Archive for the ‘ice sheet melt factor’ Category

Phoenix Glacier relic ice

Tuesday, September 10th, 2013

I’m in South Greenland drilling low tech metal pipes into the ice to calibrate high tech satellite, aircraft, and model data.

Flying over this landscape, it’s stunning how much the ice has retreated. Annual (let alone summer) average air temperatures at nearby Narsarsuaq have been above the melting point 39 of the past 51 years [1]. Unequivocal evidence of rapid ice retreat; relic stranded ice [2] was what led Denmark to support scientists at GEUS to install modern ice monitoring measurements in 2001. The observations are now called “Q transect” as part of the PROMICE network around Greenland.

I was stunned to witness (and photograph) more stranded relic ice on the sides of the glacier. Notice how no ice is feeding Phoenix’s wings from upstream.

The glacier’s current shape resembles a Phoenix, with wings (relic ice) outstretched to the front, and the phoenix has a demise, like this glacier.

We’re here surveying the damage with Shane Smith of Vice media for an up coming spot on HBO.

Vice supported the installation of six ablation stakes at elevations between 390 and 1100 m on the Qassimiut lobe of the ice sheet, hence the name Q transect.

 The stakes are carefully tied into a coordinate system using the antenna at the upper right recording the site elevation and horizontal position by differential GPS.

This Phoenix should of course rise again, but not until after another ice age. When that happens? It’s gonna be a while.

Follow @PromiceGL on Twitter.

Work Cited

  • [1] Cappelen, John, DMI Monthly Climate Data Collection 1768-2010, Denmark, The Faroe Islands and Greenland. Dansk Meteorol. Inst. Tech. Rap., 11-05, 54 pp, 2011.
  • [2] Podlech; Steffen, Christoph Mayer, Carl Egede Bøggild, Glacier Retreat, Mass-Balance and Thinning: Sermilik Glacier, South Greenland, Geografiska Annaler: Series A, Physical Geography, Volume 86, Issue 4, pages 305–317, December 2004, DOI: 10.1111/j.0435-3676.2004.00234.x

Visiting and monitoring South Greenland dark ice

Friday, August 16th, 2013

I’m spending a week flying out of Narsarsuaq, south Greenland, with colleague Dr. Robert Fausto, to maintain climate stations equipped to monitor surface ice melt in great detail. Part of the Danish PROMICE network, the stations obtain surface energy and mass budget closure. The closure means that calculated melt matches with observed melt.

coming in to land at a PROMICE climate station, one of 22 on Greenland ice operated by GEUSPhoto J. Box.

Flying across this vast space and on the ground, I’m is struck by how abundant snow algae and other light absorbing impurities can be. The low reflectivity impurities amplify the effects of the increasing melt season. Increased melt means a shorter duration of highly reflective snow cover. The prolonged exposure of an impurity-rich bare ice surface multiplies melt rates. I’ve calculated that without this albedo feedback, the increase in melt rates would amount to half of what’s observed. Some of this feedback is due to ice crystal rounding. Some is due to the impurities. Measuring the relative importance of metamorphic and impurity driven albedo reduction is a subject of our work.

boots on the ice offer a close look (and to sample) impurities concentrating at the surface. The fact is, much of this dark material is from cyanobacteria and blue-green algae. Photo J. Box.

puddles often form with this kind of algal slick’. Photo J. Box.

It’s exciting to be working with Dr. Marek Stibal who studies the microbial environment on Arctic ice. Together with his data, the surface energy exchange data from the PROMICE climate stations and Danish Meteorological Institute’s regional climate modeling (Follow @Greenlandsmb), we have a powerful approach to unravel more detail from the melt story in Greenland.

South Greenland Dark Ice. Photo J. Box.

Snow accumulates in crevasses forming snow bridges that one would rather fly over. In between, impurity-rich ice absorbs up to 80% of the Sun’s energy. Photo J. Box.

Surface melt water mingles with impurity rich Greenland ice. Photo J. Box.

Robert Fausto maintains a climate station equipped to measure downward and upward solar energy, among many other climate parameters as part of the Danish PROMICE network (Follow @PromiceGL). Photo J. Box. (Follow @Climate_Ice)

Greenland 2013 melt is over the hill

Monday, August 12th, 2013

While average sea ice minimum occurs in September, the Greenland ice albedo minimum occurs in July. This year, the albedo minimum occurred 31 July, coinciding with a record setting warm episode.

By 9 August, fresh snowfall concentrated along the southeastern ice sheet brought up the ice sheet albedo.

Across the northwestern ice sheet, melting increased the first 10 days of August, darkening the surface from a brighter than normal pattern associated with abnormally large snow accumulation that made difficult the Japanese SIGMA expedition.

Ice sheet albedo remains anomalously low along the western upper ablation area. The most persistent low albedo this melt season has been along the northwest, in the vicinity of Storstrømmen glacier.

Heat transport into the Arctic bypassed Greenland to it’s east. Svalbard has had a warm summer.

A reliable feature of climate is the poleward transport of heat in the atmosphere (and ocean) and the main contuit into the Arctic is the North Atlantic. So, what we see in this figure is normal and Greenland just didn’t get much exposure to this warm air stream (marked with up-pointing purple arrows). This extra heat bypassed Greenland much of this summer.

Greenland high near-surface air temperature record set

Saturday, August 3rd, 2013

It’s worth adding that the large scale circulation, if (likely) delivering (excess, anthropogenic) heat and moisture via south air advection, is arguably a legitimate part of a climate change narrative. The foehn effect may not be an aside if atmospheric humidity were increased by climate warming, yielding additional latent heat release in the downslope compression of the foehn effect…

Greenland soars to its highest temperature ever recorded, almost 80 degrees F.

By Jason Samenow, Published: August 1 at 1:47 pmE-mail the writer


The Danish Meteorological Institute is reporting that on Tuesday, July 30, the mercury rose to 25.9 C (78.6 F) at a station in Greenland, the highest temperature measured in the Arctic country since records began in 1958.

The balmy reading was logged at the observing station Maniitsoq / Sugar Loaf, which is on Greenland’s southwest coast, the DMI reports. It exceeded the 25.5 C (77.9 F) reading taken at  Kangerlussuaq on July 27, 1990, in the same general area. Mantiitsoq is Greenland’s sixth-largest town, with a 2010 population of 2,784.

4880007af6Weather pattern responsible for record warmth in southwest Greenland (Danish Meteorological Institute)

The DMI says the record warmth was brought about by southeasterly winds, funneled by the flow between a large area of high pressure over continental Greenland, and low pressure over Baffin Island to the west.

It adds the warmth may have been enhanced by a phenomenon known as the Foehn Effect, in which air flows over nearby elevated terrain and compresses and heats on its way down. In this case, DMI believes the air may have passed over the elevated Sugar Loaf ice cap and then dried and warmed up as it descended (or downsloped) on its leeward side into Maniitsoq.

Via the Danish Meteorological Institute: "Satellite photo of the area around Maniitsoq and Sugar Loaf Mountain on Tuesday 30 July 2013. Photo from NASA's Terra satellite."Via the Danish Meteorological Institute: “Satellite photo of the area around Maniitsoq and Sugar Loaf Mountain on Tuesday 30 July 2013. Photo from NASA’s Terra satellite.”
(IPCC)Conceptual model of how a warming baseline climate increases the chance of record-breaking weather (IPCC)

The DMI says the warmth was not “unnatural”, but explains it fits into a long-term pattern of climate warming.

“[T]here is an indisputable gradual increase in temperature in Greenland,”DMI writes. “Along the way, any ‘warm event’ thus have a higher probability of being slightly warmer than the previous one.”

Related, from 2012: Greenland ice sheet surface melt: massive meltdown or meaningless trickle?

This warm temperature extreme in Greenland comes on the heels of an astonishing heat wave in northern Siberia.

Wunderground weather historian Christopher Burt described a “perhaps unprecedented” streak of 10 days in the central Arctic region of Russia in which temperatures exceeded 86 degrees F (30 C) in mid-to-late July.

Prior to this, it was the desert southwest reaching heat milestones.  Recall Death Valley set the record for hottest U.S. temperature ever recorded in June, climbing to a blistering 129 degrees.

At the moment, China is in the midst of a record-breaking heat wave.  And in Alaska,Fairbanks and Anchorage have ongoing historically long streaks of warm weather.

These heat events were all likely set up predominantly by the configuration of naturally varying weather patterns.  But  elevated greenhouse gas concentrations may well be tacking on a small warming contribution, nudging these extreme events into record territory.

Jason Samenow is the Capital Weather Gang’s chief meteorologist and serves as the Washington Post’s Weather Editor. He earned BA and MS degrees in atmospheric science from the University of Virginia and University of Wisconsin-Madison.

Too late now for 2013 to produce Greenland ice surface melting anywhere near as large as in 2012

Monday, July 22nd, 2013

We’ve made it to the middle of the melt season 2013. It’s been a roller coaster for Greenland climate in 2013.

The year started out with an astonishing low albedo from a snow drought that made huge melt possible. Yet this was punctuated by the return of snow late April and prolonged low temperatures as the North Atlantic Oscillation (NAO) shifted from persistent negative that had been causing west Greenland temperatures to be abnormally warm while Copenhagen thad its coldest late winter and early spring in decades. The dipole in temperatures between NW Europe and W Greenland has been recognized for more than a century and called the “seesaw” in temperature (van Loon and Rogers, 1978).

Like in 2012, melt came on strong by early June but was shut down again by abnormally low temperatures, accompanied by additional snowfalls [1, Ruth Mottram, Danish Meteorological Institute, personal communication] in some areas, that lasted until mid July. The key difference between 2013 and the previous 6 summers (2007-2012) is the absence of a persistent negative NAO that drove south air over Greenland, heating it while promoting clear skies that maximized the impact of surface darkening through the albedo feedback (Box et al. 2012). With this much of a delayed start, the albedo feedback has not had enough time to produce strong melt. Given now that we are at the mid point of the melt season, it is too late now for 2013 to produce melting anywhere nearly as large as we saw in 2012.

The NASA MODIS data indicate that the 2013 Greenland mid melt season (mid-July) albedo is at its lowest in 4 years; behind 2009, 2010, 2011, and 2012.

The 2013 June ice sheet is more reflective across the southern third than the average of the recent decade. This may also be partly a consequence of the late season snowfall which was concentrated in the south eastern quarter (Ruth Mottram, DMI). Across the northern 2/3 of the ice sheet, the difference is below average, though not as far below average as in previous years, especially 2010, 2012.

But the bigger story seems to be the preliminary July 2013 average (the first 20 days of the month) where much of the lower elevation ablation area is more reflective than the recent decade (2000-2011). This is slowing down accumulated melt. Meanwhile, the upper elevations (inland) have below average reflectivity. Why are the upper elevations (inland) somewhat below normal reflectivity? While Dark Snow project was successful in gathering surface reflectivity samples from southwest Greenland this 8th and 9th July, the samples were not from where the high July albedo anomaly is. Were it anyway North American fire smoke contributing to the reduced ice reflectivity, it could be a.) lower than normal snowfall at the upper elevations over the year . Could the albedo of 2013 literally be reflecting the ice of 2012 buried less than 1 m below the surface? The albedo signal can originate from some 10s of cm below the surface. According to DMI’s HIRLAM model estimates, there is less than 1 m of snow accumulation over much of the higher elevations. Then again, the fire factor may also be at play. We’ll be looking into this with Dark Snow project.

  Works Cited

  • [1] Ruth Mottram, Danish Meteorological Institute (DMI), personal communication. The DMI High Resolution Limited Area Model (HIRLAM) simulates snowfall in southeast and east Greenland. The cumulative surface mass balance indicated net mass accumulation. HIRLAM is initialized by observations from satellites, weather balloons, aircraft, ground stations, buoys, etc.
  • Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012. open access
  • van Loon, Harry, Jeffery C. Rogers, 1978: The Seesaw in Winter Temperatures between Greenland and Northern Europe. Part I: General Description. Mon. Wea. Rev., 106, 296–310. doi:<0296:TSIWTB>2.0.CO;2

Quebec fires in NASA CALIPSO data, drifting to Greenland

Sunday, July 21st, 2013

On the lower limit of this 4 July NASA CALIPSO laser scan, between latitude 42.60 N, longitude -68.93 W, evident is a rising smoke plume. The plume seeds cloud formation toward Greenland, reaching the southwest of the island.

The orange areas are smoke aerosols.

On 12 July, when Dark Snow scientist McKenzie Skiles, after camping, was picked up along Greenland’s longest road for a ride back to town, without prompt the driver remarked on haze in the sky from Canadian fires. McKenzie Skiles “It was the first thing he said after I got in the car, as if apologizing for the haze in the air (which was noticeable).”

hazy Kangerlussuaq, West Greenland. Photo McKenzie Skiles

9 July, 2013, we gathered snow and ice core samples from the surface and down through the 2012 melt layer, and we left only footprints. We’ll eventually see how much soot the laboratory and field spectral reflectance measurements tell us is there.

GRACE-cast: Greenland ice sheet mass loss *this week* turns toward average

Saturday, July 6th, 2013

In my new position, Professor of Glaciology at the Geological Survey of Denmark and Greenland (GEUS), I’ve started to gather momentum working with a fine group of people to establish for the first time, a Greenland ice sheet total mass balance product that estimates what the GRACE satellite measures and posting the estimate on-line 2-3 months ahead of the GRACE processing.

Our new “Nowcast” of Greenland ice sheet mass balance has as little as 24 h delay from realtime.

The product exploits the fact that on average, 90% of the time, when monthly all ice sheet reflectivity (also called “albedo”) goes up, the rate of total ice sheet mass change goes down and visa versa.

The Nowcast only works in the sunlit period from mid April to mid September.

So, now as we’re mid-melt season (6 July), we finally have some interesting news…delay of the 2013 melt season due to relatively northerly air flow along west Greenland has led to the lowest elevations of the ice sheet having an above average reflectivity due primarily to more persistent snowcover (snow patches) and secondarily due to summer snowfall in some areas. According to the empirical relationship, the rate of ice melt water loss from the ice sheet to the surrounding seas has declined and now approaches the average of the 2003-2009 period.

People involved with what I like to call the “GRACE-cast” include: GEUS glaciology post-doc William Colgan; Danish Meteorological Institute (DMI) ice climatologists Dr. Peter Langer and Dr. Ruth Mottram, and Danish Tecnhical University (DTU) geodesists Dr. Valentina Barletta and Dr. Rene Forsberg.

Technical details are documented in a .pdf file at the new product’s new home:
The cumulative sea level contribution is also updated on the new Danish web site.

Greenland ice sheet ablation area albedo above average, upper elevations below average

Saturday, July 6th, 2013

A delayed melting at low elevations and probably some summer snowfall blanketing the Greenland ice sheet ablation area with (highly reflective) fresh snow have resulted in an important slow down of Greenland melting. This pattern is in contrast to this time last year (in 2012) when record melting was emerging.

Greenland steep fluctuations of 2013 warm and cold

Thursday, July 4th, 2013
Greenland melt of 2013 year has had fits and starts.

It’s been dipping in and out of abnormal warmth and cold.

The drama began with very low pre-melt albedo March to -mid-April due to a snow drought that made high melt in 2013 seem more than likely. Then, an about face, a lot of snow and relatively cold weather washed over Greenland for the next 6 weeks (20 April – early June)!

Melt then came on strong 3 June yet was punctuated 22 June by a return of cold weather that has remained in place and is forecast through at least 8 July. 
It now seems more than likely 2013 won’t hit 2012 melt record, this after 6 summers in a row of negative North Atlantic Oscillation that favored Greenland heating. The persistence of that pattern had me wondering if, for example, the drop in Arctic sea ice or the complete ablation of snow cover on land had ~permanently altered large scale atmospheric circulation. Yet, what we see with 2013 suggests a more complex situation with extreme fluctuations of warm and cold.

Greenland – an albedo feedback laboratory

Sunday, June 30th, 2013

Surface reflectivity of sunlight is called “albedo”. Albedo is a Latin-based word referring to whiteness. The higher the albedo, the more sunlight can be reflected. As albedo decreases, more sunlight can be absorbed.

Snow and ice impurities concentrate in “cryoconite” holes on the Greenland ice sheet surface. Photo. J. Box

The absorption of sunlight is the largest single source of melt energy on the Greenland ice sheet.

Surface albedo across Greenland is mapped using data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) satellite-borne sensors. Before melting is underway, albedo is above 80%.

The NASA albedo data have an accuracy better than 5% (Stroeve et al. 2006; Box et al. 2012).

During melting, the rounding of ice crystals by heating causes the albedo to drop.
A freshly fallen snow crystal has numerous facets to reflect sunlight (left). Warming causes the grains to round at the edges and clump together (right). Scanning electron microscope photos courtesy the Electron and Confocal Microscopy Laboratory, USDA Agricultural Research Service.
In some areas of the ice sheet, by the time winter snow cover melt away, bare glacier ice is exposed. Where impurities congregate, the surface albedo drops below 30%.
Aerial oblique view of the lower elevations of the ice sheet in August 2005 from an area near the point of lowest reflectivity on the ice sheet. Photo J. Box

Impurities are composed of dust, algae, wildfire soot. Their relative importance to surface albedo remains incompletely understood.

As part of Dark Snow Project’s 2013 expedition, Dr. Marek Stibal gathers samples from an area of concentration near the darkest point on the Western Greenland ice sheet.

An increase in atmospheric heating of Greenland ice is a driver of Greenland ice albedo decline in summer, in part due to the expansion of bare ice areas, in part due to the heating effect on rounding ice crystals, and in part if the concentration of impurities increases.

In the period of high quality observations beginning early 2000, June 2013 albedo for the ice sheet is ranked 3rd lowest.

Greenland albedo started out very low in 2013 due to a snow drought exposing darker bare ice around the ice sheet periphery.

The albedo feedback with climate is responsible for doubling the temperature changes when climate warms or cools. This amplifier helps Earth’s climate system swing into and out of ice ages. The feedback is complex, including the effects of heating and light absorbing impurities, in a process that compounds through time.

Light absorbing impurities like black carbon from wildfire and industrial sources acts like a multiplier of the albedo feedback.

The Dark Snow Project aims to better understand the black carbon aspect of the albedo feedback through field data gathering and laboratory analysis.


Click here to visit the Dark Snow Youtube Channel.

Works Cited

  1. Box, J. E., X. Fettweis, J.C. Stroeve, M. Tedesco, D.K. Hall, and K. Steffen: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012. open access
  2. Stroeve, J.C., Box, J.E., Haran, T., 2006: Evaluation of the MODIS (MOD10A1) daily snow albedo product over the Greenland ice sheet, Remote Sensing of Environment, 105(2), 155-171.
  3. Stibal, M. M. Šabacká, and J. Žárský, Biological processes on glacier and ice sheet surfaces, Nature Geoscience 5, 771–774, 2012, doi:10.1038/ngeo1611