Hydrographic data collected from research cruises, bottom‐anchored moorings, drifting Ice‐Tethered Profilers, and satellite altimetry in the Beaufort Gyre region of the Arctic Ocean document an ...increase of more than 6,400 km3 of liquid freshwater content from 2003 to 2018: a 40% growth relative to the climatology of the 1970s. This fresh water accumulation is shown to result from persistent anticyclonic atmospheric wind forcing (1997–2018) accompanied by sea ice melt, a wind‐forced redirection of Mackenzie River discharge from predominantly eastward to westward flow, and a contribution of low salinity waters of Pacific Ocean origin via Bering Strait. Despite significant uncertainties in the different observations, this study has demonstrated the synergistic value of having multiple diverse datasets to obtain a more comprehensive understanding of Beaufort Gyre freshwater content variability. For example, Beaufort Gyre Observational System (BGOS) surveys clearly show the interannual increase in freshwater content, but without satellite or Ice‐Tethered Profiler measurements, it is not possible to resolve the seasonal cycle of freshwater content, which in fact is larger than the year‐to‐year variability, or the more subtle interannual variations.
Plain Language
The Beaufort Gyre centered in the Canada Basin of the Arctic Ocean is the major reservoir of fresh water in the Arctic. The primary focus of this study is on quantifying variability and trends in liquid (water) and solid (sea ice) freshwater content in this region. The Beaufort Gyre Exploration Program was initiated in 2003 to synthesize results of historical data analysis, design and conduct long‐term observations, and to provide information for numerical modeling under the umbrella of the FAMOS (Forum for Arctic Observing and Modeling Synthesis) project. The data collected from research cruises, moorings, Ice‐Tethered Profiler observations, and satellite altimetry document an increase of more than 6,400 km3 of liquid freshwater content from 2003 to 2018, a 40% growth relative to the climatology of the 1970s. This fresh water volume is comparable to the fresh water volume released to the sub‐arctic seas during the Great Salinity Anomaly episode of the 1970s. Thus, since the 2000s, the stage has been set for another possible release of fresh water to lower latitudes with accompanying climate impacts, including changes to sea ice conditions, ocean circulation, and ecosystems of the Sub‐Arctic similar to the influence of the Great Salinity Anomaly observed in the 1970s.
Key Points
Beaufort Gyre freshwater content time series (2003–2018) from different data sets are updated, compared, and analyzed
Qualitative and quantitative estimates of factors and mechanisms driving freshwater content changes are provided
In 2003–2018, the major sources of accumulated fresh water were sea ice melt, Mackenzie River runoff, and Bering Strait transport
Time series of ice draft from 2003 to 2012 from moored sonar data are used to investigate variability and describe the reduction of the perennial sea ice cover in the Beaufort Gyre (BG), culminating ...in the extreme minimum in 2012. Negative trends in median ice drafts and most ice fractions are observed, while open water and thinnest ice fractions (<0.3 m) have increased, attesting to the ablation or removal of the older sea ice from the BG over the 9 year period. Monthly anomalies indicate a shift occurred toward thinner ice after 2007, in which the thicker ice evident at the northern stations was reduced. Differences in the ice characteristics between all of the stations also diminished, so that the ice cover throughout the region became statistically homogenous. The moored data are used in a relationship with satellite radiometer data to estimate ice volume changes throughout the BG. Summer solid fresh water content decreased drastically in consecutive years from 730 km3 in 2006 to 570 km3 in 2007, and to 240 km3 in 2008. After a short rebound, solid fresh water fell below 220 km3 in 2012. Meanwhile, hydrographic data indicate that liquid fresh water in the BG in summer increased 5410 km3 from 2003 to 2010 and decreased at least 210 km3 by 2012. The reduction of both solid and liquid fresh water components indicates a net export of approximately 320 km3 of fresh water from the region occurred between 2010 and 2012, suggesting that the anticyclonic atmosphere‐ocean circulation has weakened.
Key Points
Sea ice in the Beaufort Gyre became thinner and largely homogenous after 2007
Total summer freshwater increased until 2010 and has decreased slightly since
Thick sea ice declined from nearly 10 to 4% of the total summer freshwater budget
Electromagnetic–induction (EM) instruments can be used to estimate Sea-ice thickness because of the large contrast in the conductivities of Sea ice and Sea water, and are currently used in ...investigations of Sea-ice thickness. In this Study we analyze Several Snow, ice and Sea-water Samples and attempt to derive an appropriate formula to transform the apparent conductivity obtained from EM measurements to the total thickness of Snow and ice for all regions and Seasons. This was done to Simplify the EM tuning procedure. Surface EM measurement transects with the instrument at varying heights above the ice were made in the Chukchi Sea, off East Antarctica, in the Sea of Okhotsk and in Saroma-ko (lagoon). A Standardized transformation formula based on a one-dimensional multi-layer model was developed that also considers the effects of water-filled gaps between deformed ice, a Saline Snow Slush layer, and the increase in the footprint Size caused by increasing the instrument height. The overall average error in ice thickness determined with the Standardized transform was <7%, and the regional average errors were 2.2% for the Arctic, 7.0% for the Antarctic, 6.5% for the Sea of Okhotsk and 4.4% for Saroma-ko.
In this study, we prepared the Bi2223 multifilamentary tapes with Ca2CuO3 as interfilamentary resistive barriers and evaluated their AC magnetization loss properties at 77K. The Bi2223 tapes with ...thin barrier layers of Ca2CuO3 around the filaments were prepared by using a standard powder-in-tube (PIT) method. To fabricate the Ca2CuO3 layers around each filament, the outside surface of monocore Ag-sheathed wires was coated by Ca2CuO3 with the slurry. After the heat treatment to decompose and evaporate the organic binder in the slurry, the several coated monocore wires were stacked and packed into another Ag-tube. Then, the packed tube was drawn and rolled into tape shape. The tape was subsequently sintered to form Bi2223 phase inside filaments. The AC magnetization losses in an AC transverse magnetic field were measured by a pick-up coil method. The loss properties in the barrier tape were compared with those in the tape without barriers. The results indicated that introducing Ca2CuO3 barriers is very effective to suppress the electromagnetic coupling among the filaments and also to reduce the magnetization losses under parallel transverse field.
In this paper, we experimentally investigated the total AC loss characteristics under AC parallel transverse field for Bi2223 tapes with various filament arrangements in their cross section. The ...tapes with different filament arrangements in final tape sections were prepared by standard powder-in-tube (PIT) process with drawing using round dice and rectangular deformation process using two-axial rolling (TAR) technique. Total AC losses in the tapes carrying AC transport current in AC parallel transverse field were measured by means of the electromagnetic method. The measured loss values in the tapes were compared with the several analytical models. Based on the experimental results, the influence of filament arrangements on total AC loss behaviors is discussed, under the different operating conditions with various amplitude of current and applied field.
Sea-ice fluctuations in the Sea of Okhotsk and the Bering Sea during the winters of 1992−99 were investigated by using the Special Sensor Microwave/ Imager dataset and a new ice-property retrieval ...algorithm This algorithm can distinguish between ice types such as fast ice floes, young ice and new ice, in an area covered by concentrations of >80% ice, and also has improved display resolution because it uses one of the 85 GHz channels. The ice thicknesses derived from the ice-thickness parameter of the new algorithm were compared with ship-based ice-thickness measurements, and were assumed to be 1−10, 11−34, 35−85 and 86−120 cm for new ice, young ice, floes (first-year ice) and fast ice, respectively. The results showed that ice volume can be small even if the ice area is large, due to thinness of the ice (e.g. in 1999 in the Sea of Okhotsk). A significant out-of-phase response, i.e. ice volume is larger in the Sea of Okhotsk when ice volume is smaller in the Bering Sea, was observed. The period of this see-saw showed two different time-scales, which were short (1 week) and long (2−4 weeks).
In recent years, the sensory integration therapy (SIT) is used to treat children with developmental disorders in Japan. The play that is the occupational form with the meaning for children is offered ...in SIT and its aim is the solution to the problem of children. Often children with developmental disorders have problem on communication with other people. Therefore, we measured changes in the state of communication and interaction skills in children with developmental disorders before and after SIT using the assessment of communication and interaction skills (ACIS).
The participants were 19 boys with developmental disorders from 4 to 6 years old. The intervention frequency was from once a week to once a month and intervention period was six or three months. 10-minutes treatment scene was observed and ACIS was marked by more than three occupational therapists. Statistical analysis was performed Wilcoxon signed-ranks test by using SPSS Statistics Ver.20. This study was carried out with approval of the Tokyo Metropolitan University Arakawa Campus Institutional Review Board (#13075).
As for the ACIS % value before SIT was 80.4%±10.1SD, and the after SIT was 86.1%±8.5SD. There was meaningful improvement (P=0.028). Also, in each area of ACIS, “exchange of information” % value before SIT was 80.4%±10.1SD, and the after SIT was 86.1%±8.5SD. It was meaningful improvement (P=0.041).
It was shown that the meaningful improvement in “ACIS total % value” and “exchange of information % value” at before and after SIT intervention. It was suggest that SIT has potential improved the state of the communication and interaction skills in children with developmental disorders. This study was partially supported by JSPS Grant in Aid for Scientific Research (#26350629).
In this study, an over-head-type load-haul-dump (LHD) with a vessel (
A
dvanced
L
HD with a
V
essel: ALV) is proposed to increase the carrying capacity. As the working environment is severe for ...workers, especially in underground mines, unmanned LHD task is desirable. In this case, the cabin for the operator is not necessary. Therefore, overhead loading into the vessel will be possible. In this paper, a concept of ALV is proposed, and kinematics and dynamics of ALV is described. Furthermore, the experimental results by using the ALV model are also described. In order to obtain the mobility of ALV, the wheels and the articulated steering system are adopted for moving and steering. Furthermore, in order to increase the carrying capacity, a vessel is installed on the rear body. It was confirmed through the experiments that the working efficiency of ALV is higher than that of traditional LHD.
The effects of plating materials (Sn-10Pb, Sn-3.5Ag, Sn-3Bi, Sn-0.7Cu, and Au/Pd/Ni) on Cu leads on quad flat package (QFP) joints using a Sn-8Zn-3Bi solder were investigated. The joints with ...Sn-3.5Ag plating and Sn-8Zn-3Bi solder had the slowest growth rate of interfacial reaction layers and the highest strength. The Ag dissolution into the interfacial reaction layers causes this increased strength. The Sn-Ag plating is the best plating material for Cu leads among the five kinds of plating using Sn-8Zn-3Bi solder.
We report a 69-yr-old female with a liver mass which, when surgically resected, was believed to be the spontaneous complete necrosis of hepatocellular carcinoma. The preoperative level of ...alpha-fetoprotein was high at 1050 ng/ml, and the mass was grossly an encapsulated nodular lesion with septa. Histologically, no viable tumor cells were demonstrated. The alpha-fetoprotein level decreased to a normal range. The postoperative course was uneventful, and the patient is alive and well 1 yr after surgery.
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