While trying to find out why the TOPAZ forecast maps were no longer updated I came into contact with Dr Laurent Bertino, a research director at the Nansen Environmental and Remote Sensing Center who is responsible for the TOPAZ system that is delivered as part of the MyOcean project.
Not only did he direct me to the new dynamic viewer that contains the images of sea ice thickness (and much more), but he also consented in my request for a short interview.
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N: Laurent Bertino, thanks for this interview. What is it you do exactly over at the Nansen Environmental and Remote Sensing Center?
LB: The Nansen Center is a private research foundation (~60 persons) with various activities in climate research, remote sensing, modeling and data assimilation, the latter two are the activities I am personally involved in. See our fresh new web-site for more information: http://www.nersc.no/
What we call "data assimilation" is working out the combination of numerical model forecast and observations that makes a forecast most accurate. This is a field at the crossroads of mathematics, statistics, physics and computer sciences.
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N: There are several discrepancies between the sea ice thickness models. I discussed them in a recent blog post and follow-up. PIPS 2.0 for instance is showing a lot more thick ice than TOPAZ. What are your thoughts on this?
LB: The ice thickness in our models is not constrained by observations in any way. So it evolves over years of simulations depending on aspects such as: the atmospheric data used, the ice thermodynamic model, the ocean surface temperature and salinity ...
I do not know enough of the PIPS system to explain the difference. There are anyway very few ground truth observations in the middle of the ice pack and most of the in situ data is only available in delayed mode. So we know that the system was doing OK in reanalysis mode (between 2005 and 2007) but I would not be surprised if the ice thickness were half too thin in the forecast system, not to mention the uncertainties in the trend.
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N: How important is the CryoSat-2 data to you and your team? Do you await its results as eagerly as we do?
LB: Yes. NERSC has carried out impact studies of CryoSat data almost 10 years ago and developed the assimilation method in order to be ready to include them in the forecast system on the fly, as soon as the data is available. So now just imagine how eager we are...
NERSC follows CryoSat closely, with Stein Sandven being member of the ESA CryoSat science team and with one PhD student working on the calibration of the data.
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N: Arctic sea ice extent has been on a downward trend for a few decades now. Do you have any expectations on what will happen in the short-term and medium-term?
LB: Not much. It is a safer bet to say "downwards" but I have nothing precise to say on the short term and medium term (say, less than 10 years) because the sea ice extent is very sensitive to local weather conditions, which are hard to predict. You can check this WCRP news.
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N: Final question. Your name sounds French (and a bit Italian too). Do you speak Norwegian, and if so, how on Earth did you manage as a Frenchman? Is it possible for you to buy Camembert and Mâcon over there in Oslo?
LB: Yes, I am a Frenchman, with 100% Italian origins, living in Norway for the last 9 years. This may sound like a mess, but modern Norwegians eat more pizzas than Italians and they serve different things for "Caffè latte" and "Café au lait", so consistency is no longer an issue, I am afraid. Real Camembert and Dijon mustard have made their appearance on the shelves of supermarkets about 6 years ago and the fjords have never been more beautiful since that day.
I still need to bring my own Marsala Mandorla in my luggage, though. Seriously, Bergen is a great place to be if you are interested in data assimilation, oceanography, skiing, hiking, music, and if you don't mind short summers. Oslo has somewhat less charm.
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I don't know about you people, but those final remarks have given me an appetite. Before rushing off to the kitchen to finish my fish broth, I'd like to thank Dr Laurent Bertino of NERSC one more time for this interview.
Nice interview, Neven!
Solid information, with a personal touch. Enjoyed it very much.
It would be hard to tar Dr. Bertolino with the 'alarmist' brush, wouldn't it? "It is a safer bet to say 'downwards. . .'"
Sounds almost like British dry humor, as I think about that comment.
Posted by: Kevin McKinney | May 12, 2011 at 17:01
A BBC article. Makes you want to give up.
http://news.bbc.co.uk/1/hi/programmes/newsnight/9483790.stm
Posted by: Derek | May 12, 2011 at 17:58
"I do not know enough of the PIPS system to explain the difference."
Very diplomatic :-)
I'm glad they are following CryoSat closely, and working on the calibration already. If this summer melt season passes without *somebody* presenting some CryoSat thickness data, I will be very disappointed.
Thanks for the interview, Neven. And that dynamic viewer looks interesting...
Posted by: Anu | May 12, 2011 at 19:33
Hi everybody!
This is my first post here. I found an interesting news today about actual ice thickness measurements on the german site of Alfred Wegener Institute. They just completed their 6-week expedition over the Arctic with the Polar 5 research plane. At the moment the news is only in German, but normaly they translate it in english soon. I found some of the information in english on a site, that seems to be a denier site, but the information from the expedition in the first part of the arcticle there is better than no translation.
arcticle of Alfred-Wegener-Institut
Chris K.
Posted by: www.google.com/accounts/o8/id?id=AItOawkpUaD_uYjZAIrhpA6AA5KyEs-CSoL4zlM | May 12, 2011 at 21:55
Hi Chris K. and welcome.
I hope you don't mind, but I have deleted the link to the site with the English translation, as I don't want to attract people who will probably spoil the atmosphere here. Next time you can also use the last SIE update to link to news articles, as it is a bit off-topic here.
In fact, it fits in perfectly with this blog post I wrote two days back. See the last bit on 'circumstantial evidence' where I actually mention some AWI results from last year. I'll write an addendum tomorrow.
So thanks for letting us know!
Posted by: Neven | May 12, 2011 at 22:00
Hi Neven,
you're completely right, my post fits better to your other blog post, sorry for my confusion. And I understand your concerns about the english link, it's really better not to attract the wrong people. First I thought my browser has eaten the second link, but fortunately I read your post before I posted it again.
Posted by: www.google.com/accounts/o8/id?id=AItOawkpUaD_uYjZAIrhpA6AA5KyEs-CSoL4zlM | May 12, 2011 at 22:24
Brilliant interwiew Neven, but I must say you try to make us "Vikings" in the North look rather stereotype...
I spent 2 years in Bergen as a student, and if I had continued my study I might today have been "onboard" Bertolinos team! But I choose another direction...
Though I find his description of Bergen/Norway contra Oslo correct, but just imagine living inside a deep, deep fjord/valley with "no" sun for 6 months?! So most people live close to Oslo and dream of the "true Norway"!
But Neven, if you after you have stilled your most basic of Maslows needs (or any other!) consider paying Norway a visit, I might hang along just for the fun and perhaps for a glimpse of a glacier! It's so much to see and so little time to spend doing so....
Posted by: Christoffer Ladstein | May 12, 2011 at 23:23
Neven, I wonder if you can confirm with Dr. Bertino if they have employed NASA IceSat level 3 data in any way, such as validating TOPAZ thickness estimates? Obviously, it is the goodness-of-fit and estimated error range we want.
Posted by: Artful Dodger | May 12, 2011 at 23:47
Also, ask him when they expect to have those CryoSat results. Then we could all stop wondering!
Posted by: Steve Bloom | May 16, 2011 at 09:49