This is Neven's Typepad Profile.
Join Typepad and start following Neven's activity
Join Now!
Already a member? Sign In
Recent Activity
Here's a guest blog that was sent to me by Sam Hayes, a PhD student from Northumbria University and regular commenter at the Arctic Sea Ice Forum. For his studies Sam is out on a research expedition in the Arctic Circle. In this first guest blog Sam describes his impressions... Continue reading
Posted 3 days ago at Arctic Sea Ice
2) PIOMAS only updates monthly. Is there a volume estimate that updates daily like the NSIDC Extent graph? Not in numbers, but there are two thickness maps on the ASIG (scroll down to the volume category). DMI and ACNFS. And this melting season PIOMAS is also updated mid-month, after special request. The numbers are posted on the ASIF (not in yet for this mid-August). But that's complete guesswork without previous sea ice concentration graphs to compare against. On the ASIG there are also Concentration maps pages that allows you to compare the current Uni Bremen SIC map with those of previous years since 2005. Check it out, as it takes a lot of time to update those pages.
Toggle Commented 5 days ago on PIOMAS August 2017 at Arctic Sea Ice
The PIOMAS updates are updates of sorts, but mostly restricted to all things Arctic. Please, don't veer off every which way. At some point I'm just going to block you guys, because snipping becomes too much work (I have a forum to moderate as well).
Toggle Commented 7 days ago on PIOMAS August 2017 at Arctic Sea Ice
Thanks, Rob. I'll be going on a holiday in two weeks, and will hopefully have some time there to do some proper comparisons. I find it fascinating to see how low volume makes conventional wisdom (with regards to the influence of weather conditions on extent decrease) partially moot. I remember noticing it for the first time in 2012.
Toggle Commented Aug 11, 2017 on PIOMAS August 2017 at Arctic Sea Ice
Okay, so I've read everything, and this is a clear 'starts with a misunderstanding and then gets out of hand' situation. Bill wrote an ambiguously worded sentence: "Wonder if there is any significant clathrate contribution?" He later elucidated that he meant whether the fires would disturb the methane stuff in the permafrost, rather than the methane stuff contributing to the fires. By then it was already about the dreaded word 'clathrate'. And then the word 'piss' was thrown about as well. It's clear that these two terms don't mix well. ;-) Anyway, it's much ado about nothing. We can let it go, or we can fight some more, never to return again to this corner of the Internet. In the end it doesn't matter all that much, except that I love you all, of course. :-)
Everyone, cool down, please. I haven't read the whole exchange, because I usually tune out once it gets too long (there's a lot of text coming my way from the ASIF). I just look at the names involved. In this case, I see Susan, Dan, Bill and Jim, and go: okay, all reasonable, nice people, no problems there, even though it's about the dreaded methane clathrates. I'll go and re-read, as I love juicy Internet fights, but I'm sure most of it is a misunderstanding. Like Susan says, we're all on the same side here.
And Bob's your uncle. ;-)
According to the NOAA-ESRL measurements 2017 has been colder than 2013 and 2014 in both the Arctic and the high Arctic (80N+) over most of the May - Jul period and on average. Wow, I'm actually quite surprised by this. As I write in this blog post: "What's interesting is that despite all these weeks of ideal weather for ice retention (at least as far as sea level pressure goes, temperatures haven't been as low as 2013 or 2014)" It seems I've been wrong about this, and I must admit it was based on my subjective observations (and in my memory 2013 and 2014 were pretty cold). I didn't actually check the numbers. I'm going to have to start regularly doing that. It's too bad Andrew Slater is no longer around to make those great monthly temperature rankings. So, despite being as cloudy and cold as 2013/2014, 2017 is still digging low (JAXA shows two century breaks). That's simply amazing.
Toggle Commented Aug 9, 2017 on PIOMAS August 2017 at Arctic Sea Ice
Don't mention it, Daniel. And good to see you again.
Toggle Commented Aug 8, 2017 on PIOMAS August 2017 at Arctic Sea Ice
There are still a couple of days left to vote on the outcome of the melting season. The poll for NSIDC September average extent or monthly minimum (which is used for the SIPN Sea Ice Outlook) can be found here, and the poll for JAXA sea ice extent daily minimum can be found here.
Toggle Commented Aug 7, 2017 on PIOMAS August 2017 at Arctic Sea Ice
Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: Given the ideal weather for ice retention during July, it is no surprise that July 2017 showed the... Continue reading
Posted Aug 6, 2017 at Arctic Sea Ice
Mid-month PIOMAS update over on the ASIF.
Toggle Commented Jul 18, 2017 on PIOMAS July 2017 at Arctic Sea Ice
I would say it's because there's less 'easy ice' on the periphery.
Toggle Commented Jul 13, 2017 on PIOMAS July 2017 at Arctic Sea Ice
I don't know, Bill. What would Van Gogh say? :-P
Toggle Commented Jul 8, 2017 on Melting momentum: May 2017 at Arctic Sea Ice
suggests still 5.41 M km^2 for September 2017 Wow, Rob, that's even higher than David Schröder's 5.1 (4.6 to 5.6) million km2. Higher than every ear since 2006, and higher even than rebound years 2013 and 2014. But this year so far hasn't been nearly as cold /cyclonic as 2013 or 2014, and according to PIOMAS volume is still lowest on record, after the mildest winter on record. And then there's all that early, open water on the Siberian side of the Arctic and SSTs starting to respond strongly (not that far behind 2012 and 2016). This year appears to be a serious test for my (mostly land-snow cover based) prediction method. Yes, it's a test for the influence of snow, and its potential as a negative feedback.
Toggle Commented Jul 7, 2017 on Melting momentum: May 2017 at Arctic Sea Ice
Which is also one of the reasons I'm on a sabbatical (except for these monthly PIOMAS updates and when there's something I cannot not write about). But the 'problem' isn't that my heart isn't in it anymore, it's that my heart wants to do more than just describe the spectacle of Arctic sea ice loss (which inevitably becomes formulaic, as there are only so many ways you can describe this process).
Toggle Commented Jul 7, 2017 on PIOMAS July 2017 at Arctic Sea Ice
Dr David Schröder from the University of Reading has sent me the modelled melt pond distribution maps for June. I've posted them as well as my thoughts (and weather forecasts for the next week) on the 2017 melting season thread, over on the ASIF. Dr Schröder writes: Based on melt pond fraction in May+June we predict a mean 2017 September ice extent of 5.1 (4.6 to 5.6) mill km2 (within the range observed during last 4 years). The likehood for a new record minimum is below 1% [my emphasis; N.]. While melt pond fraction has been above 2006-2015 mean values in the western parts of the Arctic, less ponding and melting occurred in the eastern part (see anomaly figures attached) due to more snow and relatively cold temperatures. In the past the regions - where melt pond fraction is low in 2017 - were more important for September ice extent (local pond fraction in areas enclosed by thick contour line show a negative correlation with mean September ice extent of R < -0.3) than e.g. the Beaufort Sea. Consequently, we predict the September ice extent to be quite large in spite of the lowest Arctic ice volume in recent months.
Toggle Commented Jul 6, 2017 on PIOMAS July 2017 at Arctic Sea Ice
Another month has passed and so here is the updated Arctic sea ice volume graph as calculated by the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) at the Polar Science Center: Last month we finally received some good news from PIOMAS, and the good news continues this month. With... Continue reading
Posted Jul 4, 2017 at Arctic Sea Ice
Thanks, Jim. And next week I'll be showing how both these forecasts fared (for June 24-29), when compared to what happened from day to day. It's high time I learned some more about weather forecasting. ;-)
Toggle Commented Jun 23, 2017 on Melting momentum: May 2017 at Arctic Sea Ice
You should be able to find it on the Stoat's blog, D.
Thanks, John. Since 2012, we haven't seen a melting season with a high amount of preconditioning through melt ponds. Maybe it's a sign of some negative feedback kicking in. Last year still went low despite this lack of melting momentum, and this year the ice is supposedly thinner than it has been (although the gap between 2017 and 2012 has rapidly disappeared, according to the latest information on the ASIF). And there's already a substantial amount of open water in the Beaufort, Chukchi, East Siberian and Laptev Seas. So, while there's a lack of melt pond formation, it may be that the influence thereof is becoming less of a factor. In this sense, and as always, it will be interesting to see how things play out this year. Of course, once we get a year that is low volume-wise and heavy preconditioning at the start of the melting season...
Toggle Commented Jun 19, 2017 on Melting momentum: May 2017 at Arctic Sea Ice
Here's a blog post I just read on Andreas Muenchow's Icy Seas blog: Is Petermann Gletscher Breaking Apart this Summer? I am disturbed by new ocean data from Greenland every morning before breakfast these days. In 2015 we built a station that probes the ocean below Petermann Gletscher every hour.... Continue reading
Posted Jun 16, 2017 at Arctic Sea Ice
Another factor pointing to a possible rebound: concentration is looking better than the same time last year: Paddy, I think that this is another indication of low melt ponding. Normally, when the ice starts to turn bluish, that's also the start of large swathes of green/yellow/pink on the Uni Bremen SIC map. Because these swathes do not stay in the same place (most of the time), they're not really an indication sea ice concentration (ie open water vs ice), but rather of melt ponding.
Toggle Commented Jun 13, 2017 on Melting momentum: May 2017 at Arctic Sea Ice
I'm tempted to think that melt ponding may be less critical this year, because that thinner ice may be going no matter what... That could very well be true, Robert. And I'm definitely not saying that this is putting a spanner in the works of a new record. Let me put it this way: If there was extensive melt ponding going on right now, building up lots of melting momentum for July and August, I'd be willing to bet (big) money that this year all records will be broken. As it is, everything is still open. Melt ponding could still get going, or like you say, it may not matter all that much because so much of the ice is thin. One other thing speaking for 2017 staying a very serious contender, is the current weather forecast. Although the spell of (relatively high) high pressure is now coming to an end, it's not like low pressure is taking over. In fact, it seems a weak dipole is going to form over the coming week. SSTs are also on the rise. I'm waiting for June 15th to come around, as I have DMI SST anomaly maps for that date from 2012 and 2016.
Toggle Commented Jun 13, 2017 on Melting momentum: May 2017 at Arctic Sea Ice
Here's a quick blog post, which is mostly a copy of a comment I just wrote on the 2017 melting season thread on the Arctic Sea Ice Forum. For those who want to know more about what melting momentum means, read these blog posts from 2015 and 2016. I've been... Continue reading
Posted Jun 12, 2017 at Arctic Sea Ice