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!