ADDITIONAL HEAT FLOW DETERMINATIONS IN THE AREA OF MOULD BAY, ARCTIC CANADA

1966 ◽  
Vol 3 (2) ◽  
pp. 237-246 ◽  
Author(s):  
W. S. B. Paterson ◽  
L. K. Law

Seven determinations of geothermal heat flow were made in the general area of southern Prince Patrick Island in the Canadian Arctic Archipelago. Measurements were made from sea ice in water depths of between 200 and 600 m. The mean heat flow for the two stations on the continental shelf in the Arctic Ocean was 0.46 ± 0.08 μcal cm−2 s−1. The mean heat flow for the five stations in the channels to the east of Mould Bay was 1.46 ± 0.16 μcal cm−2 s−1. The instrument and field methods are described. Errors due to the instrument and to the environment are discussed.

1965 ◽  
Vol 2 (2) ◽  
pp. 59-71 ◽  
Author(s):  
L. K. Law ◽  
W. S. B. Paterson ◽  
K. Whitham

Three heat flow determinations a were made in M'Clure Strait between Prince Patrick and Banks Islands in the northwestern part of the Arctic Archipelago of Canada. The three stations lie within 55 km of a point some 130 km SSW. of Mould Bay, Prince Patrick Island, and yield a weighted mean heat flow of 0.84 ± 0.09 μcal cm−2 s−1, or 57% only of the worldwide continental average. The measurements were made from sea ice in water depths of some 430 m using a thermal probe and portable equipment carried in a fixed-wing aircraft.Instrumental limitations and errors are discussed, together with environmental factors. The uncertainties in interpreting this result as a truly subnormal equilibrium heat flow are outlined but it is concluded that the calculated systematic errors are unlikely to exceed 25%. Consequently in the absence of any known major perturbing effect, it must be concluded that the structure responsible for the suppression of vertical magnetic held variations at Mould Bay observatory does not extend 130 km to the south, is not produced by an anomalously high near-surface temperature, or is of late-Quaternary origin.


2014 ◽  
Vol 11 (2) ◽  
pp. 293-308 ◽  
Author(s):  
E. E. Popova ◽  
A. Yool ◽  
Y. Aksenov ◽  
A. C. Coward ◽  
T. R. Anderson

Abstract. The Arctic Ocean is a region that is particularly vulnerable to the impact of ocean acidification driven by rising atmospheric CO2, with potentially negative consequences for calcifying organisms such as coccolithophorids and foraminiferans. In this study, we use an ocean-only general circulation model, with embedded biogeochemistry and a comprehensive description of the ocean carbon cycle, to study the response of pH and saturation states of calcite and aragonite to rising atmospheric pCO2 and changing climate in the Arctic Ocean. Particular attention is paid to the strong regional variability within the Arctic, and, for comparison, simulation results are contrasted with those for the global ocean. Simulations were run to year 2099 using the RCP8.5 (an Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) scenario with the highest concentrations of atmospheric CO2). The separate impacts of the direct increase in atmospheric CO2 and indirect effects via impact of climate change (changing temperature, stratification, primary production and freshwater fluxes) were examined by undertaking two simulations, one with the full system and the other in which atmospheric CO2 was prevented from increasing beyond its preindustrial level (year 1860). Results indicate that the impact of climate change, and spatial heterogeneity thereof, plays a strong role in the declines in pH and carbonate saturation (Ω) seen in the Arctic. The central Arctic, Canadian Arctic Archipelago and Baffin Bay show greatest rates of acidification and Ω decline as a result of melting sea ice. In contrast, areas affected by Atlantic inflow including the Greenland Sea and outer shelves of the Barents, Kara and Laptev seas, had minimal decreases in pH and Ω because diminishing ice cover led to greater vertical mixing and primary production. As a consequence, the projected onset of undersaturation in respect to aragonite is highly variable regionally within the Arctic, occurring during the decade of 2000–2010 in the Siberian shelves and Canadian Arctic Archipelago, but as late as the 2080s in the Barents and Norwegian seas. We conclude that, for future projections of acidification and carbonate saturation state in the Arctic, regional variability is significant and needs to be adequately resolved, with particular emphasis on reliable projections of the rates of retreat of the sea ice, which are a major source of uncertainty.


2019 ◽  
Vol 19 (5) ◽  
pp. 2787-2812 ◽  
Author(s):  
Betty Croft ◽  
Randall V. Martin ◽  
W. Richard Leaitch ◽  
Julia Burkart ◽  
Rachel Y.-W. Chang ◽  
...  

Abstract. Summertime Arctic aerosol size distributions are strongly controlled by natural regional emissions. Within this context, we use a chemical transport model with size-resolved aerosol microphysics (GEOS-Chem-TOMAS) to interpret measurements of aerosol size distributions from the Canadian Arctic Archipelago during the summer of 2016, as part of the “NETwork on Climate and Aerosols: Addressing key uncertainties in Remote Canadian Environments” (NETCARE) project. Our simulations suggest that condensation of secondary organic aerosol (SOA) from precursor vapors emitted in the Arctic and near Arctic marine (ice-free seawater) regions plays a key role in particle growth events that shape the aerosol size distributions observed at Alert (82.5∘ N, 62.3∘ W), Eureka (80.1∘ N, 86.4∘ W), and along a NETCARE ship track within the Archipelago. We refer to this SOA as Arctic marine SOA (AMSOA) to reflect the Arctic marine-based and likely biogenic sources for the precursors of the condensing organic vapors. AMSOA from a simulated flux (500 µgm-2day-1, north of 50∘ N) of precursor vapors (with an assumed yield of unity) reduces the summertime particle size distribution model–observation mean fractional error 2- to 4-fold, relative to a simulation without this AMSOA. Particle growth due to the condensable organic vapor flux contributes strongly (30 %–50 %) to the simulated summertime-mean number of particles with diameters larger than 20 nm in the study region. This growth couples with ternary particle nucleation (sulfuric acid, ammonia, and water vapor) and biogenic sulfate condensation to account for more than 90 % of this simulated particle number, which represents a strong biogenic influence. The simulated fit to summertime size-distribution observations is further improved at Eureka and for the ship track by scaling up the nucleation rate by a factor of 100 to account for other particle precursors such as gas-phase iodine and/or amines and/or fragmenting primary particles that could be missing from our simulations. Additionally, the fits to the observed size distributions and total aerosol number concentrations for particles larger than 4 nm improve with the assumption that the AMSOA contains semi-volatile species: the model–observation mean fractional error is reduced 2- to 3-fold for the Alert and ship track size distributions. AMSOA accounts for about half of the simulated particle surface area and volume distributions in the summertime Canadian Arctic Archipelago, with climate-relevant simulated summertime pan-Arctic-mean top-of-the-atmosphere aerosol direct (−0.04 W m−2) and cloud-albedo indirect (−0.4 W m−2) radiative effects, which due to uncertainties are viewed as an order of magnitude estimate. Future work should focus on further understanding summertime Arctic sources of AMSOA.


2020 ◽  
Vol 57 (1) ◽  
pp. 123-132
Author(s):  
John Shaw ◽  
D. Patrick Potter ◽  
Yongsheng Wu

Data from two surveys by multi-beam sonar and two by marine/terrestrial LiDAR are used to evaluate the geomorphology of the seafloor in littoral areas of the Canadian Arctic Channels, near King William Island, Nunavut. Submarine terrains show well-preserved glacial landforms (drumlins, mega-scale glacial lineations, iceberg-turbated terrain, recessional moraines, and glaciofluvial landforms) with only slight modification by modern processes (wave action and sea-ice activity). At Gjoa Haven the seafloor is imprinted by fields of pits 2 m wide and 0.15 m deep. They may result from gas hydrate dissolution triggered by falling relative sea levels. The Arctic Archipelago displays what might be termed inverted terrains: marine terrains, chiefly beach ridge complexes, exist above modern sea level and well-preserved glacial terrains are present below modern sea level. This is the inverse of the submerging regimes of Atlantic Canada, where glacial terrains exist on land, but below sea level they have been effaced and modified by marine processes down to the lowstand depth.


2013 ◽  
Vol 118 (7) ◽  
pp. 3595-3607 ◽  
Author(s):  
Stephen E. L. Howell ◽  
Trudy Wohlleben ◽  
Mohammed Dabboor ◽  
Chris Derksen ◽  
Alexander Komarov ◽  
...  

2020 ◽  
Author(s):  
Chantal Mears ◽  
Helmuth Thomas ◽  
Paul B. Henderson ◽  
Matthew A. Charette ◽  
Hugh MacIntyre ◽  
...  

Abstract. As a shelf dominated basin, the Arctic Ocean and its biogeochemistry are heavily influenced by continental and riverine sources. Radium isotopes (226Ra, 228Ra, 224Ra, 223Ra), are transferred from the sediments to seawater, making them ideal tracers of sediment-water exchange processes and ocean mixing. 226Ra and 228Ra are the two longer-lived isotopes of the Radium Quartet (226Ra, t1/2 = 1600 y and 228Ra, t1/2 = 5.8 y). Because of their long half-lives they can provide insight into the water mass compositions, distribution patterns, as well as mixing processes and the associated timescales throughout the Canadian Arctic Archipelago (CAA). The wide range of 226Ra, 228Ra, and of the 228Ra / 226Ra ratio, measured in water samples collected during the 2015 GEOTRACES cruise, complemented by additional chemical tracers (dissolved inorganic carbon (DIC), total alkalinity (AT), barium (Ba), and the stable oxygen isotope composition of water (δ18O)) highlight the dominant biogeochemical, hydrographic and bathymetric features of the CAA. Bathymetric features, such as the continental shelf and shallow coastal sills, are critical in modulating circulation patterns within the CAA, including the bulk flow of Pacific waters and the inhibited eastward flow of denser Atlantic waters through the CAA. Using a Principal Component Analysis, we unravel the dominant mechanisms and the apparent water mass end-members that shape the tracer distributions. We identify two distinct water masses located above and below the upper halocline layer throughout the CAA, as well as distinctly differentiate surface waters in the eastern and western CAA. Furthermore, we identify water exchange across 80° W, inferring a draw of Atlantic water, originating from Baffin Bay, into the CAA. In other words, this implies the presence of an Atlantic water U-turn located at Barrow Strait, where the same water mass is seen along the northernmost edge at 80° W as well as along south-easternmost confines of Lancaster Sound. Overall, this study provides a stepping stone for future research initiatives within the Canadian Arctic Archipelago, revealing how quantifying disparities in radioactive isotopes can provide valuable information on the potential effects of climate change within vulnerable areas such as the CAA.


Geophysics ◽  
1990 ◽  
Vol 55 (8) ◽  
pp. 1105-1107 ◽  
Author(s):  
F. W. Jones ◽  
J. A. Majorowicz ◽  
A. F. Embry ◽  
A. M. Jessop

Data from eleven petroleum exploration wells along a south‐north profile in the Sverdrup Basin of the Canadian Arctic Islands indicate large variations in temperature gradients(18 ± 2 to 39 ± 2 mK/m) and heat‐flow values [Formula: see text]. High values occur near the axis of the basin and values decrease systematically toward the southern and northern flanks of the basin. The basin axis in this area is the zone of maximum crustal attenuation and Lower Cretaceous dike and sill intrusion, but any thermal anomaly associated with these events will have dissipated by now. The present heat‐flow pattern is likely the result of thermal refraction or fluid flow in the basin.


2020 ◽  
Author(s):  
Peter Gijsbers ◽  
Hester Jiskoot

<p>Marine litter and microplastics are everywhere. Even the Arctic Ocean, Svalbard and Jan Mayen Island are contaminated as various publications confirm. Little, however, is reported about marine waters and shores of the Canadian Arctic Archipelago. This poster presents the results of a privately funded citizen science observation to scan remote beaches along the Northwest Passage for marine litter pollution.</p><p>The observations were conducted while enjoying the 2019 Northwest Passage sailing expedition of the Tecla, a 1915 gaff-ketch herring drifter. The expedition started in Ilulissat, Greenland, on 1 August and ended in Nome, Alaska, on 18 September. After crossing Baffin Bay, the ship continued along Pond Inlet, Navy Board Inlet, Lancaster Sound, Barrow Strait, Peel Sound, Franklin Strait, Rea Strait, Simpson Strait, Queen Maud Gulf, Coronation Gulf, Amundsen Gulf, Beaufort Sea, Chukchi Sea and Bering Strait. The vessel anchored in the settlement harbours of Pond Inlet, Taloyoak, Gjoa Haven, Cambridge Bay and Herschel Island. In addition, Tecla’s crew made landings at remote beaches on Disko Island (Fortune Bay, Disko Fjord), Beechey Island (Union Bay), Somerset Island (Four Rivers Bay), Boothia Peninsula (Weld Harbour), King William Island (M’Clintock Bay), Jenny Lind Island, and at Kugluktuk and Tuktoyaktuk Peninsula.</p><p>Following the categorization of the OSPAR Guideline for Monitoring Marine Litter on Beaches, litter observations were conducted without penetrating the beach surfaces. Beach stretches scanned varied in length from 100-400 m. No observations were conducted at inhabited settlements or at the abandoned settlements visited on Disko Island (Nipisat) and Beechey Island (Northumberland House).</p><p>Observations on the most remote beaches found 2-5 strongly bleached or decayed items in places such as Union Bay, Four Rivers Bay, Weld Harbour, Jenny Lind Island (Queen Maud Gulf side). Landings within 15 km of local settlements (Fortune Bay, Disko Fjord, Kugluktuk, Tuktoyaktuk) or near military activity (Jenny Lind Island, bay side) showed traces of local camping, hunting or fishing activities, resulting in item counts between 7 and 29. At the lee shore spit of M’Clintock Bay, significant pollution (> 100 items: including outboard engine parts, broken ceramic, glass, clothing, decayed batteries, a crampon and a vinyl record) was found, in contrast to a near-pristine beach on the Simpson Strait side. The litter type and concentration, as well as the remains of a building and shipwrecked fishing vessel indicate that this is an abandoned settlement, possibly related to the construction of the nearby Distant Early Warning Line radar site CAM-2 of Gladman Point. DEW Line sites have long been associated with environmental disturbances.</p><p>Given the 197 beach items recorded, it can be concluded that the beaches of the Canadian Arctic Archipelago, which are blocked by sea ice during most of the year, are not pristine. Truly remote places have received marine pollution for decades to centuries. Where (abandoned) settlements are at close range pollution from local activities can be discovered, while ocean currents, wind patterns, ice rafting, distance to river mouths, and flotsam, jetsam and derelict also determine the type and amount of marine litter along the Northwest Passage.</p>


2018 ◽  
Author(s):  
Betty Croft ◽  
Randall V. Martin ◽  
W. Richard Leaitch ◽  
Julia Burkart ◽  
Rachel Y.-W. Chang ◽  
...  

Abstract. Summertime Arctic aerosol size distributions are strongly controlled by natural regional emissions. Within this context, we use a chemical transport model with size-resolved aerosol microphysics (GEOS-Chem-TOMAS) to interpret measurements of aerosol size distributions from the Canadian Arctic Archipelago during the summer of 2016, as part of the NETwork on Climate and Aerosols: addressing key uncertainties in Remote Canadian Environments (NETCARE). Our simulations suggest that condensation of secondary organic aerosol (SOA) from precursor vapors emitted in the Arctic and near Arctic marine (open ocean and coastal) regions plays a key role in particle growth events that shape the aerosol size distributions observed at Alert (82.5° N, 62.3° W), Eureka (80.1° N, 86.4° W), and along a NETCARE ship track within the Archipelago. We refer to this SOA as Arctic marine SOA (Arctic MSOA) to reflect the Arctic marine-based and likely biogenic sources for the precursors of the condensing organic vapors. Arctic MSOA from a simulated flux (500 μg m−2 d−1, north of 50° N) of precursor vapors (assumed yield of unity) reduces the summertime particle size distribution model-observation mean fractional error by 2- to 4-fold, relative to a simulation without this Arctic MSOA. Particle growth due to the condensable organic vapor flux contributes strongly (30–50 %) to the simulated summertime-mean number of particles with diameters larger than 20 nm in the study region, and couples with ternary particle nucleation (sulfuric acid, ammonia, and water vapor) and biogenic sulfate condensation to account for more than 90 % of this simulated particle number, a strong biogenic influence. The simulated fit to summertime size-distribution observations is further improved at Eureka and for the ship track by scaling up the nucleation rate by a factor of 100 to account for other particle precursors such as gas-phase iodine and/or amines and/or fragmenting primary particles that could be missing from our simulations. Additionally, the fits to observed size distributions and total aerosol number concentrations for particles larger than 4 nm improve with the assumption that the Arctic MSOA contains semi-volatile species; reducing model-observation mean fractional error by 2- to 3-fold for the Alert and ship track size distributions. Arctic MSOA accounts for more than half of the simulated total particulate organic matter mass concentrations in the summertime Canadian Arctic Archipelago, and this Arctic MSOA has strong simulated summertime pan-Arctic-mean top-of-the-atmosphere aerosol direct (−0.04 W m−2) and cloud-albedo indirect (−0.4 W m−2) radiative effects. Future work should focus on further understanding summertime Arctic sources of Arctic MSOA.


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