EGU2015, my impressions

Tempus fugit. It feels like an eternity, but it was only last week that I went to Vienna to visit the EGU 2015 General Assembly. This is the overview I wrote last week of all the oral and poster sessions I planned to attend. Here's a summary of my impressions and what I've seen, heard and learned.

Unfortunately, due to circumstances, I had to skip the morning session, but I was in time for a short talk on the results of the Climate Dialogue initiative. This interested me because it originated in the Netherlands, the country where I was born and lived for most of my life, and it gave me the chance to meet up with Bart Verheggen from the Our Changing Climate blog, who was there to present a poster for a paper he wrote on a survey that confirms the scientific consensus on human-caused global warming.

I had written about the Climate Dialogue initiative when it started back in 2012. In my opinion, it was a project that was forced upon Dutch science institutes by right-wing politicians to legitimize climate risk denial and further postpone the policy dialogue. All of it paid, of course, by the Dutch tax payer. The only really interesting happened right at the start, when both mainstream Arctic experts Walt Meier and Ron Lindsay, and climate risk denier and former Arctic expert Judith Curry, agreed during the Climate Dialogue on Arctic sea ice that the anthropogenic influence accounted for at least 50% of Arctic sea ice loss. They could've stopped the whole project right there (but they didn't, of course).

Anyway, the oral presentation on the lessons learned from the Climate Dialogue initiative (link) was informative, and I asked if it wouldn't be interesting to do a follow-up with dialogues on the things that the IPCC underestimates, like sea level rise, changes to the jet stream, the carbon cycle, etc. It would, of course, but it seems there's no funding.

I stuck around for the following talk on what the ESA had done to involve the public with the Rosetta project (the space probe that landed on a comet, quite a feat), which was a very interesting and fun presentation. I then left the session, because that gave me an extra hour to study all the posters I wanted to visit during the evening session. And that's when things almost went horribly wrong.

Maybe it was my excitement, or maybe it was because they didn't put up proper signs to all the various floors where EGU was taking place, but somehow I couldn't find the stairs to the other floors. And so I decided to take the emergency stairs, which was a really stupid idea, because the door closes behind you and can't be re-opened from the inside!

And so there I was, in this badly lit, concrete stairway, trying all the doors on different floors, which were all closed. It was like a bad zombie movie. The thought crossed my mind that I would remain stuck there and miss everything, but luckily I didn't panic and read the sign that said that the exit was at the bottom of the stairs. I went all the way down where the last door could be opened and led to the lowest cellar floor. From there I could take the elevator back up again. Phew!

I then had a look at all the posters in the various halls, jotting down questions I would ask later on, and then went to the afternoon session called Rapid changes in sea ice: processes and implications. Now, this was really interesting, right off the bat in the first talk by Dr. Torge Martin called Changing summer sea ice roughness modifies momentum transfer into the Arctic Ocean (link), wherein he showed that ocean surface stress is increasing because of thinner ice, not because of winds. Unfortunately Wieslaw Maslowski wasn't able to attend the General Assembly, but one of his collaborators, Dr. Robert Osinski, had an interesting talk on their Regional Arctic System Model.

One of the main reasons I wanted to attend EGU2015, was to hear more about how they assess the preconditioning that takes place in the transition phase from freezing to melting season. I mean, the amateur community here has got a reasonably good handle on initial conditions when the freezing season ends, and we also know how to interpret weather conditions and what they do to the sea ice once the melting season gets under way for real. But it's impossible for us to get an idea of what happens in between.

For a while now I've been convinced that this first preconditioning phase of the melting season is very important (writing about melt ponds for instance, every now and again). Of course, scientists know this too and are trying to increase their knowledge of the processes involved, using different tools like models or observations.

The third talk in this session by Dr. Christopher Cox from CIRES, was about the latter, as can be deduced from the rather longish title: Using pan-Arctic, springtime, surface radiation observations to quantify atmospheric preconditioning processes that impact the sea ice melt season (link). The idea is that longwave and shortwave radiation data from four selected stations around the Arctic (Ny-Ålesund, Barrow, Alert and Tiksi) says something about the preconditioning of the ice. Less clouds, for instance, means more melt ponds. Reconstructions following this method have shown that observed radiation anomalies can be used for a September minimum forecast that "is within the range of uncertainty of forecasts currently incorporated into the Sea Ice Prediction Network (SIPN)".

That's one way of using observations to guess the melt pond cover fraction. The other way is using satellite data, which isn't an easy task, of course. To be able to see what is what you need people down there to tell you what it is you're looking at. Indirectly, that's what the fourth talk was about: Influence of ice thickness and surface properties on light transmission through Arctic sea ice (link).

In July 2014 a test in Fram Strait was conducted with a special underwater robotic vehicle (Nereid Under Ice, see image) to measure the amount of light coming through the ice. This data might at one point be used to observe light absorption with satellites.

Models also provide a way of getting an idea of spring time preconditioning, which in turn gives an idea of where the melting season might go. David Schröder from the University of Reading wrote a really interesting paper about that last year, called September Arctic sea-ice minimum predicted by spring melt-pond fraction, which I covered here and talked about in several ASI updates. In short, he and his co-authors developed a model that estimated the fraction of melt ponds on the sea ice pack. This estimate was then used to make a forecast for the September average, which was pretty accurate in 2013 and 2014.

The next step is to incorporate this model into larger-scale models to improve the simulation of sea ice decrease that models have had problems with, and still have. That's what Dr. Schröder's talk was about: Impact of melt ponds on Arctic sea ice in the HadGEM3 global coupled climate model (link). As useful as that is in the long term, I'm mostly interested in the short term, as the Arctic Sea Ice Blog revolves in large part around the 'live' reporting of the melting season. But I enjoyed the talk and was glad to have seen Dr. Schröder, because I was hoping to have a chat with him during the poster session.

And so I skipped the final talk on the Drivers of inorganic carbon dynamics in first-year sea ice: A model study (link) to have a look at some more posters and grab a beer (I had to drive later, so better to drink early). In the first hall I first had a chat with NASA's Linette Boisvert who presented a poster based on work she had done with Julienne Stroeve, looking at AIRS (Atmospheric Infrared Sounder) satellite data for the 2003-2013 period, which revealed a warmer and wetter Arctic, lengthening the melting season.

I then had a talk with Tommasso Parrinello, the ESA's CryoSat-2 mission manager, who told me that the Centre for Polar Observation and Modelling (University College of London) was about to release near real-time sea ice thickness maps based on CryoSat-2 data, news that was covered here. Parrinello is now hoping that CryoSat-2 can stay operational long enough so that he can let it fly the same path as NASA's ICESat-2, which will be launched in 2017, and the timeseries of thickness observations can be extended.

I remained a bit longer than planned in the first poster hall because Dr. Schröder hadn't arrived yet. When he finally did, he told me that they were again planning to issue a September average forecast for the SIPN Sea Ice Outlook, based on their melt pond model, and he was willing to provide me with some melt pond distribution maps of the last 10 years that I hope to publish here for the sake of comparison (with the caveat, of course, that it's model output, not observations) towards the end of June. He also gave me a really good tip on current work done with satellite obs to map the actual melt pond cover, which I will be sure to pursue in weeks to come.

So, that was half of my mission accomplished. I went to EGU mostly because I was curious and because it's fun, but also to try to learn a bit more about melt ponds and that preconditioning phase of the melting season that plays a big role in the amount of momentum that gets built up towards the second half of the melting season. We absolutely need to get a handle on that if we want to know the range of possibilities for the September average.

In my last half hour of EGU2015 I went to other poster halls, talked about the atmospheric influence of Arctic sea ice loss, but didn't really learn anything new. I also had a chat with my namesake Neven-Stjepan Fučkar, who is doing some fascinating work on the statistical side of Arctic sea ice loss (among other things) and told me that it was the first time so much attention at EGU went out to the aspect of predicting Arctic sea ice loss. So hopefully there will be more of that next year!

And I also hope to go again next year, as this was a really exciting experience in many ways. Next time I'll have to remember to bring my camera and not take the emergency staircase.

I had planned to write a short summary, so if you've made it this far: sorry and thanks for reading!

Comments

[DavidR]

All sounds very interesting. Too many links out for me to finish it yet.

First rule of a conference is to "find out how to get around before you have to get around".

[Lennartvdl]

Nice report, Neven, thanks. On the links, this one to Torge Martin is not right:
http://meetingorganizer.copernicus.org/EGU2015/EGU2015-2018.pdf

On the regional model by Maslowski and his group: did they say anything (new) on their 2016 +/- 3yrs ice-free projection/extrapolation?

[Neven]

Thanks, Lennart, fixed now.

On the regional model by Maslowski and his group: did they say anything (new) on their 2016 +/- 3yrs ice-free projection/extrapolation?

Nope, I had hoped to ask Maslowski about that, but as I said, he couldn't attend the conference.

[Chris Reynolds]

Thanks for the report Neven.

[wayne]

Neven, always heard about those very shy ice models, they are not very public, its a mistake, to err is human for a computer to fail its bad physics. Hope they can publish their projections, its extremely helpful both ways, to the model designers and also to the reviewers.

[Robert S]

Love the story about the stairway - somehow it's very symbolic of how many of us, I suspect, feel about the whole global warming process on our off days - stuck in a dark staircase with no clear way out...

[Colorado Bob]

Significance

Microorganisms are key players in emissions of the greenhouse gas (GHG) methane from anoxic carbon-rich peat soils of the Arctic permafrost region. Although available data and modeling suggest a significant temperature-induced increase of GHG emissions from these regions by the end of this century, the controls of and interactions within the underlying microbial networks are largely unknown. This temperature-gradient study of an Arctic peat soil using integrated omics techniques reveals critical temperatures at which microbial adaptations cause changes in metabolic bottlenecks of anaerobic carbon-degradation pathways. In particular taxonomic shifts within functional guilds at different levels of the carbon degradation cascade enable a fast adaptation of the microbial system resulting in high methane emissions at all temperatures.

Abstract

[Neven]

Love the story about the stairway - somehow it's very symbolic of how many of us, I suspect, feel about the whole global warming process on our off days - stuck in a dark staircase with no clear way out...

Indeed, Robert S. And if we worry too much that we're going to miss out on something and panic, we're totally screwed. We need to man up and go down, down, down to where the open door is (in fact there were two open doors, so I was relieved twice ;-) ).

[Chris Reynolds]

Just a ramble...

To add to the Maslowski et al and Martin et al presentations:
http://psc.apl.washington.edu/lindsay/pdf_files/Zhang%202012%20GRL%20-%20dynamic%20properties%20of%20decliing%20sea%20ice.pdf

"Recent changes in the dynamic properties of declining Arctic sea ice: A model study" Zhang et al 2012.

Zhang et al finds:

"Results from a numerical model simulation show significant changes in the dynamic properties of Arctic sea ice during 2007–2011 compared to the 1979–2006 mean. These changes are linked to a 33% reduction in sea ice volume, with decreasing ice concentration, mostly in the marginal seas, and decreasing ice thickness over the entire Arctic, particularly in the western Arctic. The decline in ice volume results in a 37% decrease in ice mechanical strength and 31% in internal ice interaction force, which in turn leads to an increase in ice speed (13%) and deformation rates (17%)."

Martin et al finds:

"While in winter a thinner and thus weaker sea ice cover enables a greater ocean surface stress than in previous decades, the enormous retreat of sea ice in recent summers reduced the surface roughness of the Arctic Ocean and hence causes a negative ocean surface stress trend in this season."

Not from this EGU meeting; Carmac et al "TOWARDS QUANTIFYING THE INCREASING ROLE OF OCEANIC HEAT IN SEA ICE LOSS IN THE NEW ARCTIC"

"An analysis by Kwok et al. (2013) of
33 years of satellite-derived ice motion (1982-2009) found the largest spatially averaged trends in drift speeds between 2001 and 2009 in both winter: (+23.6% per decade) and summer (+17.7% per decade). These trends could not be explained by changes in wind speeds; instead, they coincide with the years of rapid ice thinning and the reduction in multiyear sea ice coverage during 2001-2 009, suggesting a response to changes in ice mechanics including reduced resistance to deformation."

They also find that:

"Lower-end estimates indicate that the recent AW warming episode could have contributed up to 150–200 km3 of sea ice melt per year, which would constitute about 20% of the total 900 km3/yr negative trend in sea ice volume since 2004 (Ivanov et al. 2012)."

And:

"Observations of transports through Bering Strait showed a doubling of heat flux from 2001 through 2007, enough to explain a third of 2007 summer Arctic ice volume loss (Woodgate et al. 2010)."

Which brings to mind Bitz et al "Future abrupt reductions in the summer Arctic sea ice", which I referred to on another page in this blog's comments recently.

"Over the 20th and 21st centuries, this heat transport exhibits a gradual upward trend overlaid by periods of rapid increase
(Figure 3a). These rapid ‘‘pulse-like’’ events lead changes in the sea ice by 1–2 years, which is evident from the timeseries of detrended heat transport and detrended ice thickness (Figure 3b). For Run 1, a rapid increase in heat transport starts around year 2020, modifies the ice growth/
melt rates, and triggers positive feedbacks that then accelerate the ice retreat."

How much was 2007 preciptated by ocean heat, and is there a role for declining ocean heat in the recent volume increase?? I ask because at present I don't know.

But ocean heat is not the only thing, going back to Carmac et al.

"With summer discharge temperatures of order 15degC, the associated heat flux is 3 TW averaged over an entire year, with a peak of 12 TW in June and July (Whitefield et al. 2015). On an annual average, this heat input is 10% of the sum of the AW and PW inflows. However, the strong seasonal cycle of river inputs and the dominance of discharge into the coastal domain of shallow shelf seas suggest that these inputs may have disproportionately large impacts on their proximate shelves through their effects on melting ice and affecting local albedo (Dean et al. 1994). The resulting increase in summer stratification will result in more heat being trapped in shallow upper layers, delaying ice formation in autumn."

With the warming over Siberia in spring and early melt, what does this mean for the spring melt?

I have blogged last year:
http://dosbat.blogspot.co.uk/2014/08/june-sea-ice-area-and-melt-ponding.html
And found that 62% of the enhanced extent loss within the Arctic Ocean in 2007 and 2010 to 2013 is from ice concentration between 0.8 and 0.4. That's at the edges of the pack - near where the rivers discharge.

So even if ocean heat flux is declining with a possible decline in the AMO (and I am far from convinced regards both of those). River heat flux hits its peak as ice is being primed for the rest of the season.

It's worth noting that Carmac et al refer to the New Arctic: "The Arctic has, as Jeffries et al. (2013) noted, entered a "new normal" state, with multiple
impacts on oceanic, atmospheric and terrestrial systems (Bhatt et al. 2014)."

Is anyone else impatient to see what the rest of this decade will bring?

[Neven]

Nice eclectic overview, Chris. :-)

Torge Martin's talk was indeed about how the increase in drift speed isn't caused by wind speeds, but by thinning.

With regards to river discharge, I wrote an overview back in 2011 on that: A warm river runs through it.

It's interesting to re-read the part about the Mackenzie River, and see the high temps all along it in Northwestern Canada, and the current retreat of the ice edge in the Beaufort Sea, although I vaguely remember reading last year that paradoxically a plug of fast ice in the Mackenzie Delta actually helps build up a lot of warm water, that, when released, causes massive warming of that part of the Beaufort.

But anyway, something I thought about today, and am reminded of again reading your comment, is that there are three big unknowns in the Arctic that form the lion's share of long-term unpredictability:

1) Ice thickness
2) Ocean heat flux
3) Melt pond cover fraction

And of course, atmospheric conditions, but weather will always be weather, so that doesn't count as an unknown. ;-)

So even if ocean heat flux is declining with a possible decline in the AMO (and I am far from convinced regards both of those).

That's also something I think about quite often (but not long, as I quickly realize I just don't know anything about these things), and the possible influence of the Ridiculously Resilient Ridge in the North Pacific. Because both 2013 and 2014 were similar in that they suffered more or less unchanging weather conditions during the melting season, with 2013 being cold and cloudy, and 2014 slightly less cold and cloudy, but with relatively little wind (and thus movement).

If atmospheric blocking plays a role in the way the melting season develops, I don't know if I want to see what happens when the opposite of 2013 and 2014 happens (in other words: 2007).

So yes, I'm impatient to see what the rest of the decade will bring. At the same time I don't want to know. It's perverse, really. ;-)

[Simon]

Great report, Neven, thanks for putting so much energy into covering all these topics. Maybe it's worth linking this post from the "Best of Blog" sidebar for all the useful links it contains? I'll definitely have to keep dipping back in over the summer.

Is anyone else impatient to see what the rest of this decade will bring?

:-)

[LRC]

Neven: I do understand your position on weather, but because of the blocking patterns, the resultings troughs and ridges, are we not starting to get season long weather patterns that in effect determine the outcome of the melt from the beginning of the melt/freezing season from the start?
Granted if you just look at a day to day look there is still great variability, but over all are we not starting to see predominate patterns over the season? You mentioned summers of 2013 and 2014 as a case, but there is also the case of last winter where the ridge and trough basically stood in one spot over North America for almost 3 months and that pattern sent storm after storm deep into the Arctic Ocean for most of that time greatly affecting the ability for that area to freeze at all.
I guess what I am trying to say is that have we come to a point where once a particular weather pattern is being established we can almost predict what the melt season will end up as, just because weather patterns themselves are becoming so long lasting?

"Is anyone else impatient to see what the rest of this decade will bring?"
Of two minds on that. Like how you get fixated on watching a train wreck when it is occurring, and then the great sadness of what great loss we have witnessed. On top of that when and where the next collapse will happen.

[Chris Reynolds]

Neven,

Weather certainly doesn't count as an unkown, nor should it be relied upon in predicting record lows (I've seen that done). AFAIK nobody can predict summer weather from as early as April.

I asked Dr Zhang recently if there's any PIOMAS based research into ocean heat flux impact on ice. He suggested these three papers, while saying they hadn't done much on it.

http://psc.apl.washington.edu/zhang/Pubs/zhang_etal_PW2009.pdf
http://psc.apl.washington.edu/zhang/Pubs/Steele_etal_2009JC005849.pdf
http://psc.apl.washington.edu/zhang/Pubs/Steele_etal_2010JC006803.pdf

I've already read the first of those links but was unaware of the second and third papers. The second is interesting. "Mechanisms of summertime upper Arctic Ocean warming and the effect on sea ice melt." Steele, Zhang & Ermold.

I've not had time to properly read this, just read it this lunchtime. However top melt of the ice due to atmospheric warming is strongest earlier in the summer, with bottom melt taking over as the major factor later in the summer. Overall bottom melt is the biggest factor through the whole summer, accounting for 2/3 of thickness loss. But bottom melt is strongest near the ice edge, being largely driven by the heat from warming open waters. It seems that heat from deeper in the ocean plays a relatively minor role.

This backs up the importance of:

1) Melt ponding in early summer (insolation peaks in June).

2) River heat opening open waters along the coast and giving a kick start to the ice albedo feedback at the edges.* The earlier we see open water (insolation peaks in June) the stronger ocean warming will be. e.g. the Laptev 'bite' last year. But does PIOMAS get fed data regarding river temperatures? I don't think this is explicit!

3) The more early open water, the more it can warm, the more that warmth can drive bottom melt, the stronger the thinning an creation of open water can proceed into late summer. (bottom melt is the biggest factor in late summer volume loss)

*I've been looking into river temperatures. Mainly from Siberia, since that is where the strongest summer recession is happening. However the best dataset I have found ArcticGRO and it is to sparse and too short to be of much use.
http://www.arcticgreatrivers.org/
It might be worth looking at extent in regions (I'm rambling again...). The ESS doesn't lose extent in June, it has only the Kolyma flowing into i, which has a relatively small catchment area. And if I recall correctly that flows out behind the landfast ice, so may not manifest itself as an extent decline, rather a thinning.

Looking at Laptev and Kara, they're the outlet seas for three rivers with massive catchments, Lena, Yenisey, & Ob.
http://www.arcticgreatrivers.org/images/watershedmap.jpg

Using the regions off that map I have calculated a grid box and obtained NCEP/NCAR temperatures for that region, noted in the graphic below. They're graphed together.
https://farm8.staticflickr.com/7662/17126559198_a679e285df_o.png

Might be worth digging into.

It brings to mind the talk of algal blooms off Siberia I seem to recall from discussions of the last few melt seasons. I should have paid more attention but they didn't interest me at the time. Have people been noting algal blooms in newly open water in Laptev and Kara as early as June? Could be all that fresh river water forming a bouyant warm cap over the ocean - probably already generally accepted I just wasn't paying attention.

LRC,

You know me, I'm just into it because I find it all so fascinating. At the firm where I work everybody drives and has holidays abroad, except me. Their plan to combat climate change seems to be 'Après nous, le déluge'. ;)

[Jim Hunt]

Chris - Re algal blooms, there's generally plenty of clouds obscuring the view, but what do you make of this from June 20th last year in the Laptev Sea?

http://1.usa.gov/1AicCm0

[Adam Ash]

Re Methane...

This just in from off the coast of New Zealand...

'...Surprisingly, the team discovered that every area of carbonate rock and every fault seen on the seafloor was expelling gas, and in total, they calculated there were near to 766 individual gas flares within the area.

"That was really way beyond expectations," Dr Mountjoy told the Herald tonight.

"Flares can occur in these kind of environments but seeing them in that kind of density is highly unusual - and we've certainly found nothing like it in New Zealand before."'

http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11441247

[Remko Kampen]

Terrible news, Arctic researchers Philip de Roo and Marc Cornelissen - http://coldfacts.org/expeditions - probably drowned.

[Sam]

Very sad news indeed.

http://www.explorersweb.com/polar/news.php?url=polar-skiers-missing-on-the-arctic-ice_1430393292

[Chris Reynolds]

Thanks Jim,

That's the sort of thing I was thinking of. But it's not really close to a large river, at least 100 miles from the estuary of the river to the right on that image. The Lena delta is south east of that location.

Remko, Sam,

I'm sure everbody's sympathy is with their families. I hope the recovery operation can at least recover their dog alive.

[Susan Anderson]

It might be a cautionary tale about how the ice in changing ... anyway, a moment of heartfelt sympathy to the brave ones who go out and look.