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Author Topic: Null School Sea Surface Temperature Anomalies  (Read 3321 times)

Niall Dollard

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Null School Sea Surface Temperature Anomalies
« on: November 11, 2017, 06:57:36 PM »
I could not find a thread already open specifically for null school output. I have seen this discussed before though but I am wondering can anyone shed some light on why there is always very high SSTs displayed west of Svalbard and also to the SE of Svalbard.

I know the West Spitzbergen Current is a renowned warm,salty current but the temps shown by null school are well out of line. Today for example it shows SSTs of 16 C. There are also SSTs of 13 C to the south east of Svalbard and it is also picking up very warm lake temps from Finland.

Any thoughts why it (Null School) is picking up these high values at these locations. It is very persistent also?

In contrast SSTs from the Norwegian met here

Forest Dweller

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Re: Null School Sea Surface Temperature Anomalies
« Reply #1 on: November 22, 2017, 06:33:55 PM »
Hey Niall,

Don't know if this helps but i had asked Carana the same question already a year or more ago.
I was wondering about shallow waters as a factor and he/she did seem to think the sea floor topography plays a part.
Sent me a nice image of it but in the meantime i no longer do the wretched Facebook thing so can't give it to you now.
That would only refer to the western Svalbard anomaly however.
Maybe the combined effects of that, the current conditions you mentioned as well come together and different monitoring tools may indeed be at play as well...
I forget the correct term for seafloor topography but you get what i mean i'm sure and may wanna check that, good luck.

Brigantine

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Re: Null School Sea Surface Temperature Anomalies
« Reply #2 on: November 22, 2017, 08:51:32 PM »
I'll just leave this bathymetry map here.

(Note in the right hand sidebar the arctic map option, and the top right options drop menu the regional bathymetric contours. Also turn multibeam bathymetric surveys off.)

Niall Dollard

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Re: Null School Sea Surface Temperature Anomalies
« Reply #3 on: November 22, 2017, 11:59:43 PM »
Thanks folks.

I've attached an image of bathymetry and circulation and circled the two "nullschool hot spots". Spot to the SE of Svalbard is much more shallow compared to spot west of Svalbard. So two very different sea depths (330m vs 2500m). However they are both in areas of Atlantic water.
« Last Edit: November 23, 2017, 12:06:21 AM by Niall Dollard »

Brigantine

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Re: Null School Sea Surface Temperature Anomalies
« Reply #4 on: November 23, 2017, 01:42:04 AM »
ARGO float #6902042 profiled the area of the western hotspot through most of 2015. Nothing unusual to see, temperatures around 4.3C in the top 200m in November. About 8C in August in the top 50m.

The only recent profiles have been two this October by float #3901633 - About 7.5C in the top 50m. - but that's off to the SE edge of the hotspot where Nullschool is reporting about 6C.

There's nothing with high temps (>8C) at any depth either.

In short, ARGO agrees with the Norweigian Met and HYCOM. Though with no smoking gun recent profile in the core of the hotspot.

OTOH, NOAA agrees with Nullschool. I guess they both use the output of the same model??
Yes. Nullschool use MMABs RTGSST product - the same one.

kullboys

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Null School Sea Surface Temperature Anomalies
« Reply #5 on: March 12, 2019, 05:54:17 AM »
I could not find a thread already open specifically for null school output. I have seen this discussed before though but I am wondering can anyone shed some light on why there is always very high SSTs displayed west of Svalbard and also to the SE of Svalbard.

I know the West Spitzbergen Current is a renowned warm,salty current but the temps shown by null school are well out of line. Today for example it shows SSTs of 16 C. There are also SSTs of 13 C to the south east of Svalbard and it is also picking up very warm lake temps from Finland.

Any thoughts why it (Null School) is picking up these high values at these locations. It is very persistent also?
Thanks.

b_lumenkraft

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Re: Null School Sea Surface Temperature Anomalies
« Reply #6 on: March 12, 2019, 08:51:38 AM »
That's a good thing to open a thread about kullboys!

I'm looking forward to hearing the opinions of meteorologists and everyone knowing things about climate system models.

Juan C. García

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Re: Null School Sea Surface Temperature Anomalies
« Reply #7 on: March 12, 2019, 06:39:57 PM »
« Last Edit: March 12, 2019, 06:47:22 PM by Juan C. García »
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.

Ken Feldman

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Re: Null School Sea Surface Temperature Anomalies
« Reply #8 on: March 12, 2019, 07:33:03 PM »
I could not find a thread already open specifically for null school output. I have seen this discussed before though but I am wondering can anyone shed some light on why there is always very high SSTs displayed west of Svalbard and also to the SE of Svalbard.

I know the West Spitzbergen Current is a renowned warm,salty current but the temps shown by null school are well out of line. Today for example it shows SSTs of 16 C. There are also SSTs of 13 C to the south east of Svalbard and it is also picking up very warm lake temps from Finland.

Any thoughts why it (Null School) is picking up these high values at these locations. It is very persistent also?
Thanks.

Someone asked this on Reddit:

https://www.reddit.com/r/askscience/comments/7nwovt/why_are_there_two_spots_with_higher_sea_surface/

Here is the answer they got:

Quote
I've sent an email to the Robert Grumbine, he goes over the sea surface temperature data of NOAA, the data in question.


Dear Mr. Grumbine,

Recently, I have come across a curiosity while exploring a visualisation tool for, among others, Sea Surface Temperatures. The tool, accessible online via the link https://earth.nullschool.net/, showed two spots near Svalbard where the SST was considerably higher than its surroundings, at 78°N 7°E and at 76°N 30°E. This visualisation tool cites NOAA as its source for Real Time Global Sea Surface Temperature, and linked to the website http://polar.ncep.noaa.gov/. These warmer spots are also visible on the website’s own charts: http://polar.ncep.noaa.gov/sst/ophi/archive/20180103/color_newdisp_sst_north_pole_stereo_ophi0.png These spots also seem to be present every winter.

Out of personal curiosity, I would like to know if there is an explanation for this phenomenon. Without much expertise in this field, it seems unlikely to me that these spots exist because of ocean currents. Volcanic activity also seems to fall short as an explanation for the roughly 10°C warmer water.

So I would like to ask you if it would be possible that some kind of error has occurred in the data, either during measurement takings or during data analysis, that would explain these warmer spots?

This inquiry is not for academic purposes, merely out of personal interests, but I would appreciate it if you could help me.

Thank you in advance. Yours sincerely,

His response:


Hello Mr. Reusens,

Those two areas always challenging. Both areas tend to be cloudy, so the satellites we use can't see the ocean surface. Only a microwave instrument can do so. And neither is close to much shipping, so we get no observations that way either. We're left with drifting buoys and the occasional clear day for our data. That means we're also occasionally rejecting good data because it disagrees by too much with our last good observation.

But these two spots have some pecularities that make those warm temperatures not as exceptional as you might think. In particular, the 78 N, 7 E. There are two currents between Greenland and Svalbard. One carries near-freezing water out of the Arctic down the east coast of Greenland. The other brings some of the warm North Atlantic current water from Norway in to the Arctic west and east of Svalbard. Warm being relative, of course; 6-8 is still pretty cold for swimming.

In looking at the anomaly (deviation) from climatology (which is 1961-1990), these are showing > +8 C. But you'll notice that there are other substantial areas of such extremely warmer than usual water. This is happening a lot in areas where there is historically a sharp temperature gradient (see also the Gulf Stream) in temperatures, and the transition zone has moved northward (in the Atlantic or Arctic). http://polar.ncep.noaa.gov/sst/ophi/archive/20180103/color_newdisp_anomaly_north_pole_stereo_ophi0.png

The many tight contours do look suspicious, so I'll be investigating the locations specifically for what observations we have to support them being this warm and do an update if needed.

Regards, Robert Grumbine

b_lumenkraft

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Re: Null School Sea Surface Temperature Anomalies
« Reply #9 on: March 12, 2019, 07:43:51 PM »
Great find Ken! Thank you.

Niall Dollard

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Re: Null School Sea Surface Temperature Anomalies
« Reply #10 on: March 12, 2019, 10:00:25 PM »
I could not find a thread already open specifically for null school output. .

Here is the link to the old thread on this same topic : (Maybe mods could merge them ? )

https://forum.arctic-sea-ice.net/index.php/topic,2194.0.html

Neven

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Re: Null School Sea Surface Temperature Anomalies
« Reply #11 on: March 13, 2019, 09:53:53 AM »
Thanks for this, Niall. It seems a spambot has copied that comment of yours and opened a new thread. Had me fooled. I'll try and merge the treads now.

edit: done
Il faut comparer, comparer, comparer, et cultiver notre jardin

Juan C. García

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Re: Null School Sea Surface Temperature Anomalies
« Reply #12 on: March 22, 2019, 07:51:08 PM »
Just to include today's image and link for future follow-up:
https://earth.nullschool.net/#current/ocean/primary/waves/overlay=sea_surface_temp/orthographic=18.09,75.85,1914/loc=5.573,77.895
It is interesting that after 10 days, the hot spot continues at the same place.
It doesn't seem to move.
The other hot spot is still there, but with only 5.2°C.
Which is the best answer to Sep-2012 ASI lost (compared to 1979-2000)?
50% [NSIDC Extent] or
73% [PIOMAS Volume]

Volume is harder to measure than extent, but 3-dimensional space is real, 2D's hide ~50% thickness gone.
-> IPCC/NSIDC trends [based on extent] underestimate the real speed of ASI lost.