In a flash, three months have passed since I started working at the University of Sheffield on the NERC Black and Bloom project. This exciting project aims to constrain the role of ice algae in Greenland ice sheet surface melt, building on the work of the Dark Snow Project. There are four work packages – one to examine the microbiology of the ice surface, one to examine inorganic materials on the ice surface, one to measure and model the albedo of the ice surface, and one to upscale field observations to the macroscale using satellite remote sensing. I am the PDRA on work package 3.
It has been a hectic start to the project, but amazingly, all the field kit has been purchased, inventoried and sent off on pallets to be stored in Kangerlussuaq (Greenland) ready for our field season in July. We had a great ally in CragX climbing shop in Sheffield, who helped us to procure our camp and safety equipment, and even let me put our mess tent up in their main climbing hall!
Checking the mess tent at The Foundry, Sheffield (UK)
We’ve all also been working away at refining our individual science plans and getting to grips with new equipment, techniques and experimental designs to make sure we hit the ice running in the field in July. For me, this has meant lots of time with the ASD FieldSpec – a device for measuring electromagnetic radiation at very high resolution. This device will be crucial for understanding how impurities – including ice algae – change the energy balance of ice surfaces.
Ice algae, soot and dust darken the ice surface on the Greenland Ice Sheet (photo J Cook)
I’ve also been getting my coding skills up to scratch, with help from the NCAS team (National Centre for Atmospheric Science) who provided an excellent scientific computing course at the University of Leeds.
So, with our kit currently sailing somewhere between here and western Greenland, we await our July put-in, cautiously going over our plans and developing our experimental designs. If the last three months are anything to go by, the time between now and July will be busy and exciting.
In August of 2014 I was honored and privileged to be a team member of Dark Snowʼs terminal rotation of the season in the ablation belt of Greenlandʼs Ice Cap. This would not be of particular note, except that I am not a scientist, but an artist.
Well, maybe not just any artist. I like to think that I have one foot in the world of science, and that one of my roles is to attempt to bridge the gaps between the two disciplines. I believe that the flash of creativity— the “something” where there was nothing— is identical in process in science and art. Indeed, to me, at their best both are derived from the same approach: looking very, very closely at the world, and then making some kind of interpretative sense of it. Of course there are mediocre practitioners of both, who create science about science or art about art, or other lacks of inspiration, but that is inevitable in any human endeavor.
My residence with Project Dark Snow was my fourth polar sojourn. When the NSF sent me in 1999 to The Ice (Antarctica) I became the first sculptor from any country to be sent to the “last continent” (7 weeks). They sent me again in 2006 (4 weeks). I also spent the last rotation of 2001 on Canadaʼs largest icebreaker (Louis S. St-Laurent) (5 weeks). All of these trips included a significant airborne component, in fixed and rotary wing aircraft.
On the Greenland Cap I assisted with the science work, but I also engaged in my usual observations when in the field. I get asked frequently if I sculpt on these trips: of course not. I am out there as a researcher, gathering “data” in a manner somewhat parallel to what the science folks do. For them, the data will be analyzed and interpreted back at the lab, and for me there is plenty of time to carve, weld and grind when back at my studios. On ice I photograph, sketch, observe, make notes, converse. It is imperative to keep an open mind: it is very often the unexpected that turns out to be the real prize.
After these and other trips to nourish my work, at first I am artistically stunned. Slowly, some art begins, usually fairly illustrative since I am still in thrall to the majesties I have witnessed; often this takes the form of works on paper, but not this time. Somehow, sheet marble called, and seemed a logical first step. Eventually, LED illumination wormed into things as well. Gradually, as a bit of time and labor pass, I slowly am able to inject metaphorical meaning into the work, and as it thus matures I become more and more comfortable applying my signature.
In every case, this visual, intellectual, metaphorical infusion is added to everything previous, and the entire additive structure of all my trips and other nourishment becomes enriched.
I hope that the provided images show this progression, consequent over more than a year, a normal time for these gellings to occur.
A new study by Polashenski and others find that “Neither dust nor black carbon causing apparent albedo decline in Greenland’s dry snow zone; implications for MODIS C5 surface reflectance“.
Just one point of their work I expand on here is the issue of declining MODIS Terra sensor sensitivity (Wang and others 2012; Lyapustin et al. (2014). First, Polashenski and others (2015) develop the MODIS albedo decline issue nicely. Now, rewinding back to early 2012, after becoming aware of Wang and others (2012) results, I evaluated whether the albedo decline was present in the completely independent Greenland Climate Network (GC-Net) data after Steffen and others (1996). In 2012, I wrote:
“Degrading MODIS instrument sensitivity identified by Wang et al. (2012) introduces the possibility that the declining albedo trends may be erroneous. To validate the MODIS albedo trends, coinciding observations from GC-Net AWS are examined. The ground truth data are situated across a range of elevations, spanning the ablation and accumulation areas. Analysis of the GC-Net data confirms declining albedo trends in the 2000–2010 period to be widespread in individual months from May–September. Trend statistics are computed where at least 7 yr of annual data are available from both GC-Net and MODIS Terra. Significance is designated here more strictly where the trend measured by the linear regression slope has a magnitude that exceeds 2 of the residuals from the regression. In 41 of 43 (95 %) of monthly cases May–September, the trend is found to be significant and decreasing (Table 1). In 10 of 14 (71 %) cases, for which both GC-Net and MOD10A1 trends are significant, the GC-Net declining trend is larger than the MOD10A1 trend. It therefore does not seem that MODIS sensor degradation is enhancing an existing trend.” – Box and others (2012)
Still, an update after 2010 is in order. Now, the evaluation through 2014 yields that there is still a real albedo decline for the southern part of the ice sheet, including places like Saddle or South Dome where surface melting is uncommon. Note how not only do both GC-Net and MODIS MOD10A1 show a decline, they share peaks and troughs. Given that the ground data having a footprint size of just a few square meters and the satellite data that have an effective footprint size of 5 x 5 km and that they pick up the same high and low years is impressive.
Wonk Alert: Still the bias is very likely a latitude-dependent. Notice how the GC-Net trend is even stronger than the MODIS trend in the far south (South Dome and Saddle). Consider that we have sunlight reflecting off of a highly reflective part (an ice sheet) of a sphereoid (the earth) that arcs more than 20 degrees north south. Snow and ice have reflectance depending strongly on viewing and illumination angles. So, the satellite data compensation for simple albedo are susceptible to amplification of small sensor degradation biases.
Let me add that the detected bias is smaller than the type of anomalies produced by for example the large July 2015 melting for NW Greenland. The red and yellow areas below are real local albedo anomalies due primarily to melting.
MODIS having a more negative trend than the ground data for the northern high and usually dry bright snow interior sites (See NASA-E, Tunu-N, Humboldt above) is also a real issue that Polashenski and others (2015) nicely report. While the bias we are looking forward to be compensated in the version 6 MODIS data (Lyapustin and othes 2014). As to the role of black carbon in Greenland’s albedo decline, I would say there is more to the story than what Polashenski and others (2015) report. Stay tuned.
Box, J. E., X. Fettweis, J.C. Stroeve, M. Tedesco, D.K. Hall, and K. Steffen. 2012. Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839. doi:10.5194/tc-6-821-2012
Lyapustin, A., Wang, Y., Xiong, X., Meister, G., Platnick, S., Levy, R., Franz, B., Korkin, S., Hilker, T., Tucker, J., Hall, F., Sellers, P., Wu, A., and Angal, A.: Scientific impact of MODIS C5 calibration degradation and C6+ improvements, Atmos. Meas. Tech., 7, 4353-4365, doi:10.5194/amt-7-4353-2014, 2014.
Polashenski, C.M. J.E. Dibb, M.G. Flanner, J.Y. Chen, Z.R. Courville, A.M. Lai, J.J. Schauer, M.M. Shafer and M. Bergin, 2015, Neither dust nor black carbon causing apparent albedo decline in Greenland’s dry snow zone; implications for MODIS C5 surface reflectance, DOI: 10.1002/2015GL065912
Steffen, K., Box, J. E., and AbdalatiW.: Greenland climate network: GCNet, US Army Cold Regions Reattach and Engineering (CRREL), CRREL Special Report, 98–103, 1996.
Wang, D. D., Morton, D., Masek, J., Wu, A. A., Nagol, J., Xiong, X., Levy, R., Vermote, E., and Wolfe, R.: Impact of sensor degradation on the MODIS NDVI time series, Remote Sens. Environ., 119, 5561, 2012.
Sensors in Earth orbit give us the capability to monitor vast areas, daily, in near real-time. I’ve been working with daily NASA MODIS MOD14A1 data to map seasonal fire activity since the data begin year 2000. The map below illustrates the single most active day so far in 2015 for North America with fires ravaging central western Canada and interior Alaska.
A new strongest fire season?
Through 18 July, 2015, these data indicate the cumulative radiative power of North American fires to be the highest on record in the period of observations beginning in 2000. For July, 2015 fire power is 2.5 times the sixteen summer average 2000-2015. The fire season spikes above the annual average earlier in the year than in other years.
Western Canada experienced more than 600 fires over the weekend, according to territorial authorities.
Canadian provinces and territories pool their firefighting resources in these circumstances. While the NWT has requested more backup, other provinces are perceived to have a “dire need” and are first in line.
“Saskatchewan, for instance, is undergoing a series of evacuations of communities,” said Frank Lepine, the territory’s associate director of forest management. “Manitoba is pretty close to that.
“The NWT will be receiving some single resources but no more crews at this time. [But] that may change by the end of the week.”
There are 129 fires burning in the NWT, which has experienced a total of 158 fires so far this season. The 20-year average is 66 fires for this time of year.
And the 2015 fire season is not yet over.
According to this analysis, the previous year 2014 ended by setting the annual record for cumulative fire power for North America. Year 2004 fires were concentrated around the Alaska Canada border.
Scanning past news stirs recent intense memories….
Canada’s Northwest Territories are on fire. The region is experiencing its hottest, driest summer in 50 years, and wildfire activity is more than six times the 25-year average. While blazes in sparsely populated northern Canada have a minimal impact on human safety and infrastructure, they have an outsized effect on the environment: The ancient, stunted boreal forests, or taiga, ringing the Arctic Circle contain 30 percent of the world’s land-based carbon.
July 2, 2004 — A pall of smoke the size of Texas continues to blanket most of Alaska, as several dozen wildfires continue to burn out of control. More than a million acres have burned in the state. There are currently 61 active fires in the state, mostly in the eastern interior