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uniquorn

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buoy data 22/23fr
« on: September 25, 2022, 04:00:16 PM »
Ocean surface freezing has started, we wait for evidence of bottom freezing from the 2? remaining SIMB3's still active in the CAB and Beaufort. 10 more are ready for deployment.

We also have 5 active Thermistor buoys and 3 snow buoys which were deployed over the last few weeks at the north pole, now drifting towards the Fram Strait.

Also 7 Argo floats in the West Spitsbergen current which will help cover the unfortunate loss of profiler battery voltage on whoi itp129 on aug30

Here we take a look at the last few profiles of float 6903144, sep14-18, in the marginal ice zone north of Franz Josef Land and close to the shelf break. Note the large changes in temp and salinity down to 30m depth.
https://go.nasa.gov/3r6bDIJ


 

uniquorn

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Re: buoy data 22/23fr
« Reply #1 on: September 25, 2022, 08:52:07 PM »
Float 6904222 in open water at +1.4C

Quote
Last station date
23/09/2022 07:36:31 Cycle12

Last Surface Data
6.9 dbar 1.406℃ 33.661 PSU

Note the chart: 3.5C at 40m, 0.15C at 52m
edit: added cycle11 on sep16
« Last Edit: September 25, 2022, 09:06:09 PM by uniquorn »

uniquorn

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Re: buoy data 22/23fr
« Reply #2 on: September 26, 2022, 04:08:07 PM »
Tbuoy drift and air temp update.

uniquorn

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Re: buoy data 22/23fr
« Reply #3 on: September 26, 2022, 04:09:09 PM »
2022T97 and 98 air temp

uniquorn

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Re: buoy data 22/23fr
« Reply #4 on: September 26, 2022, 04:15:14 PM »
Some delay to near surface ice cooling due to the recent warmer temps
2022T94-97, temps limited from -1.875C to +0.25C to highlight ice temperature

uniquorn

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Re: buoy data 22/23fr
« Reply #5 on: September 26, 2022, 05:13:44 PM »
2022T98 air temps, further north, didn't rise above -1.875C but near surface ice still warmed. 3 different temp scales.

uniquorn

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Re: buoy data 22/23fr
« Reply #6 on: September 26, 2022, 07:10:37 PM »
Compare T98 with SIMB3 448890, deployed near the pole on aug27. The ice appears to be warmer, ocean below a little cooler. Bottom melt continues with a 2cm tick up on sep24 while open water probably refroze at surface sep16-22.
« Last Edit: September 26, 2022, 07:21:48 PM by uniquorn »

uniquorn

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Re: buoy data 22/23fr
« Reply #7 on: September 26, 2022, 09:16:13 PM »
Going back to 2022T98, but this time looking at the heat120 data, we can see some similarities with SIMB3 448890 during sep17-22 at ice bottom and a possible tick up on sep23. This is not measured on T98 but may be indicated by the temp increase over 120sec looking more like water than ice.

I don't know how to interpret the feature at -0.6m
edit: deployment data
Quote
Additional information (comments, weather, topography, ice floe size, etc.)
Location at start of deployment: 89° 56,3592'N
38° 50,2000'E
Ca. +3°air temperature, changing cloud cover: morning very foggy, later mostly cloudy and overcast, generally
good visibility and some sun, ~5 kn wind.
First year ice, with pressure ridges and melt ponds within 20m radius (no better floe to be found for passenger
operations, deployment structure see drone pictures). Some patches of 2nd year ice and/or floes thickened by ice
dynamics. (See drone pictures.)
Meltponds with ca. 7cm ice cover on top, below ~50cm water, below ~1m ice.

3 different temp scales help to focus on the different layers.

AWI presentation for ref.
« Last Edit: September 26, 2022, 09:44:32 PM by uniquorn »

uniquorn

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Re: buoy data 22/23fr
« Reply #8 on: September 27, 2022, 07:47:16 PM »
snowbuoy update.
S116 and S117 had ~7cm snow after the recent warm spell.
2 distance sensors on S121 may have failed.

oren

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Re: buoy data 22/23fr
« Reply #9 on: September 28, 2022, 12:13:48 AM »
Going back to 2022T98, but this time looking at the heat120 data, we can see some similarities with SIMB3 448890 during sep17-22 at ice bottom and a possible tick up on sep23. This is not measured on T98 but may be indicated by the temp increase over 120sec looking more like water than ice.

I don't know how to interpret the feature at -0.6m
edit: deployment data
Quote
Additional information (comments, weather, topography, ice floe size, etc.)
Location at start of deployment: 89° 56,3592'N
38° 50,2000'E
Ca. +3°air temperature, changing cloud cover: morning very foggy, later mostly cloudy and overcast, generally
good visibility and some sun, ~5 kn wind.
First year ice, with pressure ridges and melt ponds within 20m radius (no better floe to be found for passenger
operations, deployment structure see drone pictures). Some patches of 2nd year ice and/or floes thickened by ice
dynamics. (See drone pictures.)
Meltponds with ca. 7cm ice cover on top, below ~50cm water, below ~1m ice.

3 different temp scales help to focus on the different layers.

AWI presentation for ref.
Very nice presentation. Lacking the deployment data this would have been quite weird.

uniquorn

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Re: buoy data 22/23fr
« Reply #10 on: September 30, 2022, 10:41:31 PM »
2022T96 water temps at roughly 25cm below ice, T190.
tech note:  there are many bad latlon entries in the TEMP file so the animation uses every 3rd latlon from the TS file. There is a 3sec difference, maybe it is too short
click for motion and annotated temp

uniquorn

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Re: buoy data 22/23fr
« Reply #11 on: October 01, 2022, 10:22:45 PM »
Water temp at roughly 3.5m for all 5 Tbuoys.

2022T98 and SIMB3 448890 appear to be on the same floe. Comparing the data, 448890 water temps are roughly 0.2C lower than T98
click (probably twice) for motion and annotation

uniquorn

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Re: buoy data 22/23fr
« Reply #12 on: October 01, 2022, 10:58:40 PM »
Going back to 2022T98, but this time looking at the heat120 data, we can see some similarities with SIMB3 448890 during sep17-22 at ice bottom and a possible tick up on sep23. This is not measured on T98 but may be indicated by the temp increase over 120sec looking more like water than ice.
<>

Now we have some confirmation of the possible bottom melt indicated by the heat120 data on sep23 (circled) since co-located 448890 ticked up 2cm on sep24

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Re: buoy data 22/23fr
« Reply #13 on: October 02, 2022, 02:04:12 AM »
Now we have some confirmation of the possible bottom melt indicated by the heat120 data on sep23 (circled) since co-located 448890 ticked up 2cm on sep24
Is that temperature scale right? That whole heat120 graph is confusing

uniquorn

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Re: buoy data 22/23fr
« Reply #14 on: October 02, 2022, 12:20:45 PM »
yes, it confused me for a while. They pass a current through the thermistors a resistor to heat them up and measure the mean temperature increase over 30sec and 120sec.

I get it. It's the mean temp rise over 120s. In which case it should still be valid as temps rise.
<>
added heat file ani for reference

A blast from the past, mosaic Tbuoy heat120
« Last Edit: October 02, 2022, 08:52:22 PM by uniquorn »

uniquorn

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Re: buoy data 22/23fr
« Reply #15 on: October 02, 2022, 12:33:40 PM »
Here is the full temperature range T98 heat120 from 0.375C to 4C.

0.375C to 1C above is better for looking at the ice bottom and small ocean temp changes. The resolution is not great at 0.125C but we take what we can till the mosaic data becomes available....

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Re: buoy data 22/23fr
« Reply #16 on: October 02, 2022, 01:02:08 PM »
Ok, it kind of makes sense now.

So very high values occur if the thermistor is surrounded by calm air, less so when it's windy. and then snow also gives relatively high values.

Still don't get what that -0.6m high-ish value (1.1⁰C) feature is, or rather why a melt pond (trapped water) would give high-ish values...

Unless it's that the low 0.6⁰C values are for ice near melting point  ??? (i.e. thermistor is kept cool by phase change)

And then the lowest values (0.4-0.5⁰C) happen in water with a current (forced convection). 0.7 for water with no current (free convection), and back to 1.1 at the ice-ocean interface with no current (no room above for heat to convect away)


Am I on the right track here?

uniquorn

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Re: buoy data 22/23fr
« Reply #17 on: October 02, 2022, 04:17:17 PM »
Quote
So very high values occur if the thermistor is surrounded by calm air, less so when it's windy. and then snow also gives relatively high values.

Agreed, though the snow layer may be slushy and the composition of the layer between ocean surface and ice freeboard may complicate interpretation.

Quote
Still don't get what that -0.6m high-ish value (1.1⁰C) feature is, or rather why a melt pond (trapped water) would give high-ish values...
Unless it's that the low 0.6⁰C values are for ice near melting point  ??? (i.e. thermistor is kept cool by phase change)

Tend to agree, the melt pond appears to be freezing slowly.

Quote
And then the lowest values (0.4-0.5⁰C) happen in water with a current (forced convection). 0.7 for water with no current (free convection), and back to 1.1 at the ice-ocean interface with no current (no room above for heat to convect away)

Might be interesting to overlay 0200h drift speed to see if it correlates with the higher ocean heat120 temps. Could air temp too.

A couple of papers featuring SIMBAs that may help.

Snow depth and ice thickness derived from SIMBA ice mass balance buoy data using an automated algorithm
Zeliang Liao, Bin Cheng, JieChen Zhao, Timo Vihma, Keith Jackson, Qinghua
Yang, Yu Yang, Lin Zhang, Zhijun Li, Yubao Qiu & Xiao Cheng
https://doi.org/10.1080/17538947.2018.1545877

extract:
Quote
3.2. Heating temperature regimen
Each sensor on the SIMBA thermistor chain has a heating element. A small (8 V) voltage was applied
to the resistors so that the heat energy liberated in the vicinity of each sensor would be the same. The
heating time interval typically lasted from 60 to 120 s. The sensor temperatures usually rise by varying
amounts along the thermistor chain based on whether their locations are in air, snow, ice, or water. In
practice, however, the temperature changes may not be clear enough to detect the air/snow, snow/ice,
and ice/water interfaces (Jackson et al. 2013). Consider buoy A as an example, the sensor temperature
reading after 120 s of heating is plotted in Figure 6. Visual inspection reveals very weak discrimination
of air/snow and ice/water interfaces from the colour pattern (Figure 7(a)). In June, the heating tem-
perature showed no changes, but errors were probably encountered. The strong warm-up of the in-
ice (∼1 m depth) in late December and mid-February (1 m –1.5 m depth) remain unknown.
The heating temperature also revealed two horizontal discriminated interfaces at 0 m and –
0.22 m in depth below the surface. The 0 m level was the original snow/ice interface. The second
interface (white broken line in Figure 6(a)) is the original sea water level. The initial ice was thick
(1.44 m), creating strong buoyancy that kept the upper part of the ice column above the water
level. When SIMBA was deployed, the freeboard was 21 cm positive (sea water level was below
ice surface), and this agreed well with the white broken line in Figure 7(a). When the SIMBA ther-
mistor string was deployed, the positive freeboard introduced a segment of empty boreholes between
sea level and the ice surface. This part of a borehole is usually filled with snow-slush or perhaps left
open. This layer, in this case at 21 cm in depth, was actually an intermediate mixture layer with
snow/slush and water. It takes time to completely refreeze and integrate with the ice column com-
posed by freezing sea water in the borehole below sea level. In extreme conditions, the upper bore-
hole may have had difficulty in fully refreezing if there was no water in the upper portion.
If the algorithm-retrieved air/snow (5-day running mean) is superimposed on the ice/water inter-
face in the heating temperature regimen (Figure 7(b)), the algorithm calculated interfaces are in good
agreement with the heating temperature discriminated interfaces. The heating temperature pattern
could discriminate interfaces. However, the discrimination was sometimes very weak, and it was
difficult to identify and obtain an entire time series of the interfaces.

-------------------------------------
Discrimination Algorithm and Procedure of Snow Depth and Sea Ice Thickness Determination Using Measurements of the Vertical Ice Temperature Profile by the Ice-Tethered Buoys
Guangyu Zuo, Yinke Dou,1, and Ruibo Lei2
Published online 2018 Nov 27. doi: 10.3390/s18124162
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6308795/

extract:
Quote
In cases without the deployment of the acoustic sounding instruments, the vertical temperature profile through the air, snow, ice, and upper ocean can be used to discriminate snow depth and ice thickness because both the specific heats and the heat conduction coefficients are very different among air, snow, ice and water [19,20]. Generally, the vertical temperature profile measured by ice-tethered buoys has two main change points on the top and lower interfaces of the layer of snow-covered ice and the temperature profiles segmented by these two change points show remarkable differences in vertical gradient, daily amplitude, and seasonal evolution. The interface between snow and sea ice is vague because the formation of snow-ice or a slush layer cannot be distinctly identified using only the temperature profile [21,22]. The theories of change point and maximum likelihood are considered optimization methods to implement signal segmentation for identification purposes and can be used to determine the snow depth and sea ice thickness by identifying the change points of the sea ice temperature profile.

.1.1. Interface between Air and Snow or Sea Ice

The evolution of snow depth over sea ice may be affected by synoptic processes phenomena such as storms, snowfall, and sleet, or due to melting caused by solar radiation. Thus, the temporal fluctuations of snow depth are much larger than for sea ice thickness. The daily amplitude of temperature profiles and the vertical gradients of temperature were examined because, in some cases, it was difficult to accurately distinguish the top interface by using the measurements of the temperature alone. From the data of the daily amplitude of temperature profiles and the vertical gradients of temperature, we checked the corresponding values one by one from the top of the temperature profiles to find the change points.

3.1.2. Interface between Ice and Ocean

To identify the lower ice interface (ice-ocean interface), temperature profiles for the lower ice layer were obtained from some thermistors near the bottom of the sea ice. The seawater temperature was determined using the lower five thermistors, which generally had a negligible temperature gradient from the bottom of the sea ice. The points where the temperature profile of the lower ice layer intersected the ocean temperature were regarded as the ice-ocean interface (Figure 3b). The ice-ocean interface determined by the method of seeking described above had a good accuracy in winter or sea ice growth period. This method became unreliable in summer, especially in ice melting period when the temperature gradient across the lower interface weakened. In summer, the temperature profile of sea ice became nonlinear with a C-shaped curve. Then the lower ice interface was determined from the obvious inflection point in the vertical C-shaped ice temperature profile (Figure 3d). In winter, temperature profile of sea ice remained linear and temperature of the basal ice layer was colder than the upper ocean. There will be a sharp inflection point occurring at the interface. Thus, ice-ocean interface can be estimated from the vertical gradients of sea ice temperature profile.

uniquorn

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Re: buoy data 22/23fr
« Reply #18 on: October 02, 2022, 08:12:58 PM »
More detail in this one and some interesting analysis, see fig7:
1. Natural logarithm of the ratio of temperatures rises at 15- and 60-s points during a heating cycle
We have 30sec and 120sec available from meereisportal

2. Variation of each sample from local average (i.e., current sample and two samples either side in time)

A Novel and Low-Cost Sea Ice Mass Balance Buoy
Keith Jackson1, Jeremy Wilkinson1, Ted Maksym2, David Meldrum3, Justin Beckers4, Christian Haas4, and David Mackenzie5
1 Scottish Association for Marine Science, Oban, United Kingdom | 2 Woods Hole Oceanographic Institution, Woods Hole, Massachusetts | 3 Scottish Association for Marine Science, Oban, United Kingdom | 4 University of Alberta, Edmonton, Alberta, Canada | 5 University of Oxford, Oxford, United Kingdom
Print Publication:    01 Nov 2013
https://doi.org/10.1175/JTECH-D-13-00058.1

extracts:
Quote
b. Heat cycle empirical characterization

The sensor chains have been tested in simulated sea ice conditions in a cold room (minimum temperature is −40°C) to determine the heating cycle response. Ice was grown in open-topped insulated boxes with heating pads at the bottom. This arrangement ensured ice growth occurred from the surface downward in a uniform sheet. A chain was suspended into the box before freezing, such that it had sections in air, ice, and water. The ice thickness was manually measured by drilling small holes into the ice and inserting a graduated hooked rod to feel for the underside.

The change in temperature was detected by each sensor along the chain for a heating period of 2.5 min. In water and ice, the temperature rise quickly approaches a near steady state for a 50% duty cycle (31 mW) as shown in Fig. 4. Heating continues for longer at 100% duty cycle (63 mW), providing clearer separation in saturation temperature between air and water (Fig. 5). In either case, the temperature response in water and ice does not follow a logarithmic curve as predicted by (1). Instead, the temperature approaches a saturation point where further heating produced little increase. This might reflect initiation of a hot-wire anemometer mode in water, but it cannot explain the behavior in ice. It is presumed that the nonideal geometry of the sensor chain–ice system is responsible (i.e., it is not the point source as modeled by the equations) and additional heating is dissipated by conduction along the chain itself. In air, heating provided a clear distinction with water or ice, but the behavior is not logarithmic here either, instead rising more linearly. This probably reflects the significant thermal mass of the chain relative to the surrounding air. This suggests that in the present configuration, precise determination of material properties is difficult, but media are distinguishable empirically.

For the case of an ice–water interface, identification of the boundary may be difficult based on heating cycle information alone. For the lower level of heating applied in Fig. 4, the distinction amounts to only a few sensor resolution steps. While this difference can be increased by using greater heating power, this will come at the cost of battery lifetime (an estimated reduction of 25% to double the temperature interval).

The controlled tests described above represent a steady-state environment. In field deployments the sensors in air and water will be subject to a varying flow that greatly affects the temperature rise. Given the similar responses of the sensors in static water and ice, this mechanism may be significant in helping to distinguish the two media.


7. Performance of deployments

To date, about 50 SAMS IMB buoy deployments have been made by 12 different institutions. Many of the first Arctic deployments were short lived because the ice floes quickly disintegrated (often corroborated by other instrumentation in the same place failing at the same time), but they still often revealed interesting information on the rapid melting that occurred before breakup. Wildlife also presents a risk to deployments and the destruction of one by a polar bear was witnessed in Svalbard, Norway. However, a number of deployments have fared better and lasted for periods in excess of a year.

An example of data from a deployment in the Weddell Sea in Antarctica is shown in Fig. 7. This deployment was made in ice of about 110 cm thick with about 8 cm of snow initially. The deployment was made in January and drifted for over a year before the ice in the floe on which it was deployed melted in the northern Weddell Sea. Note that as it was initially deployed through a large hole (significantly bigger than the 2-in. hole normally used), the chain took much longer to freeze before the freezing front apparent in Fig. 7 actually passed the initial ice–ocean interface (around day 100). Figure 7a shows the temperature evolution starting in air at the top, within the ice and snow, and then the upper ocean. The white lines are the estimated positions of the air–snow, snow–ice, and ice–ocean interfaces estimated by inflection points in the vertical temperature profile. The top ice surface is used as the zero depth reference. It is not possible to reliably identify the interfaces from the temperature profiles alone.

The heating cycle temperature rise clearly delineates the snow–ice boundary (Fig. 7b) as expected because of the differences in thermal conductivity. If a form of (1) held, then we would expect the heating rate to be proportional to the inverse of the effective thermal conductivity. These results suggest an apparent thermal conductivity for ice about twice that of the snow, while in reality it is about 5–7 times. This clearly shows that (1) does not hold. One possible contributing factor is that the heating in snow saturates quickly as convection is initiated, as noted by others (Sturm and Johnson 1992).

The boundaries between air and snow and between ice and water are not clearly identifiable from observation of the heating rates in situations where fluid flow reduces the distinction between lower-conductivity fluids (e.g., water) and higher-conductivity solids (e.g., ice). However, as described above, the data can be processed to make the interfaces more obvious. One approach is to take the ratio of the temperature rise during the heating cycle at two instances. A point approximately midway up the rising temperature curve and a point nearing saturation were sought so sample times at 15 and 60 s were used (Fig. 7c—note here it is actually the natural logarithm of this ratio that is shown, as this emphasizes the interfaces more clearly). This approach still shows a clear snow–ice boundary, but it also provides a clearer discrimination between the air–snow and ice–ocean interfaces.

An alternative approach is to examine the deviation of the heating rate for each sensor over the course of several adjacent samples. A “box-car type” filter covering five sample periods has been used to achieve the background average against which the deviation of a sample is measured. The choice of five samples is arbitrary, and it is noted that using longer periods seems to cause little difference to the results. The filter is centered on the sample for which the deviation is being calculated, so as not to introduce temporal shifting. The variation in heating rate due to variations in the flow rate becomes very obvious (Fig. 7d). Here, the air–snow and ice–ocean interfaces can be readily picked out because of the temporal variations in heating of sensors in the fluids (presumably primarily due to variations in flow rates of the fluids).

Later in the deployment (days 350–450), it would appear there are some internal changes apparent within the ice where higher temperatures in response to the applied heating occur. This remains unexplained as yet, but it is thought that it may be due to increasing porosity of the ice during melting conditions. Similar patterns have been noted previously (Polashenski et al. 2011).
« Last Edit: October 02, 2022, 08:29:58 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #19 on: October 03, 2022, 11:40:51 PM »
Dispatches from the 2022 BGOS & JOIS expedition
https://www2.whoi.edu/site/beaufortgyre/expeditions/2022-expedition/
Quote
2022 Expedition

2022 marks the 20th year of BGOS & JOIS expeditions to the Beaufort Gyre onboard the CCGS Louis S. St-Laurent. Bill Williams (IOS) is the Chief Scientist on the expedition. We are recovering and redeploying the three Beaufort Gyre Observing System moorings, and deploying 4 Ice-Tethered Profilers and 3 Tethered Ocean Profilers, along with 2 seasonal Ice Mass Balance Buoys and 1 Arctic Ocean Flux Buoy. IOS and collaborators are acquiring hydrographic and geochemical data at repeat stations spanning the region.




7 new WHOI buoys in the Beaufort
https://www2.whoi.edu/site/itp/data/active-systems/itp130/


Quote
ITP130 was deployed on a 0.6 m thick ice floe in the Beaufort Sea on September 25, 2022 at 77° 45.6 N, 140° 1.2 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. The ITP is operating on a fast sampling schedule of 4 one-way profiles between 5 and 760 m depth each day.

ITP131 was deployed in open water in the Beaufort Sea on September 28, 2022 at 79° 7.3 N, 146° 50.9 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. The ITP is operating on a fast sampling schedule of 4 one-way profiles between 5 and 760 m depth each day.

ITP136 was deployed on a 1.2 m thick ice floe in the Beaufort Sea on September 25, 2022 at 79° 10.6 N, 140° 14.4 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. On the same icefloe, a Tethered Ocean Profiler (TOP5), a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 ,and a Naval Postgraduate School Arctic Ocean Flux Buoy (AOFB48) were also installed. The ITP includes a dissolved oxygen sensor, is operating on a fast sampling schedule of 4 one-way profiles between 7 and 760 m depth each day and includes a fixed SAMI PCO2 with ODO and PAR at 5 m depth.

ITP137 was deployed on a 1.0 m ice floe in the Beaufort Sea on September 24, 2022 at 79° 49.1 N, 139° 58.1 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. On the same icefloe, a Tethered Ocean Profiler (TOP6) and a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 were also installed. The ITP includes a dissolved oxygen sensor, is operating on a fast sampling schedule of 4 one-way profiles between 7 and 760 m depth each day and includes a fixed SAMI PCO2 with ODO and PAR at 5 m depth.

TOP5 was deployed on an 1.7 m thick ice floe in the Beaufort Sea on September 25, 2022 at 79° 10.2 N, 140° 16.9 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. On the same icefloe, an Ice-Tethered Profiler (ITP136), a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 ,and a Naval Postgraduate School Arctic Ocean Flux Buoy (AOFB47) were also installed. The TOP is operating on a standard sampling schedule of 6 two-way profiles from the surface to 200 m depth each day.

TOP6 was deployed on an 1.1 m thick ice floe in the Beaufort Sea on September 26, 2021 at 79° 48.7 N, 139° 57.6 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. On the same icefloe, an Ice-Tethered Profiler (ITP137) and a US Army Cold Regions Research and Engineering Laboratory (CRREL) Seasonal Ice Mass Balance Buoy 3 were also installed. The TOP is operating on a standard sampling schedule of 6 two-way profiles from the surface to 200 m depth each day.

TOP7 was deployed in open water in the Beaufort Sea on October 1, 2022 at 76° 59.4 N, 149° 16.1 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. The TOP is operating on a standard sampling schedule of 6 two-way profiles from the surface to 200 m depth each day.

A new flux buoy47
https://www.oc.nps.edu/~stanton/fluxbuoy/deploy/buoy47.html

SIMB3 565600 and 566570
https://www.cryosphereinnovation.com/data/
« Last Edit: October 03, 2022, 11:59:42 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #20 on: October 04, 2022, 12:12:35 PM »
Quote
TOP7 was deployed in open water in the Beaufort Sea on October 1, 2022 at 76° 59.4 N, 149° 16.1 W as part of the Beaufort Gyre Observing System (BGOS) during the JOIS 2022 cruise on the CCGS Louis S. St. Laurent. The TOP is operating on a standard sampling schedule of 6 two-way profiles from the surface to 200 m depth each day.

If this buoy survives we might get to see temp and salinity of surface freezing and possibly rate of thickening. Last year the open water deployment failed after a few days iirc

homebrew temp contours 20m and 198m, different temp scales
whoi drift track and profile contours
aqua modis top7 loc   https://go.nasa.gov/3Rz0XNI
« Last Edit: October 04, 2022, 06:23:53 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #21 on: October 05, 2022, 12:25:05 PM »
It looks like TOP7 will also be the nearest ctd to the upcoming storm, which is now forecast to drop to 956hPa. Here we look at the rawmat, or level2, data less than 1.21dbar with the shallowest data available currently at 0.94dbar. (scale is reversed)
note that no adjustment has been made for local air pressure

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Re: buoy data 22/23fr
« Reply #22 on: October 06, 2022, 08:32:30 PM »
whoi top7 level1, different scales for 1-20m and 1-198m, temp and salinity

level2 0.9m-1.21m

whoi presentation for ref

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Re: buoy data 22/23fr
« Reply #23 on: October 06, 2022, 08:42:42 PM »
top7 1-20m temp scale above is a bit too tight. Here is vmin=-1.53, vmax=-1.31

salinity vmin=26.35, vmax=27.68

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Re: buoy data 22/23fr
« Reply #24 on: October 11, 2022, 01:46:09 PM »
569620 update. Ice is gently cooling, mostly from surface. Note the rewarming in the melt pond layer between sep7-11.
Meltwater moving?

No sign of bottom freeze yet.

https://earth.nullschool.net/#2022/09/06/1000Z/wind/surface/level/overlay=temp/orthographic=-42.97,95.15,1722/loc=-134.401,83.262

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Re: buoy data 22/23fr
« Reply #25 on: October 13, 2022, 09:30:03 PM »
itp137 reminded me of an old layer map.
https://www2.whoi.edu/site/itp/data/active-systems/itp137/

Small changes in near surface temps

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Re: buoy data 22/23fr
« Reply #26 on: October 14, 2022, 12:19:26 AM »
569620 update. Ice is gently cooling, mostly from surface. Note the rewarming in the melt pond layer between sep7-11.
Meltwater moving?

No sign of bottom freeze yet.

My understanding is, bottom freeze (thickening) is still driven by cooling from the surface... so you won't even expect to see anything until the temperature gradient from the top reaches the bottom and then into the ocean, quite a ways to go. [in contrast with the melt season, where the temperature gradient grows from both sides]

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Re: buoy data 22/23fr
« Reply #27 on: October 14, 2022, 12:53:23 PM »
1.Agreed. I tried a rough forecast last year with 052460 which turned out a bit optimistic.

2. Looking again for that buoy freezing temp was -2C to 2.5C. Note that it may have had a problem with the bottom sounder from end of sep-jan

3. 569620 should start thickening around dec12 if -2.25C is cold enough and the cooling rate is constant.
« Last Edit: October 14, 2022, 01:07:45 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #28 on: October 14, 2022, 02:50:52 PM »
569620 update. Ice is gently cooling, mostly from surface. Note the rewarming in the melt pond layer between sep7-11.
Meltwater moving?

No sign of bottom freeze yet.

My understanding is, bottom freeze (thickening) is still driven by cooling from the surface... so you won't even expect to see anything until the temperature gradient from the top reaches the bottom and then into the ocean, quite a ways to go. [in contrast with the melt season, where the temperature gradient grows from both sides]

I think we have to say 'mostly from the surface' at the moment as SIMB3 448890 deployed at the pole on aug27 shows more clearly the cooling from both top and bottom.

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Re: buoy data 22/23fr
« Reply #29 on: October 14, 2022, 04:49:06 PM »
Whereas the ice beneath SIMB3 566570 is already very close to ocean temp, so cooling is indeed only from the top. Set the snow depth to 3cm based on the deployment image for co-located itp137

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Re: buoy data 22/23fr
« Reply #30 on: October 15, 2022, 09:45:28 PM »
Radically differing profiles of Argo 6904222 as it drifts along the shelf break between Svalbard and FJL from aug25 to oct14, cycle 8-15. Currently about 20km from the ice edge, probably much closer on oct7.
Quote
Last station date
14/10/2022 13:21:20
Cycle 15
Last Surface Data
8 dbar 0.639℃ 33.768 PSU

https://fleetmonitoring.euro-argo.eu/float/6904222
https://go.nasa.gov/3D2KUnk  oct14 location
https://go.nasa.gov/3F1GoqD  oct7 loc with wv oct6
« Last Edit: October 15, 2022, 10:07:51 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #31 on: October 15, 2022, 10:28:05 PM »
Latest profile on oct12 from 6903705 in the middle of the Barents.
Quote
Last station date
12/10/2022 08:42:10
Cycle 169
Last Surface Data
4.39 dbar 2.4099℃ 34.3483 PSU

2.4C down to 38m

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Re: buoy data 22/23fr
« Reply #32 on: October 16, 2022, 09:10:09 PM »
More detail in this one and some interesting analysis, see fig7:
1. Natural logarithm of the ratio of temperatures rises at 15- and 60-s points during a heating cycle
We have 30sec and 120sec available from meereisportal

2. Variation of each sample from local average (i.e., current sample and two samples either side in time)

A Novel and Low-Cost Sea Ice Mass Balance Buoy
Keith Jackson1, Jeremy Wilkinson1, Ted Maksym2, David Meldrum3, Justin Beckers4, Christian Haas4, and David Mackenzie5
Print Publication:    01 Nov 2013
https://doi.org/10.1175/JTECH-D-13-00058.1

Had a look at log(heat120/heat30) for 2022T97 currently leading the race to the Fram.
1. Tbuoy drift
2. default ice temps optimised for looking at ice bottom
3. Heat120 temps. The increase in thermistor temperature after heating for 120seconds
4. My interpretation of 'Natural logarithm of the ratio of temperatures rises at 30-s and 120-s points during a heating cycle' as log(H120/H30)

Bottom distance from 448890 above suggests the ice bottom is cooling rather than melting.
So far.
« Last Edit: October 16, 2022, 09:22:29 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #33 on: October 16, 2022, 09:16:12 PM »
log(H120/H30) optimised for focus on the surface.

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Re: buoy data 22/23fr
« Reply #34 on: October 17, 2022, 12:48:41 PM »
<>
Bottom distance from 448890 above suggests the ice bottom is cooling rather than melting.
So far.

Following up on that, here we look at 2022T98, co-located with SIMB3 448890, temp scale optimised for looking at ice bottom and melt ponds, -1.875C to +0.25C.
Quote
SIMB3-448890
2022-10-17 00:01:01   87.73652   21.984936

2022T98
2022-10-17T00:00:15   87.736676   21.982718

Excellent deployment data for T98, 448890 maybe nearer the middle of the melt pond.
Quote
First year ice, with pressure ridges and melt ponds within 20m radius (no better floe to be found for passenger
operations, deployment structure see drone pictures). Some patches of 2nd year ice and/or floes thickened by ice
dynamics. (See drone pictures.)
Meltponds with ca. 7cm ice cover on top, below ~50cm water, below ~1m ice

1. 2022T98
2. 448890 shows a 2cm tick up of bottom melt on sep24 while the ice is cooling to ocean temp from the bottom up to ~1.15m.
3. drift, looks like a touch of megacrack (minicrack?)
« Last Edit: October 17, 2022, 12:57:29 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #35 on: October 17, 2022, 01:55:17 PM »
Perhaps we can learn from this duo how to interpret bottom melt from the Tbuoy Heat data.
1. 2022T98 Heat120
2. 2022T98 log(H120/H30)

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Re: buoy data 22/23fr
« Reply #36 on: October 18, 2022, 12:54:14 PM »
It's amazing how different these floe profiles are. Each telling a different story.
Here's another look at 2022T96.

Hmmm. 11 cm of freeboard would suggest it's floating on 1m of submerged ice. Perhaps less if the stuff above the waterline is less than 90% the density of the water. As in honeycombed out and containing significant amounts of air.
So when they say 1.93 metres thick, I guess they are referring to a 1.93 metre thick waterlogged mass of rotten ice around 50:50 ice:water.
Could be less, temp data suggests it's very fresh water it's full of.
Fresh water is about 3% less dense than seawater. So could account for up to 6cm of freeboard.
Perhaps realistically the frozen percentage of the floe called 193cm thick ice, is more like 30% ?
Nice to have a second opinion occasionally.

All the southern Tbuoys show the effects of the warm period on sep24-25, perhaps even a hint of warmer water beneath the ice. Starting to look like another ridged floe. Look into that later.
mini crack around ellesmere has closed up.
« Last Edit: October 18, 2022, 03:12:50 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #37 on: October 18, 2022, 08:30:13 PM »
All the nh snowbuoy distance sounders failed.

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Re: buoy data 22/23fr
« Reply #38 on: October 20, 2022, 05:52:48 PM »
Float 6903705 in the northern Barents showing +2C down to 40m on oct17.

Interesting article that may help analysis.

argoFloats: An R Package for Analyzing Argo Data
Dan E. Kelley, Jaimie Harbin and Clark Richards
TECHNOLOGY AND CODE article
Front. Mar. Sci., 04 May 2021
Sec. Ocean Observation
https://doi.org/10.3389/fmars.2021.635922

Quote
An R package named argoFloats has been developed to facilitate identifying, downloading, caching, and analyzing oceanographic data collected by Argo profiling floats. The analysis phase benefits from close connections between argoFloats and the oce package, which is likely to be familiar to those who already use R for the analysis of oceanographic data of other kinds. This paper outlines how to use argoFloats to accomplish some everyday tasks that are particular to Argo data, ranging from downloading data and finding subsets to handling quality control and producing a variety of diagnostic plots. The benefits of the R environment are sketched in the examples, and also in some notes on the future of the argoFloats package.

This simple code produced the first image below:
Quote
#load libraries
library(oce)
library(argoFloats)

#get buoy index
index1  <- getIndex()

#subset to buoy(s)
index2 <- subset(index1, ID="6903705")

#plot cycle locations
plot(index2, bathymetry=TRUE)

1. argofloats drift
2. https://fleetmonitoring.euro-argo.eu/float/6903705  drift
3. latest profile

« Last Edit: October 20, 2022, 06:50:03 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #39 on: October 21, 2022, 12:29:05 AM »
Animation of 6903705 profiles in the Barents, since apr30, all in the same small area so a good view of changes over time.
having trouble setting static scales but gives a good idea of the mixed layer setting up.
« Last Edit: October 21, 2022, 01:21:54 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #40 on: October 21, 2022, 01:32:10 PM »
So, oce PlotProfile uses Tlim for temp limits and Slim for salinity. Now the axes don't jump about any more.

One day someone will join in with the coding....
Quote
profiles <- getProfiles(index2)
argos3705 <- readProfiles(profiles)

for (i in 136:170 ){
prof1 <- argos3705[]
ylim <- c(200, 0)
xlimt <-c(-2, 6.5)
xlims <-c(33, 34.9)
proftime <- unlist(prof1[["time"]])
ctd <- as.ctd(unlist(prof1[["salinity"]]),
              unlist(prof1[["temperature"]]),
              unlist(prof1[["pressure"]]))

jpeg(file=paste("float/3705-",i,".jpg"))
# Plot temp to the left, and sal to the right
par(mfrow=c(1, 2))
plotProfile(ctd, xtype="temperature", Tlim =xlimt, ylim=c(200,0),  type="p", col="red")
text(x = 3.3, y = -4, labels = paste("6903705 cycle",i," ",proftime))
plotProfile(ctd, xtype="salinity", Slim=xlims, ylim=c(200,0), type="p", col="darkgreen")
dev.off()

}
« Last Edit: October 21, 2022, 05:18:47 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #41 on: October 21, 2022, 01:43:19 PM »
cmems analysis and modelling tending to agree.
https://myocean.marine.copernicus.eu/-/u0prxowa44

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Re: buoy data 22/23fr
« Reply #42 on: October 21, 2022, 05:22:59 PM »
6903589 at the entrance to the Barents has a much warmer near surface layer in summer but generally looks well mixed down to 200m.

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Re: buoy data 22/23fr
« Reply #43 on: October 23, 2022, 04:16:24 PM »
Radically differing profiles of Argo 6904222 as it drifts along the shelf break between Svalbard and FJL from aug25 to oct14, cycle 8-15. Currently about 20km from the ice edge, probably much closer on oct7.
Quote
<>
14/10/2022 13:21:20
Cycle 15
Last Surface Data
8 dbar 0.639℃ 33.768 PSU

https://fleetmonitoring.euro-argo.eu/float/6904222
https://go.nasa.gov/3D2KUnk  oct14 location
https://go.nasa.gov/3F1GoqD  oct7 loc with wv oct6

The top 30m beginning to settle down 2.5km nearer to the ice edge but, perhaps more significantly, 10km further from the shelf break.
Quote
Last station date
21/10/2022 15:27:20
Cycle 16
Last Surface Data
6.1 dbar -0.984℃ 33.578 PSU
https://fleetmonitoring.euro-argo.eu/float/6904222
https://go.nasa.gov/3f0yK5a

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Re: buoy data 22/23fr
« Reply #44 on: October 24, 2022, 08:59:47 PM »
Argo 6903143 and 3144 look interesting, both deployed on aug1 quite close to each other on a daily cycle(mostly) in the WSC, probably to compare the profiles.
edit: inverted colours for 3144
edit2: get cycle number
Quote
profcyc <- unlist(prof1[["cycleNumber"]])
« Last Edit: October 25, 2022, 07:41:14 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #45 on: October 27, 2022, 09:12:58 PM »
Another look at our two co-located buoys drifting from the pole to Fram Strait.
Quote
T98
2022-10-27T00           87.130336N   14.451516
448890
2022-10-27T00      87.130192N   14.453221

Here we are hoping to use measured data from SIMB3-448890 to identify changes in snow level and ice bottom with temperature data from 2022T98.

Using the calculated log(heat120/heat30) chart, the first increase in snow depth is easily visible, the second, not so much. From oct2 looks like there may be a frosting problem on 448890.

At the ice bottom we see the anomalous warming (green) on T98 from sep18-22 possibly indicating a phase change, so maybe melt which 448890 detects on sep24. Tempting to speculate there is a similar indication on oct14 on T98 but we don't see a tick up on 448890. The warming anomalies do tend to correlate with the large drops in bottom distance though.
« Last Edit: October 27, 2022, 09:35:26 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #46 on: October 28, 2022, 10:25:33 PM »
WSC incoming at roughly 8.7km/day north of Svalbard over the last 22days using worldview measurements.

https://fleetmonitoring.euro-argo.eu/float/4903641
Quote
Float 4903641
Cycle 1
Date: 03/10/2022 16:33:00 Quality: 1
Position: 80.999N 15.896E Quality: 1

Cycle 2
Date: 14/10/2022 22:58:00 Quality: 1
Position: 81.566N 20.112E Quality: 1

Cycle 3
Date: 25/10/2022 02:41:00 Quality: 1
Position: 81.573N 26.029E Quality: 1

https://go.nasa.gov/3U2I0V1

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Re: buoy data 22/23fr
« Reply #47 on: October 31, 2022, 12:29:00 PM »
2 floats in the Barents just east of Svalbard, oct4-27.
Water there cooling uniformly down to 40m from +3C to +0.8C
https://fleetmonitoring.euro-argo.eu/float/6990507
« Last Edit: October 31, 2022, 12:35:51 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #48 on: November 03, 2022, 08:00:03 PM »
Animation of 6903705 profiles in the Barents, since apr30, all in the same small area so a good view of changes over time.

update of mid Barents temps. Profiles are 5days apart, not much drift.
TS charts
drift
temp contours
« Last Edit: November 03, 2022, 08:06:31 PM by uniquorn »

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Re: buoy data 22/23fr
« Reply #49 on: November 05, 2022, 03:15:45 PM »
For comparison here is Float3901865 in the Norwegian Sea, sep2016-oct2022
Temp, salinity and density.
https://fleetmonitoring.euro-argo.eu/float/3901865