scholarly journals Estimation of the thin ice thickness and heat flux for the Chukchi Sea Alaskan coast polynya from Special Sensor Microwave/Imager data, 1990–2001

2004 ◽  
Vol 109 (C10) ◽  
Author(s):  
Seelye Martin
Keyword(s):  
Heat Flux ◽  
Chukchi Sea ◽  
Ice Thickness ◽  
Alaskan Coast ◽  
Microwave Imager

Comparison of MODIS-based thin-ice thicknesses with ice draft measurements in the Laptev Sea & Chukchi Sea

2021 ◽  
Author(s):  
Andreas Preußer ◽  
H. Jakob Belter ◽  
Yasushi Fukamachi ◽  
Günther Heinemann
Keyword(s):  
Sea Ice ◽  
Chukchi Sea ◽  
Reanalysis Data ◽  
Arctic Sea Ice ◽  
Balance Model ◽  
Ice Thickness ◽  
Laptev Sea ◽  
Data Set ◽  
In Situ Data ◽  
The Laptev Sea

<p>Acquiring information about the thickness of thin Arctic sea-ice is an important aspect of assessing atmosphere – sea-ice – ocean interactions, as the ice thickness directly relates to the magnitude of energy fluxes at the sea-ice interfaces. In winter, these fluxes are linked to sea-ice formation and hence accompanying processes such as physically induced upper-ocean convection and turbulent mixing of the lower atmospheric boundary layer. It remains a big challenge to validate satellite-derived thin-ice thicknesses, first and foremost due to the lack of suitable in-situ data in these remote areas.</p><p>In order to address this issue, we here present the first insight into a comparison between high-resolution (2km) MODIS thermal infrared satellite data (available for 2002/2003 to 2017/2018) and comprehensive time series of ice-draft data obtained from moored Ice Profiling Sonar (IPS) data. The IPS data set comprises winter-seasons 2009/2010 to 2011/2012 in the Chukchi Sea and winter-seasons 2013/2014 to 2014/2015 in the Laptev Sea. For the MODIS data set, a 1D energy balance model serves as the base for deriving thin-ice thicknesses (0 to 50 cm) from ice-surface temperature swath-data and ERA-Interim atmospheric reanalysis data. In order to facilitate the comparison, the 1Hz IPS ice-draft data is first empirically converted to ice thickness and afterwards resampled to 5-minute modal-values to find matching MODIS swath data.</p><p>It shows that the agreement between the MODIS and IPS ice-thickness data largely depends on the thickness of the ice sampled by the IPS. We found the highest agreement for ice thickness values below 20 cm, which tend to appear more frequently at the Chukchi Sea mooring location. More generally, we notice that MODIS seems to overestimate ice thicknesses up to approximately 40 cm. For thicker ice, the limitations of the MODIS ice-thickness retrieval result in an underestimation.</p>

scholarly journals Where to find 1.5 million yr old ice for the IPICS "Oldest-Ice" ice core

2013 ◽  
Vol 9 (6) ◽  
pp. 2489-2505 ◽  
Author(s):  
H. Fischer ◽  
J. Severinghaus ◽  
E. Brook ◽  
E. Wolff ◽  
M. Albert ◽  
...  
Keyword(s):  
Heat Flux ◽  
Ice Core ◽  
Ice Sheet ◽  
Ice Thickness ◽  
Geothermal Heat ◽  
Ice Flow ◽  
Antarctic Ice Sheet ◽  
Quaternary Climate ◽  
Drill Site ◽  
Heat Flow Model

Abstract. The recovery of a 1.5 million yr long ice core from Antarctica represents a keystone of our understanding of Quaternary climate, the progression of glaciation over this time period and the role of greenhouse gas cycles in this progression. Here we tackle the question of where such ice may still be found in the Antarctic ice sheet. We can show that such old ice is most likely to exist in the plateau area of the East Antarctic ice sheet (EAIS) without stratigraphic disturbance and should be able to be recovered after careful pre-site selection studies. Based on a simple ice and heat flow model and glaciological observations, we conclude that positions in the vicinity of major domes and saddle position on the East Antarctic Plateau will most likely have such old ice in store and represent the best study areas for dedicated reconnaissance studies in the near future. In contrast to previous ice core drill site selections, however, we strongly suggest significantly reduced ice thickness to avoid bottom melting. For example for the geothermal heat flux and accumulation conditions at Dome C, an ice thickness lower than but close to about 2500 m would be required to find 1.5 Myr old ice (i.e., more than 700 m less than at the current EPICA Dome C drill site). Within this constraint, the resolution of an Oldest-Ice record and the distance of such old ice to the bedrock should be maximized to avoid ice flow disturbances, for example, by finding locations with minimum geothermal heat flux. As the geothermal heat flux is largely unknown for the EAIS, this parameter has to be carefully determined beforehand. In addition, detailed bedrock topography and ice flow history has to be reconstructed for candidates of an Oldest-Ice ice coring site. Finally, we argue strongly for rapid access drilling before any full, deep ice coring activity commences to bring datable samples to the surface and to allow an age check of the oldest ice.

scholarly journals Environmental record of layers of bubbles in natural pond ice

2018 ◽  
Vol 64 (248) ◽  
pp. 866-876 ◽  
Author(s):  
JOLANA HRUBA ◽  
GUNTHER KLETETSCHKA
Keyword(s):  
Heat Flux ◽  
Growth Rates ◽  
Natural Waters ◽  
Gas Bubbles ◽  
Ice Thickness ◽  
Cooling Rates ◽  
Ice Growth ◽  
Order Of Magnitude ◽  
Concentration Changes ◽  
Ice Water

ABSTRACTAutonomous temperature data loggers were used to measure the temperature profile within a growing ice cover and in the water below. The ice formed under natural conditions over the pond. We observed the presence of distinct layers of gas bubbles throughout the ice thickness. Temperature measurements allowed us to determine growth rates (μm s−1) and cooling rates (°C s−1) of the ice and demonstrated that these bubble layers formed during the peak ice growth rates from 0.58 to 0.92 µm s−1. The growth rates, leading to the formation of layers of bubbles, were more than an order of magnitude lower than for bubbles produced in controlled laboratory conditions (from 3 to 80 µm s−1). This observation introduces the possibility that solid impurities play a role in natural waters and that they must lower the limit of growth rates required for bubble occurrence. Data revealed a decrease in ice growth rates while cooling rates increased. We interpret this observation as an effect of the heat flux from the water to the ice (8.34–34.11 W m−2), and of gas concentration changes in the water below. Calculations of the ice thickness using traditional methods showed the necessity to include the heat flux from the water to the ice and the effect of gas bubbles within the ice and near the ice–water interface.

scholarly journals Estimation of thin Sea-ice thickness from NOAA AVHRR data in a polynya off the Wilkes Land coast, East Antarctica

2006 ◽  
Vol 44 ◽  
pp. 269-274 ◽  
Author(s):  
Takeshi Tamura ◽  
Kay I. Ohshima ◽  
Hiroyuki Enomoto ◽  
Kazutaka Tateyama ◽  
Atsuhiro Muto ◽  
...  
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Meteorological Data ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
Flux Calculation ◽  
Ice Surface ◽  
Wilkes Land ◽  
Ice Surface Temperature

AbstractAntarctic coastal polynyas are major areas of intense ocean–atmosphere heat and moisture flux, and associated high Sea-ice production and dense-water formation. Their accurate detection, including an estimate of thin ice thickness, is therefore very important. In this paper, we apply a technique originally developed in the Arctic to an estimation of Sea-ice thickness using Us National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR) data and meteorological data in the Vincennes Bay polynya off Wilkes Land, East Antarctica. The method is based upon the heat-flux calculation using Sea-ice Surface temperature estimates from the Satellite thermal-infrared data combined with global objective analysis (European Centre for Medium-Range Weather Forecasts (ECMWF)) data. The validity of this method is assessed by comparing results with independent ice-surface temperature and ice-thickness data obtained during an Australian-led research cruise to the region in 2003. In thin-ice (polynya) regions, ice thicknesses estimated by the heat-flux calculation using AVHRR and ECMWF data Show reasonable agreement with those estimated by (a) applying the heat-flux calculation to in Situ radiation thermometer and meteorological data and (b) in Situ observations. The Standard deviation of the difference between the AVHRR-derived and in Situ data is ∽0.02 m. Comparison of the AVHRR ice-thickness retrievals with coincident Satellite passive-microwave polarization ratio data confirms the potential of the latter as a means of deriving maps of thin Sea-ice thickness on the wider Scale, uninterrupted by darkness and cloud cover.

scholarly journals Indirect measurements of the mass balance of summer Arctic sea ice with an electromagnetic induction technique

2001 ◽  
Vol 33 ◽  
pp. 194-200 ◽  
Author(s):  
H. Eicken ◽  
W. B. Tucker ◽  
D. K. Perovich
Keyword(s):  
Mass Balance ◽  
Electromagnetic Induction ◽  
Heat Budget ◽  
Chukchi Sea ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Ice Thickness ◽  
Apparent Conductivity ◽  
Melt Ponds ◽  
Sampling Statistics

AbstractIn the framework of the Surface Heat Budget of the Arctic (SHEBA) study, indirect, non-invasive ice mass-balance measurements were carried out at a drifting station in the northern Chukchi Sea between May and August 1998. Ice thickness was derived from electromagnetic induction (EM) measurements of apparent conductivity along 13 profiles (60−900 m long). As shown through sensitivity studies with a one-dimensional model, the apparent conductivity data from individual points can be inverted to yield estimates of ice thickness and ablation with an accuracy of approximately 0.05 m (for 2 m thick level ice). Ablation rates were 8−18 mm d−1, with total ablation amounting to roughly 0.9−1.2 m. Measurements of thickness and melt rates along different profiles in undeformed multi-year ice corresponded closely, indicating that the sampling statistics are adequate. The roughness of undeformed ice has been found to increase during the summer due to deepening of melt ponds and enhanced bottom melt. Ice under melt ponds was disproportionately thinner, most likely a result of thicker snow cover reducing winter accretion.

scholarly journals Characteristics of the surface heat budget during the ice-growth season in the southern Sea of Okhotsk

2001 ◽  
Vol 33 ◽  
pp. 230-236 ◽  
Author(s):  
Takenobu Toyota ◽  
Masaaki Wakatsuchi
Keyword(s):  
Heat Flux ◽  
Sea Of Okhotsk ◽  
Heat Budget ◽  
Meteorological Data ◽  
Open Water ◽  
Turbulent Heat Flux ◽  
Ice Thickness ◽  
Turbulent Heat ◽  
Polar Regions ◽  
Ice Growth

AbstractThe heat budget over the ice-covered area of the southern Sea of Okhotsk is estimated from in situ meteorological and ice observation for four years, 1996−99. The data are from about 1 week in early February in each of four years. Ice-thickness distributions required for calculating the heat budget are quantitatively obtained from video analysis. A one-dimensional thermodynamical model is used to calculate the heat flux. The total heat flux is obtained by summing up the area-weighted heat flux of each ice-thickness category. In addition, to determine the characteristics of the heat budget in this region, we also calculated the heat budget in the northern Sea of Okhotsk using Special Sensor Microwave/Imager ice-extent data and European Centre for Medium-range Weather Forecasts meteorological data, and compared the results. Our investigations show the following characteristics in the southern Sea of Okhotsk: (1) Due to relatively thin ice thickness, the average turbulent heat flux is upward. (2) Thin ice and open water contribute significantly to the total turbulent heat flux. (3) Thermodynamic ice growth is limited to about 1 cm d−1 on average. (4) The heat budget is largely characterized by abundant solar radiation. The first, third and fourth results are characteristic of this region located at a relatively low latitude, while the second one is similar to that for polar regions.

scholarly journals Sensitivity of Northern Hemisphere climate to ice–ocean interface heat flux parameterizations

2021 ◽  
Vol 14 (8) ◽  
pp. 4891-4908
Author(s):  
Xiaoxu Shi ◽  
Dirk Notz ◽  
Jiping Liu ◽  
Hu Yang ◽  
Gerrit Lohmann
Keyword(s):  
Heat Flux ◽  
Heat Exchange ◽  
Sea Ice ◽  
Temperature Difference ◽  
Climate Model ◽  
Turbulent Heat Flux ◽  
The Arctic ◽  
Ice Thickness ◽  
Turbulent Heat ◽  
Sea Ice Thickness

Abstract. We investigate the impact of three different parameterizations of ice–ocean heat exchange on modeled sea ice thickness, sea ice concentration, and water masses. These three parameterizations are (1) an ice bath assumption with the ocean temperature fixed at the freezing temperature; (2) a two-equation turbulent heat flux parameterization with ice–ocean heat exchange depending linearly on the temperature difference between the underlying ocean and the ice–ocean interface, whose temperature is kept at the freezing point of the seawater; and (3) a three-equation turbulent heat flux approach in which the ice–ocean heat flux depends on the temperature difference between the underlying ocean and the ice–ocean interface, whose temperature is calculated based on the local salinity set by the ice ablation rate. Based on model simulations with the stand-alone sea ice model CICE, the ice–ocean model MPIOM, and the climate model COSMOS, we find that compared to the most complex parameterization (3), the approaches (1) and (2) result in thinner Arctic sea ice, cooler water beneath high-concentration ice and warmer water towards the ice edge, and a lower salinity in the Arctic Ocean mixed layer. In particular, parameterization (1) results in the smallest sea ice thickness among the three parameterizations, as in this parameterization all potential heat in the underlying ocean is used for the melting of the sea ice above. For the same reason, the upper ocean layer of the central Arctic is cooler when using parameterization (1) compared to (2) and (3). Finally, in the fully coupled climate model COSMOS, parameterizations (1) and (2) result in a fairly similar oceanic or atmospheric circulation. In contrast, the most realistic parameterization (3) leads to an enhanced Atlantic meridional overturning circulation (AMOC), a more positive North Atlantic Oscillation (NAO) mode and a weakened Aleutian Low.

scholarly journals Estimating Oceanic Heat Flux from Sea-Ice Thickness and Temperature Data

1990 ◽  
Vol 14 ◽  
pp. 315-318 ◽  
Author(s):  
J.S. Wettlaufer ◽  
N. Untersteiner ◽  
R. Colony
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Mass Balance ◽  
Temperature Data ◽  
Ice Thickness ◽  
Sea Ice Thickness ◽  
North East ◽  
Oceanic Heat Flux ◽  
Ocean Models

All studies and models of air—sea-ice interactions suffer from a paucity of information about the oceanic heat flux, which exerts a controlling influence on the sea-ice energy and mass balance. The role of the oceanic heat flux in the sea-ice energy and mass balance is discussed. The performance of ice-ocean models depends on a satisfactory specification of this rarely measured oceanic parameter. A method for determining the oceanic heat flux by measuring the temperatures and thickness of sea ice is described. The results obtained using this method and the data collected during the fall of 1988 in the eastern Arctic are presented. Values of the oceanic heat flux ranging from 0 to 37 W m−2 were estimated from observations taken in the region north-east of Fram Strait. The oceanic heat flux in this region varied in both time and space.

scholarly journals Phytoplankton Bloom Changes under Extreme Geophysical Conditions in the Northern Bering Sea and the Southern Chukchi Sea

2021 ◽  
Vol 13 (20) ◽  
pp. 4035
Author(s):  
Jinku Park ◽  
Sungjae Lee ◽  
Young-Heon Jo ◽  
Hyun-Cheol Kim
Keyword(s):  
Heat Flux ◽  
Sea Ice ◽  
Bering Sea ◽  
Phytoplankton Biomass ◽  
Phytoplankton Bloom ◽  
Chukchi Sea ◽  
Open Water ◽  
The Arctic ◽  
Atmospheric Conditions ◽  
Northern Bering Sea

The northern Bering Sea and the southern Chukchi Sea are undergoing rapid regional biophysical changes in connection with the recent extreme climate change in the Arctic. The ice concentration in 2018 was the lowest since observations began in the 1970s, due to the unusually warm southerly wind in winter, which continued in 2019. We analyzed the characteristics of spring phytoplankton biomass distribution under the extreme environmental conditions in 2018 and 2019. Our results show that higher phytoplankton biomass during late spring compared to the 18-year average was observed in the Bering Sea in both years. Their spatial distribution is closely related to the open water extent following winter-onset sea ice retreat in association with dramatic atmospheric conditions. However, despite a similar level of shortwave heat flux, the 2019 springtime biomass in the Chukchi Sea was lower than that in 2018, and was delayed to summer. We confirmed that this difference in bloom timing in the Chukchi Sea was due to changes in seawater properties, determined by a combination of northward oceanic heat flux modulation by the disturbance from more extensive sea ice in winter and higher surface net shortwave heat flux than usual.

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