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Topics - Andreas T

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Arctic Background / Research Icebreaker Polarstern
« on: June 09, 2017, 09:31:09 PM »
As suggested on another thread I'm starting this to have a dedicated place for information on the activities of this German research vessel which visits both arctic and antarctic waters.

There is the Polarstern blog: some entries are only available in german it seems.
worth looking at photos nevertheless

position can be found here

Arctic Background / Interpretation of satellite images
« on: May 21, 2017, 08:40:47 PM »
As suggested by shared Humanity:
I've never posted these kinds of detailed images of the ice and, quite frankly, don't know how to do this but I think this community should try to do this across the entire basin this year. Perhaps each of us could take a sea or area of our choice and post these with analysis for the community.

Can somebody here tell me how to do this? Please keep in mind that I am old and technically challenged. Imagine having to teach your grandmother over the phone and we will be fine.

There will be some fascinating threads to follow this melt season but this is one of the most important. Lets use this thread, as a group, to increase our level of understanding, both for the community and visitors. If we do this every melt season from now on, we will be conducting research, I believe, that is not currently being done, a detailed, live analysis of the behavior of weak ice under various forces, sun, storms, waves and wind etc.

(Neven) Could you post detailed instructions here to let various regulars pick this up and run with it? Assume we are all grandmothers even though some of us are computer wiz's.

Arctic Background / Quantifying ice drift
« on: April 18, 2017, 05:20:42 PM »
I have experimented with tracking floes in AMSR images on Worldview
squashing the colour scale to 155 / 270K I have produced this animation with an attempt at measuring area exported through Fram strait in the 30 days from 2. March to 1. April
The northern edge of the marked area is at 83.8N and the area exported through Fram amounts to 178 ,400 km2
I marked another area north of Spitsbergen which shrunk by about 70,000 km2
what that means is another question, some ice cover will have will have been compacted some could have melted from below due to the warm current into this area, some will have been exported on the eastern side of Spitsbergen.

Arctic sea ice / The 2016/2017 freezing season
« on: July 20, 2016, 02:07:49 PM »
prompted  by a discussion on the melting season thread I have started this a more than a month earlier than last year.
I hope nobody thinks this is to signify an early start to the refreeze, I don't believe in spells, jinxes and that sort of "magical" thinking.
It is interesting by the way to have a look at the start of last years thread with the benefit of hindsight. We are trying to learn from our observations and wish to derive an understanding which lets us detect signs of what the future will bring. I have learned that there is huge complexity in the melting and freezing of arctic sea ice and that makes me cautious with predictions. But we are all amateurs here (despite the expertise some people bring here from related areas or by doing a lot of research as a leisure activity) and that give us the benefit of not having to worry too much about making a guess and seeing something it turn out very differently. Trying to make that guess can make us work harder at understanding and being critical of ourselves as of others. So lets see how much what we have learned so far can help us in our guessing and where we need to learn more.

Arctic Background / interpretation of MODIS imagery
« on: June 05, 2016, 01:27:46 AM »
I feel I need to learn more about interpreting the imagery outside the visible spectrum and  prompted by a question by seaicesailor I have been reading a bit more on the topic. I hope this could be a good place to collect observations which could help us and others who want to make better use of this resource.

To start things off here is a comparison of visible and 7-2-1 bands which shows the ability of 7-2-1 images to distinguish between grey shades due to water on ice (blue arrow) and grey shades due to transparent (thin) ice showing dark water under the ice (red arrow)

Arctic Background / AMSR2 on Worldview
« on: March 29, 2016, 12:27:24 PM »
I recently spotted that  these channels are available on Worldview:
 Sea Ice Brightness Temperature 6km 89H GCOM-W1 / AMSR2
as well as the .... 89V .... version
I am trying to learn what it tells me and how it can be useful.
What is great on Worldview is of course how easy it is to switch between aligned images from visible  to IR and AMSR, and to flick from one date to the next for comparison.
I have attached some views of Wrangel island as an example. Coastline overlay has to be moved to the top to show in AMSR, it took me a while to figure that out   ::)
The resolution of AMSR is clearly lower than IR which is lower than visible as one would expect.
Leads show up warmer in both IR and AMSR and surface temperature changes due to weather show up in both too. But in IR view of the surface is obscured by cloud or fog. AMSR also shows patterns in the ice which persist over long times which seem to indicate different thickness. These areas cool more rapidly and warm up more slowly than others.
But this is me guessing and drawing conclusions from comparing these images. Does anyone have more information or can point me to sources.
This could be a very useful tool for us but it seems it is not straightforward to interpret  it.

Arctic sea ice / Svalbard
« on: March 22, 2016, 09:40:58 AM »
Of course people usually like to post in the main thread where most of the conversation happens, but links etc which are interesting for follow up later get easily lost in fast filling threads. So I'd like to start another regional thread on Svalbard which has some very good resources in weather stations and webcams.
the japanese NIPR also links to two webcams at Ny Alesund

this is a clickable map which gives weather forecasts for any point on the map, neat for getting wind, air and water temperature (modelled I guess) in one place

to make these links easy to find I am collecting them in the top post:
current ice area and monthly climatology:
ice charts etc from NMI:

Arctic sea ice / Siberian Arctic coast
« on: June 08, 2014, 07:47:07 PM »
I thought it would be nice to have a place to come back to and see details of developments along the Siberian coast similar to the threads on Greenlands glaciers. I will try to link to some of the recent posts here which show the Lena delta with interesting comparisons to previous years.

Arctic Background / Radiative balance in the Arctic
« on: February 15, 2014, 05:15:15 PM »
This is a topic which comes up in other threads (naturally, since we are talking about the consequences of radiative imbalance) but then I can't remember where I read some useful information or discussion so I'll try to make this a collection of links and info on this topic. Help from others appreciated.
ktonine brought up the topic of OLR  [Edit, per request: OLR = Outgoing Longwave (infra-red) Radiation] recently but I can't find the graphs he showed.
IIRC it was surface OLR plotted like this:

Arctic Background / records of past climate in arctic
« on: October 25, 2013, 09:27:48 PM »
I could not find a place for this, so started a new thread. If there is a better place, let me know.
Prompted be a comment on the forum blog I found these accessible articles:
On age of Baffin island ice caps:
On ice core record for temp proxy on Severnaya Zemlya

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