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Author Topic: Arctic Ocean salinity, temperature and waves  (Read 107976 times)

nanning

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Re: Arctic Ocean salinity, temperature and waves
« Reply #750 on: September 12, 2020, 06:57:09 PM »
Great animations you've provided uniquorn, thank you. The first link is just an image of the colour scale if I open it.
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uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #751 on: September 12, 2020, 10:04:20 PM »
yes, I used to get told off for posting animations without the scale but including it in the animation makes the file size larger so I post it separately, if I remember. hmm

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Re: Arctic Ocean salinity, temperature and waves
« Reply #752 on: September 12, 2020, 10:10:54 PM »
yes, I used to get told off for posting animations without the scale but including it in the animation makes the file size larger so I post it separately, if I remember. hmm
thanks for including the scale it helps your method seems like a good compromise

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #753 on: September 12, 2020, 10:57:14 PM »
mercator 34m salinity, jun1-sep11
Mercator not showing anything unusual north of greenland at 34m (short term)
« Last Edit: September 12, 2020, 11:16:22 PM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #754 on: September 13, 2020, 10:29:48 PM »
nsidc ice age update

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #755 on: September 17, 2020, 05:09:01 PM »
Signs of turbulence north east end of the yermak plateau. https://go.nasa.gov/3iLPHNq

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #756 on: September 19, 2020, 09:58:07 PM »
mosaic iabp buoy names and relative locations for ref

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #757 on: September 19, 2020, 10:38:32 PM »
@Bruce Steele, whoi itp117 temperature spike on SAMI
edit: similar spike on itp105, Mackenzie river water?
« Last Edit: September 19, 2020, 11:02:30 PM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #758 on: September 20, 2020, 09:42:39 PM »

Bruce Steele

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Re: Arctic Ocean salinity, temperature and waves
« Reply #759 on: September 20, 2020, 10:50:43 PM »
 
The averaged salinity in the global ocean is  35.5 PSU, varying from less than 15 PSU at the mouth of the rivers to more than 40 PSU in the Dead Sea.

Uniquorn
So I was thinking ITP 105 had melted out and was sending questionable info. When I saw PSU at less than 20 I wasn’t thinking Mackenzie water. Then ITP 117 hit warm water. Too bad ITP 117 doesn’t  have salinity.  The other ITP buoys seem to be getting colder.


uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #760 on: September 20, 2020, 11:14:07 PM »
I hoped dissolved oxygen on 117 might mean more to you than it does to me. Actually it could be a battery problem, it has been going for a year.

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #761 on: September 21, 2020, 08:46:01 PM »
Thanks to u300673 for this great article from 2012
Sea ice inertial oscillations in the Arctic Basin
F. Gimbert, D. Marsan, J. Weiss, N. C. Jourdain, and B. Barnier
https://tc.copernicus.org/articles/6/1187/2012/tc-6-1187-2012.pdf
Quote
As observed from buoy drift data, the sea ice  mean  speed  over  the  Arctic  increased  at  a  rate  of  9% per decade from 1979 to 2007, whereas the mean deformation rate increased by more than 50 % per decade over the same period (Rampal et al.,2009). These two aspects of recent sea ice evolution, i.e. strong decline in terms of ice extent and thickness, and accelerated kinematics, are strongly coupled within the albedo feedback loop. Increasing deformation means increasing fracturing, hence more lead opening and a decreasing albedo (Zhang et al.,2000). As a result, ocean warming, in turn, favours sea ice thinning in summer  and  delays  refreezing  in  early  winter,  i.e.  strengthens sea ice decline. This thinning should decrease the mechanical strength, therefore allowing even more fracturing, hence larger speed and deformation. A consequence is the acceleration of the export of sea ice through Fram Strait, with a significant impact on sea ice mass balance (Rampal et al.,2009,2011; Haas et al.,2008), and ice age (Nghiem et al.,2007). Moreover, sea ice mechanical weakening decreases the likelihood of arch formation along Nares Strait, therefore allowing old, thick ice to be exported through this strait (Kwok et al.,2010).

A-Team

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Re: Arctic Ocean salinity, temperature and waves
« Reply #762 on: September 21, 2020, 09:17:42 PM »
Might take a look at the 2009 L Kalescke paper as he could be available to answer questions. Prolific sea ice expert R Kwok has also been on this since forever. Some of these papers could only base on 3 hr sampling whereas with the buoys of today, hourly or even half-hourly GPS reports are the rule. What's more, the GPS is a lot more accurate today. Tides in the central Arctic have period ½M2 or 12hr 42min.

Observation of cyclone-induced inertial sea-ice oscillation in Fram Strait
A Lammert B Brummer and L. Kaleschke

In this paper we present measurements of an intense cyclone, which occurred during FRAMZY 2007. The cyclone moved very fast from south to north through the Fram Strait and caused substantial inertial ice-motions lasting for several days. Inertial sea-ice oscillations are a known process both in the Arctic and the Antarctic. However, to the authors’ knowledge no observations of such a strong inertial oscillation in the Arctic have been presented in the literature before.

Sub-daily sea ice motion and deformation from RADARSAT observations
R Kwok  GF Cunningham WD Hibler 2003
https://trs.jpl.nasa.gov/bitstream/handle/2014/37327/03-2404.pdf?

We find a persistent level of oscillatory sea ice motion and deformation, superimposed on the large-scale wind-driven field, in May 2002 (spring) and February 2003 (midwinter), in the high Arctic over a region centered at (85N, 135W). At this latitude, the RADARSAT wide-swath SAR coverage provides 4 – 5 sequential observations every day, for ice motion retrieval, with a sampling interval at the orbital period of 101 minutes. Periodic correlations in ice motion and deformation can be seen in length scales from 10 km and above, and suggest a 12-hr oscillation that is more likely associated with inertial rather than tidal frequencies.

https://scholar.google.com/citations?hl=en&user=OtzTNwkAAAAJ&view_op=list_works&sortby=pubdate

Internal wave observations from the Arctic environmental drifting buoy
AJ Plueddemann August 1992

Near-Inertial Internal Gravity Waves in the Ocean
MHAlford et al
https://www.annualreviews.org/doi/abs/10.1146/annurev-marine-010814-015746

We review the physics of near-inertial waves (NIWs) in the ocean and the observations, theory, and models that have provided our present knowledge. NIWs appear nearly everywhere in the ocean as a spectral peak at and just above the local inertial period f, and the longest vertical wavelengths can propagate at least hundreds of kilometers toward the equator from their source regions; shorter vertical wavelengths do not travel as far and do not contain as much energy, but lead to turbulent mixing owing to their high shear. NIWs are generated by a variety of mechanisms, including the wind, nonlinear interactions with waves of other frequencies, lee waves over bottom topography, and geostrophic adjustment; the partition among these is not known, although the wind is likely the most important. NIWs likely interact strongly with mesoscale and submesoscale motions, in ways that are just beginning to be understood.
 
See also:

"W Munk: It was to be thirty years until Rob Pinkel showed that arctic observations were inconsistent with the assumed factoring of the spectrum. By then Chris had gotten nervous and claimed that the G in GM referred to his great uncle Arthur Garrett. A few years later Pinkel demonstrated that one could go a long way with just two Doppler-smeared spectral lines: the M2 tidal frequency and the local inertial frequency. Here I refer to the smearing of the spatial fine structure by the vertical orbital motion of the long internal waves"

https://www.researchgate.net/profile/R_Pinkel/publications
https://link.springer.com/chapter/10.1007%2F978-3-642-12087-9_7
« Last Edit: September 21, 2020, 09:47:49 PM by A-Team »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #763 on: September 21, 2020, 10:29:13 PM »
Overview of iabp buoys, will be taking a closer look at some of them tomorrow

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #764 on: September 22, 2020, 02:23:37 PM »
Overview of available iabp buoys north of Greenland and a closer animation of 300234065497190, 300234068810610 and 300234068027940.
csv data attached as text.

https://betterexplained.com/articles/an-interactive-guide-to-the-fourier-transform/
« Last Edit: September 22, 2020, 02:45:19 PM by uniquorn »

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Re: Arctic Ocean salinity, temperature and waves
« Reply #765 on: September 22, 2020, 08:53:17 PM »
Go through enough journal articles and eventually ones will show up that actually explain near-inertial waves and the history of their research. Note too F Gimbert fired off a small burst of articles on this, not just the one above.

Dynamics of the Changing Near-Inertial Internal Wave Field in the Arctic Ocean
Hayley V. Dosser; Luc Rainville
J. Phys. Oceanogr. (2016) 46 (2): 395–415.
https://journals.ametsoc.org/jpo/article/46/2/395/12534

'The dynamics of the wind-generated near-inertial internal wave field in the Canada Basin of the Arctic Ocean are investigated using the drifting Ice-Tethered Profiler dataset for the years 2005 to 2014, during a decade when sea ice extent and thickness decreased dramatically. This time series, with nearly 10 years of measurements and broad spatial coverage, is used to quantify a seasonal cycle and inter-annual trend for internal waves in the Arctic, using estimates of the amplitude of near-inertial waves derived from isopycnal displacements.

'The internal wave field is found to be most energetic in summer when sea ice is at a minimum, with a second maximum in early winter during the period of maximum wind speed.

'The standard picture of Arctic internal waves derives from observations made during the 1980s and 1990s [e.g., the Arctic Internal Waves Experiment (AIWEX) in spring of 1985 (Levine et al. 1987; D’Asaro and Morehead 1991; Merrifield and Pinkel 1996) and the Surface Heat Budget of the Arctic Experiment (SHEBA) in 1997 to 1998 (Pinkel 2005)], which found a quiescent Arctic Ocean with an internal wave field energy level an order of magnitude or more below that at lower latitudes (Levine et al. 1985, 1987).

'Low internal wave energy levels in the Arctic are attributed to the presence of sea ice, which causes dissipation of internal waves in the under-ice surface boundary layer, limiting energy propagation across the Arctic (Morison et al. 1985; Pinkel 2005; Fer 2014). It has been suggested that sea ice impedes momentum transfer from the wind to the water column (Plueddemann et al. 1998), with ice deformation being of more importance to internal wave generation (Halle and Pinkel 2003).

'Most of the energy in the internal wave field is contained in the near-inertial frequency band, from roughly f–1.1f, where f is the local Coriolis or inertial frequency (Garrett and Munk 1972; Garrett 2001). In the Arctic Ocean, observations of the internal wave spectrum show the expected peak at the inertial frequency (Halle and Pinkel 2003; Fer 2014; Cole et al. 2014). Near-inertial internal waves can be generated whenever wind stress resonantly forces the air–ice or air–water interface at or near the inertial frequency. In the Northern Hemisphere, anticyclonic or clockwise inertial oscillations are set up in the sea ice and mixed layer.

These purely horizontal oscillations create disturbances at the base of the mixed layer, generating a freely propagating near-inertial wave in the stratified water column below (D’Asaro 1985). The result is vertical propagation of energy through the water column to depths at which the internal waves can become unstable and break (Gregg et al. 1986; Hebert and Moum 1994).

'Near-inertial internal waves can also be generated as a result of the motion of drifting sea ice. The rough bottom of the ice impulsively forces the water column, or there may be horizontal variations in bottom roughness that cause vertical motion of the fluid below. This results in a pattern of forcing related to ice roughness and ice–ocean drag that is moving at the velocity of the sea ice, which can generate internal waves (McPhee and Kantha 1989) with horizontal and spatial scales consistent with observations of near-inertial waves in the Arctic Ocean (D’Asaro and Morehead 1991).'


Recent mechanical weakening of the Arctic sea ice cover
as revealed from larger inertial oscillations
F Gimbert NC Jourdain D Marsan J Weiss B. Barnier

Our approach, performed at the basin and multi-decadal scales from the International Arctic Buoy Programme (IABP) data set, consists in the analysis of the response of sea ice to the well-defined Coriolis force. As this specific forcing is constant over time, an evolution of the response, i.e., of ice motion around the inertial frequency f0 ≈ 2 cycles.d1 within the arctic basin, would be a signature of a change in the mechanical behavior of the ice cover.

Ww performed a statistical analysis of the magnitude of inertial motion, relatively to the norm of the velocities, and revealed spatial and seasonal patterns in agreement with the corresponding ice concentration and thickness patterns, i.e., inertial motion is more pronounced in regions (Beaufort Sea, eastern Arctic) and seasons (summers) where ice is thinner and less concentrated. This analysis also revealed a significant strengthening of ice inertial motion at the basin scale, in both summer and winter, in recent years.

This evolution, we suggested, is likely to be the signature of a mechanical weakening of the ice cover and a decrease of the magnitude of internal stresses. This analysis, however, did not allow to differentiate precisely the direct effect of ice thinning, the effect of a possible modification of vertical penetration of turbulent momentum within the ocean boundary layer, or that of an actual mechanical weakening, onto this strengthening of inertial motion.

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #766 on: September 23, 2020, 11:54:58 PM »
Thanks for those articles.

2 new whoi itp buoys, 120 and 121

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #767 on: September 25, 2020, 12:01:58 PM »
Images of the area of 'flash freezing' in the Beaufort.
Worldview terra modis true colour (adaptive contrast) with amsr2-awi-v103 overlay
Polarview S1B with worldview true colour overlay (click)
A cropped comparison of 2 small areas of interest.
« Last Edit: September 25, 2020, 12:07:38 PM by uniquorn »

Glen Koehler

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Re: Arctic Ocean salinity, temperature and waves
« Reply #768 on: September 29, 2020, 03:07:10 AM »
Ocean Stratification is Not Good News. Very Not Good.
https://climatecrocks.com/2020/09/28/ocean-stratification-is-not-good-news-very-not-good/

"This seemingly technical finding has profound and troubling implications. The more stable the upper ocean, the less vertical mixing that takes place. This mixing is a primary means by which the ocean buries warming surface waters. So the surface warms up even faster. It’s what we call a “positive feedback”—a vicious cycle."

"Our study suggests that key positive feedbacks (amplifying factors) related to reduced ocean heat might lead to more rapid surface warming in the decades ahead than many of the models predict."

Freegrass

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Re: Arctic Ocean salinity, temperature and waves
« Reply #769 on: October 01, 2020, 08:42:30 PM »
The next step in my evolution is learning more about salinity. But I don't know how the read Uniquorn's graphs... I'm unable to visualize it...

Isn't there a way to turn the Mercator 2D images into a 3D graphical presentation? They have salinity at all levels, so isn't it possible to use that data to create something like this?

« Last Edit: October 01, 2020, 08:48:06 PM by Freegrass »
Now let's pray...

If the science don't fit our beliefs, we pray to God and cuddle up in our own delusional fantasy where everything makes sense again...

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #770 on: October 02, 2020, 05:21:52 PM »
Nice. Underwater waterfalls.

Glen Koehler

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Re: Arctic Ocean salinity, temperature and waves
« Reply #771 on: October 02, 2020, 07:15:13 PM »
The next step in my evolution is learning more about salinity. But I don't know how the read Uniquorn's graphs... I'm unable to visualize it...

Isn't there a way to turn the Mercator 2D images into a 3D graphical presentation? They have salinity at all levels, so isn't it possible to use that data to create something like this?


    That would make a lovely live-feed wallscreen animation for NSIDC headquarters.

Freegrass

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Re: Arctic Ocean salinity, temperature and waves
« Reply #772 on: October 03, 2020, 07:27:45 AM »
Nice. Underwater waterfalls.
Saltwaterfalls...

There are more visualisations on their YouTube page.

CEN Climate Visualization Laboratory
https://www.youtube.com/user/KlimaCampus/videos

https://www.cen.uni-hamburg.de/en/facilities/visualization.html
« Last Edit: October 03, 2020, 07:43:28 AM by Freegrass »
Now let's pray...

If the science don't fit our beliefs, we pray to God and cuddle up in our own delusional fantasy where everything makes sense again...

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #773 on: October 03, 2020, 01:34:08 PM »
It's not just the salinity, Atlantic water returning from the Arctic Ocean is also cooler with higher density.

Key Physical Variables in the Ocean: Temperature, Salinity, and Density


Quote
Figure 1: A vertical profile of temperature and salinity at 39°N, 152°W in the North Pacific (data courtesy of the CLIVAR and Carbon Hydrographic Data Office, cchdo.uscd.edu).
a) Vertical profiles of in-situ temperature t, potential temperature θ, and Conservative Temperature Θ. Inset shows an expanded view of deep ocean values. Potential and Conservative temperature are within 0.0003°C in the deep ocean. Note that heat content (proportional to Θ) actually decreases with depth, but pressure effects cause a rise in the in-situ temperature t. b) Vertical profiles of Practical Salinity SP (with no units), Reference Salinity SR, and Absolute Salinity SA. c) Vertical profiles of in-situ density (σ), potential density referenced to the sea surface (σθ), and potential density referenced to 4000 dbar (σ4). Most of the in-situ density increase with depth is due to pressure effects, which are removed in the calculation of potential densities, showing how weakly stratified the ocean actually is.
© 2013 Nature Education All rights reserved. View Terms of Use

or a simpler way of looking at it, though not that relevant to the arctic.

Also an 'interesting' section of itp110 drift path showing how density changes with temperature and salinity, 7m-80m from 2019, day123-218 (best viewed at half speed)
density green, temperature purple, salinity red
temp    -1.8 to 0.6C
salinity  27.5 to 31.2
density 1021.5 to 1025kg/m^3

http://www.csgnetwork.com/water_density_calculator.html
Quote
The equation used in this calculator can be found in:
Millero, F, C. Chen, A Bradshaw, and K. Schleicher, 1980: A new high pressure equation of state for seawater, Deep Sea Research, Part A, 27, 255-264.
doi:10.1080/15210608209379435

It would be nice to have someone else check the calculations:
Quote
function CalcDen(form) {
//function sig=sigma(p,t,s)

// calculates in situ density.
// millero et al 1980, deep-sea res.,27a,255-264
// jpots ninth report 1978,tenth report 1980
// units:
//       pressure        p        decibars
//       temperature     t        deg celsius (ipts-68)
//       salinity        s        nsu (ipss-78)
//                       sigma    (10.**-3)g/cm**3
//
// r. schlitzer  (5/18/89)


var p = document.denform.pressure.value;
var t = document.denform.temp.value;
var s = document.denform.conc.value;
// change pressure from input units of decibars to bars
// square root salinity.
p=p/10;sr= Math.sqrt(Math.abs(s));
// density pure water at atm press in kg/m3 = (10**-3)gm/cm3
r1=((((6.536332e-9*t-1.120083e-6)*t+1.001685e-4)*t-9.095290e-3)*t+6.793952e-2)*t- .157406;
// seawater density atm press.
r2=(((5.3875e-9*t-8.2467e-7)*t+7.6438e-5)*t-4.0899e-3)*t+0.824493;
r3=(-1.6546e-6*t+1.0227e-4)*t-5.72466e-3; r4=4.8314e-4;
sig=(r4*s + r3*sr + r2)*s + r1;
// compute compression terms
e=(9.1697e-10*t+2.0816e-8)*t-9.9348e-7;
bw=(5.2787e-8*t-6.12293e-6)*t+8.50935e-5; b=bw+e*s;
c=(-1.6078e-6*t-1.0981e-5)*t+2.2838e-3;
aw=((-5.77905e-7*t+1.16092e-4)*t+1.43713e-3)*t+3.239908;
a=(1.91075e-4*sr+c)*s+aw;
b1=(-5.3009e-4*t+1.6483e-2)*t+7.944e-2;
a1=((-6.1670e-5*t+1.09987e-2)*t-0.603459)*t+54.6746;
kw=(((-5.155288e-5*t+1.360477e-2)*t-2.327105)*t+148.4206)*t+19652.21;
k0=(b1*sr+a1)*s+kw;
// evaluate pressure polynomial and return
k=(b*p+a)*p+k0;
sig=(k*sig+1000*p)/(k-p);
// sig remains unchanged since is (10**-3)gm/cm**3
document.denform.density.value = perRound(sig+1000);
}
« Last Edit: October 03, 2020, 10:12:54 PM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #774 on: October 14, 2020, 01:06:31 PM »
Tidally Forced Lee Waves Drive Turbulent Mixing Along the Arctic Ocean Margins
Ilker Fer, Zoé Koenig, Igor E. Kozlov, Marek Ostrowski, Tom P. Rippeth,, Laurie Padman, Anthony Bosse, Eivind Kolås
First published: 06 August 2020

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2020GL088083

Quote
Abstract

In the Arctic Ocean, limited measurements indicate that the strongest mixing below the atmospherically forced surface mixed layer occurs where tidal currents are strong. However, mechanisms of energy conversion from tides to turbulence and the overall contribution of tidally driven mixing to Arctic Ocean state are poorly understood. We present measurements from the shelf north of Svalbard that show abrupt isopycnal vertical displacements of 10–50 m and intense dissipation associated with cross‐isobath diurnal tidal currents of ∼0.15 m s−1. Energy from the barotropic tide accumulated in a trapped baroclinic lee wave during maximum downslope flow and was released around slack water. During a 6‐hr turbulent event, high‐frequency internal waves were present, the full 300‐m depth water column became turbulent, dissipation rates increased by a factor of 100, and turbulent heat flux averaged 15 W m−2 compared with the background rate of 1 W m−2.

binntho

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Re: Arctic Ocean salinity, temperature and waves
« Reply #775 on: October 14, 2020, 03:25:53 PM »
Interesting article, Uniqorn. It is clear that turbulence mixing caused by tidal currents + bathymetry are a significant factor in the transfer of heat verticaly. But what strikes me is the extremely low speed of 0.15 m/s - only one tenth of normal walking speed. But then again, the volume must be large.
because a thing is eloquently expressed it should not be taken to be as necessarily true
St. Augustine, Confessions V, 6

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #776 on: October 23, 2020, 04:18:24 PM »
amsr2, awi dev v103 overlaid onto mercator 0m ocean temperature and salinity, sep4-oct22  (8MB)
Combined these two ani's from the freezing season thread to make it easier to compare daily changes.

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Re: Arctic Ocean salinity, temperature and waves
« Reply #777 on: October 27, 2020, 09:31:12 PM »
Thank you, I like this animation very much
By using it with the forecasts, we could really have a good anticipation of the evolution of the extent at 4 to 6 days, and more by taking into account the atmospheric forecasts.
But I do not have the skills and the equipment to develop such animations.
But I will try, consulting forecasts, to do it in my mind
Sorry, excuse my bad english

uniquorn

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Sorry, excuse my bad english

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #780 on: October 28, 2020, 11:35:26 PM »
whoi-itp121 update

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Re: Arctic Ocean salinity, temperature and waves
« Reply #781 on: October 30, 2020, 01:12:11 PM »
http://bulletin.mercator-ocean.fr/en/permalink/PSY4/animation/3/20201020/20201027/1/1
Thanks, this will ne vert usefull for me :)
Sorry, i want to Say "Thanks, this will be very usefull for me"
But cause to my bad english and cause to my french phone i wrote a wrong sentence, sorry
Thank you again for the link 😊
Sorry, excuse my bad english

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #782 on: November 04, 2020, 02:23:41 PM »
A good read:

A Tale of Two Spicy Seas
Jennifer A. MacKinnon ,  Jonathan D. Nash,  Matthew H. Alford ,  Andrew J. Lucas,  John B. Mickett,  Emily L. Shroyer,  Amy F. Waterhouse,  Amit Tandon ,  Debasis Sengupta,  Amala Mahadevan,  M. Ravichandran,  Robert Pinkel ,  Daniel L. Rudnick,  Caitlin B. Whalen,  Marion S. Alberty,  J. Sree Lekha,  Elizabeth C. Fine,  Dipanjan Chaudhuri,  Gregory L. Wagner
Quote
Abstract
Upper-ocean turbulent heat fluxes in the Bay of Bengal and the Arctic Ocean drive regional monsoons and sea ice melt, respectively, important issues of societal interest. In both cases, accurate prediction of these heat transports depends on proper representation of the small-scale structure of vertical stratification, which in turn is created by a host of complex submesoscale processes. Though half a world apart and having dramatically different temperatures, there are surprising similarities between the two: both have (1) very fresh surface layers that are largely decoupled from the ocean below by a sharp halocline barrier, (2) evidence of interleaving lateral and vertical gradients that set upper-ocean stratification, and (3) vertical turbulent heat fluxes within the upper ocean that respond sensitively to these structures. However, there are clear differences in each ocean’s horizontal scales of variability, suggesting that despite similar background states, the sharpening and evolution of mesoscale gradients at convergence zones plays out quite differently. Here, we conduct a qualitative and statistical comparison of these two seas, with the goal of bringing to light fundamental underlying dynamics that will hopefully improve the accuracy of forecast models in both parts of the world.

Tor Bejnar

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Re: Arctic Ocean salinity, temperature and waves
« Reply #783 on: November 06, 2020, 04:22:20 PM »
The latest Zach Labe (ZLabe) Arctic temperature chart (from here).

Arctic ice is healthy for children and other living things.

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #784 on: November 13, 2020, 11:09:24 PM »
mercator (model) salinity at 34m, sep2018-nov2020
« Last Edit: November 13, 2020, 11:16:47 PM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #785 on: November 15, 2020, 07:55:50 PM »
some doubts about atlantic water affecting ice concentration in the Laptev above the SE Nansen shelf. Here is an overlay of amsr2uhh onto gmrt bathymetry, oct20-29, 2013-2020.
accepted that correlation (if it can be seen) is not causation.
I don't have some older days or they have poor data

Brigantine

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Re: Arctic Ocean salinity, temperature and waves
« Reply #786 on: November 19, 2020, 09:56:02 AM »
That one ARGO float following the West Spitzbergen Current all the way to 37E... She's still kicking.
(another one is somewhere around 90E, but I'm pretty sure that one's dead)

There's been some mixing there over the last 3 days. (or the float moved into a more mixed area)
The halocline has been quite diluted - currently not enough to support freezing point temperatures above the 3.7°C Atlantic water.
« Last Edit: November 19, 2020, 10:14:10 AM by Brigantine »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #787 on: November 19, 2020, 11:30:47 AM »
Thanks, forgot about that argo. Barents water coming through the gap perhaps. It seems there are 3 still active though 550 hasn't reported for nearly a month. csv data is in a different format, no time to work on them at the moment.

https://fleetmonitoring.euro-argo.eu/float/3902107
« Last Edit: November 19, 2020, 11:53:52 AM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #788 on: November 19, 2020, 07:04:41 PM »
A quick look at itp116 drift path for old times sake.

JayW

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Re: Arctic Ocean salinity, temperature and waves
« Reply #789 on: November 21, 2020, 02:51:42 AM »
Yermak plateau area.  36 hour loop
Band I4 inverted colors

"To defy the laws of tradition, is a crusade only of the brave" - Les Claypool

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #790 on: November 21, 2020, 10:32:47 AM »
Thanks for keeping an eye on the Yermak JayW, a rare cloud free period.
Band I4 3.74µm "Shortwave IR Window"    https://col.st/Ip3ih (roughly)

Probably not seasonal then.
« Last Edit: November 21, 2020, 10:51:57 AM by uniquorn »

uniquorn

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Re: Arctic Ocean salinity, temperature and waves
« Reply #791 on: November 23, 2020, 12:02:15 AM »
update on itp113 back in the middle of the Beaufort. A big difference to itp121 further north