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Arctic sea ice / Re: MOSAiC news
« on: December 10, 2019, 01:43:33 PM »
Oops, should've specified. I was looking at this dot on the left. I assumed the one moving due north was the PS. I was trying to get both in the view
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RAMMB-SLIDER not updating.
Yeah, very cool indeed. It's from NASA Worldview, Kevin.You would be able to see the lab in the RAMMB, but they haven't updated the day night band, nor the geocolor since the day we located Polarstern. Weird, as its the only bands not updating...
It's amazing what you can see via satellite. We found the Oden via Sentinel. JayW recently spotted the Polarstern lights via RAMMB-SLIDER with the JPSS satellite.
Link >> https://worldview.earthdata.nasa.gov/?v=-354648.7354030085,-835142.1726658549,-162769.01034700847,-728372.445177855&p=arctic&t=2019-10-28-T20%3A00%3A00Z&l=VIIRS_SNPP_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor(hidden),MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),Reference_Features(hidden),Reference_Labels,Graticule(hidden),VIIRS_SNPP_Thermal_Anomalies_375m_Day(hidden),MODIS_Aqua_Brightness_Temp_Band31_Day(hidden),AMSRU2_Sea_Ice_Brightness_Temp_89H(hidden),AMSRU2_Sea_Ice_Brightness_Temp_89V(hidden),VIIRS_SNPP_DayNightBand_ENCC,MODIS_Terra_Sea_Ice(hidden),Coastlines(hidden),MODIS_Aqua_Sea_Ice(hidden),AMSRU2_Sea_Ice_Concentration_12km(hidden),MODIS_Terra_Ice_Surface_Temp_Day(hidden),MODIS_Aqua_Ice_Surface_Temp_Day(hidden),SSMIS_Sea_Ice_Concentration(hidden),SSMIS_Sea_Ice_Concentration_Snow_Extent(hidden),VIIRS_SNPP_Brightness_Temp_BandI5_Night(hidden),VIIRS_SNPP_Brightness_Temp_BandI5_Day(hidden)
It seems to me that the stall these last few weeks compared to 2012 is mostly due to dispersion. Late August 2012 saw the inner ice a lot more compacted, especially towards the Pacific side.
Dispersion obviously causes higher extent, but then area seems to be stalling as well. But how reliable are the area measurements, particularly with highly dispersed ice under cloudy skies? I don't know.
But it does seem to me that a good "compaction event" on the Pacific side could lose several 100 k's without any extra melt.
And that leads me to wonder if the difference between 2012 and now lies not so much in how much ice has melted as in how it is distributed - admittedly, 2012 had less ice, but the difference probably wasn't nowhere as big as the current extent numbers indicate.
Mobile, isn't it?Sure seems like it reacts quickly to winds, and it's marching towards the Atlantic, as it has for the most part.
Heavy action in Jøkelbugt (Glacier Bay) notice how the calved icebergs in front or Zachariae Isstrøm are sucked away from the sea ice movements further out:
Better seen here:
What is the reason that ice, that still linger in Hudson Bay, my intuition tells me, that it should he have melted out by now, which it clearly hasn’t ...Are you sure it's there? (I can't look at Worldview at the moment).
Is this due to lack of mixing/heat transfer, or are we looking at the last of thicker ice, from rindging or som other ice thickening process ?
If it is, then surely it's the remains of extremely thick ice from ridging. There's enough heat there to melt normal first year ice.
Yes, mine is shorter. rammb eats up my broadband volume. Thanks for the links. I definitely couldn't go searching for these.
The RAMMB slider is awesome. The public access is total.
I wish all science was like this.
I can't see you finding anything like slider anywhere else. Three satelliites in geostationary orbit giving you everything all the time.
A glimpse through the clouds gave a peak at the Prince Gustav Adolph Sea today.Just a silly question: Why does the coastline appear twice? Is this ebb/flood change area or the borders of usually fast ice?
This is why i prefer other sat-img-services, depending on the zoom level this can at time cover too many pixels and zooming in is not always an option if one wants to see the big picture.
This is personal preference whatever.
I think it's simply imperfect overlay of coastlines, why there are two, I haven't a clue. I just know the lines don't exactly match the coasts. I often toggle then off, but when clouds are present it helps. I'd also note that the rammb is still in beta I believe. As blumenkraft mentioned, one can always send feedback and suggestions.A glimpse through the clouds gave a peak at the Prince Gustav Adolph Sea today.Just a silly question: Why does the coastline appear twice? Is this ebb/flood change area or the borders of usually fast ice?
Similar to the one discussed earlier off Svalbard.Yep, that one is still making it's daily appearance as well. I misspoke when I initially posted that one and said it was at 80°N , 5°E, I had the latitude line confused on the slider, it's actually 82.5°N, 5°E.
Wind/ cloud effects..
I think it might be both winds and melt water pushing in. To me, it looks like you can see sediment rich water moving west through the channel.Well the problem with meltwater is that I'm not at all sure that there could be enough of it to cause such a strong movement in a (presumably) deep fjord. But you are right, there is discoloration that follows the ice retreat, possibly just reflecting a change in temperature?
Meltwater would be brown, but the discoloration seems more bluish. Perhaps an extremly rapid spread of algae? I don't know.QuoteHere is an interesting feature at about 80°N, 5°W.Very interesting, with those circular movements. Is it the wind doing that, or ocean currents? This Rammb slider thing is really showing us details that I for one didn't know existed.
This is M8 band showing the Lincoln Sea at Nares Strait.
This darkening coexistent with the wind pattern on this day.
Doesn't look like ice condition change to me.
Jay, can you comment on what you are seeing here?
Imagej default rgb and cropped high contrast (clahe 127,4.1)
Is that a plane flying over? No, probably swath edges.
This was an interesting spot yesterday. I posted about it in the Petermann thread:
I'm pretty sure it rained there because we obviously had precipitation. On the ice sheet, it fell as snow, but closer to Nares, the temperatures are pretty high atm.
The how to is posted here https://forum.arctic-sea-ice.net/index.php/topic,1259.msg211015.html#msg211015
Let's continue there so as not to disrupt this thread. Looking forward to the next test.
Jayw, thanks for looking at the area suggested, maybe best not to clog up this thread with too many images for now.
create my own RGB compositesIf you can provide 3gifs of the same size of exactly the same area with matching timestamps I would be interested to put them together for a test. I'm on metered broadband so I don't play with rammb much.
btw this area east of svalbard looks interesting and quite clear recently. https://go.nasa.gov/325M64G
Worldview with bathymetry inlay
edit: aqua modis is better https://go.nasa.gov/32bUzmK
I believe the geo color and natural color are already composites, that's why they take so long to load.If you can provide 3gifs of the same size of exactly the same area with matching timestamps I would be interested to put them together for a test. I'm on metered broadband so I don't play with rammb much.
What do you need? 3 different bands? Which ones?
That could be tricky because often times the times don't match. For example, you get more 'day/night' shots per day than 'geo-colours'.