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uniquorn

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Re: What the Buoys are telling
« Reply #2050 on: January 28, 2021, 05:01:49 PM »
Great animation. While looking at it, the concept of a "Beaufort Gyre" seems more absurd than ever. Sometimes the buoys make a concerted effort to drift clockwise, but most of the time they just go every which way. And even when they do  follow a pattern, it's not the same pattern every time, the directions are different.
I think there's a hint of gyre there. An overlay of nullschool wind might show whether it's all wind drift or there is also an ocean current component.

Here's the full arctic ocean version, jan2016-jan2021.
January 1st data has been removed as it gives animation errors and some other data has been removed to clean things up a bit
Quote
data <- data[which(data$Lat < 90 ),]
data <- data[which(data$Lon > -180 ),]
data <- data[which(data$Lon < 360 ),]
data <- data[which(data$drift < 0.99),]
data <- data[which(data$drift > 0),]
Obviously many more things could be improved upon. Reluctant to increase compression to reduce file size any further.

uniquorn

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Re: What the Buoys are telling
« Reply #2051 on: January 30, 2021, 02:13:45 PM »
5 years of daily iabp buoy drift and nullschool wind at 1000hPa. 2016-jan2021   11.3MB mp4 beware

Quote
ffmpeg -i buoy.avi -i wind.avi -filter_complex "
  • crop=w=448:h=438:x=4:y=20[c1]; [1]crop=w=448:h=438:x=0:y=0[c2]; [c2][c1]blend=all_mode='overlay':all_opacity=1[m];
  • [m]overlay=x=4:y=20" -crf 34 buoywind-crf34.mp4[/size]
interesting. Forum turns 0 in square brackets into bullet points

Best viewed at half speed. (four and a half minutes you'll never get back ;)  )
« Last Edit: January 30, 2021, 02:20:40 PM by uniquorn »

uniquorn

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Re: What the Buoys are telling
« Reply #2052 on: February 02, 2021, 11:54:04 AM »
The whoi itp113 profiler is struggling with shallower water and/or a low battery voltage. It really has done a great job since September 18, 2019. Would have been great if it could have recorded more of the changes crossing the chukchi plateau though.
All temperature and salinity profiles from jan1-feb2 (click 8.4MB, using x to help show single data points)
Profile contours, drift path (off the map) and rough latest location.




Brigantine

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Re: What the Buoys are telling
« Reply #2053 on: February 13, 2021, 11:59:14 PM »
An ARGO float in the WSC north of Svalbard, which last reported in October, has woken up again!

Float ID 7900550.

Just a scratch of a halocline, and a 2-300m layer of Atlantic water still at ~2.5C.

Really pretty similar to some of the profiles from October, sans the halocline. Or rather, with the halocline being absorbed into the Atlantic layer.

uniquorn

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Re: What the Buoys are telling
« Reply #2054 on: February 14, 2021, 06:21:18 PM »
Float ID 7900550.
Just a scratch of a halocline, and a 2-300m layer of Atlantic water still at ~2.5C.<<>>>
You probably know more than me... keeping an eye on it though

Sepp

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Re: What the Buoys are telling
« Reply #2055 on: February 15, 2021, 10:07:43 AM »
An ARGO float in the WSC north of Svalbard, which last reported in October, has woken up again!

Float ID 7900550.

Just a scratch of a halocline, and a 2-300m layer of Atlantic water still at ~2.5C.

Really pretty similar to some of the profiles from October, sans the halocline. Or rather, with the halocline being absorbed into the Atlantic layer.

Nice visualisation! Could you give a hint how to get historical data to compare this with some years ago?

Niall Dollard

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Re: What the Buoys are telling
« Reply #2056 on: February 15, 2021, 01:33:53 PM »
Hi Sepp.

There is a wealth of detailed studies, freely available here, mostly between circa 2014 and 2016, of the Sofia Deep, north of Svalbard. It is quite a large file with the start in french and then english.

https://tel.archives-ouvertes.fr/tel-01721467/file/these_archivage_3003710o.pdf

The ocean interactions are very complex at this location. But I have attached a sample profile for winters 2014 to 2016 at approximately the same location as the float 7900550   

Sepp

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Re: What the Buoys are telling
« Reply #2057 on: February 17, 2021, 10:42:48 PM »
Thank you very much.

I was actually interested in the movement of the zone of relative high Salinity/Temperature (Halocline?) upwards over the last years in general. I remember having seen it somewhere in the forum in a year-to-year comparison and it looked quite upsetting, so I suspect, I was a bit offtopic with my question here.

Anyway, thanks again (:

Brigantine

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Re: What the Buoys are telling
« Reply #2058 on: February 18, 2021, 01:35:46 AM »
Nice visualisation! Could you give a hint how to get historical data to compare this with some years ago?

I mostly just use the "preview profile" feature on this USGODAE Argo GDAC Data Browser. You can go back and look at the data from whatever year... but only when there's a float in your target region to get data from! AFAIK there weren't any that far north until the last year or two.

Occasionally download the data and run it through some equations to plot density (buoyancy). Tried to predict how the surface mixed layer would grow, but without any success. The floats seem to pop up in a different idiosyncratic pocket each new profile.

You probably know more than me... keeping an eye on it though
Not at all! I keep an eye on what the floats are seeing in certain regions, but I'm not in any position of knowledge, and as far as the why and the what next, I'm just as confused as anyone. So I appreciate anything you have to say on it!

uniquorn

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Re: What the Buoys are telling
« Reply #2059 on: February 18, 2021, 01:03:13 PM »
There is a wealth of detailed studies, freely available here, mostly between circa 2014 and 2016, of the Sofia Deep, north of Svalbard. It is quite a large file with the start in french and then english.
https://tel.archives-ouvertes.fr/tel-01721467/file/these_archivage_3003710o.pdf
The ocean interactions are very complex at this location. But I have attached a sample profile for winters 2014 to 2016 at approximately the same location as the float 7900550
Handy to have all those studies in one file.

Update on float 6903547 in the Fram Strait, Feb16 (feb6 below) A deeper cold layer on this profile.
https://fleetmonitoring.euro-argo.eu/float/6903547
@Brigantine I struggled a bit with the .nc format with the USGODAE Argo GDAC Data Browser. It's quick for previews though.
« Last Edit: February 18, 2021, 01:09:20 PM by uniquorn »

uniquorn

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Re: What the Buoys are telling
« Reply #2060 on: February 18, 2021, 03:40:55 PM »
interested in the movement of the zone of relative high Salinity/Temperature (Halocline?) upwards over the last years<<>>
argo float 3901910 made it up the WSC north Svalbard branch during aug-dec 2018. Some posts about it here

Though perhaps you are thinking about the Aug2020 Polyakov paper discussed here
« Last Edit: February 18, 2021, 04:37:59 PM by uniquorn »

uniquorn

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Re: What the Buoys are telling
« Reply #2061 on: February 22, 2021, 10:09:39 PM »
SIMB3 443910 is paired with whoi itp120 in the beaufort.
Quote
Instrument experienced a dynamic event on 09/29/2020 which caused a downward shift in the rangefinder values and failure of the temperature string.

Ice+snow appear to have thickened by 64cm to 1.716m

uniquorn

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Re: What the Buoys are telling
« Reply #2062 on: February 22, 2021, 10:27:00 PM »
SIMB3 344910 is paired with whoi itp121 in the beaufort.

Ice+snow appear to have thickened by 65cm to 2.753m

uniquorn

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Re: What the Buoys are telling
« Reply #2063 on: February 27, 2021, 02:47:14 PM »
An ARGO float in the WSC north of Svalbard, which last reported in October, has woken up again!
Float ID 7900550.
Just a scratch of a halocline, and a 2-300m layer of Atlantic water still at ~2.5C.
Really pretty similar to some of the profiles from October, sans the halocline. Or rather, with the halocline being absorbed into the Atlantic layer.

and again on 20th, must have been under ice for a while previously. Temp at 5m depth = -0.077C, atlantic water(mixed layer?) down to ~200m

uniquorn

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Re: What the Buoys are telling
« Reply #2064 on: February 27, 2021, 06:31:19 PM »
argo 3902108 approaching the NW corner of Svalbard, 3.3C at 3m depth on feb24

argo 6903547 a little further west in the Fram, 3.36C at 2.8m depth on feb26
« Last Edit: February 27, 2021, 06:51:25 PM by uniquorn »

SimonF92

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Re: What the Buoys are telling
« Reply #2065 on: February 27, 2021, 08:13:25 PM »
An ARGO float in the WSC north of Svalbard, which last reported in October, has woken up again!
Float ID 7900550.
Just a scratch of a halocline, and a 2-300m layer of Atlantic water still at ~2.5C.
Really pretty similar to some of the profiles from October, sans the halocline. Or rather, with the halocline being absorbed into the Atlantic layer.

and again on 20th, must have been under ice for a while previously. Temp at 5m depth = -0.077C, atlantic water(mixed layer?) down to ~200m

-0.07 at that depth and location in winter seems pretty warm to me? Just goes to show how bad halocline disturbance by storms can be for the ice
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