scholarly journals Estimation of thermodynamic and dynamic contributions to sea ice growth in the Central Arctic using ICESat-2 and MOSAiC SIMBA buoy data

2021 ◽  
Vol 267 ◽  
pp. 112730
Author(s):  
YoungHyun Koo ◽  
Ruibo Lei ◽  
Yubing Cheng ◽  
Bin Cheng ◽  
Hongjie Xie ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Growth ◽  
Buoy Data

scholarly journals Sea-ice growth and water-mass modification in the Mertz Glacier polynya, East Antarctica, during winter

2001 ◽  
Vol 33 ◽  
pp. 399-406 ◽  
Author(s):  
N. L. Bindoff ◽  
G. D. Williams ◽  
I. Allison
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Fresh Water ◽  
Acoustic Doppler Current Profiler ◽  
Water Masses ◽  
Surface Velocity ◽  
Return Flow ◽  
Shelf Water ◽  
Ice Growth ◽  
Current Profiler

AbstractIn July-September 1999, an extensive oceanographic survey (87 conductivity-, temperature-and depth-measuring stations) was conducted in the Mertz Glacier polynya over the Adélie Depression off the Antarctic coast between 145° and 150° E. We identify and describe four key water masses in this polynya: highly modified circumpolar deep water (HMCDW), winter water (WW), ice-shelf water (ISW) and high-salinity shelf water (HSSW). Combining surface velocity data (from an acoustic Doppler current-profiler) with three hydrographic sections, we found the HMCDW to be flowing westward along the shelf break (0.7 Sv), the WW and HSSW flowing eastwards underneath Mertz Glacier (2.0 Sv) and that there was a westward return flow of ISW against the continent (1.2 Sv). Using a simple box model for the exchanges of heat and fresh water between the principal water masses, we find that the polynya was primarily a latent-heat polynya with 95% of the total heat flux caused by sea-ice formation. This heat flux results from a fresh-water-equivalent sea-ice growth rate of 4.9−7.7 cm d−1 and a mass exchange between HMCDW and WW of 1.45 Sv The inferred ocean heat flux is 8−14 W m−2 and compares well with other indirect estimates.

scholarly journals Importance of open-water ice growth and ice concentration evolution: a study based on FESOM-ECHAM6

2015 ◽  
Vol 6 (2) ◽  
pp. 2137-2179
Author(s):  
X. Shi ◽  
G. Lohmann
Keyword(s):  
Sea Ice ◽  
Surface Albedo ◽  
Global Climate Model ◽  
Open Water ◽  
Arctic Sea Ice ◽  
Meridional Overturning Circulation ◽  
The Arctic ◽  
Water Ice ◽  
Ice Growth ◽  
Ice Concentration

Abstract. A newly developed global climate model FESOM-ECHAM6 with an unstructured mesh and high resolution is applied to investigate to what degree the area-thickness distribution of new ice formed in open water affects the ice and ocean properties. A sensitivity experiment is performed which reduces the horizontal-to-vertical aspect ratio of open-water ice growth. The resulting decrease in the Arctic winter sea-ice concentration strongly reduces the surface albedo, enhances the ocean heat release to the atmosphere, and increases the sea-ice production. Furthermore, our simulations show a positive feedback mechanism among the Arctic sea ice, the Atlantic Meridional Overturning Circulation (AMOC), and the surface air temperature in the Arctic, as the sea ice transport affects the freshwater budget in regions of deep water formation. A warming over Europe, Asia and North America, associated with a negative anomaly of Sea Level Pressure (SLP) over the Arctic (positive phase of the Arctic Oscillation (AO)), is also simulated by the model. For the Southern Ocean, the most pronounced change is a warming along the Antarctic Circumpolar Current (ACC), especially for the Pacific sector. Additionally, a series of sensitivity tests are performed using an idealized 1-D thermodynamic model to further investigate the influence of the open-water ice growth, which reveals similar results in terms of the change of sea ice and ocean temperature. In reality, the distribution of new ice on open water relies on many uncertain parameters, for example, surface albedo, wind speed and ocean currents. Knowledge of the detailed processes is currently too crude for those processes to be implemented realistically into models. Our sensitivity experiments indicate a pronounced uncertainty related to open-water sea ice growth which could significantly affect the climate system.

scholarly journals Upper ocean stratification and sea ice growth rates during the summer-fall transition, as revealed by Elephant seal foraging in the Adélie Depression, East Antarctica

Ocean Science ◽  
2011 ◽  
Vol 7 (2) ◽  
pp. 185-202 ◽  
Author(s):  
G. D. Williams ◽  
M. Hindell ◽  
M.-N. Houssais ◽  
T. Tamura ◽  
I. C. Field
Keyword(s):  
Sea Ice ◽  
Continental Shelf ◽  
Mixed Layer ◽  
Growth Rates ◽  
Shelf Break ◽  
Upper Ocean ◽  
Ocean Stratification ◽  
Glacier Tongue ◽  
Ice Growth ◽  
Continental Shelf Break

Abstract. Southern elephant seals (Mirounga leonina), fitted with Conductivity-Temperature-Depth sensors at Macquarie Island in January 2005 and 2010, collected unique oceanographic observations of the Adélie and George V Land continental shelf (140–148° E) during the summer-fall transition (late February through April). This is a key region of dense shelf water formation from enhanced sea ice growth/brine rejection in the local coastal polynyas. In 2005, two seals occupied the continental shelf break near the grounded icebergs at the northern end of the Mertz Glacier Tongue for several weeks from the end of February. One of the seals migrated west to the Dibble Ice Tongue, apparently utilising the Antarctic Slope Front current near the continental shelf break. In 2010, immediately after that year's calving of the Mertz Glacier Tongue, two seals migrated to the same region but penetrated much further southwest across the Adélie Depression and sampled the Commonwealth Bay polynya from March through April. Here we present observations of the regional oceanography during the summer-fall transition, in particular (i) the zonal distribution of modified Circumpolar Deep Water exchange across the shelf break, (ii) the upper ocean stratification across the Adélie Depression, including alongside iceberg C-28 that calved from the Mertz Glacier and (iii) the convective overturning of the deep remnant seasonal mixed layer in Commonwealth Bay from sea ice growth. Heat and freshwater budgets to 200–300 m are used to estimate the ocean heat content (400→50 MJ m−2), flux (50–200 W m−2 loss) and sea ice growth rates (maximum of 7.5–12.5 cm day−1). Mean seal-derived sea ice growth rates were within the range of satellite-derived estimates from 1992–2007 using ERA-Interim data. We speculate that the continuous foraging by the seals within Commonwealth Bay during the summer/fall transition was due to favorable feeding conditions resulting from the convective overturning of the deep seasonal mixed layer and chlorophyll maximum that is a reported feature of this location.

scholarly journals New insight from CryoSat-2 sea ice thickness for sea ice modelling

2018 ◽  
Author(s):  
David Schröder ◽  
Danny L. Feltham ◽  
Michel Tsamados ◽  
Andy Ridout ◽  
Rachel Tilling
Keyword(s):  
Sea Ice ◽  
Thickness Distribution ◽  
Arctic Sea Ice ◽  
Ice Thickness ◽  
Atmospheric Conditions ◽  
Sea Ice Concentration ◽  
Sea Ice Thickness ◽  
Ice Growth ◽  
Melt Pond ◽  
The Impact

Abstract. Estimates of Arctic sea ice thickness are available from the CryoSat-2 (CS2) radar altimetry mission during ice growth seasons since 2010. We derive the sub-grid scale ice thickness distribution (ITD) with respect to 5 ice thickness categories used in a sea ice component (CICE) of climate simulations. This allows us to initialize the ITD in stand-alone simulations with CICE and to verify the simulated cycle of ice thickness. We find that a default CICE simulation strongly underestimates ice thickness, despite reproducing the inter-annual variability of summer sea ice extent. We can identify the underestimation of winter ice growth as being responsible and show that increasing the ice conductive flux for lower temperatures (bubbly brine scheme) and accounting for the loss of drifting snow results in the simulated sea ice growth being more realistic. Sensitivity studies provide insight into the impact of initial and atmospheric conditions and, thus, on the role of positive and negative feedback processes. During summer, atmospheric conditions are responsible for 50 % of September sea ice thickness variability through the positive sea ice and melt pond albedo feedback. However, atmospheric winter conditions have little impact on winter ice growth due to the dominating negative conductive feedback process: the thinner the ice and snow in autumn, the stronger the ice growth in winter. We conclude that the fate of Arctic summer sea ice is largely controlled by atmospheric conditions during the melting season rather than by winter temperature. Our optimal model configuration does not only improve the simulated sea ice thickness, but also summer sea ice concentration, melt pond fraction, and length of the melt season. It is the first time CS2 sea ice thickness data have been applied successfully to improve sea ice model physics.

Overview of sea ice growth and properties

Sea Ice ◽  
2016 ◽  
pp. 1-41 ◽  
Author(s):  
Chris Petrich ◽  
Hajo Eicken
Keyword(s):  
Sea Ice ◽  
Ice Growth

scholarly journals Thermodynamic sea ice growth in the central Weddell Sea, observed in upward-looking sonar data

2015 ◽  
Vol 120 (3) ◽  
pp. 2270-2286 ◽  
Author(s):  
A. Behrendt ◽  
W. Dierking ◽  
H. Witte
Keyword(s):  
Sea Ice ◽  
Weddell Sea ◽  
Ice Growth

scholarly journals The Effect of Finite Heat Content and Thermal Diffusion on the Growth of a Sea-Ice Cover

1964 ◽  
Vol 5 (39) ◽  
pp. 315-324 ◽  
Author(s):  
Peter Schwerdtfeger
Keyword(s):  
Thermal Diffusivity ◽  
Sea Ice ◽  
Basic Equation ◽  
Heat Content ◽  
Ice Cover ◽  
Hudson Bay ◽  
Growth Equation ◽  
Ice Growth ◽  
Classical Work ◽  
Practical Analysis

AbstractThe practical analysis of the growth of a sea-ice cover is discussed with initial reference to the classical work of Stefan, whose basic equation connecting surface temperature with the growth of a uniform ice cover of negligible specific heat and hence infinite diffusivity is extended to cover “real” cases. The separate effects of a finite heat content and thermal diffusivity are derived theoretically and semi-empirically respectively, and combined in a more general ice-growth equation which is then tested in the analysis of annual sea-ice growth on Hudson Bay.

Sea Ice Growth, Melt, and Modeling: A Survey

2000 ◽  
pp. 549-587 ◽  
Author(s):  
Michael Steele ◽  
Gregory M. Flato
Keyword(s):  
Sea Ice ◽  
Ice Growth

scholarly journals The 2018 North Greenland polynya observed by a newly introduced merged optical and passive microwave sea-ice concentration dataset

2019 ◽  
Vol 13 (7) ◽  
pp. 2051-2073 ◽  
Author(s):  
Valentin Ludwig ◽  
Gunnar Spreen ◽  
Christian Haas ◽  
Larysa Istomina ◽  
Frank Kauker ◽  
...  
Keyword(s):  
Sea Ice ◽  
Growth Yield ◽  
Thermal Infrared ◽  
Passive Microwave ◽  
Pressure System ◽  
Sea Ice Concentration ◽  
Sea Ice Thickness ◽  
Ice Growth ◽  
Spatial Coverage ◽  
Ice Concentration

Abstract. Observations of sea-ice concentration are available from satellites year-round and almost weather-independently using passive microwave radiometers at resolutions down to 5 km. Thermal infrared radiometers provide data with a resolution of 1 km but only under cloud-free conditions. We use the best of the two satellite measurements and merge thermal infrared and passive microwave sea-ice concentrations. This yields a merged sea-ice concentration product combining the gap-free spatial coverage of the passive microwave sea-ice concentration and the 1 km resolution of the thermal infrared sea-ice concentration. The benefit of the merged product is demonstrated by observations of a polynya which opened north of Greenland in February 2018. We find that the merged sea-ice concentration product resolves leads at sea-ice concentrations between 60 % and 90 %. They are not resolved by the coarser passive microwave sea-ice concentration product. The benefit of the merged product is most pronounced during the formation of the polynya. Next, the environmental conditions during the polynya event are analysed. The polynya was caused by unusual southerly winds during which the sea ice drifted northward instead of southward as usual. The daily displacement was 50 % stronger than normal. The polynya was associated with a warm-air intrusion caused by a high-pressure system over the Eurasian Arctic. Surface air temperatures were slightly below 0 ∘C and thus more than 20 ∘C higher than normal. Two estimates of thermodynamic sea-ice growth yield sea-ice thicknesses of 60 and 65 cm at the end of March in the area opened by the polynya. This differed from airborne sea-ice thickness measurements, indicating that sea-ice growth processes in the polynya are complicated by rafting and ridging. A sea-ice volume of 33 km3 was produced thermodynamically.

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