and variance vary with latitude. They give up to 250 years warning before AMOC collapse, after ~550 years of monitoring. Future work is needed to clarify suggested dynamical mechanisms driving critical slowing down as the AMOC collapse is approached.

 

http://www.nature.com/ncomms/2014/141208/ncomms6752/full/ncomms6752.html

 

 

Overview of the article here http://phys.org/news/2014-12-early-abrupt-climate.html

 

Interesting and this adds another dimension to the Younger Dryas cold epoch although in a sense it has already been postulated.

 

Schematic of the Atlantic meridional overturning circulation

Edited December 9, 2014 by knocker

[knocker]

Warmer Pacific Ocean could release millions of tons of seafloor methane

 

Off the West Coast of the United States, methane gas is trapped in frozen layers below the seafloor. New research from the University of Washington shows that water at intermediate depths is warming enough to cause these carbon deposits to melt, releasing methane into the sediments and surrounding water.

 

Researchers found that water off the coast of Washington is gradually warming at a depth of 500 meters, about a third of a mile down. That is the same depth where methane transforms from a solid to a gas. The research suggests that ocean warming could be triggering the release of a powerful greenhouse gas.

 

"We calculate that methane equivalent in volume to the Deepwater Horizon oil spill is released every year off the Washington coast," said Evan Solomon, a UW assistant professor of oceanography. He is co-author of a paper to appear in Geophysical Research Letters.

 

http://www.eurekalert.org/pub_releases/2014-12/uow-wpo120914.php

[Gray-Wolf]

Warmer Pacific Ocean could release millions of tons of seafloor methane

 

http://www.eurekalert.org/pub_releases/2014-12/uow-wpo120914.php

 

 

We had been seeing methane anoms over Baffin at certain times of the year? I wonder if this is related?

[knocker]

Dramatically increasing chance of extremely hot summers since the 2003 European heatwave

 

Socio-economic stress from the unequivocal warming of the global climate system¹ could be mostly felt by societies through weather and climate extremes². The vulnerability of European citizens was made evident during the summer heatwave of 2003 (refs 3, 4) when the heat-related death toll ran into tens of thousands⁵. Human influence at least doubled the chances of the event according to the first formal event attribution study⁶, which also made the ominous forecast that severe heatwaves could become commonplace by the 2040s. Here we investigate how the likelihood of having another extremely hot summer in one of the worst affected parts of Europe has changed ten years after the original study was published, given an observed summer temperature increase of 0.81 K since then. Our analysis benefits from the availability of new observations and data from several new models. Using a previously employed temperature threshold to define extremely hot summers, we find that events that would occur twice a century in the early 2000s are now expected to occur twice a decade. For the more extreme threshold observed in 2003, the return time reduces from thousands of years in the late twentieth century to about a hundred years in little over a decade.

 

http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2468.html

 

Commentary

http://www.metoffice.gov.uk/news/releases/archive/2014/heatwave-increase?utm_source=twitterfeed&utm_medium=twitter

[knocker]

Past Global Warming Similar to Today’s

 

Dec. 15, 2014 – The rate at which carbon emissions warmed Earth’s climate almost 56 million years ago resembles modern, human-caused global warming much more than previously believed, but involved two pulses of carbon to the atmosphere, University of Utah researchers and their colleagues found.

 

The findings mean the so-called Paleocene-Eocene thermal maximum, or PETM, can provide clues to the future of modern climate change. The good news: Earth and most species survived. The bad news: It took millennia to recover from the episode, when temperatures rose by 5 to 8 degrees Celsius (9 to 15 degrees Fahrenheit).

 

http://unews.utah.edu/news_releases/past-global-warming-similar-to-todays/

Edited December 15, 2014 by knocker

[knocker]

Enhanced 20th-century heat transfer to the Arctic simulated in the context of climate variations over the last millennium

 

Abstract. Oceanic heat transport variations, carried by the northward-flowing Atlantic Water, strongly influence Arctic sea-ice distribution, ocean–atmosphere exchanges, and pan-Arctic temperatures. Palaeoceanographic reconstructions from marine sediments near Fram Strait have documented a dramatic increase in Atlantic Water temperatures over the 20th century, unprecedented in the last millennium. Here we present results from Earth system model simulations that reproduce and explain the reconstructed exceptional Atlantic Water warming in Fram Strait in the 20th century in the context of natural variability during the last millennium. The associated increase in ocean heat transfer to the Arctic can be traced back to changes in the ocean circulation in the subpolar North Atlantic. An interplay between a weakening overturning circulation and a strengthening subpolar gyre as a consequence of 20th-century global warming is identified as the driving mechanism for the pronounced warming along the Atlantic Water path toward the Arctic. Simulations covering the late Holocene provide a reference frame that allows us to conclude that the changes during the last century are unprecedented in the last 1150 years and that they cannot be explained by internal variability or natural forcing alone.

 

http://www.clim-past.net/10/2201/2014/cp-10-2201-2014.pdf

[knocker]

Recent advances in understanding the Arctic climate system state and change from a sea ice perspective: a review

 

Abstract. Sea ice is the central component and most sensitive indicator of the Arctic climate system. Both the depletion and areal decline of the Arctic sea ice cover, observed since the 1970s, have accelerated since the millennium. While the relationship of global warming to sea ice reduction is evident and underpinned statistically, it is the connecting mechanisms that are explored in detail in this review.

Sea ice erodes both from the top and the bottom. Atmospheric, oceanic and sea ice processes interact in non-linear ways on various scales. Feedback mechanisms lead to an Arctic amplification of the global warming system: the amplification is both supported by the ice depletion and, at the same time, accelerates ice reduction. Knowledge of the mechanisms of sea ice decline grew during the 1990s and deepened when the acceleration became clear in the early 2000s. Record minimum summer sea ice extents in 2002, 2005, 2007 and 2012 provide additional information on the mechanisms.

This article reviews recent progress in understanding the sea ice decline. Processes are revisited from atmospheric, oceanic and sea ice perspectives. There is strong evidence that decisive atmospheric changes are the major driver of sea ice change. Feedbacks due to reduced ice concentration, surface albedo, and ice thickness allow for additional local atmospheric and oceanic influences and self-supporting feedbacks. Large-scale ocean influences on Arctic Ocean hydrology and circulation are highly evident. Northward heat fluxes in the ocean are clearly impacting the ice margins, especially in the Atlantic sector of the Arctic. There is little indication of a direct and decisive influence of the warming ocean on the overall sea ice cover, due to an isolating layer of cold and fresh water underneath the sea ice.

 

http://www.atmos-chem-phys.net/14/13571/2014/acp-14-13571-2014.pdf