scholarly journals Thin ice, deep snow and surface flooding in Kotzebue Sound: landfast ice mass balance during two anomalously warm winters and implications for marine mammals and subsistence hunting

2021 ◽  
pp. 1-15
Author(s):  
Andrew R. Mahoney ◽  
Kate E. Turner ◽  
Donna D. W. Hauser ◽  
Nathan J. M. Laxague ◽  
Jessica M. Lindsay ◽  
...  

Abstract The inaugural data from the first systematic program of sea-ice observations in Kotzebue Sound, Alaska, in 2018 coincided with the first winter in living memory when the Sound was not choked with ice. The following winter of 2018–19 was even warmer and characterized by even less ice. Here we discuss the mass balance of landfast ice near Kotzebue (Qikiqtaġruk) during these two anomalously warm winters. We use in situ observations and a 1-D thermodynamic model to address three research questions developed in partnership with an Indigenous Advisory Council. In doing so, we improve our understanding of connections between landfast ice mass balance, marine mammals and subsistence hunting. Specifically, we show: (i) ice growth stopped unusually early due to strong vertical ocean heat flux, which also likely contributed to early start to bearded seal hunting; (ii) unusually thin ice contributed to widespread surface flooding. The associated snow ice formation partly offset the reduced ice growth, but the flooding likely had a negative impact on ringed seal habitat; (iii) sea ice near Kotzebue during the winters of 2017–18 and 2018–19 was likely the thinnest since at least 1945, driven by a combination of warm air temperatures and a persistent ocean heat flux.

2014 ◽  
Vol 119 (1) ◽  
pp. 537-547 ◽  
Author(s):  
Ruibo Lei ◽  
Na Li ◽  
Petra Heil ◽  
Bin Cheng ◽  
Zhanhai Zhang ◽  
...  

2001 ◽  
Vol 33 ◽  
pp. 399-406 ◽  
Author(s):  
N. L. Bindoff ◽  
G. D. Williams ◽  
I. Allison

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.


2021 ◽  
Author(s):  
David Lipson ◽  
Kim Reasor ◽  
Kååre Sikuaq Erickson

<p>In this project we analyze artwork and recorded statements of 5<sup>th</sup> grade students from the community of Utqiaġvik, Alaska, who participated in a science-art outreach activity. The team consisted of a scientist (Lipson), an artist (Reasor) and an outreach specialist (Erickson) of Inupiat heritage from a village in Alaska. We worked with four 5th grade classes of about 25 students each at Fred Ipalook Elementary. The predominantly Inupiat people of Utqiaġvik are among those who will be most impacted by climate change and the loss of Arctic sea ice in the near future. Subsistence hunting of marine mammals associated with sea ice is central to the Inupiat way of life. Furthermore, their coastal homes and infrastructure are increasingly subject to damage from increased wave action on ice-free Beaufort and Chukchi Seas. While the people of this region are among the most directly vulnerable to climate change, the teachers reported that the subject is not generally covered in the elementary school curriculum.</p><p>The scientist and the local outreach specialist gave a short presentation about sea ice and climate change in the Arctic, with emphasis on local impacts to hunting and infrastructure. We then showed the students a large poster of historical and projected sea ice decline, and asked the students to help us fill in the white space beneath the lines. The artist led the children in making small paintings that represent things that are important to their lives in Utqiaġvik (they were encouraged to paint animals, but they were free to do whatever they wanted). We returned to the class later that week and had each student briefly introduce themselves and their painting, and place it on the large graph of sea ice decline, which included the dire predictions of the RCP8.5 scenario. Then we added the more hopeful RCP2.6 scenario to end on a positive note.</p><p>Common themes expressed in the students’ artwork included subsistence hunting, other aspects of traditional Inupiat culture, nature and family. Modern themes such as sports and Pokémon were also common. The students reacted to the topic of climate change with pictures of whales, polar bears and other animals, and captions such as “Save the world/ice/animals.” There were several paintings showing unsuccessful hunts for whales or seals. Some students displayed an understanding of ecosystem science in their recorded statements. For example, a student who painted the sun and another who painted a krill both succinctly described energy flow in food webs that support the production of whales (for example, “I drew krill because without krill there wouldn’t be whales”). Some of the students described the consequences of sea ice loss to local wildlife with devastating succinctness (sea ice is disappearing and polar bears will go extinct). The overall sense was that the children had a strong grasp of the potential consequences of climate change to their region and way of life.</p>


2011 ◽  
Vol 52 (57) ◽  
pp. 271-278 ◽  
Author(s):  
Katherine C. Leonard ◽  
Ted Maksym

AbstractSnow distribution is a dominating factor in sea-ice mass balance in the Bellingshausen Sea, Antarctica, through its roles in insulating the ice and contributing to snow-ice production. the wind has long been qualitatively recognized to influence the distribution of snow accumulation on sea ice, but the relative importance of drifting and blowing snow has not been quantified over Antarctic sea ice prior to this study. the presence and magnitude of drifting snow were monitored continuously along with wind speeds at two sites on an ice floe in the Bellingshausen Sea during the October 2007 Sea Ice Mass Balance in the Antarctic (SIMBA) experiment. Contemporaneous precipitation measurements collected on board the RVIB Nathaniel B. Palmer and accumulation measurements by automated ice mass-balance buoys (IMBs) allow us to document the proportion of snowfall that accumulated on level ice surfaces in the presence of high winds and blowing-snow conditions. Accumulation on the sea ice during the experiment averaged <0.01 m w.e. at both IMB sites, during a period when European Centre for Medium-Range Weather Forecasts analyses predicted >0.03 m w.e. of precipitation on the ice floe. Accumulation changes on the ice floe were clearly associated with drifting snow and high winds. Drifting-snow transport during the SIMBA experiment was supply-limited. Using these results to inform a preliminary study using a blowing-snow model, we show that over the entire Southern Ocean approximately half of the precipitation over sea ice could be lost to leads.


2020 ◽  
Author(s):  
Caixin Wang ◽  
Mats A. Granskog ◽  
Jens Boldingh Debernard ◽  
Keguang Wang

&lt;p&gt;Sea ice is a critical component of the Earth system, playing an important role in high-latitude&lt;br&gt;surface radiation balance and heat, moisture and momentum exchange between atmosphere&lt;br&gt;and ocean. In recent years, rapid changes have been occurring in Arctic sea ice, including&lt;br&gt;decline in ice extent/area, decreasing in ice thickness and volume, and shifting towards a first-&lt;br&gt;year ice (FYI) dominated, rather than multi-year ice (MYI) dominated ice pack. These are one&lt;br&gt;of the most well-known and striking examples of climate change. However, representing&lt;br&gt;these changes in the model is still in question since most of our knowledge is based on MYI.&lt;br&gt;CICE is a sea ice model developed at Los Alamos National Laboratory since 1994. It is&lt;br&gt;widely used to simulate the growth, melt and movement of sea ice, and to resolve the&lt;br&gt;biogeochemical processes. Its column version, Icepack, has been separated from CICE after&lt;br&gt;CICE V5.1.2, which provides additional opportunity for simulating the evolution of drifting&lt;br&gt;sea ice floes. How about the representation of sea ice in a column model (Icepack) and a 3d&lt;br&gt;model (CICE)? In 2012, an ice mass balance buoy (IMB) and a Spectral Radiation Buoy&lt;br&gt;(SRB) were deployed on FYI near the North Pole, and later drifted towards Fram Strait. These&lt;br&gt;buoys collected a complete summer melt season of in-band (350-800 nm) spectral solar&lt;br&gt;radiation and sea ice mass balance data. In this study, we apply the Icepack (version 1.1.1)&lt;br&gt;and CICE (version 5.1.2) to investigate the seasonal evolution of sea ice in 2012 in these two models, and&lt;br&gt;assess how well the physical processes are represented in CICE and Icepack, with the focus&lt;br&gt;on the surface changes.&lt;/p&gt;


2020 ◽  
Author(s):  
Bin Cheng ◽  
Timo Vihma ◽  
Zeling Liao ◽  
Ruibo Lei ◽  
Mario Hoppmann ◽  
...  

&lt;p&gt;A thermistor-string-based Snow and Ice Mass Balance Array (SIMBA) has been developed in recent years and used for monitoring snow and ice mass balance in the Arctic Ocean. SIMBA measures vertical environment temperature (ET) profiles through the air-snow-sea ice-ocean column using a thermistor string (5 m long, sensor spacing 2cm). Each thermistor sensor equipped with a small identical heating element. A small voltage was applied to the heating element so that the heat energy liberated in the vicinity of each sensor is the same. The heating time intervals lasted 60 s and 120 s, respectively. The heating temperatures (HT) after these two intervals were recorded. The ET was measured 4 times a day and once per day for the HT.&lt;/p&gt;&lt;p&gt;A total 15 SIMBA buoys have been deployed in the Arctic Ocean during the Chinese National Arctic Research Expedition (CHINARE) 2018 and the Nansen and Amundsen Basins Observational System (NABOS) 2018 field expeditions in late autumn. We applied a recently developed SIMBA algorithm to retrieve snow and ice thickness using SIMBA ET and HT temperature data. We focus particularly on sea ice bottom evolution during Arctic winter.&lt;/p&gt;&lt;p&gt;In mid-September 2018, 5 SIMBA buoys were deployed in the East Siberian Sea (NABOS2018) where snow was in practical zero cm and ice thickness ranged between 1.8 m &amp;#8211; 2.6 m. By the end of May, those SIMBA buoys were drifted in the central Arctic where snow and ice thicknesses were around 0.05m - 0.2m and 2.6m &amp;#8211; 3.2m, respectively. For those 10 SIMBA buoys deployed by the CHINARE2018 in the Chukchi Sea and Canadian Basin, the initial snow and ice thickness were ranged between 0.05m &amp;#8211; 0.1cm and 1.5m &amp;#8211; 2.5m, respectively. &amp;#160;By the end of May, those SIMBA buoys were drifted toward the north of Greenland where snow and ice thicknesses were around 0.2m - 0.3m and 2.0m &amp;#8211; 3.5m, respectively. The ice bottom evolution derived by SIMBA algorithm agrees well with SIMBA HT identified ice-ocean interfaces. We also perform a preliminary investigation of sea ice bottom evolution measured by several SIMBA buoys deployed during the MOSAiC leg1 field campaign in winter 2019/2020.&amp;#160;&amp;#160;&lt;/p&gt;


2021 ◽  
Author(s):  
Sean Horvath ◽  
Linette Boisvert ◽  
Chelsea Parker ◽  
Melinda Webster ◽  
Patrick Taylor ◽  
...  

Abstract. Since the early 2000s, sea ice has experienced an increased rate of decline in thickness and extent and transitioned to a seasonal ice cover. This shift to thinner, seasonal ice in the 'New Arctic' is accompanied by a reshuffling of energy flows at the surface. Understanding the magnitude and nature of this reshuffling and the feedbacks therein remains limited. A novel database is presented that combines satellite observations, model output, and reanalysis data with daily sea ice parcel drift tracks produced in a Lagrangian framework. This dataset consists of daily time series of sea ice parcel locations, sea ice and snow conditions, and atmospheric states. Building on previous work, this dataset includes remotely sensed radiative and turbulent fluxes from which the surface energy budget can be calculated. Additionally, flags indicate when sea ice parcels travel within cyclones, recording distance and direction from the cyclone center. The database drift track was evaluated by comparison with sea ice mass balance buoys. Results show ice parcels generally remain within 100km of the corresponding buoy, with a mean distance of 82.6 km and median distance of 54 km. The sea ice mass balance buoys also provide recordings of sea ice thickness, snow depth, and air temperature and pressure which were compared to this database. Ice thickness and snow depth typically are less accurate than air temperature and pressure due to the high spatial variability of the former two quantities when compared to a point measurement. The correlations between the ice parcel and buoy data are high, which highlights the accuracy of this Lagrangian database in capturing the seasonal changes and evolution of sea ice. This database has multiple applications for the scientific community; it can be used to study the processes that influence individual sea ice parcel time series, or to explore generalized summary statistics and trends across the Arctic. Applications such as these may shed light on the atmosphere-snow-sea ice interactions in the changing Arctic environment.


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