45 CFR 2301.130 - General prohibitions against discrimination.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false General prohibitions against discrimination. 2301.130 Section 2301.130 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH... THE UNITED STATES ARCTIC RESEARCH COMMISSION § 2301.130 General prohibitions against discrimination...

45 CFR 2301.152-2301.159 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2301.152-2301.159 Section 2301.152-2301.159 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.152-2301.159 [Reserved] ...

45 CFR 2301.171-2301.999 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false [Reserved] 2301.171-2301.999 Section 2301.171-2301.999 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.171-2301.999 [Reserved] ...

45 CFR 2301.161-2301.169 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2301.161-2301.169 Section 2301.161-2301.169 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.161-2301.169 [Reserved] ...

45 CFR 2301.171-2301.999 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2301.171-2301.999 Section 2301.171-2301.999 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.171-2301.999 [Reserved] ...

45 CFR 2301.149 - Program accessibility: Discrimination prohibited.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Program accessibility: Discrimination prohibited. 2301.149 Section 2301.149 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC... CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH COMMISSION § 2301.149 Program accessibility: Discrimination...

45 CFR 2301.149 - Program accessibility: Discrimination prohibited.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Program accessibility: Discrimination prohibited. 2301.149 Section 2301.149 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC... CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH COMMISSION § 2301.149 Program accessibility: Discrimination...

45 CFR 2301.152-2301.159 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false [Reserved] 2301.152-2301.159 Section 2301.152-2301.159 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.152-2301.159 [Reserved] ...

45 CFR 2301.112-2301.129 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2301.112-2301.129 Section 2301.112-2301.129 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.112-2301.129 [Reserved] ...

45 CFR 2301.141-2301.148 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false [Reserved] 2301.141-2301.148 Section 2301.141-2301.148 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.141-2301.148 [Reserved] ...

45 CFR 2301.161-2301.169 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false [Reserved] 2301.161-2301.169 Section 2301.161-2301.169 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.161-2301.169 [Reserved] ...

45 CFR 2301.104-2301.109 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false [Reserved] 2301.104-2301.109 Section 2301.104-2301.109 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.104-2301.109 [Reserved] ...

45 CFR 2301.130 - General prohibitions against discrimination.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false General prohibitions against discrimination. 2301.130 Section 2301.130 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH... THE UNITED STATES ARCTIC RESEARCH COMMISSION § 2301.130 General prohibitions against discrimination...

45 CFR 2301.104-2301.109 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2301.104-2301.109 Section 2301.104-2301.109 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.104-2301.109 [Reserved] ...

45 CFR 2301.141-2301.148 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2301.141-2301.148 Section 2301.141-2301.148 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.141-2301.148 [Reserved] ...

45 CFR 2301.131-2301.139 - [Reserved

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2301.131-2301.139 Section 2301.131-2301.139 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.131-2301.139 [Reserved] ...

45 CFR 2301.112-2301.129 - [Reserved

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false [Reserved] 2301.112-2301.129 Section 2301.112-2301.129 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION... STATES ARCTIC RESEARCH COMMISSION §§ 2301.112-2301.129 [Reserved] ...

36 CFR 13.1002 - Subsistence resident zone.

Code of Federal Regulations, 2014 CFR

2014-07-01

....1002 Section 13.1002 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and... resident zone for Gates of the Arctic National Park: Alatna, Allakaket, Ambler, Anaktuvuk Pass, Bettles...

45 CFR 2301.102 - Application.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Application. 2301.102 Section 2301.102 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.101 - Purpose.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Purpose. 2301.101 Section 2301.101 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.140 - Employment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Employment. 2301.140 Section 2301.140 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.160 - Communications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Communications. 2301.160 Section 2301.160 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.111 - Notice.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Notice. 2301.111 Section 2301.111 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.160 - Communications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Communications. 2301.160 Section 2301.160 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.150 - Program accessibility: Existing facilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Program accessibility: Existing facilities. 2301.150 Section 2301.150 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH... THE UNITED STATES ARCTIC RESEARCH COMMISSION § 2301.150 Program accessibility: Existing facilities. (a...

45 CFR 2301.150 - Program accessibility: Existing facilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Program accessibility: Existing facilities. 2301.150 Section 2301.150 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH... THE UNITED STATES ARCTIC RESEARCH COMMISSION § 2301.150 Program accessibility: Existing facilities. (a...

45 CFR 2301.101 - Purpose.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Purpose. 2301.101 Section 2301.101 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.111 - Notice.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Notice. 2301.111 Section 2301.111 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.102 - Application.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Application. 2301.102 Section 2301.102 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.140 - Employment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Employment. 2301.140 Section 2301.140 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.110 - Self-evaluation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Self-evaluation. 2301.110 Section 2301.110 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

45 CFR 2301.110 - Self-evaluation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Self-evaluation. 2301.110 Section 2301.110 Public Welfare Regulations Relating to Public Welfare (Continued) ARCTIC RESEARCH COMMISSION ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE UNITED STATES ARCTIC RESEARCH...

Effect of visual target blurring on accommodation under distance viewing

NASA Astrophysics Data System (ADS)

Iwata, Yo; Handa, Tomoya; Ishikawa, Hitoshi

2018-04-01

Abstract Purpose To examine the effect of visual target blurring on accommodation. Methods We evaluated the objective refraction values when the visual target (asterisk; 8°) was changed from the state without Gaussian blur (15 s) to the state with Gaussian blur adapted [0(without blur) → 10, 0 → 50, 0 → 100: 15 s each]. Results In Gaussian blur 10, when blurring of the target occurred, refraction value did not change significantly. In Gaussian blur 50 and 100, when blurring of the target occurred, the refraction value became significantly myopic. Conclusion Blurring of the distant visual target results in intervention of accommodation.

Musculoskeletal pain in Arctic indigenous and non-indigenous adolescents, prevalence and associations with psychosocial factors: a population-based study.

PubMed

Eckhoff, Christian; Kvernmo, Siv

2014-06-18

Pain is common in otherwise healthy adolescents. In recent years widespread musculoskeletal pain, in contrast to single site pain, and associating factors has been emphasized. Musculoskeletal pain has not been examined in Arctic indigenous adolescents. The aim of this study was to explore the prevalence of widespread musculoskeletal pain and its association with psychosocial factors, with emphasis on gender- and ethnic differences (Sami vs. non-Sami), and the influence of pain related functional impairment. This is a cross-sectional study based on The Norwegian Arctic Adolescent Health Study; a school-based survey responded by 4,881 10th grade students (RR: 83%) in North Norway, in 2003-2005. 10% were indigenous Sami. Musculoskeletal pain was based on reported pain in the head, shoulder/neck, back and/or arm/knee/leg, measured by the number of pain sites. Linear multiple regression was used for the multivariable analyses. The prevalence of musculoskeletal pain was high, and significantly higher in females. In total, 22.4% reported 3-4 pain sites. We found a strong association between musculoskeletal pain sites and psychosocial problems, with a higher explained variance in those reporting pain related functional impairment and in females. There were no major differences in the prevalence of musculoskeletal pain in Sami and non-Sami, however the associating factors differed somewhat between the indigenous and non-indigenous group. The final multivariable model, for the total sample, explained 21.2% of the variance of musculoskeletal pain. Anxiety/depression symptoms was the dominant factor associated with musculoskeletal pain followed by negative life events and school-related stress. Anxiety/depression, negative life events, and school-related stress were the most important factors associated with musculoskeletal pain, especially in those reporting pain related functional impairment. The most important sociocultural aspect is the finding that the indigenous Sami are not worse off.

Piscine reovirus (PRV) in wild Atlantic salmon, Salmo salar L., and sea-trout, Salmo trutta L., in Norway.

PubMed

Garseth, Å H; Fritsvold, C; Opheim, M; Skjerve, E; Biering, E

2013-05-01

This is the first comprehensive study on the occurrence and distribution of piscine reovirus (PRV) in Atlantic salmon, Salmo salar L., caught in Norwegian rivers. PRV is a newly discovered reovirus associated with heart and skeletal muscle inflammation (HSMI), a serious and commercially important disease affecting farmed Atlantic salmon in Norway. A cross-sectional survey based on real-time RT-PCR screening of head kidney samples from wild, cultivated and escaped farmed Atlantic salmon caught from 2007 to 2009 in Norwegian rivers has been conducted. In addition, anadromous trout (sea-trout), Salmo trutta L., caught from 2007 to 2010, and anadromous Arctic char, Salvelinus alpinus (L.), caught from 2007 to 2009, were tested. PRV was detected in Atlantic salmon from all counties included in the study and in 31 of 36 examined rivers. PRV was also detected in sea-trout but not in anadromous Arctic char. In this study, the mean proportion of PRV positives was 13.4% in wild Atlantic salmon, 24.0% in salmon released for stock enhancement purposes and 55.2% in escaped farmed salmon. Histopathological examination of hearts from 21 PRV-positive wild and one cultivated salmon (Ct values ranging from 17.0 to 39.8) revealed no HSMI-related lesions. Thus, it seems that PRV is widespread in Atlantic salmon returning to Norwegian rivers, and that the virus can be present in high titres without causing lesions traditionally associated with HSMI. © 2012 Blackwell Publishing Ltd.

Moball-Buoy Network: A Near-Real-Time Ground-Truth Distributed Monitoring System to Map Ice, Weather, Chemical Species, and Radiations, in the Arctic

NASA Astrophysics Data System (ADS)

Davoodi, F.; Shahabi, C.; Burdick, J.; Rais-Zadeh, M.; Menemenlis, D.

2014-12-01

The work had been funded by NASA HQ's office of Cryospheric Sciences Program. Recent observations of the Arctic have shown that sea ice has diminished drastically, consequently impacting the environment in the Arctic and beyond. Certain factors such as atmospheric anomalies, wind forces, temperature increase, and change in the distribution of cold and warm waters contribute to the sea ice reduction. However current measurement capabilities lack the accuracy, temporal sampling, and spatial coverage required to effectively quantify each contributing factor and to identify other missing factors. Addressing the need for new measurement capabilities for the new Arctic regime, we propose a game-changing in-situ Arctic-wide Distributed Mobile Monitoring system called Moball-buoy Network. Moball-buoy Network consists of a number of wind-propelled self-powered inflatable spheres referred to as Moball-buoys. The Moball-buoys are self-powered. They use their novel mechanical control and energy harvesting system to use the abundance of wind in the Arctic for their controlled mobility and energy harvesting. They are equipped with an array of low-power low-mass sensors and micro devices able to measure a wide range of environmental factors such as the ice conditions, chemical species wind vector patterns, cloud coverage, air temperature and pressure, electromagnetic fields, surface and subsurface water conditions, short- and long-wave radiations, bathymetry, and anthropogenic factors such as pollutions. The stop-and-go motion capability, using their novel mechanics, and the heads up cooperation control strategy at the core of the proposed distributed system enable the sensor network to be reconfigured dynamically according to the priority of the parameters to be monitored. The large number of Moball-buoys with their ground-based, sea-based, satellite and peer-to-peer communication capabilities would constitute a wireless mesh network that provides an interface for a global control system. This control system will ensure arctic-wide coverage, will optimize Moball-buoys monitoring efforts according to their available resources and the priority of local areas of high scientific value within the Arctic region. Moball-buoy Network is expected to be the first robust and persistent Arctic-wide environment monitoring system capable of providing reliable readings in near real time

Selected References on Arctic and Subarctic Prehistory and Ethnology. Revised.

ERIC Educational Resources Information Center

Fitzhugh, William, Comp.; Loring, Stephen, Comp.

This bibliography provides an introduction to the current literature, in English, on arctic and subarctic prehistory and ethnology. Leads for further research will be found in section 1. Publications listed are not available from the Smithsonian Institution but copies may be found in larger libraries or obtained through inter-library loan.…

Atmosphere-Ice-Ocean-Ecosystem Processes in a Thinner Arctic Sea Ice Regime: The Norwegian Young Sea ICE (N-ICE2015) Expedition

NASA Astrophysics Data System (ADS)

Granskog, Mats A.; Fer, Ilker; Rinke, Annette; Steen, Harald

2018-03-01

Arctic sea ice has been in rapid decline the last decade and the Norwegian young sea ICE (N-ICE2015) expedition sought to investigate key processes in a thin Arctic sea ice regime, with emphasis on atmosphere-snow-ice-ocean dynamics and sea ice associated ecosystem. The main findings from a half-year long campaign are collected into this special section spanning the Journal of Geophysical Research: Atmospheres, Journal of Geophysical Research: Oceans, and Journal of Geophysical Research: Biogeosciences and provide a basis for a better understanding of processes in a thin sea ice regime in the high Arctic. All data from the campaign are made freely available to the research community.

Effect of Thaw Depth on Fluxes of CO2 and CH4 in Manipulated Arctic Coastal Tundra of Barrow, Alaska

NASA Astrophysics Data System (ADS)

Kim, Y.

2014-12-01

Changes in CO2 and CH4 emissions represent one of the most significant consequences of drastic climate change in the Arctic, by way of thawing permafrost, a deepened active layer, and decline of thermokarst lakes in the Arctic. This study conducted flux-measurements of CO2 and CH4, as well as environmental factors such as temperature, moisture, and thaw depth, as part of a water table manipulation experiment in the Arctic coastal plain tundra of Barrow, Alaska during autumn. The manipulation treatment consisted of draining, controlling, and flooding treated sections by adjusting standing water. Inundation increased CH4 emission by a factor of 4.3 compared to non-flooded sections. This may be due to the decomposition of organic matter under a limited oxygen environment by saturated standing water. On the other hand, CO2 emission in the dry section was 3.9-fold higher than in others. CH4 emission tends to increase with deeper thaw depth, which strongly depends on the water table; however, CO2 emission is not related to thaw depth. Quotients of global warming potential (GWPCO2) (dry/control) and GWPCH4 (wet/control) increased by 464 and 148 %, respectively, and GWPCH4 (dry/control) declined by 66 %. This suggests that CO2 emission in a drained section is enhanced by soil and ecosystem respiration, and CH4 emission in a flooded area is likely stimulated under an anoxic environment by inundated standing water. The findings of this manipulation experiment during the autumn period demonstrate the different production processes of CO2 and CH4, as well as different global warming potentials, coupled with change in thaw depth. Thus the outcomes imply that the expansion of tundra lakes leads the enhancement of CH4 release, and the disappearance of the lakes causes the stimulated CO2 production in response to the Arctic climate change.

Arctic Ocean Gravity Field Derived From ERS-1 Satellite Altimetry.

PubMed

Laxon, S; McAdoo, D

1994-07-29

The derivation of a marine gravity field from satellite altimetry over permanently ice-covered regions of the Arctic Ocean provides much new geophysical information about the structure and development of the Arctic sea floor. The Arctic Ocean, because of its remote location and perpetual ice cover, remains from a tectonic point of view the most poorly understood ocean basin on Earth. A gravity field has been derived with data from the ERS-1 radar altimeter, including permanently ice-covered regions. The gravity field described here clearly delineates sections of the Arctic Basin margin along with the tips of the Lomonosov and Arctic mid-ocean ridges. Several important tectonic features of the Amerasia Basin are clearly expressed in this gravity field. These include the Mendeleev Ridge; the Northwind Ridge; details of the Chukchi Borderland; and a north-south trending, linear feature in the middle of the Canada Basin that apparently represents an extinct spreading center that "died" in the Mesozoic. Some tectonic models of the Canada Basin have proposed such a failed spreading center, but its actual existence and location were heretofore unknown.

An aircraft-based case study of new particle formation and growth in the summertime Arctic

NASA Astrophysics Data System (ADS)

Willis, M. D.; Abbatt, J.; Burkart, J.; Bozem, H.; Koellner, F.; Schneider, J.; Hoor, P. M.; Herber, A. B.; Leaitch, W. R.

2015-12-01

Motivated by the changing climate of the Arctic and decreasing summer sea-ice extent, we aim to better understand how atmospheric composition will impact, or be impacted by, climate and environmental change in this region. Much attention has been paid to springtime Arctic aerosol owing to significant anthropogenic influence on this remote environment, but the cleaner, more locally influenced summertime Arctic is not well characterized. We present results of vertically resolved, particle number, aerosol size distributions, submicron aerosol composition from an aerosol mass spectrometer (AMS), and cloud condensation nuclei (CCN) concentrations from the NETCARE 2014 Polar 6 aircraft campaign. The campaign was based in the high Arctic, at Resolute Bay, Nunavut, Canada (74°N, 94°W), allowing measurements from 60 to 2900 meters over ice, open water and near the ice-edge. The focus of this case study is a new particle formation and growth event observed at the eastern end of Lancaster Sound (74°N, 81°W) on July 12, 2014 under clear sky conditions. During this flight Polar 6 travelled to the end of Lancaster Sound at 2900 m and subsequently descended to 60-70 m above the surface heading due west, with winds from the west. At the lowest altitude we observed a significant increase in particles > 4 nm, between 20 - 100 nm, and > 100 nm, indicating the presence of small particles between 4 - 20 nm and growth to larger sizes. In addition, CCN concentrations were enhanced up to ~ 200/cm3 from background levels of ≤ 100/cm3. Concurrently, the AMS indicated enhanced levels of methane sulfonic acid (MSA) and marine-like organic aerosol (OA) correlated in time with the presence of larger particles, as well as an iodide signal which correlated with the presence of small particles. These observations suggest that iodine oxides could be one contributor to particle formation, and that marine-like OA and MSA could contribute to particle growth in the summertime Arctic.

Relationship between sea ice freeboard and draft in the Arctic Basin, and implications for ice thickness monitoring

NASA Technical Reports Server (NTRS)

Wadhams, P.; Tucker, W. B., III; Krabill, W. B.; Swift, R. N.; Comiso, J. C.; Davis, N. R.

1992-01-01

This study confirms the finding of Comiso et al. (1991) that the probability density function (pdf) of the ice freeboard in the Arctic Ocean can be converted to a pdf of ice draft by applying a simple coordinate factor. The coordinate factor, R, which is the ratio of mean draft to mean freeboard pdf is related to the mean material (ice plus snow) density, rho(m), and the near-surface water density rho(w) by the relationship R = rho(m)/(rho(w) - rho(m)). The measured value of R was applied to each of six 50-km sections north of Greenland of a joint airborne laser and submarine sonar profile obtained along nearly coincident tracks from the Arctic Basin north of Greenland and was found to be consistent over all sections tested, despite differences in the ice regime. This indicates that a single value of R might be used for measurements done in this season of the year. The mean value R from all six sections was found to be 7.89.

33 CFR 165.T13-221 - Safety Zone; Arctic Drilling and Support Vessels, Puget Sound, Washington.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Support Vessels, Puget Sound, Washington. 165.T13-221 Section 165.T13-221 Navigation and Navigable Waters... Coast Guard District § 165.T13-221 Safety Zone; Arctic Drilling and Support Vessels, Puget Sound... Sector Puget Sound Captain Of The Port (COTP) Zone as defined in 33 CFR 3.65-10. (b) Regulations. In...

The Arctic Report Card: Communicating the State of the Rapidly Changing Arctic to a Diverse Audience via the Worldwide Web

NASA Astrophysics Data System (ADS)

Jeffries, M. O.; Richter-Menge, J.; Overland, J. E.; Soreide, N. N.

2013-12-01

Rapid change is occurring throughout the Arctic environmental system. The goal of the Arctic Report Card is to communicate the nature of the many changes to a diverse audience via the Worldwide Web. First published in 2006, the Arctic Report Card is a peer-reviewed publication containing clear, reliable and concise scientific information on the current state of the Arctic environment relative to observational records. Available only online, it is intended to be an authoritative source for scientists, teachers, students, decision-makers, policy-makers and the general public interested in the Arctic environment and science. The Arctic Report Card is organized into five sections: Atmosphere; Sea Ice & Ocean; Marine Ecosystem; Terrestrial Ecosystem; Terrestrial Cryosphere. Arctic Report Card 2012, the sixth annual update, comprised 20 essays on physical and biological topics prepared by an international team of 141 scientists from 15 different countries. For those who want a quick summary, the Arctic Report Card home page provides highlights of key events and findings, and a short video that is also available on YouTube. The release of the Report Card each autumn is preceded by a NOAA press release followed by a press conference, when the Web site is made public. The release of Arctic Report Card 2012 at an AGU Fall Meeting press conference on 5 December 2012 was subsequently reported by leading media organizations. The NOAA Arctic Web site, of which the Report Card is a part, is consistently at the top of Google search results for the keyword 'arctic', and the Arctic Report Card Web site tops search results for keyword "arctic report" - pragmatic indications of a Web site's importance and popularity. As another indication of the Web site's impact, in December 2012, the month when the 2012 update was released, the Arctic Report Card Web site was accessed by 19,851 unique sites in 105 countries, and 4765 Web site URLs referred to the Arctic Report Card. The 2012 Arctic Report Card YouTube video has been viewed 36,074 times by viewers in 152 countries and has been embedded in over two dozen Web sites. We are confident that the Arctic Report Card is succeeding in communicating the state of the rapidly changing Arctic to many people, but we need to learn more about its broader impact. Consequently, we are considering a study of how diverse an audience is being reached, and the extent to which, outside of the scientific community, the content of the Arctic Report Card is understood, is perceived as a credible, unbiased and non-threatening resource, and is overcoming prior beliefs.

Arctic National Wildlife Refuge land cover mapping project users guide

USGS Publications Warehouse

Markon, Carl J.

1986-01-01

Section 1002 of the Alaska National Interest Lands Conservation Act of 1980 (ANILCA, 1980) requires the Secretary of Interior to conduct a continuing study of fish, wildlife, and habitats on the coastal plain of the Arctic National Wildlife Refuge (ANWR). Included in this study is a determination of the extent, location, and carrying capacity of fish and wildlife habitats.

Version 2.0 of the International Bathymetric Chart of the Arctic Ocean: A new Database for Oceanographers and Mapmakers

NASA Astrophysics Data System (ADS)

Jakobsson, M.; Macnab, R.; Edwards, M.; Schenke, H.; Hatzky, J.

2007-12-01

The International Bathymetric Chart of the Arctic Ocean (IBCAO) was first released to the public after its introduction at the American Geophysical Union (AGU) Fall Meeting in 1999 (Jakobsson et al., 2000). This first release consisted of a Digital Bathymetric Model (DBM) on a Polar stereographic projection with grid cell spacing of 2.5 x 2.5 km derived from an accumulated database of all available bathymetric data at the time of compilation. The IBCAO bathymetric database included soundings collected during past and modern expeditions as well as digitized isobaths and depth soundings from published maps. Compared to previous bathymetric maps of the Arctic Ocean, the first released IBCAO compilation was based upon a significantly enhanced database, particularly in the high Arctic. For example, de-classified echo soundings acquired during US and British submarine cruises between 1958 and 1988 were included as well as soundings from icebreaker cruises conducted by Sweden and Germany at the end of the last century. Despite the newly available data in 1999, there were still large areas of the Arctic Ocean where publicly available data were completely absent. Some of these areas had been mapped by Russian agencies, and since these observations were not available to IBCAO, depth contours from the bathymetric contour map published by the Head Department of Navigation and Hydrography (HDNO) (Naryshkin, 1999) were digitized and incorporated in the database. The new IBCAO Version 2.0 comprises the largest update since the first release; moreover, the grid spacing has been decreased to 2 x 2 km. Numerous multibeam data sets that were collected by ice breakers, e.g. USCGC Healy, R/V James Clarke Ross, R/V Polarstern, IB Oden, now form part of the database, as do the swath bathymetric observations acquired during the 1999 SCICEX expedition. The portrayal of the Eastern Arctic Basin is vastly improved due to e.g. the Arctic Mid Ocean Ridge Expedition 2001 (AMORE) and Arctic Gakkel Vents 2007 (AGAVE) expedition while mapping missions aboard the USCGC Healy have revealed the "real" shape of the sea floor of the central Lomonosov Ridge and in areas off Northern Alaska in the Western Arctic. This paper presents an overview of the new data included in Version 2.0 as well as a brief discussion on the improvements and their possible implications for IBCAO users. Jakobsson, M., Cherkis, N., Woodward, J., Macnab, R. and Coakley, B., 2000. New grid of Arctic bathymetry aids scientists and mapmakers. EOS, Transactions American Geophysical Union, 81: 89, 93, 96. Naryshkin, G., 1999. Bottom relief of the Arctic Ocean. In: H.D.o.N.a. Oceanography and A.-R.R.I.f.G.a.M.R.o.t.W. Ocean (Editors). Russian Academy of Sciences, pp. Bathymetric contour map.

Relationship between central and peripheral corneal astigmatism in elderly patients

NASA Astrophysics Data System (ADS)

Kawamorita, Takushi; Shimizu, Kimiya; Hoshikawa, Rie; Kamiya, Kazutaka; Shoji, Nobuyuki

2018-03-01

Abstract Purpose We investigated the relationship between central and peripheral corneal astigmatism in elderly patients. Methods Seventy-six eyes of 76 elderly subjects (mean age = 72.6 ± 3.0 years) were included in the study. Corneal shape was evaluated using the Pentacam HR (Oculus, Wetzlark, Germany), which is comprised of a rotating Scheimpflug camera and a short-wavelength slit light. The power distribution map was selected and corneal astigmatism was calculated using front K-Readings in zones centered on the pupil. Analyzed zones were 2.0-6.0 mm in diameter. Results Corneal astigmatism decreased as diameter increased, similar to what was observed in eyes with with-the-rule astigmatism and against-the-rule astigmatism (ANOVA, p < 0.01). This effect was more pronounced in eyes with a large central corneal astigmatism (Spearman's rank-correlation coefficient test, r = 0.51, p < 0.01). There was no change as to axis of corneal astigmatism (ANOVA, p = 0.98). Conclusion These results suggest that the relationship between central and peripheral corneal astigmatism should be taken into consideration to optimize vision when astigmatic correction is needed.

49 CFR 572.192 - Head assembly.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly. 572.192 Section 572.192... Test Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

49 CFR 572.192 - Head assembly.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly. 572.192 Section 572.192... Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180-1000...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

49 CFR 572.192 - Head assembly.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly. 572.192 Section 572.192... Test Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

49 CFR 572.192 - Head assembly.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly. 572.192 Section 572.192... Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180-1000...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

49 CFR 572.192 - Head assembly.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.192 Section 572.192... Dummy, Small Adult Female § 572.192 Head assembly. (a) The head assembly consists of the head (180-1000...) of this section, the head assembly shall meet performance requirements specified in paragraph (c) of...

Comparative analysis of marine paleogene sections and biota from West Siberia and the Arctic Region

NASA Astrophysics Data System (ADS)

Akhmet'ev, M. A.; Zaporozhets, N. I.; Iakovleva, A. I.; Aleksandrova, G. N.; Beniamovsky, V. N.; Oreshkina, T. V.; Gnibidenko, Z. N.; Dolya, Zh. A.

2010-12-01

The analysis of the main biospheric events that took place in West Siberia and the Arctic region during the Early Paleogene revealed the paleogeographic and paleobiogeographic unity of marine sedimentation basins and close biogeographic relations between their separate parts. Most biotic and abiotic events of the first half of the Paleogene in the Arctic region and West Siberia were synchronous, unidirectional, and interrelated. Shelf settings, sedimentation breaks, and microfaunal assemblages characteristic of these basins during the Paleogene are compared. The comparative analysis primarily concerned events of the Paleocene-Eocene thermal maximum (PETM) and beds with Azolla (aquatic fern). The formation of the Eocene Azolla Beds in the Arctic region and West Siberia was asynchronous, although it proceeded in line with a common scenario related to the development of a system of estuarine-type currents in a sea basin partly isolated from the World Ocean.

Ergonomics in the arctic - a study and checklist for heavy machinery in open pit mining.

PubMed

Reiman, Arto; Sormunen, Erja; Morris, Drew

2016-11-22

Heavy mining vehicle operators at arctic mines have a high risk of discomfort, musculoskeletal disorders and occupational accidents. There is a need for tailored approaches and safety management tools that take into account the specific characteristics of arctic work environments. The aim of this study was to develop a holistic evaluation tool for heavy mining vehicles and operator well-being in arctic mine environments. Data collection was based on design science principles and included literature review, expert observations and participatory ergonomic sessions. As a result of this study, a systemic checklist was developed and tested by eight individuals in a 350-employee mining environment. The checklist includes sections for evaluating vehicle specific ergonomic and safety aspects from a technological point of view and for checking if the work has been arranged so that it can be performed safely and fluently from an employee's point of view.

Body Temperature and Energy Metabolism of Brown Lemming in Relation to Running Speed,

DTIC Science & Technology

1979-01-01

ADASOG 382 ARCTIC INST OF NORTH AMERICA ARLINGTON VA F/B 6/16 BOOT TEMPERATURE AND ENERGY METABOLISM OF BROWN LEMMING IN RELA--ETC(U) W4LSIID 1979 T...M CASEY N00014-75-C-0635UNCLASSIFIEDh l o I - Body temperature and energy metabolism *of brown lemming in relation to running speed) by Timothy M...Casey Dept. of E. Physiology Cook College, Rutgers University New Brunswick, New Jersey 08903 C2 Running head: Metabolism and Tb of running lemmings. ALU

Morphological peculiarities of respiratory compartments of arctic animal lungs.

PubMed

Shishkin, G S; Ustyuzhaninova, N V

1997-04-01

Morphological and ultrastructural peculiarities of interalveolar septa in endemic arctic animals (reindeer, polar fox, lemming) are compared with laboratory animals (rat,dog). For light microscopy, tissue samples were taken from the central and peripheral sections of all lobes of the right lung. They were fixed in 10% neutral formalin and embedded in paraffin. For electron microscopy, samples were taken from subpleural sections of the caudal lobe of the right lung, fixed in 4% paraformaldehyde for 24 hours, subsequently postfixed in 2% OsO4. for 2.0 hours. Samples were dehydrated in acetone and embedded in a mixture of Epon 812 and Araldite. Ultrathin sections were photographed at a magnification of x4,000. For each interalveolar septum, lengths and diameters were recorded and the squares of septa surface, air-blood barrier surface and the number of the structures were determined. The topography of capillaries and the ultrastructure of interstitium were described. Acini in the arctic animals (reindeer, polar fox, lemming) are compact. In all lobes they are fully expanded and uniformly filled with air. There is no physiological atelectasis. Alveoli appear straight and homogeneous in form and size. In the polar fox, the quantity of interalveolar pores of Kohn is twice that in the dog. The number of pores in the lemming are similar to those in the rat but their size is 1.6 times greater in diameter. In arctic animals more capillaries connect with both alveolar surfaces by an air-blood barrier and simultaneously participate in the gas exchange of two adjoining alveoli. In the polar fox and lemming the thickness of the air-blood barrier is 1.3-1.4 times less than that in the dog and rat. The set of morpho-functional peculiarities of the acini of arctic animals allows for an increase in gas exchange in the respiratory compartments of the lungs and provides necessary oxygenation of arterial blood at a low partial pressure of oxygen in the alveolar gas.

Physical and Hydraulic Properties at Recently Burned and Long-Unburned Boreal Forest Areas in Interior Alaska, USA

NASA Astrophysics Data System (ADS)

Ebel, B. A.; Koch, J. C.; Walvoord, M. A.

2017-12-01

Boreal forest regions in interior Alaska, USA are subject to recurring wildfire disturbance and climate shifts. These "press" and "pulse" disturbances impact water, solute, carbon, and energy fluxes, with feedbacks and consequences that are not adequately characterized. The NASA Arctic Boreal Vulnerability Experiment (ABoVE) seeks to understand susceptibility to disturbance in boreal regions. Subsurface physical and hydraulic properties are among the largest uncertainties in cryohydrogeologic modeling aiming to predict impacts of disturbance in Arctic and boreal regions. We address this research gap by characterizing physical and hydraulic properties of soil across a gradient of sites covering disparate soil textures and wildfire disturbance in interior Alaska. Samples were collected in the field within the domain of the NASA ABoVE project and analyzed in the laboratory. Physical properties measured include soil organic matter fraction, soil-particle size distribution, dry bulk density, and saturated soil-water content. Hydraulic properties measured include soil-water retention and field-saturated hydraulic conductivity using tension infiltrometers (-1 cm applied pressure head). The physical and hydraulic properties provide the foundation for site conceptual model development, cryohydrogeologic model parameterization, and integration with geophysical data. This foundation contributes to the NASA ABoVE objectives of understanding the underlying physical processes that control vulnerability in Arctic and Boreal landscapes.

Transcriptional dynamics of a conserved gene expression network associated with craniofacial divergence in Arctic charr.

PubMed

Ahi, Ehsan Pashay; Kapralova, Kalina Hristova; Pálsson, Arnar; Maier, Valerie Helene; Gudbrandsson, Jóhannes; Snorrason, Sigurdur S; Jónsson, Zophonías O; Franzdóttir, Sigrídur Rut

2014-01-01

Understanding the molecular basis of craniofacial variation can provide insights into key developmental mechanisms of adaptive changes and their role in trophic divergence and speciation. Arctic charr (Salvelinus alpinus) is a polymorphic fish species, and, in Lake Thingvallavatn in Iceland, four sympatric morphs have evolved distinct craniofacial structures. We conducted a gene expression study on candidates from a conserved gene coexpression network, focusing on the development of craniofacial elements in embryos of two contrasting Arctic charr morphotypes (benthic and limnetic). Four Arctic charr morphs were studied: one limnetic and two benthic morphs from Lake Thingvallavatn and a limnetic reference aquaculture morph. The presence of morphological differences at developmental stages before the onset of feeding was verified by morphometric analysis. Following up on our previous findings that Mmp2 and Sparc were differentially expressed between morphotypes, we identified a network of genes with conserved coexpression across diverse vertebrate species. A comparative expression study of candidates from this network in developing heads of the four Arctic charr morphs verified the coexpression relationship of these genes and revealed distinct transcriptional dynamics strongly correlated with contrasting craniofacial morphologies (benthic versus limnetic). A literature review and Gene Ontology analysis indicated that a significant proportion of the network genes play a role in extracellular matrix organization and skeletogenesis, and motif enrichment analysis of conserved noncoding regions of network candidates predicted a handful of transcription factors, including Ap1 and Ets2, as potential regulators of the gene network. The expression of Ets2 itself was also found to associate with network gene expression. Genes linked to glucocorticoid signalling were also studied, as both Mmp2 and Sparc are responsive to this pathway. Among those, several transcriptional targets and upstream regulators showed differential expression between the contrasting morphotypes. Interestingly, although selected network genes showed overlapping expression patterns in situ and no morph differences, Timp2 expression patterns differed between morphs. Our comparative study of transcriptional dynamics in divergent craniofacial morphologies of Arctic charr revealed a conserved network of coexpressed genes sharing functional roles in structural morphogenesis. We also implicate transcriptional regulators of the network as targets for future functional studies.

Circumpolar measurements of speciated mercury, ozone and carbon monoxide in the boundary layer of the Arctic Ocean

NASA Astrophysics Data System (ADS)

Sommar, J.; Andersson, M. E.; Jacobi, H.-W.

2010-06-01

Using the Swedish icebreaker Oden as a platform, continuous measurements of airborne mercury (gaseous elemental mercury (Hg0), divalent gaseous mercury species HgIIX2(g) (acronym RGM) and mercury attached to particles (PHg)) and some long-lived trace gases (carbon monoxide CO and ozone O3) were performed over the North Atlantic and the Arctic Ocean. The measurements were performed for nearly three months (July-September 2005) during the Beringia 2005 expedition (from Göteborg, Sweden via the proper Northwest Passage to the Beringia region Alaska - Chukchi Penninsula - Wrangel Island and in-turn via a north-polar transect to Longyearbyen, Spitsbergen). The Beringia 2005 expedition was the first time that these species have been measured during summer over the Arctic Ocean going from 60° to 90° N. During the North Atlantic transect, concentration levels of Hg0, CO and O3 were measured comparable to typical levels for the ambient mid-hemispheric average. However, a rapid increase of Hg0 in air and surface water was observed when entering the ice-covered waters of the Canadian Arctic archipelago. Large parts of the measured waters were supersaturated with respect to Hg0, reflecting a strong disequilibrium. Heading through the sea ice of the Arctic Ocean, a fraction of the strong Hg0 pulse in the water was transferred with some time-delay into the air samples collected ~20 m above sea level. Several episodes of elevated Hg0 in air were encountered along the sea ice route with higher mean concentration (1.81±0.43 ng m-3) compared to the marine boundary layer over ice-free Arctic oceanic waters (1.55±0.21 ng m-3). In addition, the bulk of the variance in the temporal series of Hg0 concentrations was observed during July. The Oden Hg0 observations compare in this aspect very favourably with those at the coastal station Alert. Atmospheric boundary layer O3 mixing ratios decreased when initially sailing northward. In the Arctic, an O3 minimum around 15-20 ppbV was observed during summer (July-August). Alongside the polar transect during the beginning of autumn, a steady trend of increasing O3 mixing ratios was measured returning to initial levels of the expedition (>30 ppbV). Ambient CO was fairly stable (84±12 ppbV) during the expedition. However, from the Beaufort Sea and moving onwards steadily increasing CO mixing ratios were observed (0.3 ppbV day-1). On a comparison with coeval archived CO and O3 data from the Arctic coastal strip monitoring sites Barrow and Alert, the observations from Oden indicate these species to be homogeneously distributed over the Arctic Ocean. Neither correlated low ozone and Hg0 events nor elevated concentrations of RGM and PHg were at any extent sampled, suggesting that atmospheric mercury deposition to the Arctic basin is low during the Polar summer and autumn.

49 CFR 572.182 - Head assembly.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly. 572.182 Section 572.182... Test Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the..., the head assembly shall meet performance requirements specified in paragraph (c) of this section. (b...

49 CFR 572.182 - Head assembly.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.182 Section 572.182... Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the head... assembly shall meet performance requirements specified in paragraph (c) of this section. (b) Test procedure...

49 CFR 572.182 - Head assembly.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly. 572.182 Section 572.182... Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the head... assembly shall meet performance requirements specified in paragraph (c) of this section. (b) Test procedure...

49 CFR 572.182 - Head assembly.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly. 572.182 Section 572.182... Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the head... assembly shall meet performance requirements specified in paragraph (c) of this section. (b) Test procedure...

49 CFR 572.182 - Head assembly.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly. 572.182 Section 572.182... Test Dummy, 50th Percentile Adult Male § 572.182 Head assembly. (a) The head assembly consists of the..., the head assembly shall meet performance requirements specified in paragraph (c) of this section. (b...

Extreme nitrogen deposition can change methane oxidation rate in moist acidic tundra soil in Arctic regions

NASA Astrophysics Data System (ADS)

Lee, J.; Kim, J.; Kang, H.

2017-12-01

Recently, extreme nitrogen(N) deposition events are observed in Arctic regions where over 90% of the annual N deposition occurred in just a few days. Since Arctic ecosystems are typically N-limited, input of extremely high amount of N could substantially affect ecosystem processes. CH4 is a potent greenhouse gas that has 25 times greater global warming potential than CO2 over a 100-year time frame. Ammonium is known as an inhibitor of methane oxidation and nitrate also shows inhibitory effect on it in temperate ecosystems. However, effects of N addition on Arctic ecosystems are still elusive. We conducted a lab-scale incubation experiment with moist acidic tundra (MAT) soil from Council, Alaska to investigate the effect of extreme N deposition events on methane oxidation. Zero point five % methane was added to the head space to determine the potential methane oxidation rate of MAT soil. Three treatments (NH4NO3-AN, (NH4)2SO4-AS, KNO3-PN) were used to compare effects of ammonium, nitrate and salts. All treatments were added in 3 levels: 10μg N gd.w-1(10), 50μg N gd.w-1(50) and 100μg N gd.w-1(100). AN10 and AN50 increased methane oxidation rate 1.7, 6% respectively. However, AN100 shows -8.5% of inhibitory effect. In AS added samples, all 3 concentrations (AN10, AN50, AN100) stimulated methane oxidation rate with 4.7, 8.9, 4%, respectively. On the contrary, PN50 (-9%) and PN100 (-59.5%) exhibited a significant inhibitory effect. We also analyzed the microbial gene abundance and community structures of methane oxidizing bacteria using a DNA-based fingerprinting method (T-RFLP) Our study results suggest that NH4+ can stimulate methane oxidation in Arctic MAT soil, while NO3- can inhibit methane oxidation significantly.

13 CFR 101.109 - Do SBA regulations include the section headings?

Code of Federal Regulations, 2010 CFR

2010-01-01

... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Do SBA regulations include the section headings? 101.109 Section 101.109 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION ADMINISTRATION Overview § 101.109 Do SBA regulations include the section headings? Yes. All SBA regulations must...

13 CFR 101.109 - Do SBA regulations include the section headings?

Code of Federal Regulations, 2011 CFR

2011-01-01

... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false Do SBA regulations include the section headings? 101.109 Section 101.109 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION ADMINISTRATION Overview § 101.109 Do SBA regulations include the section headings? Yes. All SBA regulations must...

The Arctic Coastal Erosion Problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frederick, Jennifer M.; Thomas, Matthew Anthony; Bull, Diana L.

Permafrost-dominated coastlines in the Arctic are rapidly disappearing. Arctic coastal erosion rates in the United States have doubled since the middle of the twentieth century and appear to be accelerating. Positive erosion trends have been observed for highly-variable geomorphic conditions across the entire Arctic, suggesting a major (human-timescale) shift in coastal landscape evolution. Unfortunately, irreversible coastal land loss in this region poses a threat to native, industrial, scientific, and military communities. The Arctic coastline is vast, spanning more than 100,000 km across eight nations, ten percent of which is overseen by the United States. Much of area is inaccessible bymore » all-season roads. People and infrastructure, therefore, are commonly located near the coast. The impact of the Arctic coastal erosion problem is widespread. Homes are being lost. Residents are being dispersed and their villages relocated. Shoreline fuel storage and delivery systems are at greater risk. The U.S. Department of Energy (DOE) and Sandia National Laboratories (SNL) operate research facilities along some of the most rapidly eroding sections of coast in the world. The U.S. Department of Defense (DOD) is struggling to fortify coastal radar sites, operated to ensure national sovereignty in the air, against the erosion problem. Rapid alterations to the Arctic coastline are facilitated by oceanographic and geomorphic perturbations associated with climate change. Sea ice extent is declining, sea level is rising, sea water temperature is increasing, and permafrost state is changing. The polar orientation of the Arctic exacerbates the magnitude and rate of the environmental forcings that facilitate coastal land area loss. The fundamental mechanics of these processes are understood; their non-linear combination poses an extreme hazard. Tools to accurately predict Arctic coastal erosion do not exist. To obtain an accurate predictive model, a coupling of the influences of evolving wave dynamics, thermodynamics, and sediment dynamics must be developed. The objective of this document is to present the state-of-the-science and outline the key steps for creation of a framework that will allow for improved prediction of Arctic coastal erosion rates. This is the first step towards the quantification of coastal hazards that will allow for sustainable planning and development of Arctic infrastructure.« less

Transient nature of Arctic spring systems driven by subglacial meltwater

NASA Astrophysics Data System (ADS)

Scheidegger, J. M.; Bense, V. F.; Grasby, S. E.

2012-06-01

In the High Arctic, supra- and proglacial springs occur at Borup Fiord Pass, Ellesmere Island. Spring waters are sulfur bearing and isotope analysis suggests springs are fed by deeply circulating glacial meltwater. However, the mechanism maintaining spring flow is unclear in these areas of thick permafrost which would hamper the discharge of deep groundwater to the surface. It has been hypothesized that fracture zones along faults focus groundwater which discharges initially underneath wet-based parts of the ice. With thinning ice, the spring head is exposed to surface temperatures, tens of degrees lower than temperatures of pressure melting, and permafrost starts to develop. Numerical modeling of coupled heat and fluid flow suggest that focused groundwater discharge should eventually be cut off by permafrost encroaching into the feeding channel of the spring. Nevertheless, our model simulations show that these springs can remain flowing for millennia depending on the initial flow rate and ambient surface temperature. These systems might provide a terrestrial analog for the possible occurrence of Martian springs recharged by polar ice caps.

77 FR 76706 - Endangered and Threatened Species; Threatened Status for the Arctic, Okhotsk, and Baltic...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-28

...We, NMFS, issue a final determination to list the Arctic (Phoca hispida hispida), Okhotsk (Phoca hispida ochotensis), and Baltic (Phoca hispida botnica) subspecies of the ringed seal (Phoca hispida) as threatened and the Ladoga (Phoca hispida ladogensis) subspecies of the ringed seal as endangered under the Endangered Species Act (ESA). We will propose to designate critical habitat for the Arctic ringed seal in a future rulemaking. To assist us in this effort, we solicit information that may be relevant to the designation of critical habitat for Arctic ringed seals. In light of public comments and upon further review, we are withdrawing the proposed ESA section 4(d) protective regulations for threatened subspecies of the ringed seal because we have determined that such regulations are not necessary or advisable for the conservation of the Arctic, Okhotsk, or Baltic subspecies of the ringed seal at this time. Given their current population sizes, the long-term nature of the primary threat to these subspecies (habitat alteration stemming from climate change), and the existing protections under the Marine Mammal Protection Act, it is unlikely that the proposed protective regulations would provide appreciable conservation benefits.

Changes in the Composition of the Fram Strait Freshwater Outflow

NASA Astrophysics Data System (ADS)

Dodd, Paul; Granskog, Mats; Fransson, Agneta; Chierici, Melissa; Stedmon, Colin

2016-04-01

Fram Strait is the largest gateway and only deep connection between the Arctic Ocean and the subpolar oceans. Monitoring the exchanges through Fram Strait allows us to detect and understand current changes occurring in the Arctic Ocean and to predict the effects of those changes on the Arctic and Subarctic climate and ecosystems. Polar water, recirculating Atlantic Water and deeper water masses exported from the Arctic Ocean through western Fram Strait are monitored year-round by an array of moored instruments along 78°50'N, continuously maintained by the Norwegian Polar Institute since the 1990s. Complimentary annual hydrographic sections have been repeated along the same latitude every September. This presentation will focus on biogeochemical tracer measurements collected along repeated sections from 1997-2015, which can be used to identify freshwater from different sources and reveal the causes of variations in total volume of freshwater exported e. g.: pulses of freshwater from the Pacific. Repeated tracer sections across Fram Strait reveal significant changes in the composition of the outflow in recent years, with recent sections showing positive fractions of sea ice meltwater at the surface near the core of the EGC, suggesting that more sea ice melts back into the surface than previously. The 1997-2015 time series of measurements reveals a strong anti-correlation between run-off and net sea ice meltwater inventories, suggesting that run-off and brine may be delivered to Fram Strait together from a common source. While the freshwater outflow at Fram Strait typically exhibits a similar run-off to net sea ice meltwater ratio to the central Arctic Ocean and Siberian shelves, we find that the ratio of run-off to sea ice meltwater at Fram Strait is decreasing with time, suggesting an increased surface input of sea ice meltwater in recent years. In 2014 and 2015 measurements of salinity, δ18O and total alkalinity were collected from sea ice cores as well as the underlying water column in Fram Strait. We use this dataset to investigate the feasibility of using concurrent δ18O and total alkalinity measurements to separately identify precipitation, which probably makes up a significant fraction of the freshwater in Fram Strait, but has so far not been separately monitored.

PROJECT HEAD START--SUMMER 1966. FINAL REPORT. SECTION ONE, SOME CHARACTERISTICS OF CHILDREN IN THE HEAD START PROGRAM.

ERIC Educational Resources Information Center

STEWART, E. ELIZABETH; WILLIAMS, RICHARD H.

THIS DOCUMENT IS SECTION 1 OF A 3-PART REPORT BY THE EDUCATIONAL TESTING SERVICE. THIS SECTION DESCRIBES, IN EXTENSIVE STATISTICAL TERMS, A SAMPLE OF 445 HEAD START CHILDREN IN TERMS OF THEIR SCORES ON (1) THE STANFORD-BINET L-M, (2) THE CALDWELL PRESCHOOL INVENTORY, AND (3) THE PROJECT HEAD START BEHAVIOR INVENTORY. THE SAMPLING PROCEDURES USED…

Circumpolar measurements of speciated mercury, ozone and carbon monoxide in the boundary layer of the Arctic Ocean

NASA Astrophysics Data System (ADS)

Sommar, J.; Andersson, M. E.; Jacobi, H.-W.

2009-10-01

Using the Swedish icebreaker Oden as a platform, continuous measurements of airborne mercury (gaseous elemental mercury (Hg0), divalent mercury HgII(g) (acronym RGM) and mercury attached to particles (PHg)) and some long-lived trace gases (carbon monoxide CO and ozone O3) were performed over the North Atlantic and the Arctic Ocean. The measurements were performed for nearly three months (July-September, 2005) during the Beringia 2005 expedition (from Göteborg, Sweden via the proper Northwest Passage to the Beringia region Alaska - Chukchi Penninsula - Wrangel Island and in-turn via a north-polar transect to Longyearbyen, Spitsbergen). The Beringia 2005 expedition was the first time that these species have been measured during summer over the Arctic Ocean going from 60° to 90° N. During the North Atlantic transect, concentration levels of Hg0, CO and O3 were measured comparable to typical levels for the ambient mid-hemispheric average. However, a rapid increase of Hg0 in air and surface water was observed when entering the ice-covered waters of the Canadian Arctic archipelago. Large parts of the measured waters were supersaturated with respect to Hg0, reflecting a strong disequilibrium. Heading through the sea ice of the Arctic Ocean, a fraction of the strong Hg0} pulse in the water was spilled with some time-delay into the air samples collected 20 m a.s.l. Several episodes of elevated Hg0(g) were encountered along the sea ice route with higher mean concentration (1.81±0.43 ng m-3) compared to the marine boundary layer over ice-free oceanic waters (1.55±0.21 ng m-3). In addition, an overall majority of the variance in the temporal series of Hg0 concentrations was observed during July. Atmospheric boundary layer {O3} mixing ratios decreased when initially sailing northward. In the Arctic, an O3 minimum around 15-20 ppbv was observed during summer (July-August). Alongside the polar transect during the beginning of autumn, a steady trend of increasing O3 mixing ratios was measured returning to initial levels of the expedition (>30 ppbv). Ambient CO was fairly stable (84±12 ppbv) during the expedition. However, from the Beaufort Sea and moving onwards steadily increasing CO mixing ratios were observed (0.3 ppbv day-1). On a comparison with coeval archived CO and O3 data from the Arctic coastal strip monitoring sites Barrow and Alert, the observations from Oden indicate these species to be homogeneously distributed over the Arctic Ocean. Neither correlated low ozone and GEM events nor elevated concentrations of RGM and PHg were at any extent sampled, suggesting that atmospheric mercury deposition to the Arctic basin is low during the Polar summer and autumn. Elevated levels of Hg0 and CO were episodically observed in air along the Chukchi Peninsula indicating transport of regional pollution.

Late Quaternary environmental changes inferred from stable carbon, nitrogen and oxygen isotope values at Teshekpuk Lake, North Slope, Alaska

NASA Astrophysics Data System (ADS)

Randall, J. J.; Booth, A. L.; Wooller, M. J.; Jones, B. M.; Gaglioti, B.

2012-12-01

Global surface air temperatures increased by ~0.74°C between 1906-2005, with average temperatures in the Arctic increasing at almost twice the rate as the rest of the planet. The Arctic Coastal Plain of Alaska is particularly susceptible and responsive to these fluctuations in climate. Better understanding both short- and long-term climate variability is important as this ecosystem provides food and habitat for hundreds of thousands of migratory birds and caribou. Despite the ecological importance of the Arctic Coastal Plain, relatively few studies exist that provide multi-proxy paleoclimatic data for the region and thus the rate at which climate and ecosystems have changed during the past century lack a longer term context. Here we present stable carbon and nitrogen isotope values from the analysis of bulk organic matter in samples from a ~6 m sediment core from Teshekpuk Lake, 80 miles southeast of Barrow, Alaska. AMS 14C dates on a nearby core indicate a basal age of ~15 kyr. The relatively low C/N values (mean <11) throughout the core infer that the organic matter is largely composed of autochthonous organic matter. Stable carbon isotope values from analyses of this organic material increase from ~-27‰ at the base of the core to peaks of ~-23‰ between ~10 and 8 kyr, inferring highs in lake production during this time. We also present stable oxygen isotope values from analyses of chironomid and aquatic invertebrate chitin preserved in the core. Non-biting midges in the family Chironomidae begin their lifecycles in freshwater. During their larval stages chironomids synthesize and molt chitinous head capsules. These head capsules record the oxygen isotopic composition of the lake water present at the time of synthesis, and are well preserved in lake sediments. These isotopic results are interpreted in terms of other recent isotope data from the north slope of Alaska in addition to a pollen reconstruction from the same core and their implications in terms of past environmental changes.

7 CFR 245.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... child, a Migrant child, a Head Start child and a Runaway child, as defined in this section, are also... this section; a Homeless child, a Migrant child, a Head Start child and a Runaway child, as defined in... for a Migrant child, Homeless child, Runaway child, or Head Start child, as defined in this section...

7 CFR 245.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... child, a Migrant child, a Head Start child and a Runaway child, as defined in this section, are also... this section; a Homeless child, a Migrant child, a Head Start child and a Runaway child, as defined in... for a Migrant child, Homeless child, Runaway child, or Head Start child, as defined in this section...

Research studies on advanced optical module/head designs for optical devices

NASA Technical Reports Server (NTRS)

Burke, James J.

1991-01-01

A summary is presented of research in optical data storage materials and of research at the center. The first section contains summary reports under the general headings of: (1) Magnetooptic media: modeling, design, fabrication, characterization, and testing; (2) Optical heads: holographic optical elements; and (3) Optical heads: integrated optics. The second section consist of a proposal entitled, Signal Processing Techniques for Optical Data Storage. And section three presents various publications prepared by the center.

Frozen Section Evaluation of Margin Status in Primary Squamous Cell Carcinomas of the Head and Neck: A Correlation Study of Frozen Section and Final Diagnoses.

PubMed

Layfield, Eleanor M; Schmidt, Robert L; Esebua, Magda; Layfield, Lester J

2018-06-01

Frozen section is routinely used for intraoperative margin evaluation in carcinomas of the head and neck. We studied a series of frozen sections performed for margin status of head and neck tumors to determine diagnostic accuracy. All frozen sections for margin control of squamous carcinomas of the head and neck were studied from a 66 month period. Frozen and permanent section diagnoses were classified as negative or malignant. Correlation of diagnoses was performed to determine accuracy. One thousand seven hundred and ninety-six pairs of frozen section and corresponding permanent section diagnoses were obtained. Discordances were found in 55 (3.1%) pairs. In 35 pairs (1.9%), frozen section was reported as benign, but permanent sections disclosed carcinoma. In 21 cases, the discrepancy was due to sampling and in the remaining cases it was an interpretive error. In 20 cases (1.1%), frozen section was malignant, but the permanent section was interpreted as negative. Frozen section is an accurate method for evaluation of operative margins for head and neck carcinomas with concordance between frozen and permanent results of 97%. Most errors are false negative results with the majority of these being due to sampling issues.

Is neonatal head circumference related to caesarean section for failure to progress?

PubMed

de Vries, Bradley; Bryce, Bianca; Zandanova, Tatiana; Ting, Jason; Kelly, Patrick; Phipps, Hala; Hyett, Jon A

2016-12-01

There is global concern about rising caesarean section rates. Identification of risk factors could lead to preventative measures. To describe the association between neonatal head circumference and (i) caesarean section for failure to progress, (ii) intrapartum caesarean section overall. This was a retrospective cohort study of 11 687 singleton live births with cephalic presentation, attempted vaginal birth and at least 37 completed weeks gestation from January 2005 to June 2009. Neonatal head circumference was grouped into quartiles and multiple logistic regressions performed. The rates of caesarean section for failure to progress were 4.1, 6.4, 8.8 and 14.3% in successive head circumference quartiles. Rates of intrapartum caesarean section overall were 8.7, 12.1, 15.8 and 21.5%. The odds ratios for caesarean section for failure to progress were: 1.00, 1.33 (95% CI 1.02- 1.73), 1.54 (1.18-2.02) and 1.93 (1.44-2.57) for successive head circumference quartiles after adjusting for multiple demographic and clinical factors. The adjusted odds ratios for intrapartum caesarean section for any indication were: 1.00, 1.52 (95% CI 1.24-1.87), 1.99 (1.62-2.46) and 2.38 (1.89-3.00), respectively. There is a strong positive relationship between head circumference quartile and both caesarean section for failure to progress and caesarean for any indication. If this finding is confirmed using ultrasound measurements, there is potential for head circumference to be incorporated into predictive models for intrapartum caesarean section with a view to offering interventions to reduce the risk of caesarean section. © 2016 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.

Arctic Refuge coastal plain terrestrial wildlife research summaries

USGS Publications Warehouse

Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

2002-01-01

In 1980, when the U.S. Congress enacted the Alaska National Interest Lands Conservation Act (ANILCA), it also mandated a study of the coastal plain of the Arctic National Wildlife Refuge. Section 1002 of ANILCA stated that a comprehensive inventory of fish and wildlife resources would be conducted on 1.5 million acres of the Arctic Refuge coastal plain (1002 Area). Potential petroleum reserves in the 1002 Area were also to be evaluated from surface geological studies and seismic exploration surveys. Results of these studies and recommendations for future management of the Arctic Refuge coastal plain were to be prepared in a report to Congress.In 1987, the Department of the Interior published the Arctic National Wildlife Refuge, Alaska, Coastal Plain Resource Assessment - Report and Recommendations to the Congress of the United States and Final Environmental Impact Statement. This report to Congress identified the potential for oil and gas production (updated* most recently by the U.S. Geological Survey in 2001), described the biological resources, and evaluated the potential adverse effects to fish and wildlife resources. The 1987 report analyzed the potential environmental consequences of five management alternatives for the coastal plain, ranging from wilderness designation to opening the entire area to lease for oil and gas developement. The report's summary recommended opening the 1002 Area to an orderly oil and gas leasing program, but cautioned that adverse effects to some wildlife populations were possible.Congress did not act on this recommendation nor any other alternative for the 1002 Area, and scientists continued studies of key wildlife species and habitats on the coastal plain of the Arctic Refuge and surrounding areas. This report contains updated summaries of those scientific investigations of caribou, muskoxen, predators (grizzly bears, wolves, golden eagles), polar bears, snow geese, and their wildlife habitats.Contributions to this report were made by scientists affiliated with the U.S. Geological Survey; U.S. Fish and Wildlife Service; Alaska Department of Fish and Game; University of Alaska-Fairbanks; Canadian Wildlife Service; Yukon Department of Renewable Resources; and the Northwest Territories Department of Resources, Wildlife, and Economic Development.Sections of the report presenting new information on caribou and forage plants were peer-reviewed by three independent, non-affiliated scientists. The remaining sections summarize previously published peer-reviewed scientific papers and were reviewed by a single independent scientist. The U.S. Geological Survey and the U.S. Fish and Wildlife Service collaborated in the publication of this report.

Using a Cross Section to Train Veterinary Students To Visualize Anatomical Structures in Three Dimensions.

ERIC Educational Resources Information Center

Provo, Judy; Lamar, Carlton; Newby, Timothy

2002-01-01

Uses a cross section to enhance three-dimensional knowledge of the anatomy of a canine head. Involves (n=124) veterinary students dissecting the head and experimental groups also identifying structures on a cross section of the head. Reports a positive impact of this experience on participant students. (Contains 52 references.) (Author/YDS)

Long-Endurance, Ice-capable Autonomous Seagliders

NASA Astrophysics Data System (ADS)

Lee, C. M.; Gobat, J. I.; Shilling, G.; Curry, B.

2012-12-01

Autonomous Seagliders capable of extended (many months) operation in ice-covered waters have been developed and successfully employed as part of the US Arctic Observing Network. Seagliders operate routinely in lower-latitude oceans for periods of up to 9 months to provide persistent sampling in difficult, remote conditions, including strong boundary currents and harsh wintertime subpolar seas. The Arctic Observing Network calls for sustained occupation of key sections within the Arctic Ocean and across the critical gateways that link the Arctic to lower-latitude oceans, motivating the extension of glider technologies to permit operation in ice-covered waters. When operating in open water, gliders rely on GPS for navigation and Iridium satellite phones for data and command telemetry. Ice cover blocks access to the sea surface and thus prevents gliders from using these critical services. When operating under ice, ice-capable Seagliders instead navigate by trilateration from an array of RAFOS acoustic sound sources and employ advanced autonomy to make mission-critical decisions (previously the realm of the human pilot) and identify and exploit leads in the ice to allow intermittent communication through Iridium. Davis Strait, one of the two primary pathways through which Arctic waters exit into the subpolar North Atlantic, provided a convenient site for development of ice-capable Seagliders at a location where the resulting measurements could greatly augment the existing observing system. Initial testing of 780 Hz RAFOS sources in Davis Strait, substantiated by the performance of the operational array, indicates effective ranges of 100-150 km in ice-covered waters. Surface ducting and reflection off the ice bottom significantly degrade the range from the 500+ km expected in ice-free conditions. Comparisons between GPS and acoustically-derived positions collected during operations in ice-free conditions suggest 1-2 km uncertainty in the acoustically-derived positions. The first successful section across the ice-covered Davis Strait occurred in 2006, while the first full mission took place September - February 2008. Mission duration was 25 weeks, with over 800 km of under-ice transit over 51 days. The glider was able to identify and surface through leads 10 times during under-ice operations. Most recently, a pair of successful missions collected continuous sections across Davis Strait from October 2010 through June 2011, including operations between January and June, when the strait was nearly entirely ice-covered and the glider rarely gained access to the surface. These missions provide the first year-round time series of high-resolution sections across Davis Strait. In the Antarctic, ice-capable Seagliders successfully transited beneath a 40-km ice bridge and self-extracted after being carried beneath the Ross ice shelf during missions conducted without the support of an acoustic navigation array. Ice-capable Seagliders can provide sustainable, continuous occupation of critical sections in ice-covered regions, including the marginal ice zone, with typical horizontal resolution of 3 km and routine sampling of the important, but hazardous, region near the ice-ocean interface. Future directions include development of basin-scale acoustic navigation ('underwater GPS' for the Arctic) and use of existing high-frequency acoustic communications for short-range data transfer.

Long-Endurance, Ice-capable Autonomous Seagliders

NASA Astrophysics Data System (ADS)

Lee, Craig; Gobat, Jason; Shilling, Geoff; Curry, Beth

2013-04-01

Autonomous Seagliders capable of extended (many months) operation in ice-covered waters have been developed and successfully employed as part of the US Arctic Observing Network. Seagliders operate routinely in lower-latitude oceans for periods of up to 9 months to provide persistent sampling in difficult, remote conditions, including strong boundary currents and harsh wintertime subpolar seas. The Arctic Observing Network calls for sustained occupation of key sections within the Arctic Ocean and across the critical gateways that link the Arctic to lower-latitude oceans, motivating the extension of glider technologies to permit operation in ice-covered waters. When operating in open water, gliders rely on GPS for navigation and Iridium satellite phones for data and command telemetry. Ice cover blocks access to the sea surface and thus prevents gliders from using these critical services. When operating under ice, ice-capable Seagliders instead navigate by trilateration from an array of RAFOS acoustic sound sources and employ advanced autonomy to make mission-critical decisions (previously the realm of the human pilot) and identify and exploit leads in the ice to allow intermittent communication through Iridium. Davis Strait, one of the two primary pathways through which Arctic waters exit into the subpolar North Atlantic, provided a convenient site for development of ice-capable Seagliders at a location where the resulting measurements could greatly augment the existing observing system. Initial testing of 780 Hz RAFOS sources in Davis Strait, substantiated by the performance of the operational array, indicates effective ranges of 100-150 km in ice-covered waters. Surface ducting and reflection off the ice bottom significantly degrade the range from the 500+ km expected in ice-free conditions. Comparisons between GPS and acoustically-derived positions collected during operations in ice-free conditions suggest 1-2 km uncertainty in the acoustically-derived positions. The first successful section across the ice-covered Davis Strait occurred in 2006, while the first full mission took place September - February 2008. Mission duration was 25 weeks, with over 800 km of under-ice transit over 51 days. The glider was able to identify and surface through leads 10 times during under-ice operations. Most recently, a pair of successful missions collected continuous sections across Davis Strait from October 2010 through June 2011, including operations between January and June, when the strait was nearly entirely ice-covered and the glider rarely gained access to the surface. These missions provide the first year-round time series of high-resolution sections across Davis Strait. In the Antarctic, ice-capable Seagliders successfully transited beneath a 40-km ice bridge and self-extracted after being carried beneath the Ross ice shelf during missions conducted without the support of an acoustic navigation array. Ice-capable Seagliders can provide sustainable, continuous occupation of critical sections in ice-covered regions, including the marginal ice zone, with typical horizontal resolution of 3 km and routine sampling of the important, but hazardous, region near the ice-ocean interface. Future directions include development of basin-scale acoustic navigation ('underwater GPS' for the Arctic) and use of existing high-frequency acoustic communications for short-range data transfer.

ICESCAPE Mission

NASA Image and Video Library

2010-07-03

Benny Hopson from the Barrow (Alaska) Arctic Science Consortium drills a core sample from sea ice in the Chukchi Sea on July 4, 2010. The core is sliced up into puck-sized sections and stored onboard the U.S. Coast Guard Healy for analysis in the ship's lab. Impacts of Climate change on the Eco-Systems and Chemistry of the Arctic Pacific Environment (ICESCAPE) is a multi-year NASA shipborne project. The bulk of the research will take place in the Beaufort and Chukchi Sea’s in summer of 2010 and fall of 2011. Photo Credit: (NASA/Kathryn Hansen)

Anoxia and high primary production in the Paleogene central Arctic Ocean: First detailed records from Lomonosov Ridge

NASA Astrophysics Data System (ADS)

Stein, Ruediger; Boucsein, Bettina; Meyer, Hanno

2006-09-01

Except for a few discontinuous fragments of the Late Cretaceous/Early Cenozoic climate history and depositional environment, the paleoenvironmental evolution of the pre-Neogene central Arctic Ocean was virtually unknown prior to the IODP Expedition 302 (Arctic Ocean Coring Expedition-ACEX) drilling campaign on Lomonosov Ridge in 2004. Here we present detailed organic carbon (OC) records from the entire ca. 200 m thick Paleogene OC-rich section of the ACEX drill sites. These records indicate euxinic "Black Sea-type" conditions favorable for the preservation of labile aquatic (marine algae-type) OC occur throughout the upper part of the early Eocene and the middle Eocene, explained by salinity stratification due to freshwater discharge. The superimposed short-term ("Milankovitch-type") variability in amount and composition of OC is related to changes in primary production and terrigenous input. Prominent early Eocene events of algae-type OC preservation coincide with global δ13C events such as the PETM and Elmo events. The Elmo δ13C Event has been identified in the Arctic Ocean for the first time.

A Simple and Efficient Device for Demonstrating Cross-Sectional Anatomy of the Head

ERIC Educational Resources Information Center

Zamarioli, Ariane; Demaman, Aline Santos; Bim, Waldeci Roberto; Homem, Jefferson Mallman; Thomazini, Jose Antonio

2010-01-01

Described in this article is a novel device that facilitates study of the cross-sectional anatomy of the human head. In designing our device, we aimed to protect sections of the head from the destructive action of handling during anatomy laboratory while also ensuring excellent visualization of the anatomic structures. We used an electric saw to…

Stories from the Arctic field

NASA Astrophysics Data System (ADS)

Cain, Michelle

2016-04-01

I will discuss my experience co-ordinating a range of communication activities for a multi-university research programme called Methane in the Arctic: Measurements and Modelling. The project included ground- and aircraft-based fieldwork in the European Arctic, as well as computer modelling. Our communication activities included: our own field blog (www.arcticmethane.wordpress.com), which was syndicated to the Scientific American Expeditions blog; writing articles for other blogs with a wider audience than our own; use of twitter; and podcasting our field work. The grand finale to our communications work was a live event at a science festival, in which we took the audience along with us on a recreated research flight, complete with a life-size mock up of a section of our research aircraft. I will discuss my experiences of these forms of communication, and give an evaluation of their successes and failures.

Martian Arctic Landscape Panorama Video

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] Click on image for animation

Typical view if you were standing on Mars and slowly turned around for a look. Starting at the north, SSI sees its shadow and turns its head viewing solar arrays, the lander deck and landscape. Note very few rocks on the hummocky terrain and network of troughs, typical of polar surfaces here on Earth.

The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

Morphological and molecular characterization of Sarcocystis arctica-like sarcocysts from the Arctic fox (Vulpes lagopus) from Alaska, USA

USGS Publications Warehouse

Cerqueira-Cézar, Camila K.; Thompson, Peter C.; Verma, Shiv K.; Mowery, Joseph; Calero-Bernal, Rafael; Antunes Murata, Fernando H.; Sinnett, David R.; Van Hemert, Caroline R.; Rosenthal, Benjamin M.; Dubey, Jitender P.

2017-01-01

The muscles of herbivores commonly harbor sarcocysts of parasites belonging to species in the genus Sarcocystis, but such muscle parasites are rare in carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA, for the first time. The tongues of 56 foxes were examined for Sarcocystis infection using several methods. Sarcocystis bradyzoites were detected in pepsin digests of 13 (23.2%), and sarcocysts were found in histological sections stained with hematoxylin and eosin (HE) of 9 (16.0%). By light microscopy, sarcocysts were up to 4 mm long and up to 245 μm wide. In HE-stained sections, the sarcocyst wall appeared smooth and up to 1.5 μm thick without visible protrusions. By transmission electron microscopy, the sarcocyst wall had a wavy parasitophorous vacuolar membrane (pvm) folded as pleomorphic villar protrusions (vp), sometimes with anastomoses of villar tips. The vp and the ground substance (gs) layer were smooth and without microtubules. The gs was up to 2.0 μm thick. The total width of the wall including vp and the gs was up to 4.0 μm. The vp were up to 3.0 μm long and most closely resembled “type 9c.” All sarcocysts were mature and contained numerous 8.1 × 2.1 μm sized bradyzoites. Molecular characterization (at 18S rDNA, 28S rDNA, ITS-1, and cox1) showed the highest affinity for S. arctica of the Arctic fox (V. lagopus) from Norway. In the present investigation, we provide evidence that sarcocysts are common in tongues of Alaskan Arctic foxes suggesting that these carnivores are serving as intermediate hosts, and we also provide ultrastructure of S. arctica from the Arctic fox for the first time.

Sedimentary Cover of the Central Arctic

NASA Astrophysics Data System (ADS)

Kireev, Artem; Poselov, Viktor; Butsenko, Viktor; Smirnov, Oleg

2017-04-01

Partial revised Submission of the Russian Federation for establishment of the OLCS (outer limit of the continental shelf) in the Arctic Ocean is made to include in the extended continental shelf of the Russian Federation, in accordance with article 76 of the Convention, the seabed and its subsoil in the central Arctic Ocean which is natural prolongation of the Russian land territory. To submit partial revised Submission in 2016, in 2005 - 2014 the Russian organizations carried out a wide range of geophysical studies, so that today over 23000 km of MCS lines, over hundreds of wide-angle reflection/refraction seismic sonobuoy soundings and 4000 km of deep seismic sounding are accomplished. All of these MCS and seismic soundings data were used to establish the seismic stratigraphy model of the Arctic region. Stratigraphy model of the sedimentary cover was successively determined for the Cenozoic and pre-Cenozoic parts of the section and was based on correlation of the Russian MCS data and seismic data documented by existing boreholes. Interpretation of the Cenozoic part of the sedimentary cover was based on correlation of the Russian MCS data and AWI91090 section calibrated by ACEX-2004 boreholes on the Lomonosov Ridge for Amerasia basin and by correlation of onlap contacts onto oceanic crust with defined magnetic anomalies for Eurasia basin, while interpretation of the Pre-Cenozoic part of the sedimentary cover was based on correlation with MCS and boreholes data from Chukchi sea shelf. Six main unconformities were traced: regional unconformity (RU), Eocene unconformity (EoU) (for Eurasia basin only), post-Campanian unconformity (pCU), Brookian (BU - base of the Lower Brookian unit), Lower Cretaceous (LCU) and Jurassic (JU - top of the Upper Ellesmerian unit). The final step in our research was to estimate the total thickness of the sedimentary cover of the Arctic Ocean and adjacent Eurasian shelf using top of acoustic basement correlation data and bathymetry data. Structural prolongation of the shallow shelf into deep-water could be observed on this sedimentary map.

Morphological and molecular characterization of Sarcocystis arctica-like sarcocysts from the Arctic fox (Vulpes lagopus) from Alaska, USA.

PubMed

Cerqueira-Cézar, Camila K; Thompson, Peter C; Verma, Shiv Kumar; Mowery, Joseph; Calero-Bernal, Rafael; Antunes Murata, Fernando H; Sinnett, David R; Van Hemert, Caroline; Rosenthal, Benjamin M; Dubey, Jitender P

2017-07-01

The muscles of herbivores commonly harbor sarcocysts of parasites belonging to species in the genus Sarcocystis, but such muscle parasites are rare in carnivores. Here, we report Sarcocystis arctica-like sarcocysts in muscles of Arctic foxes (Vulpes lagopus) from Alaska, USA, for the first time. The tongues of 56 foxes were examined for Sarcocystis infection using several methods. Sarcocystis bradyzoites were detected in pepsin digests of 13 (23.2%), and sarcocysts were found in histological sections stained with hematoxylin and eosin (HE) of 9 (16.0%). By light microscopy, sarcocysts were up to 4 mm long and up to 245 μm wide. In HE-stained sections, the sarcocyst wall appeared smooth and up to 1.5 μm thick without visible protrusions. By transmission electron microscopy, the sarcocyst wall had a wavy parasitophorous vacuolar membrane (pvm) folded as pleomorphic villar protrusions (vp), sometimes with anastomoses of villar tips. The vp and the ground substance (gs) layer were smooth and without microtubules. The gs was up to 2.0 μm thick. The total width of the wall including vp and the gs was up to 4.0 μm. The vp were up to 3.0 μm long and most closely resembled "type 9c." All sarcocysts were mature and contained numerous 8.1 × 2.1 μm sized bradyzoites. Molecular characterization (at 18S rDNA, 28S rDNA, ITS-1, and cox1) showed the highest affinity for S. arctica of the Arctic fox (V. lagopus) from Norway. In the present investigation, we provide evidence that sarcocysts are common in tongues of Alaskan Arctic foxes suggesting that these carnivores are serving as intermediate hosts, and we also provide ultrastructure of S. arctica from the Arctic fox for the first time.

Heat transfer coefficient: Medivance Arctic Sun Temperature Management System vs. water immersion.

PubMed

English, M J; Hemmerling, T M

2008-07-01

To improve heat transfer, the Medivance Arctic Sun Temperature Management System (Medivance, Inc., Louisville, CO, USA) features an adhesive, water-conditioned, highly conductive hydrogel pad for intimate skin contact. This study measured and compared the heat transfer coefficient (h), i.e. heat transfer efficiency, of this pad (hPAD), in a heated model and in nine volunteers' thighs; and of 10 degrees C water (hWATER) in 33 head-out immersions by 11 volunteers. Volunteer studies had ethical approval and written informed consent. Calibrated heat flux transducers measured heat flux (W m-2). Temperature gradient (DeltaT) was measured between skin and pad or water temperatures. Temperature gradient was changed through the pad's water temperature controller or by skin cooling on immersion. The heat transfer coefficient is the slope of W m-2/DeltaT: its unit is W m-2 degrees C-1. Average with (95% CI) was: model, hPAD = 110.4 (107.8-113.1), R2 = 0.99, n = 45; volunteers, hPAD = 109.8 (95.5-124.1), R2 = 0.83, n = 51; and water immersion, hWATER = 107.1 (98.1-116), R2 = 0.86, n = 94. The heat transfer coefficient for the pad was the same in the model and volunteers, and equivalent to hWATER. Therefore, for the same DeltaT and heat transfer area, the Arctic Sun's heat transfer rate would equal water immersion. This has important implications for body cooling/rewarming rates.

Information And Data-Sharing Plan of IPY China Activity

NASA Astrophysics Data System (ADS)

Zhang, X.; Cheng, W.

2007-12-01

Polar Data-Sharing is an effective resolution to global system and polar science problems and to interdisciplinary and sustainable study, as well as an important means to deal with IPY scientific heritages and realize IPY goals. Corresponding to IPY Data-Sharing policies, Information and Data-Sharing Plan was listed in five sub-plans of IPY Chinese Programme launched in March, 2007,they are Scientific research program of the Prydz Bay, Amery Ice Shelf and Dome A transects(short title:'PANDA'), the Arctic Scientific Research Expedition Plan, International Cooperation Plan, Information and Data-Sharing Plan, Education and Outreach. China, since the foundation of Antarctic Zhongshan Station in 1989, has carried out systematic scientific expeditions and researches in Larsemann Hills, Prydz Bay and the neighbouring sea areas, organized 14 Prydz Bay oceanographic investigations, 3 Amery Ice Shelf expeditions, 4 Grove Mountains expeditions and 5 inland ice cap scientific expeditions. 2 comprehensive oceanographic investigations in the Arctic Ocean were conducted in 1999 and 2003, acquired a large amount of data and samples in PANDA section and fan areas of Pacific Ocean in the Arctic Ocean. A mechanism of basic data submitting ,sharing and archiving has been gradually set up since 2000. Presently, Polar Science Database and Polar Sample Resource Sharing Platform of China with the aim of sharing polar data and samples has been initially established and began to provide sharing service to domestic and oversea users. According to IPY Chinese Activity, 2 scientific expeditions in the Arctic Ocean, 3 in the South Ocean, 2 at Amery Ice Shelf, 1 on Grove Mountains and 2 inland ice cap expeditions on Dome A will be carried out during IPY period. According to the experiences accumulated in the past and the jobs in the future, the Information and Data- Sharing Plan, during 2007-2010, will save, archive, and provide exchange and sharing services upon the data obtained by scientific expeditions on the site of IPY Chinese Programme. Meanwhile, focusing on areas in east Antarctic Dome A-Grove Mountain-Zhongshan Station-Amery Ice Shelf-Prydz Bay Section and the fan areas of Pacific Ocean in the Arctic Ocean, the Plan will also collect and integrate IPY data and historical data and establish database of PANDA Section and the Arctic Ocean. The details are as follows: On the basis of integrating the observed data acquired during the expeditions of China, the Plan will, adopting portal technology, develop 5 subject databases (English version included):(1) Database of Zhongshan Station- Dome A inner land ice cap section;(2) Database of interaction of ocean-ice-atmosphere-ice shelf in east Antarctica;(3) Database of geological and glaciological advance and retreat evolvement in Grove Mountains; (4) Database of Solar Terrestrial Physics at Zhongshan Station; (5) Oceanographic database of fan area of Pacific Ocean in the Arctic Ocean. CN-NADC of PRIC is the institute which assumes the responsibility for the Plan, specifically, it coordinates and organizes the operation of the Plan which includes data management, developing the portal of data and information sharing, and international exchanges. The specific assignments under the Plan will be carried out by research institutes under CAS (Chinese Academy of Sciences), SOA ( State Oceanic Administration), State Bureau of Surveying and Mapping and Ministry of Education.

Relationship between sea ice freeboard and draft in the Arctic Basin, and implications for ice thickness monitoring

NASA Astrophysics Data System (ADS)

Wadhams, P.; Tucker, W. B.; Krabill, W. B.; Swift, R. N.; Comiso, J. C.; Davis, N. R.

1992-12-01

We have confirmed our earlier finding that the probability density function (pdf) of ice freeboard in the Arctic Ocean can be converted to a pdf of ice draft by applying a simple coordinate transformation based on the measured mean draft and mean elevation. This applies in each of six 50-km sections (north of Greenland) of joint airborne laser and submarine sonar profile obtained along nearly coincident tracks from the Arctic Basin north of Greenland and tested for this study. Detailed differences in the shape of the pdf can be explained on the basis of snow load and can, in principle, be compensated by the use of a more sophisticated freeboard-dependent transformation. The measured "density ratio" R (actually mean draft/mean elevation ratio) for each section was found to be consistent over all sections tested, despite differences in the ice regime, indicating that a single value of R might be used for measurements done in this season of the year. The mean value from all six sections is 7.89; on the assumption that all six values are drawn from the same population, the standard deviation is 0.55 for a single 50-km section, and thus 0.22 for 300 km of track. In attempting to infer ice draft from laser-measured freeboard, we would therefore expect an accuracy of about ±28 cm in 50 km of track (if mean draft is about 4 m) and about ±11 cm in 300 km of track; these accuracies are compatible with the resolution of predictions from numerical models. A simple model for the variability of R with season and with mean ice thickness gives results in reasonable agreement with observations. They show that although there is a large seasonal variability due to snow load, there is a stable period from November to April when the variability is chiefly dependent on the mean ice thickness alone. Thus, in principle, R can be mapped over the Arctic Ocean as a basis for interpreting survey data. Better field data are needed on the seasonal and spatial variability of three key quantities: area-averaged snow load, mean density of first-year and multiyear ice (including the effect of ridging with these two ice regimes), and density of near-surface water.

Arctic transitions in the Land - Atmosphere System (ATLAS): Background, objectives, results, and future directions

USGS Publications Warehouse

McGuire, A.D.; Sturm, M.; Chapin, F. S.

2003-01-01

This paper briefly reviews the background, objectives, and results of the Arctic Transitions in the Land-Atmosphere System (ATLAS) Project to date and provides thoughts on future directions. The key goal of the ATLAS Project is to improve understanding of controls over spatial and temporal variability of terrestrial processes in the Arctic that have potential consequences for the climate system, i.e., processes that affect the exchange of water and energy with the atmosphere, the exchange of radiatively active gases with the atmosphere, and the delivery of freshwater to the Arctic Ocean. Three important conclusions have emerged from research associated with the ATLAS Project. First, associated with the observation that the Alaskan Arctic has warmed significantly in the last 30 years, permafrost is warming, shrubs are expanding, and there has been a temporary release of carbon dioxide from tundra soils. Second, the winter is a more important period of biological activity than previously appreciated. Biotic processes, including shrub expansion and decomposition, affect snow structure and accumulation and affect the annual carbon budget of tundra ecosystems. Third, observed vegetation changes can have a significant positive feedback to regional warming. These vegetation effects are, however, less strong than those exerted by land-ocean heating contrasts and the topographic constraints on air mass movements. The papers of this special section provide additional insights related to these conclusions and to the overall goal of ATLAS.

Ocean Wave Energy Regimes of the Circumpolar Coastal Zones

NASA Astrophysics Data System (ADS)

Atkinson, D. E.

2004-12-01

Ocean wave activity is a major enviromental forcing agent of the ice-rich sediments that comprise large sections of the arctic coastal margins. While it is instructive to possess information about the wind regimes in these regions, direct application to geomorphological and engineering needs requires knowledge of the resultant wave-energy regimes. Wave energy information has been calculated at the regional scale using adjusted reanalysis model windfield data. Calculations at this scale are not designed to account for local-scale coastline/bathymetric irregularities and variability. Results will be presented for the circumpolar zones specified by the Arctic Coastal Dynamics Project.

Cyst-theca relationship of the arctic dinoflagellate cyst Islandinium minutum (Dinophyceae) and phylogenetic position based on SSU rDNA and LSU rDNA.

PubMed

Potvin, Éric; Rochon, André; Lovejoy, Connie

2013-10-01

Round brown spiny cysts constitute a morphological group common in high latitude dinoflagellate cyst assemblages. The dinoflagellate cyst Islandinium minutum (Harland et Reid) Head, Harland et Matthiessen is the main paleoecological indicator of seasonal sea-ice cover in the Arctic. Despite the importance of this cyst in paleoceanographical studies, its biological affinity has so far been unknown. The biological affinity of the species I. minutum and its phylogenetic position based on the small subunit ribosomal RNA gene (SSU rDNA) and the large subunit ribosomal RNA gene (LSU rDNA) were established from cyst incubation experiments in controlled conditions, optical and scanning electron microscopy, and single-cell PCR. The thecal motile cell obtained was undescribed. Although the motile cell was similar to Archaeperidinium minutum (Kofoid) Jörgensen, the motile cell of I. minutum lacked a transitional plate in the cingular series, which is present in Archaeperidinium spp. Islandinium minutum and Archaeperidinium spp. were paraphyletic in all phylogenetic analyses. Furthermore, Protoperidinium tricingulatum, which also lacks a transitional plate, was closely related to I. minutum and transfered to the genus Islandinium. Based on available data, it is clear that Islandinium is distinct from Archaeperidinium. Therefore, we considered Islandinium Head, Harland et Matthiessen as a non-fossil genus and emend its description, as well as the species I. minutum. This is the first description of a cyst-theca relationship and the first study that reports molecular data based on SSU rDNA and LSU rDNA on a species assigned to the genus Islandinium. © 2013 Phycological Society of America.

Reconstruction of past methane availability in an Arctic Alaska wetland indicates climate influenced methane release during the past ~12,000 years

USGS Publications Warehouse

Wooller, Matthew J.; Pohlman, John W.; Gaglioti, Benjamin V.; Langdon, Peter; Jones, Miriam; Anthony, Katey M. Walter; Becker, Kevin W.; Hinrichs, Kai-Uwe; Elvert, Marcus

2012-01-01

Atmospheric contributions of methane from Arctic wetlands during the Holocene are dynamic and linked to climate oscillations. However, long-term records linking climate variability to methane availability in Arctic wetlands are lacking. We present a multi-proxy ~12,000 year paleoecological reconstruction of intermittent methane availability from a radiocarbon-dated sediment core (LQ-West) taken from a shallow tundra lake (Qalluuraq Lake) in Arctic Alaska. Specifically, stable carbon isotopic values of photosynthetic biomarkers and methane are utilized to estimate the proportional contribution of methane-derived carbon to lake-sediment-preserved benthic (chironomids) and pelagic (cladocerans) components over the last ~12,000 years. These results were compared to temperature, hydrologic, and habitat reconstructions from the same site using chironomid assemblage data, oxygen isotopes of chironomid head capsules, and radiocarbon ages of plant macrofossils. Cladoceran ephippia from ~4,000 cal year BP sediments have δ13C values that range from ~−39 to −31‰, suggesting peak methane carbon assimilation at that time. These low δ13C values coincide with an apparent decrease in effective moisture and development of a wetland that included Sphagnum subsecundum. Incorporation of methane-derived carbon by chironomids and cladocerans decreased from ~2,500 to 1,500 cal year BP, coinciding with a temperature decrease. Live-collected chironomids with a radiocarbon age of 1,640 cal year BP, and fossil chironomids from 1,500 cal year BP in the core illustrate that ‘old’ carbon has also contributed to the development of the aquatic ecosystem since ~1,500 cal year BP. The relatively low δ13C values of aquatic invertebrates (as low as −40.5‰) provide evidence of methane incorporation by lake invertebrates, and suggest intermittent climate-linked methane release from the lake throughout the Holocene.

Velocity Models of the Sedimentary Cover and Acoustic Basement, Central Arctic

NASA Astrophysics Data System (ADS)

Bezumov, D. V.; Butsenko, V.

2017-12-01

As the part of the Russian Federation Application on the Extension of the outer limit of the continental shelf in the Arctic Ocean to the Commission for the limits of the continental shelf the regional 2D seismic reflection and sonobuoy data was obtained in 2011, 2012 and 2014 years. Structure and thickness of the sedimentary cover and acoustic basement of the Central Arctic ocean can be refined due to this data. "VNIIOkeangeologia" created a methodology for matching 2D velocity model of the sedimentary cover based on vertical velocity spectrum calculated from wide-angle reflection sonobuoy data and the results of ray tracing of reflected and refracted waves. Matched 2D velocity models of the sedimentary cover in the Russian part of the Arctic Ocean were computed along several seismic profiles (see Figure). Figure comments: a) vertical velocity spectrum calculated from wide-angle reflection sonobuoy data. RMS velocity curve was picked in accordance with interpreted MCS section. Interval velocities within sedimentary units are shown. Interval velocities from Seiswide model are shown in brackets.b) interpreted sonobuoy record with overlapping of time-distance curves calculated by ray-tracing modelling.c) final depth velocity model specified by means of Seiswide software.

Scientific Drilling in the Arctic Ocean: A challenge for the next decades

NASA Astrophysics Data System (ADS)

Stein, R.; Coakley, B.

2009-04-01

Although major progress in Arctic Ocean research has been made during the last decades, the knowledge of its short- and long-term paleoceanographic and paleoclimatic history as well as its plate-tectonic evolution is much behind that from the other world's oceans. That means - despite the importance of the Arctic in the climate system - the data base we have from this area is still very weak, and large parts of the climate history have not been recovered at all in sedimentary sections. This lack of knowledge is mainly caused by the major technological/ logistic problems in reaching this permanently ice-covered region with normal research vessels and in retrieving long and undisturbed sediment cores. With the successful completion of IODP Expedition 302 ("Arctic Coring Expedition" - ACEX), the first Mission Specific Platform (MSP) expedition within the Integrated Ocean Drilling Program - IODP, a new era in Arctic research has begun. For the first time, a scientific drilling in the permanently ice-covered Arctic Ocean was carried out, penetrating about 430 meters of Quaternary, Neogene, Paleogene and Campanian sediment on the crest of Lomonosov Ridge close to the North Pole. The success of ACEX has certainly opened the door for further scientific drilling in the Arctic Ocean, and will frame the next round of questions to be answered from new drill holes to be taken during the next decades. In order to discuss and plan the future of scientific drilling in the Arctic Ocean, an international workshop was held at the Alfred Wegener Institute (AWI) in Bremerhaven/Germany, (Nov 03-05, 2008; convenors: Bernard Coakley/University of Alaska Fairbanks and Ruediger Stein/AWI Bremerhaven). About 95 scientists from Europe, US, Canada, Russia, Japan, and Korea, and observers from oil companies participated in the workshop. Funding of the workshop was provided by the Consortium for Ocean Leadership (US), the European Science Foundation, the Arctic Ocean Sciences Board, and the Nansen Arctic Drilling Program as well as by sponsorships from British Petroleum, ConocoPhillips, ExxonMobil, Norwegian Petroleum Directorate, StatoilHydro, and Shell International. The major targets of the workshop were: (1) to bring together an international group of Arctic scientists, young scientists and ocean drilling scientists to learn and exchange ideas, experience and enthusiasm about the Arctic Ocean; (2) to develop a scientific drilling strategy to investigate the tectonic and paleoceanographic history of the Arctic Ocean and its role in influencing the global climate system; (3) to summarize the technical needs, opportunities, and limitations of drilling in the Arctic; (4) to define scientific and drilling targets for specific IODP-type campaigns in Arctic Ocean key areas to be finalized in the development of drilling proposals. Following overview presentations about the history of the Arctic Ocean, legacy of high-latitude ocean drilling, existing site-survey database, technical needs for high-latitude drilling, possibilities of collaboration with industry, and the process of developing ocean-drilling legs through IODP, the main part of the workshop was spent in thematic and regional break-out groups discussing the particular questions to be addressed by drilling and the particular targets for Arctic scientific drilling. Within the working groups, key scientific questions (related to the overall themes paleoceanography, tectonic evolution, petrology/geochemistry of basement, and gas hydrates) and strategies for reaching the overall goals were discussed and - as one of the main results - core groups for further developing drilling proposals were formed. Based on discussions at this workshop, approximately ten new pre-proposals are planned to be submitted to IODP for the April 01- 2009 deadline. We hope that the development of new scientific objectives through the pre-proposal process will help reshape plans for scientific ocean drilling beyond 2013 and direct the program north towards these critical priorities and advance exploration of the Arctic.

Quaternary dinoflagellate cysts in the Arctic Ocean: Potential and limitations for stratigraphy and paleoenvironmental reconstructions

NASA Astrophysics Data System (ADS)

Matthiessen, Jens; Schreck, Michael; De Schepper, Stijn; Zorzi, Coralie; de Vernal, Anne

2018-07-01

The Arctic Ocean is a siliciclastic depositional environment which lacks any rock-forming biogenic calcareous and siliceous components during large parts of its Quaternary history. These hemipelagic sediments are nevertheless suitable for the study of organic-walled microfossils of which the fossil remains of dinoflagellates - dinoflagellate cysts - are the most important group. Dinoflagellate cysts have become an important tool in paleoceanography of the high northern latitudes, but their potential for Quaternary biostratigraphy has remained largely unexplored. Dinoflagellate cysts are the dominant marine palynomorph group which is more continuously present in the marginal seas (e.g. Barents Sea, Bering Sea) than in the Arctic Ocean itself throughout the Quaternary. Most species have long stratigraphic ranges, are temporary absent and show abundance variations on glacial-interglacial timescales. Of the more than 30 taxa recorded, only Habibacysta tectata and Filisphaera filifera became extinct in the Pleistocene. The highest persistent occurrence of H. tectata at ca. 2.0 Ma and the top of F. filifera acme at ca. 1.8 Ma can be used for supra-regional stratigraphic correlation between the Arctic Ocean and adjacent basins. These events corroborate a slow sedimentation rate model for the Quaternary section on the central Lomonosov Ridge, but a combination of different methods will have to be applied to provide a detailed chronostratigraphy. The occurrence of cysts of phototrophic dinoflagellates in certain stratigraphic intervals on Lomonosov Ridge supports published evidence of episodic opening of the multiyear Arctic sea ice cover during the Quaternary probably related to a stronger inflow of Atlantic water. This contradicts the hypothesis of a permanently ice covered central Arctic Ocean in the Quaternary.

Aeolian stratigraphy describes ice-age paleoenvironments in unglaciated Arctic Alaska

NASA Astrophysics Data System (ADS)

Gaglioti, Benjamin V.; Mann, Daniel H.; Groves, Pamela; Kunz, Michael L.; Farquharson, Louise M.; Reanier, Richard E.; Jones, Benjamin M.; Wooller, Matthew J.

2018-02-01

Terrestrial paleoenvironmental records with high dating resolution extending into the last ice age are rare from the western Arctic. Such records can test the synchronicity and extent of ice-age climatic events and define how Arctic landscapes respond to rapid climate changes. Here we describe the stratigraphy and sedimentology of a yedoma deposit in Arctic Alaska (the Carter Section) dating to between 37,000 and 9000 calibrated radiocarbon years BP (37-9 ka) and containing detailed records of loess and sand-sheet sedimentation, soil development, carbon storage, and permafrost dynamics. Alternation between sand-sheet and loess deposition provides a proxy for the extent and activity of the Ikpikpuk Sand Sea (ISS), a large dune field located immediately upwind. Warm, moist interstadial times (ca. 37, 36.3-32.5, and 15-13 ka) triggered floodplain aggradation, permafrost thaw, reduced loess deposition, increased vegetation cover, and rapid soil development accompanied by enhanced carbon storage. During the Last Glacial Maximum (LGM, ca. 28-18 ka), rapid loess deposition took place on a landscape where vegetation was sparse and non-woody. The most intense aeolian activity occurred after the LGM between ca. 18 and 15 ka when sand sheets fringing the ISS expanded over the site, possibly in response to increasingly droughty conditions as summers warmed and active layers deepened. With the exception of this lagged LGM response, the record of aeolian activity at the Carter Section correlates with other paleoenvironmental records from unglaciated Siberia and Alaska. Overall, rapid shifts in geomorphology, soils, vegetation, and permafrost portray an ice-age landscape where, in contrast to the Holocene, environmental change was chronic and dominated by aeolian processes.

Hybrid Welding Possibilities of Thick Sections for Arctic Applications

NASA Astrophysics Data System (ADS)

Bunaziv, Ivan; Akselsen, Odd M.; Ren, Xiaobo; Salminen, Antti

The arctic shelf contains about 20% of all undiscovered hydrocarbons on our planet, therefore oil and gas industry requires advanced steels to be used which withstand appropriate fracture toughness up to -60 °C and suitable welding technologies. High brightness laser with combination with arc source can be appropriate joining process even for very high strength advanced steels above 700 MPa for low temperature applications. Hybrid welding has improved each year becoming more standardized and reliable welding process. However, until now, its application was limited to shipbuilding and pipeline industry. Due to many reasonable advantages, hybrid welding, especially when it is combined with MIG/MAG, can be used in every possible industry. Inherent filler wire addition from the MIG/MAG source can improve fracture toughness at lower temperatures and increase overall productivity. This paper provides information about recent breakthrough in hybrid welding of thick section high-strength steels.

KSC-07pd1549

NASA Image and Video Library

2007-06-18

KENNEDY SPACE CENTER, FLA. -- The first stage of a Delta II rocket arrives on Launch Pad 17-A at Cape Canaveral Air Force Station. The rocket is the launch vehicle for the Phoenix spacecraft, targeted for launch on Aug. 3 heading for Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. Landing on Mars is planned in May 2008 on arctic ground where a mission currently in orbit, Mars Odyssey, has detected high concentrations of ice just beneath the top layer of soil. Photo credit: NASA/Amanda Diller

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

The influence of fetal head circumference on labor outcome: a population-based register study.

PubMed

Elvander, Charlotte; Högberg, Ulf; Ekéus, Cecilia

2012-04-01

To investigate the association between postnatal head circumference and the occurrence of the three main indications for instrumental delivery, namely prolonged labor, signs of fetal distress and maternal distress. We also studied the association between postnatal fetal head circumference and the use of vacuum extraction and emergency cesarean section. Population-based register study. Nationwide study in Sweden. A total of 265 456 singleton neonates born to nulliparous women at term between 1999 and 2008 in Sweden. Register study with data from the Swedish Medical Birth Register. Prolonged labor, signs of fetal distress, maternal distress, use of vacuum extraction and emergency cesarean section. The prevalence of each outcome increased gradually as the head circumference increased. Compared with women giving birth to a neonate with average size head circumference (35 cm), women giving birth to an infant with a very large head circumference (39-41 cm) had significantly higher odds of being diagnosed with prolonged labor [odds ratio (OR) 1.49, 95% confidence interval (CI) 1.33-1.67], signs of fetal distress (OR 1.73, 95% CI 1.49-2.03) and maternal distress (OR 2.40, 95% CI 1.96-2.95). The odds ratios for vacuum extraction and cesarean section were thereby elevated to 3.47 (95% CI 3.10-3.88) and 1.22 (95% CI 1.04-1.42), respectively. The attributable risk proportion percentages associated with vacuum extraction and cesarean section were 46 and 39%, respectively among the cases exposed to a head circumference of 37-41 cm. Large fetal head circumference is associated with complicated labor and is etiological to a considerable proportion of assisted vaginal births and emergency cesarean sections. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

230Th and 231Pa: Tracers for Deep Water Circulation and Particle Fluxes in the Arctic Ocean

NASA Astrophysics Data System (ADS)

Valk, O.; Rutgers van der Loeff, M.; Puigcorbe Lacueva, V.; Paffrath, R.; Gdaniec, S.

2016-02-01

230Th and 231Pa data from the central Arctic Ocean is very limited. 230Th and 231Pa are produced at a constant rate in the water column by radioactive decay of Uranium isotopes (234U and 235U respectively) (e.g. Anderson et al., 1983). They are both particle reactive and are scavenged on settling particles. As 230Th is more particle reactive than 231Pa, their distribution in the water column and activity ratio give us information about particle fluxes and circulation patterns and -intensities (Henderson et al., 1999; Scholten et al., 2001). The Arctic Ocean is an almost landlocked ocean with limited connections to the Atlantic and Pacific and a high input of river water. About 10 % of the global river run-off is delivered to the Arctic Ocean. Due to climate change the Arctic Ocean will undergo dramatic changes in sea ice cover and supply of fresh water, while increasing coastal erosion will cause an increased input of terrestrial material (Peterson et al., 2002). This will influence the biogeochemical cycling and transport of carbon, nutrients and trace elements (IPCC, 2007). We expect that the distribution of 230Th and 231Pa will reflect changes in particle fluxes and shelf-basin exchange (Roy-Barman, 2009). We will present the first results of 230Th and 231Pa, in combination with on board measured particulate 234Th, collected during the 2015 Polarstern section (GEOTRACES section GN04 2015) through the Nansen, Amundsen, and Makarov Basins. Anderson, R. F., et al. (1983). EPSL 62: 7-23. Henderson, G. M., et al. (1999). DSR I 46: 1861-1893. IPCC, 2007. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S. et al.]. Cambridge University Press. Peterson, B. J., et al. (2002). Science 298: 2171-2173. Roy-Barman, M. (2009). Biogeosciences 6: 3091-3107. Scholten, J. C., et al. (2001). DSR II 48: 2383-2408.

Use of Head Guards in AIBA Boxing Tournaments-A Cross-Sectional Observational Study.

PubMed

Loosemore, Michael P; Butler, Charles F; Khadri, Abdelhamid; McDonagh, David; Patel, Vimal A; Bailes, Julian E

2017-01-01

This study looks at the changes in injuries after the implementation of a new rule by the International Boxing Association (AIBA) to remove head guards from its competitions. A cross-sectional observational study performed prospectively. This brief report examines the removal of head guards in 2 different ways. The first was to examine the stoppages due to blows to the head by comparing World Series Boxing (WSB), without head guards, to other AIBA competitions with head guards. Secondly, we examined the last 3 world championships: 2009 and 2011 (with head guards) and 2013 (without head guards). World Series Boxing and AIBA world championship boxing. Boxers from WSB and AIBA world championships. The information was recorded by ringside medical physicians. Stoppages per 10 000 rounds; stoppages per 1000 hours. Both studies show that the number of stoppages due to head blows was significantly decreased without head guards. The studies also showed that there was a notable increase in cuts. Removing head guards may reduce the already small risk of acute brain injury in amateur boxing.

Paleoclimate records at high latitude in Arctic during the Paleogene

NASA Astrophysics Data System (ADS)

Salpin, Marie; Schnyder, Johann; Baudin, François; Suan, Guillaume; Labrousse, Loïc; Popescu, Speranta; Suc, Jean-Pierre

2015-04-01

Paleoclimate records at high latitude in Arctic during the Paleogene SALPIN Marie1,2, SCHNYDER Johann1,2, BAUDIN François1,2, SUAN Guillaume3, LABROUSSE Loïc1,2, POPESCU Speranta4, SUC Jean-Pierre1,4 1: Sorbonne Universités, UPMC Univ Paris 06, UMR 7193, Institut des Sciences de la Terre Paris (iSTeP), F 75005, Paris, France 2: CNRS, UMR 7193, Institut des Sciences de la Terre Paris (iSTeP), F 75005 Paris, France 3: UCB Lyon 1, UMR 5276, LGLTPE, 69622 Villeurbanne Cedex, France 4: GEOBIOSTRATDATA.CONSULTING, 385 Route du Mas Rillier 69140 Rillieux la Pape, France The Paleogene is a period of important variations of the Earth climate system either in warming or cooling. The climatic optima of the Paleogene have been recognized both in continental and marine environment. This study focus on high latitudes of the northern hemisphere, in the Arctic Basin. The basin has had an influence on the Cenozoic global climate change according to its polar position. Is there a specific behaviour of the Arctic Basin with respect to global climatic stimuli? Are there possible mechanisms of coupling/decoupling of its dynamics with respect to the global ocean? To answer these questions a unique collection of sedimentary series of Paleogene age interval has been assembled from the Laurentian margin in Northern Yukon (Canada) and from the Siberian margin (New Siberian Islands). Selected continental successions of Paleocene-Eocene age were used to study the response of the Arctic system to known global events, e.g. the climatic optima of the Paleogene (the so-called PETM, ETM2 or the Azolla events). Two sections of Paleocene-Eocene age were sampled near the Mackenzie delta, the so-called Coal Mine (CoMi) and Caribou Hills (CaH) sections. The aim of the study is to precise the climatic fluctuations and to characterise the source rock potential of the basin, eventually linked to the warming events. This study is based on data of multi-proxy analyses: mineralogy on bulk and clay fraction, Rock-Eval pyrolysis, palynology, palynofacies, carbon isotopes. The organic matter of the two sections is dominated by Type III kerogens. First results from palynology and clay minerals proportions suggest episodes of warming that could be compared to similar warming intervals recorded on the Siberian margin. In addition, in the northern Yukon the mineralogical results suggests fluctuations of the local detrital sources, either driven by tectonic or eustatism, that could be surimposed on the climatic patterns.

Arctic and Arctic-like rabies viruses: distribution, phylogeny and evolutionary history

PubMed Central

KUZMIN, I. V.; HUGHES, G. J.; BOTVINKIN, A. D.; GRIBENCHA, S. G.; RUPPRECHT, C. E.

2008-01-01

SUMMARY Forty-one newly sequenced isolates of Arctic and Arctic-like rabies viruses, were genetically compared to each other and to those available from GenBank. Four phylogenetic lineages of Arctic viruses were identified. Arctic-1 viruses circulate in Ontario, Arctic-2 viruses circulate in Siberia and Alaska, Arctic-3 viruses circulate circumpolarly, and a newly described lineage Arctic-4 circulates locally in Alaska. The oldest available isolates from Siberia (between 1950 and 1960) belong to the Arctic-2 and Arctic-3 lineages and share 98·6–99·2% N gene identity with contemporary viruses. Two lineages of Arctic-like viruses were identified in southern Asia and the Middle East (Arctic-like-1) and eastern Asia (Arctic-like-2). A time-scaled tree demonstrates that the time of the most recent common ancestor (TMRCA) of Arctic and Arctic-like viruses is dated between 1255 and 1786. Evolution of the Arctic viruses has occurred through a northerly spread. The Arctic-like-2 lineage diverged first, whereas Arctic viruses share a TMRCA with Arctic-like-1 viruses. PMID:17599781

Arctic and Arctic-like rabies viruses: distribution, phylogeny and evolutionary history.

PubMed

Kuzmin, I V; Hughes, G J; Botvinkin, A D; Gribencha, S G; Rupprecht, C E

2008-04-01

Forty-one newly sequenced isolates of Arctic and Arctic-like rabies viruses, were genetically compared to each other and to those available from GenBank. Four phylogenetic lineages of Arctic viruses were identified. Arctic-1 viruses circulate in Ontario, Arctic-2 viruses circulate in Siberia and Alaska, Arctic-3 viruses circulate circumpolarly, and a newly described lineage Arctic-4 circulates locally in Alaska. The oldest available isolates from Siberia (between 1950 and 1960) belong to the Arctic-2 and Arctic-3 lineages and share 98.6-99.2% N gene identity with contemporary viruses. Two lineages of Arctic-like viruses were identified in southern Asia and the Middle East (Arctic-like-1) and eastern Asia (Arctic-like-2). A time-scaled tree demonstrates that the time of the most recent common ancestor (TMRCA) of Arctic and Arctic-like viruses is dated between 1255 and 1786. Evolution of the Arctic viruses has occurred through a northerly spread. The Arctic-like-2 lineage diverged first, whereas Arctic viruses share a TMRCA with Arctic-like-1 viruses.

Deep seismic exploration into the Arctic Lithosphere: Arctic-2012 Russian wide-angle seismic experiment

NASA Astrophysics Data System (ADS)

Kashubin, S.

2013-12-01

Integrated geological and geophysical studies of the Earth's crust and upper mantle (the Russian project 'Arctic-2012') were carried out in 2012 in the Mendeleev Rise, central Arctic. The set of studies included wide-angle seismic observations along the line crossing the Mendeleev Rise in its southern part. The DSS seismic survey was aimed at the determination of the Mendeleev Rise crust type. A high-power air gun (120 liters or 7320 cu.in) and ocean stations with multi-component recording (X, Y, Z geophone components and a hydrophone) were used for the DSS. The line was studied using a dense system of observation: bottom station spacing was from 10 to 20 km, excitation point spacing (seismic traces interval) was 315 m. Observation data were obtained in 27 location points of bottom stations, the distance between the first and the last stations was 480 km, the length of the excitation line was 740 km. In DSS wave fields, in the first and later arrivals, there are refracted and reflected waves associated with boundaries in the sedimentary cover, with the top of the basement, and with boundaries in the consolidated crust, including its bottom (Moho discontinuity). The waves could be traced for offsets up to 170-240 km. The DSS line coincides with the near-vertical CMP line worked out with the use of a 4500-m-long seismic streamer and with a 50 m shot point interval that allowed essential detalization of the upper part of the section and taking it into account in the construction of a deep crust model. The deep velocity model was constructed using ray-trace modeling of compressional, shear, and converted waves with the use of the SeisWide program. Estimates were obtained for Vp/Vs velocity ratios, which played an important role in determining the type of crust. The results of the interpretation show that the Mendeleev Rise section corresponds to sections of a thin continental crust of shelf seas and a thinned continental crust of submarine ridges and rises.

Traditional and market food access in Arctic Canada is affected by economic factors.

PubMed

Lambden, Jill; Receveur, Olivier; Marshall, Joan; Kuhnlein, Harriet V

2006-09-01

This study aimed to evaluate the access that Indigenous women have to traditional and market foods in 44 communities across Arctic Canada. This secondary data analysis used a cross-sectional survey of 1771 Yukon First Nations, Dene/Métis and Inuit women stratified by age. Socio-cultural questionnaires were used to investigate food access and chi-square testing was used to ascertain the distribution of subject responses by age and region. There was considerable regional variation in the ability to afford adequate food, with between 40% and 70% saying they could afford enough food. Similarly, regional variation was reflected in the percentage of the population who could afford, or had access to, hunting or fishing equipment. Up to 50% of the responses indicated inadequate access to fishing and hunting equipment, and up to 46% of participants said they could not afford to go hunting or fishing. Affordability of market food and accessibility to hunting and fishing in Arctic Canada were major barriers to Indigenous women's food security.

Salinity of the Eocene Arctic Ocean from oxygen isotope analysis of fish bone carbonate

NASA Astrophysics Data System (ADS)

Waddell, Lindsey M.; Moore, Theodore C.

2008-03-01

Stable isotope analysis was performed on the structural carbonate of fish bone apatite from early and early middle Eocene samples (˜55 to ˜45 Ma) recently recovered from the Lomonosov Ridge by Integrated Ocean Drilling Program Expedition 302 (the Arctic Coring Expedition). The δ18O values of the Eocene samples ranged from -6.84‰ to -2.96‰ Vienna Peedee belemnite, with a mean value of -4.89‰, compared to 2.77‰ for a Miocene sample in the overlying section. An average salinity of 21 to 25‰ was calculated for the Eocene Arctic, compared to 35‰ for the Miocene, with lower salinities during the Paleocene Eocene thermal maximum, the Azolla event at ˜48.7 Ma, and a third previously unidentified event at ˜47.6 Ma. At the Azolla event, where the organic carbon content of the sediment reaches a maximum, a positive δ13C excursion was observed, indicating unusually high productivity in the surface waters.

Mid-section of a can-annular gas turbine engine with an improved rotation of air flow from the compressor to the turbine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Little, David A.; Schilp, Reinhard; Ross, Christopher W.

A midframe portion (313) of a gas turbine engine (310) is presented and includes a compressor section with a last stage blade to orient an air flow (311) at a first angle (372). The midframe portion (313) further includes a turbine section with a first stage blade to receive the air flow (311) oriented at a second angle (374). The midframe portion (313) further includes a manifold (314) to directly couple the air flow (311) from the compressor section to a combustor head (318) upstream of the turbine section. The combustor head (318) introduces an offset angle in the airmore » flow (311) from the first angle (372) to the second angle (374) to discharge the air flow (311) from the combustor head (318) at the second angle (374). While introducing the offset angle, the combustor head (318) at least maintains or augments the first angle (372).« less

A novel protocol for generating intact, whole-head spider cephalothorax tissue sections.

PubMed

Long, Skye M

2018-04-01

The diversity of spider behavior and sensory systems provides an excellent opportunity for comparative studies of the relationship between the brain and behavior. However, the morphology of spiders poses a challenge for histologists since the spider cephalothorax contains heterogeneous tissues and has both tough external and internal sclerotized regions. Unlike the heads of insects, the cephalothorax is highly pressurized, which can cause tissues to shift during processing and can reduce tissue cohesion in thick sections. This work describes a novel protocol for producing thick whole-head sections for morphological study by softening the exoskeleton and stabilizing friable tissue, without freezing or dehydration. It also presents an effective whole-head DiI staining method that uses minimal dehydration and highlights neural structures.

49 CFR 572.122 - Head assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.122 Section...-year-old Child Test Dummy, Beta Version § 572.122 Head assembly and test procedure. (a) The head assembly for this test consists of the complete head (drawing 127-1000), a six-axis neck transducer...

49 CFR 572.122 - Head assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.122 Section...-year-old Child Test Dummy, Beta Version § 572.122 Head assembly and test procedure. (a) The head assembly for this test consists of the complete head (drawing 127-1000), a six-axis neck transducer...

49 CFR 572.122 - Head assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.122 Section...-year-old Child Test Dummy, Beta Version § 572.122 Head assembly and test procedure. (a) The head assembly for this test consists of the complete head (drawing 127-1000), a six-axis neck transducer...

49 CFR 572.122 - Head assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.122 Section...-year-old Child Test Dummy, Beta Version § 572.122 Head assembly and test procedure. (a) The head assembly for this test consists of the complete head (drawing 127-1000), a six-axis neck transducer...

29 CFR 1620.21 - Head of household.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 4 2010-07-01 2010-07-01 false Head of household. 1620.21 Section 1620.21 Labor Regulations Relating to Labor (Continued) EQUAL EMPLOYMENT OPPORTUNITY COMMISSION THE EQUAL PAY ACT § 1620.21 Head of household. Since a “head of household” or “head of family” status bears no relationship to the...

Patient size and x-ray technique factors in head computed tomography examinations. I. Radiation doses.

PubMed

Huda, Walter; Lieberman, Kristin A; Chang, Jack; Roskopf, Marsha L

2004-03-01

We investigated how patient age, size and composition, together with the choice of x-ray technique factors, affect radiation doses in head computed tomography (CT) examinations. Head size dimensions, cross-sectional areas, and mean Hounsfield unit (HU) values were obtained from head CT images of 127 patients. For radiation dosimetry purposes patients were modeled as uniform cylinders of water. Dose computations were performed for 18 x 7 mm sections, scanned at a constant 340 mAs, for x-ray tube voltages ranging from 80 to 140 kV. Values of mean section dose, energy imparted, and effective dose were computed for patients ranging from the newborn to adults. There was a rapid growth of head size over the first two years, followed by a more modest increase of head size until the age of 18 or so. Newborns have a mean HU value of about 50 that monotonically increases with age over the first two decades of life. Average adult A-P and lateral dimensions were 186+/-8 mm and 147+/-8 mm, respectively, with an average HU value of 209+/-40. An infant head was found to be equivalent to a water cylinder with a radius of approximately 60 mm, whereas an adult head had an equivalent radius 50% greater. Adult males head dimensions are about 5% larger than for females, and their average x-ray attenuation is approximately 20 HU greater. For adult examinations performed at 120 kV, typical values were 32 mGy for the mean section dose, 105 mJ for the total energy imparted, and 0.64 mSv for the effective dose. Increasing the x-ray tube voltage from 80 to 140 kV increases patient doses by about a factor of 5. For the same technique factors, mean section doses in infants are 35% higher than in adults. Energy imparted for adults is 50% higher than for infants, but infant effective doses are four times higher than for adults. CT doses need to take into account patient age, head size, and composition as well as the selected x-ray technique factors.

Phanerozoic stratigraphy of Northwind Ridge, magnetic anomalies in the Canada Basin, and the geometry and timing of rifting in the Amerasia Basin, Arctic Ocean

USGS Publications Warehouse

Grantz, A.; Clark, D.L.; Phillips, R.L.; Srivastava, S.P.; Blome, C.D.; Gray, L.-B.; Haga, H.; Mamet, B.L.; McIntyre, D.J.; McNeil, D.H.; Mickey, M.B.; Mullen, M.W.; Murchey, B.I.; Ross, C.A.; Stevens, C.H.; Silberling, Norman J.; Wall, J.H.; Willard, D.A.

1998-01-01

Cores from Northwind Ridge, a high-standing continental fragment in the Chukchi borderland of the oceanic Amerasia basin, Arctic Ocean, contain representatives of every Phanerozoic system except the Silurian and Devonian systems. Cambrian and Ordovician shallow-water marine carbonates in Northwind Ridge are similar to basement rocks beneath the Sverdrup basin of the Canadian Arctic Archipelago. Upper Mississippian(?) to Permian shelf carbonate and spicularite and Triassic turbidite and shelf lutite resemble coeval strata in the Sverdrup basin and the western Arctic Alaska basin (Hanna trough). These resemblances indicate that Triassic and older strata in southern Northwind Ridge were attached to both Arctic Canada and Arctic Alaska prior to the rifting that created the Amerasia basin. Late Jurassic marine lutite in Northwind Ridge was structurally isolated from coeval strata in the Sverdrup and Arctic Alaska basins by rift shoulder and grabens, and is interpreted to be a riftogenic deposit. This lutite may be the oldest deposit in the Canada basin. A cape of late Cenomanian or Turonian rhyodacite air-fall ash that lacks terrigenous material shows that Northwind Ridge was structurally isolated from the adjacent continental margins by earliest Late Cretaceous time. Closing Amerasia basin by conjoining seafloor magnetic anomalies beneath the Canada basin or by uniting the pre-Jurassic strata of Northwind Ridge with kindred sections in the Sverdrup basin and Hanna trough yield simular tectonic reconstructions. Together with the orientation and age of rift-marine structures, these data suggest that: 1) prior to opening of the Amerasia basin, both northern Alaska and continental ridges of the Chukchi borderland were part of North America, 2) the extension that created the Amerasia basin formed rift-margin graben beginning in Early Jurassic time and new oceanic crust probably beginning in Late Jurassic or early Neocomian time. Reconstruction of the Amerasia basin on the basis of the stratigraphy of Northwind Ridge and sea-floor magnetic anomalies in the Canada basin accounts in a general way for the major crustal elements of the Americasia basin, including the highstanding ridges of the Chukchi borderland, and supports S.W. Carye's hypothesis that the Amerasia basin is the product of anticlockwise rotational rifting of Arctic Alaska from North America.

Arctic Ocean circulation during the anoxic Eocene Azolla event

NASA Astrophysics Data System (ADS)

Speelman, Eveline; Sinninghe Damsté, Jaap; März, Christian; Brumsack, Hans; Reichart, Gert-Jan

2010-05-01

The Azolla interval, as encountered in Eocene sediments from the Arctic Ocean, is characterized by organic rich sediments ( 4wt% Corg). In general, high levels of organic matter may be caused by increased productivity, i.e. extensive growth of Azolla, and/or enhanced preservation of organic matter, or a combination of both. Anoxic (bottom) water conditions, expanded oxygen minimum zones, or increased sedimentation rates all potentially increase organic matter preservation. According to plate tectonic, bathymetric, and paleogeographic reconstructions, the Arctic Ocean was a virtually isolated shallow basin, with one possible deeper connection to the Nordic Seas represented by a still shallow Fram Strait (Jakobsson et al., 2007), hampering ventilation of the Arctic Basin. During the Azolla interval surface waters freshened, while at the same time bottom waters appear to have remained saline, indicating that the Arctic was highly stratified. The restricted ventilation and stratification in concert with ongoing export of organic matter most likely resulted in the development of anoxic conditions in the lower part of the water column. Whereas the excess precipitation over evaporation maintained the freshwater lid, sustained input of Nordic Sea water is needed to keep the deeper waters saline. To which degree the Arctic Ocean exchanged with the Nordic Seas is, however, still largely unknown. Here we present a high-resolution trace metal record (ICP-MS and ICP-OES) for the expanded Early/Middle Eocene section capturing the Azolla interval from Integrated Ocean Drilling Program (IODP) Expedition 302 (ACEX) drilled on the Lomonosov Ridge, central Arctic Ocean. Euxinic conditions throughout the interval resulted in the efficient removal of redox sensitive trace metals from the water column. Using the sedimentary trace metal record we also constrained circulation in the Arctic Ocean by assessing the relative importance of trace metal input sources (i.e. fluvial, eolian, and through seawater inflow). Excess vanadium accumulation during the Azolla event (80 ppm), basin volume and surface area, average vanadium sea (1.8 ppb) and river water (1.0 ppb) concentrations, together indicate that an inflow of Nordic Sea water of 0.2 Sv is needed to sustain vanadium levels. The same calculation using molybdenum gives an inflow of only 0.02 Sv. These low inflow rates imply Arctic Ocean (deep) water residence times of 2000 - 20000 years, respectively. Based on climate modeling we calculated a summed net amount of precipitation for the Eocene Arctic Basin (Precipitation - Evaporation + Runoff) of 0.46 Sv. Together these notions indicate that a compensating inflow of saline North Atlantic water occurred, accompanied by an outflow of more fresh waters, resulting in a bi-directional, two-layer flow through the (proto-) Fram Strait. Consequently, the limited exchange of water through the Fram Strait implies that a relatively low export productivity would have been sufficient to render Arctic bottom waters anoxic. Jakobsson, M., Backman, J., Rudels, B., Nycander, J., Frank, M., Mayer, L., Jokat, W., Sangiorgi, F., O'Regan, M., Brinkhuis, H., King, J., Moran, K. (2007). The early Miocene onset of a ventilated circulation regimen in the Arctic Ocean. Nature 447, 986-990.

50 CFR 37.31 - Environmental protection.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 50 Wildlife and Fisheries 9 2014-10-01 2014-10-01 false Environmental protection. 37.31 Section 37... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Environmental Protection § 37.31 Environmental protection. (a...

50 CFR 37.31 - Environmental protection.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 50 Wildlife and Fisheries 9 2013-10-01 2013-10-01 false Environmental protection. 37.31 Section 37... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Environmental Protection § 37.31 Environmental protection. (a...

50 CFR 37.31 - Environmental protection.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Environmental protection. 37.31 Section 37... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Environmental Protection § 37.31 Environmental protection. (a...

50 CFR 37.31 - Environmental protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Environmental protection. 37.31 Section 37... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Environmental Protection § 37.31 Environmental protection. (a...

50 CFR 37.31 - Environmental protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Environmental protection. 37.31 Section 37... (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Environmental Protection § 37.31 Environmental protection. (a...

50 CFR 37.54 - Disclosure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Disclosure. 37.54 Section 37.54 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

50 CFR 37.54 - Disclosure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Disclosure. 37.54 Section 37.54 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

Northern Nutrition.

ERIC Educational Resources Information Center

Northwest Territories Dept. of Education, Yellowknife.

This guide contains nutrition information and nutrition education strategies aimed at residents of the Canadian Arctic. Section I: (1) defines nutrition terms; (2) describes the sources and functions of essential nutrients; (3) explains Canada's food guide and special considerations for the traditional northern Native diet and for lactose…

Regional variability in food availability for Arctic marine mammals.

PubMed

Bluhm, Bodil A; Gradinger, Rolf

2008-03-01

This review provides an overview of prey preferences of seven core Arctic marine mammal species (AMM) and four non-core species on a pan-Arctic scale with regional examples. Arctic marine mammal species exploit prey resources close to the sea ice, in the water column, and at the sea floor, including lipid-rich pelagic and benthic crustaceans and pelagic and ice-associated schooling fishes such as capelin and Arctic cod. Prey preferred by individual species range from cephalopods and benthic bivalves to Greenland halibut. A few AMM are very prey-, habitat-, and/or depth-specific (e.g., walrus, polar bear), while others are rather opportunistic and, therefore, likely less vulnerable to change (e.g., beluga, bearded seal). In the second section, we review prey distribution patterns and current biomass hotspots in the three major physical realms (sea ice, water column, and seafloor), highlighting relations to environmental parameters such as advection patterns and the sea ice regime. The third part of the contribution presents examples of documented changes in AMM prey distribution and biomass and, subsequently, suggests three potential scenarios of large-scale biotic change, based on published observations and predictions of environmental change. These scenarios discuss (1) increased pelagic primary and, hence, secondary production, particularly in the central Arctic, during open-water conditions in the summer (based on surplus nutrients currently unutilized); (2) reduced benthic and pelagic biomass in coastal/shelf areas (due to increased river runoff and, hence, changed salinity and turbidity conditions); and (3) increased pelagic grazing and recycling in open-water conditions at the expense of the current tight benthic-pelagic coupling in part of the ice-covered shelf regions (due to increased pelagic consumption vs. vertical flux). Should those scenarios hold true, pelagic-feeding and generalist AMM might be advantaged, while the range for benthic shelf-feeding, ice-dependent AMM such as walrus would decrease. New pelagic feeding grounds may open up to AMM and subarctic marine mammal species in the High Arctic basins while nearshore waters might provide less abundant food in the future.

49 CFR 572.172 - Head assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.172 Section... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.172 Head assembly and test procedure. (a) The head assembly for this test consists of the complete head (drawing 420-1000), a six-axis neck...

49 CFR 572.142 - Head assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter plate...

49 CFR 572.172 - Head assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.172 Section... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.172 Head assembly and test procedure. (a) The head assembly for this test consists of the complete head (drawing 420-1000), a six-axis neck...

49 CFR 572.172 - Head assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.172 Section... Hybrid III 10-Year-Old Child Test Dummy (HIII-10C) § 572.172 Head assembly and test procedure. (a) The head assembly for this test consists of the complete head (drawing 420-1000), a six-axis neck...

49 CFR 572.132 - Head assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.132 Section... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.132 Head assembly and test procedure. (a) The head assembly (refer to § 572.130(a)(1)(i)) for this test consists of the complete head (drawing...

49 CFR 572.142 - Head assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter plate...

49 CFR 572.132 - Head assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.132 Section... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.132 Head assembly and test procedure. (a) The head assembly (refer to § 572.130(a)(1)(i)) for this test consists of the complete head (drawing...

49 CFR 572.142 - Head assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter plate...

49 CFR 572.132 - Head assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.132 Section... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.132 Head assembly and test procedure. (a) The head assembly (refer to § 572.130(a)(1)(i)) for this test consists of the complete head (drawing...

49 CFR 572.132 - Head assembly and test procedure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly and test procedure. 572.132 Section... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.132 Head assembly and test procedure. (a) The head assembly (refer to § 572.130(a)(1)(i)) for this test consists of the complete head (drawing...

49 CFR 572.142 - Head assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.142 Section...-year-Old Child Crash Test Dummy, Alpha Version § 572.142 Head assembly and test procedure. (a) The head assembly (refer to § 572.140(a)(1)(i)) for this test consists of the head (drawing 210-1000), adapter plate...

49 CFR 572.132 - Head assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.132 Section... Hybrid III 5th Percentile Female Test Dummy, Alpha Version § 572.132 Head assembly and test procedure. (a) The head assembly (refer to § 572.130(a)(1)(i)) for this test consists of the complete head (drawing...

KSC-07pd1554

NASA Image and Video Library

2007-06-18

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-A at Cape Canaveral Air Force Station, the first stage of a Delta II rocket has been lifted into the mobile service tower. The rocket is the launch vehicle for the Phoenix spacecraft, targeted for launch on Aug. 3 heading for Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. Landing on Mars is planned in May 2008 on arctic ground where a mission currently in orbit, Mars Odyssey, has detected high concentrations of ice just beneath the top layer of soil. Photo credit: NASA/Amanda Diller

KSC-07pd1553

NASA Image and Video Library

2007-06-18

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-A at Cape Canaveral Air Force Station, the first stage of a Delta II rocket is ready for lifting up into the mobile service tower. The rocket is the launch vehicle for the Phoenix spacecraft, targeted for launch on Aug. 3 heading for Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. Landing on Mars is planned in May 2008 on arctic ground where a mission currently in orbit, Mars Odyssey, has detected high concentrations of ice just beneath the top layer of soil. Photo credit: NASA/Amanda Diller

KSC-07pd1550

NASA Image and Video Library

2007-06-18

KENNEDY SPACE CENTER, FLA. -- The truck and transporter carrying the first stage of a Delta II rocket pull beneath the mobile service tower on Launch Pad 17-A at Cape Canaveral Air Force Station. The rocket is the launch vehicle for the Phoenix spacecraft, targeted for launch on Aug. 3,heading for Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. Landing on Mars is planned in May 2008 on arctic ground where a mission currently in orbit, Mars Odyssey, has detected high concentrations of ice just beneath the top layer of soil. Photo credit: NASA/Amanda Diller

KSC-07pd1552

NASA Image and Video Library

2007-06-18

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-A at Cape Canaveral Air Force Station, the first stage of a Delta II rocket is raised off the transporter beneath the mobile service tower. The rocket is the launch vehicle for the Phoenix spacecraft, targeted for launch on Aug. 3 heading for Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. Landing on Mars is planned in May 2008 on arctic ground where a mission currently in orbit, Mars Odyssey, has detected high concentrations of ice just beneath the top layer of soil. Photo credit: NASA/Amanda Diller

Head Start Instructional Professionals' Inclusion Perceptions and Practices

ERIC Educational Resources Information Center

Muccio, Leah S.; Kidd, Julie K.; White, C. Stephen; Burns, M. Susan

2014-01-01

This study considered the facilitators and barriers of successful inclusion in Head Start classrooms by examining the perspectives and practices of instructional professionals. A cross-sectional survey design was combined with direct observation in inclusive Head Start classrooms. Survey data were collected from 71 Head Start instructional…

49 CFR 571.202 - Standard No. 202; Head restraints; Applicable at the manufacturers option until September 1, 2009.

Code of Federal Regulations, 2010 CFR

2010-10-01

....2, S4.4 or S4.5 of this section. S4.2Except for school buses, a head restraint that conforms to... position. For school buses, a head restraint that conforms to either S4.2 (a) or (b) of this section must... one of the following occurs: (i) Failure of the seat or seat back; or, (ii) Application of a load of...

49 CFR 571.202 - Standard No. 202; Head restraints; Applicable at the manufacturers option until September 1, 2009.

Code of Federal Regulations, 2011 CFR

2011-10-01

....2, S4.4 or S4.5 of this section. S4.2Except for school buses, a head restraint that conforms to... position. For school buses, a head restraint that conforms to either S4.2 (a) or (b) of this section must... one of the following occurs: (i) Failure of the seat or seat back; or, (ii) Application of a load of...

50 CFR 37.51 - Operational reports.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Operational reports. 37.51 Section 37.51 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

50 CFR 37.25 - Revision.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Revision. 37.25 Section 37.25 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL...

50 CFR 37.51 - Operational reports.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Operational reports. 37.51 Section 37.51 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

50 CFR 37.13 - Group participation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Group participation. 37.13 Section 37.13 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

50 CFR 37.46 - Cost reimbursement.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Cost reimbursement. 37.46 Section 37.46 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

50 CFR 37.46 - Cost reimbursement.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Cost reimbursement. 37.46 Section 37.46 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

50 CFR 37.14 - Bonding.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Bonding. 37.14 Section 37.14 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL...

50 CFR 37.14 - Bonding.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Bonding. 37.14 Section 37.14 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL...

50 CFR 37.25 - Revision.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Revision. 37.25 Section 37.25 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL...

50 CFR 37.52 - Records.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Records. 37.52 Section 37.52 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL...

50 CFR 37.52 - Records.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Records. 37.52 Section 37.52 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL...

50 CFR 37.13 - Group participation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Group participation. 37.13 Section 37.13 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

Dissolved methane concentrations in the water column and surface sediments of Hanna Shoal and Barrow Canyon, Northern Chukchi Sea

NASA Astrophysics Data System (ADS)

Lapham, Laura; Marshall, Kathleen; Magen, Cédric; Lyubchich, Viacheslav; Cooper, Lee W.; Grebmeier, Jacqueline M.

2017-10-01

Current estimates of methane (CH4) flux suggest that Arctic shelves may be a significant source of atmospheric CH4, a potent greenhouse gas. However, little information is known about the CH4 flux from most Arctic shelves, other than the East Siberian Arctic Shelf. We report here dissolved CH4 concentrations in the water column and within surface sediments of the Northern Chukchi Sea. We hypothesized that this area contains high concentrations of CH4 because it receives nutrient rich waters through the Bering Strait, promoting primary production that enhances an organic-rich material flux to the seafloor and eventual microbial methanogenesis in the sediments. In August 2012, as part of the Chukchi Sea Offshore Monitoring in Drilling Area (COMIDA) project, fourteen stations were sampled on Hanna Shoal, a shallow feature on the shelf, and ten stations across the undersea Barrow Canyon. On Hanna Shoal, water column CH4 concentrations ranged from 14 to 74 nM, and surface concentrations were up to 15 times supersaturated in CH4 compared to equilibrium with the average atmospheric concentrations (3 nM). CH4 concentrations at the sediment-water interface were around 1,500 nM, and typically increased with depth in the sediment. At the head of Barrow Canyon, water column CH4 concentrations ranged from 5 to 46 nM, with the highest concentrations in the deepest waters that were sampled (118 m). Overall, the calculated fluxes to the atmosphere ranged from 1 to 80 μmol CH4 m-2 d-1 for Hanna Shoal and 4 to 17 μmol CH4 m-2 d-1 across the Barrow Canyon stations. Although there was a large range in these fluxes, the average atmospheric flux (20 μmol CH4 m-2 d-1) across Hanna Shoal was 12 times lower than the flux reported from the East Siberian Arctic Shelf in summer. We conclude that while there is a positive flux of CH4 to the atmosphere, this part of the Chukchi Sea is not a significant source of atmospheric CH4 compared to the East Siberian Sea shelf.

Lepidoptera Larvae as an Indicator of Multi-trophic Level Responses to Changing Seasonality in an Arctic Tundra Ecosystem

NASA Astrophysics Data System (ADS)

Daly, K. M.; Steltzer, H.; Boelman, N.; Weintraub, M. N.; Darrouzet-Nardi, A.; Wallenstein, M. D.; Sullivan, P.; Gough, L.; Rich, M.; Hendrix, C.; Kielland, K.; Philip, K.; Doak, P.; Ferris, C.; Sikes, D.

2011-12-01

Earlier snowmelt and warming temperatures in the Arctic will impact multiple trophic levels through the timing and availability of food resources. Lepidoptera are a vital link within the ecosystem; their roles include pollinator, parasitized host for other pollinating insects, and essential food source for migrating birds and their fledglings. Multiple environmental cues including temperature initiate plant growth, and in turn, trigger the emergence of Lepidoptera and the migrations of birds. If snowmelt is accelerated and temperature is increased, it is expected that the Lepidoptera larvae will respond to early plant growth by increasing their abundance within areas that have accelerated snowmelt and warmer conditions. In May of 2011 in a moist acidic tussock tundra system, we accelerated snowmelt by 15 days through the use of radiation-absorbing fabric and warmed air and soil temperatures using open-top chambers, individually and in combination. Every 1-2 days from May 27th to July 8th, 2 minute searches were performed for Lepidoptera larvae in all treatments; when an animal was found, their micro-habitat, surface temperature, behavior, food source, and time of day were noted. The length, body and head width were measured, and the animals were examined for braconid wasp and tachinid fly parasites. Lepidoptera larvae collected in pitfall traps from May 26th to July 7th were also examined and measured. Total density of parasitized larvae accounted for 54% of observed specimens and 50% of pitfall specimens, indicating that Lepidoptera larvae serve an integral role as a host for other pollinators. Total larvae density was highest within the accelerated snowmelt plots compared to the control plots; 66% of observed live specimens and 63% of pitfall specimens were found within the accelerated snowmelt plots. Ninety percent of the total observed animals were found within the open-top warming chambers. Peak density of animals occurred at Solar Noon between 14:00 -15:00, the warmest part of the Arctic day. An earlier, warmer Arctic summer will alter the timing of Lepidoptera and pollinator-dependent life cycles, which could then affect the bird migration timing through greater food availability.

5 CFR 1320.7 - Agency head and Senior Official responsibilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Agency head and Senior Official... CONTROLLING PAPERWORK BURDENS ON THE PUBLIC § 1320.7 Agency head and Senior Official responsibilities. (a) Except as provided in paragraph (b) of this section, each agency head shall designate a Senior Official...

46 CFR 76.23-25 - Sprinkler heads.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 3 2011-10-01 2011-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

46 CFR 76.23-25 - Sprinkler heads.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 3 2012-10-01 2012-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

46 CFR 76.23-25 - Sprinkler heads.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 3 2014-10-01 2014-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

46 CFR 76.23-25 - Sprinkler heads.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

46 CFR 76.23-25 - Sprinkler heads.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 3 2013-10-01 2013-10-01 false Sprinkler heads. 76.23-25 Section 76.23-25 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PASSENGER VESSELS FIRE PROTECTION EQUIPMENT Manual Sprinkling System, Details § 76.23-25 Sprinkler heads. (a) Sprinkler heads shall be of an approved...

21 CFR 868.1930 - Stethoscope head.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stethoscope head. 868.1930 Section 868.1930 Food... DEVICES ANESTHESIOLOGY DEVICES Diagnostic Devices § 868.1930 Stethoscope head. (a) Identification. A stethoscope head is a weighted chest piece used during anesthesia to listen to a patient's heart, breath, and...

48 CFR 702.170-9 - Head of agency.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Head of agency. 702.170-9 Section 702.170-9 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT GENERAL DEFINITIONS OF WORDS AND TERMS Definitions 702.170-9 Head of agency. Head of agency means, for USAID, the...

29 CFR 1926.100 - Head protection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 29 Labor 8 2010-07-01 2010-07-01 false Head protection. 1926.100 Section 1926.100 Labor... § 1926.100 Head protection. (a) Employees working in areas where there is a possible danger of head... protected by protective helmets. (b) Helmets for the protection of employees against impact and penetration...

Molecular epidemiological study of Arctic rabies virus isolates from Greenland and comparison with isolates from throughout the Arctic and Baltic regions.

PubMed

Mansfield, K L; Racloz, V; McElhinney, L M; Marston, D A; Johnson, N; Rønsholt, L; Christensen, L S; Neuvonen, E; Botvinkin, A D; Rupprecht, C E; Fooks, A R

2006-03-01

We report a molecular epidemiological study of rabies in Arctic countries by comparing a panel of novel Greenland isolates to a larger cohort of viral sequences from both Arctic and Baltic regions. Rabies virus isolates originating from wildlife (Arctic/red foxes, raccoon-dogs and reindeer), from domestic animals (dogs/cats) and from two human cases were investigated. The resulting 400 bp N-gene sequences were compared with isolates representing neighbouring Arctic or Baltic countries from North America, the former Soviet Union and Europe. Phylogenetic analysis demonstrated similarities between sequences from the Arctic and Arctic-like viruses, which were distinct from rabies isolates originating in the Baltic region of Europe, the Steppes in Russia and from North America. The Arctic-like group consist of isolates from India, Pakistan, southeast Siberia and Japan. The Arctic group was differentiated into two lineages, Arctic 1 and Arctic 2, with good bootstrap support. Arctic 1 is mainly comprised of Canadian isolates with a single fox isolate from Maine in the USA. Arctic 2 was further divided into sub-lineages: 2a/2b. Arctic 2a comprises isolates from the Arctic regions of Yakutia in northeast Siberia and Alaska. Arctic 2b isolates represent a biotype, which is dispersed throughout the Arctic region. The broad distribution of rabies in the Arctic regions including Greenland, Canada and Alaska provides evidence for the movement of rabies across borders.

Strategic War Game - Arctic Response

DTIC Science & Technology

2010-11-01

Heather Hrychuk; DRDC CORA TM 2010-240; R & D pour la défense Canada – CARO; Novembre 2010. S1. La section d’Élaboration de concepts et de...10 2.4.3 Scoring System.................................................................................. 13 2.4.3.1 Air Force... 13 2.4.3.2 Adversary

36 CFR 13.1006 - Customary trade.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Customary trade. 13.1006 Section 13.1006 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and Preserve...

36 CFR 13.1004 - Aircraft use.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 1 2014-07-01 2014-07-01 false Aircraft use. 13.1004 Section 13.1004 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and Preserve...

50 CFR 37.24 - Plan of operation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Plan of operation. 37.24 Section 37.24 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

36 CFR 13.1004 - Aircraft use.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 1 2011-07-01 2011-07-01 false Aircraft use. 13.1004 Section 13.1004 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and Preserve...

50 CFR 37.23 - Special use permit.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Special use permit. 37.23 Section 37.23 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

50 CFR 37.23 - Special use permit.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Special use permit. 37.23 Section 37.23 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

36 CFR 13.1004 - Aircraft use.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Aircraft use. 13.1004 Section 13.1004 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and Preserve...

50 CFR 37.24 - Plan of operation.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 50 Wildlife and Fisheries 8 2011-10-01 2011-10-01 false Plan of operation. 37.24 Section 37.24 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC...

Late MIS3 to modern central Arctic Paleoceanography based on Ostracode Faunal Assemblages

NASA Astrophysics Data System (ADS)

Gemery, L.; Cronin, T. M.; Jakobsson, M.; Poirier, R. K.; Pearce, C.; Barrientos, N.

2016-12-01

Continuous, highly abundant and well preserved fossil ostracodes were studied in one to two centimeter intervals from AMS-dated cores collected on the Lomonosov Ridge that indicate varying oceanographic conditions during the last 40 ka. Ostracode assemblages from cores taken during the SWERUS 2014 Expedition, Leg 2, reflect paleoenvironmental changes during glacial, deglacial, and interglacial transitions including changes in sea-ice cover and inflow of Atlantic-derived water into the Eurasian Basin. Notably, SWERUS 2014 obtained ridge, slope and shelf cores in relatively poorly studied regions of the Arctic. The composition of benthic ostracode assemblages from a multicore and complimentary gravity core (32 MUC4; 85.14, 151.59, in 837mwd and 32 GC2, section 1, 85.15, 151.66 in 826mwd), were analyzed and compared to prior results from various central Arctic expeditions to the Mendeleev, Northwind and Lomonosov Ridges. Key taxa used as indicators of specific water masses include: Acetabulastoma arcticum and Pseudocythere caudata (perennial sea ice), Polycope spp. (productivity and sea ice), Krithe hunti (partially sea-ice free conditions, deep water formation), and Rabilimis mirabilis (Atlantic water influx). Results indicate seasonally sea-ice free conditions during MIS 3 and less LGM ice cover than in more central regions of the Arctic. Intermittent periods of perennial sea ice began to develop during the late Holocene.

Rapid decrease of radar cross section of meteor head echo observed by the MU radar

NASA Astrophysics Data System (ADS)

Nakamura, T.; Nishio, M.; Sato, T.; Tsutsumi, S.; Tsuda, T.; Fushimi, K.

The meteor head echo observation using the MU (Middle and Upper atmosphere) radar (46.5M Hz, 1MW), Shigaraki, Japan, was carried out simultaneously with a high sensitive ICCD (Image-intensified CCD) camera observation in November 2001. The time records were synchronized using GPS satellite signals, in order to compare instantaneous radar and optical meteor magnitudes. 26 faint meteors were successfully observed simultaneously by both equipments. Detailed comparison of the time variation of radar echo intensity and absolute optical magnitude showed that the radar scattering cross section is likely to decrease rapidly by 5 - 20 dB without no corresponding magnitude variation in the optical data. From a simple modeling, we concluded that such decrease of RCS (radar cross section ) is probably due to the transition from overdense head echo to underd ense head echo.

Sea ice ridging in the eastern Weddell Sea

NASA Astrophysics Data System (ADS)

Lytle, V. I.; Ackley, S. F.

1991-10-01

In August 1986, sea ice ridge heights and spatial frequency in the eastern Weddell Sea were measured using a ship-based acoustical sounder. Using a minimum ridge sail height of 0.75 m, a total of 933 ridges were measured along a track length of 415 km. The ridge frequency varied from 0.4 to 10.5 ridges km-1. The mean height of the ridges was found to be about 1.1 m regardless of the ridge frequency. These results are compared to other ridging statistics from the Ross Sea and found to be similar. Comparison with Arctic data, however, indicates that the height and frequency of the ridges are considerably less in the Weddell Sea than in the Arctic. Whereas in the Arctic the mean ridge height tends to increase with the ridge frequency, we found that this was not the case in the Weddell Sea, where the mean ridge height remained constant irrespective of the ridge frequency. Estimates of the contribution of deformed ice to the total ice thickness are generally low except for a single 53-km section where the ridge frequency increased by an order of magnitude. This resulted in an increase in the equivalent mean ice thickness due to ridging from 0.04 m in the less deformed areas to 0.45 m in the highly deformed section. These values were found to be consistent with values obtained from drilled profile lines during the same cruise.

Proceedings of the Conference Arctic '85; Civil Engineering in the Artic offshore

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, F.L.; Machemehl, J.L.

1985-01-01

Topics of the 1985 Conference included: Arctic construction, Arctic foundation, Arctic structures, and ocean effects. Arctic terminals and coastal offshore bases, protecting the Arctic environment, and probabilistic methods in Arctic offshore engineering were also discussed. Ice mechanics, marine pipelines in the Arctic, and the role of universities in training civil engineers for Arctic offshore development were highlighted. Sessions on remote sensing, surveying, and mapping were included, and offshore installations in the Bering Sea were discussed. Another topic of discussion was research in Civil Engineering for development of the Arctic offshore. The overall thrust of the conference was the application ofmore » Arctic offshore engineering principles and research in the field of oil and gas exploration and exploitation activity.« less

Growth in Inuit children exposed to polychlorinated biphenyls and lead during fetal development and childhood.

PubMed

Dallaire, Renée; Dewailly, Éric; Ayotte, Pierre; Forget-Dubois, Nadine; Jacobson, Sandra W; Jacobson, Joseph L; Muckle, Gina

2014-10-01

Because of their geographical location and traditional lifestyle, Canadian Inuit children are highly exposed to polychlorinated biphenyls (PCBs) and lead (Pb), environmental contaminants that are thought to affect fetal and child growth. We examined the associations of these exposures with the fetal and postnatal growth of Inuit children. We conducted a prospective cohort study among Inuit from Nunavik (Arctic Québec). Mothers were recruited at their first prenatal visit; children (n=290) were evaluated at birth and at 8-14 years of age. Concentrations of PCB 153 and Pb were determined in umbilical cord and child blood. Weight, height and head circumference were measured at birth and during childhood. Cord blood PCB 153 concentrations were not associated with anthropometric measurements at birth or school age, but child blood PCB 153 concentrations were associated with reduced weight, height and head circumference during childhood. There was no association between cord Pb levels and anthropometric outcomes at birth, but cord blood Pb was related to smaller height and shows a tendency of a smaller head circumference during childhood. Our results suggest that chronic exposure to PCBs during childhood is negatively associated with skeletal growth and weight, while prenatal Pb exposure is related to reduced growth during childhood. This study is the first to link prenatal Pb exposure to poorer growth in school-age children. Copyright © 2014 Elsevier Inc. All rights reserved.

Quantitative trace analysis of polyfluorinated alkyl substances (PFAS) in ambient air samples from Mace Head (Ireland): A method intercomparison

NASA Astrophysics Data System (ADS)

Jahnke, Annika; Barber, Jonathan L.; Jones, Kevin C.; Temme, Christian

A method intercomparison study of analytical methods for the determination of neutral, volatile polyfluorinated alkyl substances (PFAS) was carried out in March, 2006. Environmental air samples were collected in triplicate at the European background site Mace Head on the west coast of Ireland, a site dominated by 'clean' westerly winds coming across the Atlantic. Extraction and analysis were performed at two laboratories active in PFAS research using their in-house methods. Airborne polyfluorinated telomer alcohols (FTOHs), fluorooctane sulfonamides and sulfonamidoethanols (FOSAs/FOSEs) as well as additional polyfluorinated compounds were investigated. Different native and isotope-labelled internal standards (IS) were applied at various steps in the analytical procedure to evaluate the different quantification strategies. Field blanks revealed no major blank problems. European background concentrations observed at Mace Head were found to be in a similar range to Arctic data reported in the literature. Due to trace-levels at the remote site, only FTOH data sets were complete and could therefore be compared between the laboratories. Additionally, FOSEs could partly be included. Data comparison revealed that despite the challenges inherent in analysis of airborne PFAS and the low concentrations, all methods applied in this study obtained similar results. However, application of isotope-labelled IS early in the analytical procedure leads to more precise results and is therefore recommended.

1 Mixing state and absorbing properties of black carbon during Arctic haze

NASA Astrophysics Data System (ADS)

Zanatta, Marco; Gysel, Martin; Eleftheriadis, Kosas; Laj, Paolo; Hans-Werner, Jacobi

2016-04-01

The Arctic atmosphere is periodically affected by the Arctic haze occurring in spring. One of its particulate components is the black carbon (BC), which is considered to be an important contributor to climate change in the Arctic region. Beside BC-cloud interaction and albedo reduction of snow, BC may influence Arctic climate interacting directly with the solar radiation, warming the corresponding aerosol layer (Flanner, 2013). Such warming depends on BC atmospheric burden and also on the efficiency of BC to absorb light, in fact the light absorption is enhanced by mixing of BC with other atmospheric non-absorbing materials (lensing effect) (Bond et al., 2013). The BC reaching the Arctic is evilly processed, due to long range transport. Aging promote internal mixing and thus absorption enhancement. Such modification of mixing and is quantification after long range transport have been observed in the Atlantic ocean (China et al., 2015) but never investigated in the Arctic. During field experiments conducted at the Zeppelin research site in Svalbard during the 2012 Arctic spring, we investigated the relative precision of different BC measuring techniques; a single particle soot photometer was then used to assess the coating of Arctic black carbon. This allowed quantifying the absorption enhancement induced by internal mixing via optical modelling; the optical assessment of aged black carbon in the arctic will be of major interest for future radiative forcing assessment.Optical characterization of the total aerosol indicated that in 2012 no extreme smoke events took place and that the aerosol population was dominated by fine and non-absorbing particles. Low mean concentration of rBC was found (30 ng m-3), with a mean mass equivalent diameter above 200 nm. rBC concentration detected with the continuous soot monitoring system and the single particle soot photometer was agreeing within 15%. Combining absorption coefficient observed with an aethalometer and rBC mass concentration from SP2, a mass absorption cross section of 6.0 m2 g-1 was found at a wavelength of 880 nm. Concerning mixing, rBC cores with a dimeter between 170 nm and 280 nm were found to be covered by a layer of non-absorbing material having a median thickness of 50 nm. From Mie calculation, such mixing would lead to an enhancement of absorption of 46% compared to a bare BC core. The aforementioned absorption enhancement would lead to a net decrease of single scattering albedo of the total aerosol of less than 1%. The reliability of Mie approach was confirmed by agreement with observations, while MAC values commonly used in radiative forcing models might lead to discrepancies up to 80%. Our work provides all the major optical properties of total aerosol and BC to minimize the uncertainty of radiative estimations based on a priori assumptions.

New tectonic concept of the Arctic region evolution

NASA Astrophysics Data System (ADS)

Petrov, O. V.; Morozov, A.; Grikurov, G.; Shokalsky, S.; Kashubin, S.; Sobolev, N. V.; Petrov, E.

2012-12-01

The international project "Atlas of Geological Maps of Circumpolar Arctic at 1:5 million scale" was launched in 2003. It was initiated by geological surveys of Circum-Arctic states with active support from the UNESCO Commission for the Geological Map of the World (CGMW). This work engages a number of scientists from national academies of sciences and universities. As of today, international working groups have accomplished the compilation of geological, magnetic and gravity maps at 1:5 million scale. Upon completion of those basic maps, it became possible to undertake the compilation of the Tectonic Map of the Arctic - TeMAr. The final draft of this map is being demonstrated at GeoExpo here in Brisbane. Analysis of the new tectonic map clearly shows the Neoproterozoic - Paleozoic - late Mesozoic Paleoasian oceanic structures. Among those structures are the Neoproterozoic Timan Orogen, the Baikalian fold basement in the Pre-Yenisey zone and the collisional systems of Uralides and Kimmerides whose age becomes successively younger northward from Late Carboniferous - Early Permian to Triassic - Jurassic. Seismic and isotope-geochemistry data recently obtained on Lomonosov Ridge and Mendeleev Rise suggest the possibility that Neoproterozoic-Mesozoic orogenic structures of the High Arctic may incorporate isolated blocks of Early Precambrian continental crust. The north-directed decrease of age refers not only to orogenies caused by gradual closing of the Asian paleo-ocean but also to post-orogenic rift-related processes superposed on continental crust and reflected in the first place in the formation of LIPs. This is well exemplified by transition from the Early Triassic Siberian trap province to Triassic West Siberian province and then to Late Jurassic - Cretaceous, locally Cenozoic basaltic province of the High Arctic. The center of the Canadian Basin so far remains enigmatic: it was probably formed by seafloor spreading that could follow intensive Jurassic-Early Cretaceous continental rifting and volcanic activity. Reactivation of rifting in the Central Arctic at the beginning of Cenozoic led to the onset of spreading 56 million years ago along the emerging Gakkel Ridge and to the subsequent formation of the Eurasian Basin. Approximately 33 million years ago, the newly formed Eurasian oceanic basin connected with the Norwegian-Greenland Basin of the North Atlantic. Combined interpretation of seismostratigraphic data and drilling results suggests that during the Paleogene shallow-water sedimentation in the Central Arctic occurred, which indicates the high-standing sea level. Only in the Early Miocene (about 20 million years ago) the sea bottom sank sharply reaching its present-day depth and causing transition to deep-water deposition. This essential tectonic event is recorded throughout the Central Arctic elevations by a regional unconformity in seismostratigraphic sections. The Cenozoic expansion of the North Atlantic into the Central Arctic occurred across the structural assemblages whose formation was controlled by the preceding evolution of the Asian paleo-ocean.

Proxy Constraints on a Warm, Fresh Late Cretaceous Arctic Ocean

NASA Astrophysics Data System (ADS)

Super, J. R.; Li, H.; Pagani, M.; Chin, K.

2015-12-01

The warm Late Cretaceous is thought to have been characterized by open Arctic Ocean temperatures upwards of 15°C (Jenkyns et al., 2004). The high temperatures and low equator-to-pole temperature gradient have proven difficult to reproduce in paleoclimate models, with the role of the atmospheric hydrologic cycle in heat transport being particularly uncertain. Here, sediments, coprolites and fish teeth of Santonian-Campanian age from two high-latitude mixed terrestrial and marine sections on Devon Island in the Canadian High Arctic (Chin et al., 2008) were analyzed using a suite of organic and inorganic proxies to evaluate the temperature and salinity of Arctic seawater. Surface temperature estimates were derived from TEX86 estimates of near-shore, shallow (~100 meters depth) marine sediments (Witkowski et al., 2011) and MBT-CBT estimates from terrestrial intervals and both suggest mean annual temperatures of ~20°C, consistent with previous estimates considering the more southerly location of Devon Island. The oxygen isotope composition of non-diagenetic phosphate from vertebrate coprolites and bony fish teeth were then measured, giving values ranging from +13‰ to +19‰. Assuming the TEX86 temperatures are valid and using the temperature calibration of Puceat 2010, the δ18O values of coprolites imply Arctic Ocean seawater δ18O values between -4‰ and -10‰, implying very fresh conditions. Lastly, the δD of precipitation will be estimated from the hydrogen isotope composition of higher plant leaf waxes (C-25, C-27, C-29 and C-31 n-alkanes) from both terrestrial and marine intervals. Data are used to model the salinity of seawater and the meteoric relationship between δD and δ18O, thereby helping to evaluate the northern high-latitude meteoric water line of the Late Cretaceous.

Geology and assessment of undiscovered oil and gas resources of the Yukon Flats Basin Province, 2008

USGS Publications Warehouse

Bird, Kenneth J.; Stanley, Richard G.; Moore, Thomas E.; Gautier, Donald L.

2017-12-22

The hydrocarbon potential of the Yukon Flats Basin Province in Central Alaska was assessed in 2004 as part of an update to the National Oil and Gas Assessment. Three assessment units (AUs) were identified and assessed using a methodology somewhat different than that of the 2008 Circum-Arctic Resource Appraisal (CARA). An important difference in the methodology of the two assessments is that the 2004 assessment specified a minimum accumulation size of 0.5 million barrels of oil equivalent (MMBOE), whereas the 2008 CARA assessment specified a minimum size of 50 MMBOE. The 2004 assessment concluded that >95 percent of the estimated mean undiscovered oil and gas resources occur in a single AU, the Tertiary Sandstone AU. This is also the only AU of the three that extends north of the Arctic Circle.For the CARA project, the number of oil and gas accumulations in the 2004 assessment of the Tertiary Sandstone AU was re-evaluated in terms of the >50-MMBOE minimum accumulation size. By this analysis, and assuming the resource to be evenly distributed across the AU, 0.23 oil fields and 1.20 gas fields larger than 50 MMBOE are expected in the part of the AU north of the Arctic Circle. The geology suggests, however, that the area north of the Arctic Circle has a lower potential for oil and gas accumulations than the area to the south where the sedimentary section is thicker, larger volumes of hydrocarbons may have been generated, and potential structural traps are probably more abundant. Because of the low potential implied for the area of the AU north of the Arctic Circle, the Yukon Flats Tertiary Sandstone AU was not quantitatively assessed for the 2008 CARA.

Paleogene blackshales in the central Arctic Ocean and paleoenvironment: Anoxia vs. high primary production vs. terrigenous input

NASA Astrophysics Data System (ADS)

Stein, R.; Weller, P.; Boucsein, B.

2006-12-01

During IODP Expedition 302 (Arctic Ocean Coring Experiment ACEX), the first scientific drilling campaign in the permantly ice-covered central Arctic Ocean on Lomonosov Ridge, a 430 m thick sequence of upper Cretaceaous to Quaternary sediments has been drilled. Here we present detailed organic carbon (OC) records from the entire ca. 200 m thick, upper Paleocene to middle Eocene blackshale-type section of the ACEX drill sites, characterized by OC contents of about 1 to 6%. Based on a multi-proxy organic geochemical approach (hydrogen indices, C/N and C/S ratios, stable carbon isotopes, biomarkers, and maceral composition), organic-carbon sources and paleoenvironmental conditions were reconstructed. The late Paleocene interval is characterized by oxic conditions and a predominance of reworked terrigenous OC. In contrast, euxinic "Black Sea-type" conditions favorable for the preservation of labile aquatic (marine algae-type) OC occur throughout the upper part of the early Eocene and the middle Eocene, explained by salinity stratification due to freshwater discharge. The superimposed short-term ("Milankovitch-type") variability in amount and composition of OC is related to changes in primary production and terrigenous input. Prominent early Eocene events of algae-type OC preservation coincide with global 13C events such as the Paleocene- Eocece Thermal Maximum (PETM) and Elmo events. During Eocene times of anoxia, OC accumulation rates were 5-20 times higher than modern ones. Whereas very low organic carbon accumulation rates of about 0.005 gC cm-2 ky-1 are typical for the modern (Holocene) central Arctic Ocean on Lomonosov Ridge, values of up to 0.1-0.15 gC cm-2 ky-1 were calculated for the Eocene ACEX section. Because major part of the OC deposited during Eocene times is of aquatic (marine) origin and the OC deposited during Holocene times is almost entirely of terrigenous origin, the difference between the modern and Eocene situation becomes even more drastic when comparing the values for aquatic (marine) OC accumulation. During the Eocene, primary productivity in the central Arctic Ocean may may have reached values of 50-75 gC m-2 y-1, i.e., values 5-10 times higher than modern ones.

Head Start Program and Cost Data Analysis: Final Report - Volume II.

ERIC Educational Resources Information Center

Cordes, Joseph; And Others

This second volume of the Head Start Program and Cost Data Analysis Final Report analyzes data from sources other than the Head Start Program Information Report (PIR). The report is divided into three sections: Distributional Impact of Head Start Financing, Pilot Study of Program Compliance, and Recommendations for Secondary Data Analysis. The…

49 CFR 179.200-8 - Tank heads.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Tank heads. 179.200-8 Section 179.200-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-8 Tank heads. (a) All external tank heads...

49 CFR 179.100-8 - Tank heads.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Tank heads. 179.100-8 Section 179.100-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-8 Tank heads. (a) The tank head shape...

49 CFR 179.200-8 - Tank heads.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Tank heads. 179.200-8 Section 179.200-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-8 Tank heads. (a) All external tank heads...

49 CFR 179.220-8 - Tank heads.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Tank heads. 179.220-8 Section 179.220-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner...

49 CFR 179.220-8 - Tank heads.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Tank heads. 179.220-8 Section 179.220-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank heads of the inner...

10 CFR 1706.4 - Head of the contracting activity.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Head of the contracting activity. 1706.4 Section 1706.4 Energy DEFENSE NUCLEAR FACILITIES SAFETY BOARD ORGANIZATIONAL AND CONSULTANT CONFLICTS OF INTERESTS § 1706.4 Head of the contracting activity. The head of the contracting activity for the Board shall be...

10 CFR 1706.4 - Head of the contracting activity.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Head of the contracting activity. 1706.4 Section 1706.4 Energy DEFENSE NUCLEAR FACILITIES SAFETY BOARD ORGANIZATIONAL AND CONSULTANT CONFLICTS OF INTERESTS § 1706.4 Head of the contracting activity. The head of the contracting activity for the Board shall be...

10 CFR 1706.4 - Head of the contracting activity.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Head of the contracting activity. 1706.4 Section 1706.4 Energy DEFENSE NUCLEAR FACILITIES SAFETY BOARD ORGANIZATIONAL AND CONSULTANT CONFLICTS OF INTERESTS § 1706.4 Head of the contracting activity. The head of the contracting activity for the Board shall be...

10 CFR 1706.4 - Head of the contracting activity.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Head of the contracting activity. 1706.4 Section 1706.4 Energy DEFENSE NUCLEAR FACILITIES SAFETY BOARD ORGANIZATIONAL AND CONSULTANT CONFLICTS OF INTERESTS § 1706.4 Head of the contracting activity. The head of the contracting activity for the Board shall be...

10 CFR 1706.4 - Head of the contracting activity.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Head of the contracting activity. 1706.4 Section 1706.4 Energy DEFENSE NUCLEAR FACILITIES SAFETY BOARD ORGANIZATIONAL AND CONSULTANT CONFLICTS OF INTERESTS § 1706.4 Head of the contracting activity. The head of the contracting activity for the Board shall be...

49 CFR 572.162 - Head assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.162 Section... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ...

49 CFR 572.162 - Head assembly and test procedure.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly and test procedure. 572.162 Section... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ...

49 CFR 572.162 - Head assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.162 Section... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ...

49 CFR 572.162 - Head assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.162 Section... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ...

49 CFR 572.162 - Head assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.162 Section... Hybrid III Six-Year-Old Weighted Child Test Dummy § 572.162 Head assembly and test procedure. The head assembly is assembled and tested as specified in 49 CFR 572.122 (Subpart N). ...

Rehabilitation of the head and neck cancer patient: Psychosocial aspects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blitzer, A.; Baredes, S.; Kutscher, A.

1985-01-01

This book contains 42 chapters divided among six sections. Some of the chapter titles are: The Challenge of Cancer; Communicaton Needs of Head and Neck Cancer Patients; Normal Tissue Effects of the Radiotherapy of Head and Neck Cancer; Chemotherapy in the Treatment of Head and Neck Cancer; and Thyroid Cancer.

Frequency of consumption of foods and beverages by Inuvialuit adults in Northwest Territories, Arctic Canada.

PubMed

Zotor, Francis; Sheehy, Tony; Lupu, Madalina; Kolahdooz, Fariba; Corriveau, Andre; Sharma, Sangita

2012-11-01

Limited data exist regarding nutrient intakes and overall dietary quality in Canadian Arctic populations. This cross-sectional study determined the frequency of consumption of traditional meats (e.g. caribou, polar bear, seal, char and whale) and non-traditional store-bought foods including non-traditional meats (e.g. beef, pork and chicken), grains, dairy, fruits, vegetables and non-nutrient dense foods (NNDFs) (e.g. butter, chocolate, chips, candy and pop) by Inuvialuit adults (175 women, mean age 44 ± 14 years; 55 men, mean age 41 ± 13 years) in three remote communities in the Northwest Territories. Using a validated quantitative food frequency questionnaire, frequency of consumption over a 30-day period was determined for 141 commonly reported foods. Mean consumption of traditional meats (1.6 times/day), fruits (1 time/day) and vegetables (0.6 times/day) was less frequent than that of NNDFs (5.0 times/day). Nutritional intervention strategies are needed to promote more frequent consumption of nutrient-rich foods and less frequent consumption of NNDFs in these Arctic communities.

A Cold Temperature Evaluation of the Bonding Adhesives Used for the MUST Inflatable Shelters

DTIC Science & Technology

1975-04-01

been known as the US Army Natick Laboratories (NLABS), and the US Army Natick Development Center ( NDC ). AMIN 1W 5Th Whit# WIN~ zD DI• ~kti u...section throughout the test period. The arctic climatic chamber is a closed ci;•uit wind tunnel in which the temperature can be lowered, controlled...and maintained at any level down to -54WC (-65°F). The shelter section was too large to fit in the test section of the tunnel . The shelter had to be

49 CFR 214.113 - Head protection.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Head protection. 214.113 Section 214.113 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... conform to the national consensus standards for industrial head protection (American National Standards...

The Indigenous World 1993-94 = El Mundo Indigena 1993-94.

ERIC Educational Resources Information Center

Parellada, Alejandro, Ed.; And Others

This book addresses the oppression and discrimination that indigenous populations face and discusses their efforts to regain basic rights to control their own cultural, economic, political, and social development. The first section discusses the social status and living conditions of indigenous populations in the Arctic (including Saamiland and…

36 CFR 13.1008 - Solid waste disposal.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Section 13.1008 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and Preserve § 13.1008 Solid waste disposal. (a) A solid waste disposal site may accept non-National Park Service...

Interactions of the Cloudy Arctic Boundary Layer with Variable Surface Conditions and Large-Scale Circulations

NASA Technical Reports Server (NTRS)

Randell, David A.

2001-01-01

Our project included a variety of activities, ranging from model development to data manipulation and even participation in the SHEBA and FIRE field experiments. The following sections outline the work accomplished under these tasks. A collection of reprints is attached to this report.

50 CFR 37.51 - Operational reports.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 50 Wildlife and Fisheries 9 2012-10-01 2012-10-01 false Operational reports. 37.51 Section 37.51 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR (CONTINUED) THE NATIONAL WILDLIFE REFUGE SYSTEM GEOLOGICAL AND GEOPHYSICAL EXPLORATION OF THE COASTAL PLAIN, ARCTIC NATIONAL WILDLIFE REFUGE, ALASKA Reporting...

7 CFR 3560.11 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

.... Unless otherwise noted, terms listed in this part shall be defined as follows: Administrator. The head of... occur: (1) As defined in section 501(b) of the Housing Act of 1949. The person is the head of household... if such person has a developmental disability as defined in section 102(7) of the Developmental...

7 CFR 3560.11 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... Unless otherwise noted, terms listed in this part shall be defined as follows: Administrator. The head of... occur: (1) As defined in section 501(b) of the Housing Act of 1949. The person is the head of household... if such person has a developmental disability as defined in section 102(7) of the Developmental...

7 CFR 3560.11 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

.... Unless otherwise noted, terms listed in this part shall be defined as follows: Administrator. The head of... occur: (1) As defined in section 501(b) of the Housing Act of 1949. The person is the head of household... if such person has a developmental disability as defined in section 102(7) of the Developmental...

7 CFR 3560.11 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... Unless otherwise noted, terms listed in this part shall be defined as follows: Administrator. The head of... occur: (1) As defined in section 501(b) of the Housing Act of 1949. The person is the head of household... if such person has a developmental disability as defined in section 102(7) of the Developmental...

21 CFR 184.1979b - Reduced minerals whey.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Lactose content, maximum 85 percent—as determined by the methods prescribed in section 16.057 (liquid sample), entitled “Gravimetric Method—Official Final Action” under the heading “Lactose,” or in section 31.061 (dry sample), entitled “Lane-Eynon General Volumetric Method” under the heading “Lactose...

21 CFR 184.1979b - Reduced minerals whey.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Lactose content, maximum 85 percent—as determined by the methods prescribed in section 16.057 (liquid sample), entitled “Gravimetric Method—Official Final Action” under the heading “Lactose,” or in section 31.061 (dry sample), entitled “Lane-Eynon General Volumetric Method” under the heading “Lactose...

Using a cross section to train veterinary students to visualize anatomical structures in three dimensions

NASA Astrophysics Data System (ADS)

Provo, Judy; Lamar, Carlton; Newby, Timothy

2002-01-01

A cross section was used to enhance three-dimensional knowledge of anatomy of the canine head. All veterinary students in two successive classes (n = 124) dissected the head; experimental groups also identified structures on a cross section of the head. A test assessing spatial knowledge of the head generated 10 dependent variables from two administrations. The test had content validity and statistically significant interrater and test-retest reliability. A live-dog examination generated one additional dependent variable. Analysis of covariance controlling for performance on course examinations and quizzes revealed no treatment effect. Including spatial skill as a third covariate revealed a statistically significant effect of spatial skill on three dependent variables. Men initially had greater spatial skill than women, but spatial skills were equal after 8 months. A qualitative analysis showed the positive impact of this experience on participants. Suggestions for improvement and future research are discussed.

Soft tissue examination of the fetal rat and rabbit head by magnetic resonance imaging.

PubMed

French, Julian M; Woodhouse, Neil

2013-01-01

The use of magnetic resonance imaging of the fetal rat and rabbit head, as an alternative to the traditional methods of fixation and preparation of serial sections, is described. Labeled magnetic resonance images of normal head anatomy have been provided as a reference for use when evaluating the internal structures of the head.

21 CFR 868.5560 - Gas mask head strap.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Gas mask head strap. 868.5560 Section 868.5560...) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5560 Gas mask head strap. (a) Identification. A gas mask head strap is a device used to hold an anesthetic gas mask in position on a patient's...

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

Head Start Social Services Training Manual for Coordinators and Staff.

ERIC Educational Resources Information Center

Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

This training manual is designed for use by local Head Start programs in training current and new entry-level staff to deliver comprehensive social services to Head Start families. The introductory section of the manual provides an overview of Head Start, describes its social service component, and explains the organization of the manual. The…

Cross-sectional imaging in cancers of the head and neck: how we review and report.

PubMed

Tshering Vogel, Dechen Wangmo; Thoeny, Harriet C

2016-08-03

Cancer of the head and neck is the sixth most frequent cancer worldwide and associated with significant morbidity. The head and neck area is complex and divided into various anatomical and functional subunits. Imaging is performed by cross-sectional modalities like computed tomography, magnetic resonance imaging, ultrasound and positron emission tomography-computed tomography, usually with fluorine-18-deoxy-D-glucose. Therefore, knowledge of the cross-sectional anatomy is very important. This article seeks to give an overview of the various cross-sectional imaging modalities used in the evaluation of head and neck cancers. It briefly describes the anatomy of the extracranial head and neck and the role of imaging as well as the imaging appearance of tumours and their extension to lymph nodes, bone and surrounding tissue. The advantages and disadvantages as well as basic requirements of the various modalities are described along with ways of optimizing imaging quality. A general guideline for prescription of the various modalities is given. Pitfalls are many and varied and can be due to anatomical variation, due to pathology which can be misinterpreted and technical due to peculiarities of the various imaging modalities. Knowledge of these pitfalls can help to avoid misinterpretation. The important points to be mentioned while reporting are also enumerated.

KSC-07pd1553A

NASA Image and Video Library

2007-06-18

KENNEDY SPACE CENTER, FLA. -- On Launch Pad 17-A at Cape Canaveral Air Force Station, workers prepare the first stage of a Delta II rocket to be lifted up into the mobile service tower. The rocket is the launch vehicle for the Phoenix spacecraft, targeted for launch on Aug. 3 heading for Mars. Phoenix will land in icy soils near the north polar permanent ice cap of Mars and explore the history of the water in these soils and any associated rocks, while monitoring polar climate. Landing on Mars is planned in May 2008 on arctic ground where a mission currently in orbit, Mars Odyssey, has detected high concentrations of ice just beneath the top layer of soil. Photo credit: NASA/Amanda Diller

Reconstruction of Arctic surface temperature in past 100 years using DINEOF

NASA Astrophysics Data System (ADS)

Zhang, Qiyi; Huang, Jianbin; Luo, Yong

2015-04-01

Global annual mean surface temperature has not risen apparently since 1998, which is described as global warming hiatus in recent years. However, measuring of temperature variability in Arctic is difficult because of large gaps in coverage of Arctic region in most observed gridded datasets. Since Arctic has experienced a rapid temperature change in recent years that called polar amplification, and temperature risen in Arctic is faster than global mean, the unobserved temperature in central Arctic will result in cold bias in both global and Arctic temperature measurement compared with model simulations and reanalysis datasets. Moreover, some datasets that have complete coverage in Arctic but short temporal scale cannot show Arctic temperature variability for long time. Data Interpolating Empirical Orthogonal Function (DINEOF) were applied to fill the coverage gap of NASA's Goddard Institute for Space Studies Surface Temperature Analysis (GISTEMP 250km smooth) product in Arctic with IABP dataset which covers entire Arctic region between 1979 and 1998, and to reconstruct Arctic temperature in 1900-2012. This method provided temperature reconstruction in central Arctic and precise estimation of both global and Arctic temperature variability with a long temporal scale. Results have been verified by extra independent station records in Arctic by statistical analysis, such as variance and standard deviation. The result of reconstruction shows significant warming trend in Arctic in recent 30 years, as the temperature trend in Arctic since 1997 is 0.76°C per decade, compared with 0.48°C and 0.67°C per decade from 250km smooth and 1200km smooth of GISTEMP. And global temperature trend is two times greater after using DINEOF. The discrepancies above stress the importance of fully consideration of temperature variance in Arctic because gaps of coverage in Arctic cause apparent cold bias in temperature estimation. The result of global surface temperature also proves that global warming in recent years is not as slow as thought.

A randomised controlled trial of the effect of a head-elevation pillow on intrathecal local anaesthetic spread in caesarean section.

PubMed

Elfil, H; Crowley, L; Segurado, R; Spring, A

2015-11-01

A head-elevation pillow places a patient in a ramped posture, which maximises the view of the larynx during laryngoscopy, particularly in obese parturients. In our institution an elevation pillow is used pre-emptively for neuraxial anaesthesia. We hypothesised that head-elevation may impair cephalad spread of local anaesthetic before caesarean section resulting in a lower block or longer time to achieve a T6 level. We aimed to investigate the effect of head-elevation on spread of intrathecal local anaesthetics during anaesthesia for caesarean section. One-hundred parturients presenting for caesarean section under combined spinal-epidural anaesthesia were randomised to either the standard supine position with lateral displacement or in the supine position with lateral displacement on an head-elevation pillow. Each patient received intrathecal hyperbaric bupivacaine 11 mg, morphine 100 μg and fentanyl 15 μg. Patients were assessed for adequacy of sensory block (T6 or higher) at 10 min. Sensory block to T6 was achieved within 10 min in 65.9% of parturients in the Elevation Pillow Group compared to 95.7% in the Control Group (P<0.05). Compared to the Control Group, patients in the Elevation Pillow Group had greater requirements for epidural supplementation (43.5% vs 2.1%, P<0.001) or conversion to general anaesthesia (9.3% vs 0%, P<0.04). Use of a ramped position with an head-elevation pillow following injection of the intrathecal component of a combined spinal-epidural anaesthetic for scheduled caesarean section was associated with a significantly lower block height at 10min. Copyright © 2015 Elsevier Ltd. All rights reserved.

78 FR 12033 - Programs and Research Projects Affecting the Arctic

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-21

... ARCTIC RESEARCH COMMISSION Programs and Research Projects Affecting the Arctic Notice is hereby given that the U.S. Arctic Research Commission will hold its 100th meeting in Anchorage and Bethel... presentations concerning Arctic research activities The focus of the meeting will be Arctic research activities...

49 CFR 572.6 - Head.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Head. 572.6 Section 572.6 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 50th Percentile Male § 572.6 Head. (a) The...

49 CFR 572.6 - Head.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head. 572.6 Section 572.6 Transportation Other Regulations Relating to Transportation (Continued) NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) ANTHROPOMORPHIC TEST DEVICES 50th Percentile Male § 572.6 Head. (a) The...

The Arctic Research Consortium of the United States (ARCUS): Connecting Arctic Research

NASA Astrophysics Data System (ADS)

Rich, R. H.; Wiggins, H. V.; Creek, K. R.; Sheffield Guy, L.

2015-12-01

This presentation will highlight the recent activities of the Arctic Research Consortium of the United States (ARCUS) to connect Arctic research. ARCUS is a nonprofit membership organization of universities and institutions that have a substantial commitment to research in the Arctic. ARCUS was formed in 1988 to serve as a forum for planning, facilitating, coordinating, and implementing interdisciplinary studies of the Arctic; to act as a synthesizer and disseminator of scientific information on arctic research; and to educate scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS, in collaboration with the broader science community, relevant agencies and organizations, and other stakeholders, coordinates science planning and educational activities across disciplinary and organizational boundaries. Examples of ARCUS projects include: Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. Sea Ice for Walrus Outlook - a resource for Alaska Native subsistence hunters, coastal communities, and others that provides weekly reports with information on sea ice conditions relevant to walrus in Alaska waters. PolarTREC (Teachers and Researchers Exploring and Collaborating) - a program whereby K-12 educators and researchers work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. ArcticInfo mailing list, Witness the Arctic newsletter, and the Arctic Calendar - communication tools for the arctic science community to keep apprised of relevant news, meetings, and announcements. Coordination for the Study of Environmental Arctic Change (SEARCH) program, which aims to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. More information about these and other ARCUS activities can be found at the ARCUS website at: http://www.arcus.org.

Scenarios Creation and Use in the Arctic Council's Arctic Marine Shipping Assessment

NASA Astrophysics Data System (ADS)

Brigham, L. W.

2016-12-01

The Arctic Council's Arctic Marine Shipping Assessment (AMSA), conducted 2004-2009, used a scenarios-based approach to reveal the complexity of future Arctic marine navigation and to develop a set of plausible futures. The initial task was to use experts and stakeholders in brainstorming sessions to identify the key drivers and uncertainties for Arctic marine navigation. AMSA scenario participants identified 120 driving forces or factors that may influence future levels of marine activity. This effort illustrated the broad, global connections that can impact future use of the Arctic Ocean. Two primary factors were selected to anchor, as axes of uncertainty, the scenarios matrix: resources and trade (the level of demand for Arctic natural resources and trade); and, governance (the degree of relative stability of rules and standards for marine use both within the Arctic and internationally). Four scenarios were created by crossing the two primary drivers: a Polar Lows scenario (low demand and unstable governance); an Arctic Race scenario (high demand and unstable governance); a Polar Preserve scenario (low demand and stable governance); and, an Arctic Saga scenario (high demand and stable governance). The AMSA scenarios effort proved to be an effective and powerful way to communicate to the Arctic Council diplomats, Arctic indigenous peoples, maritime stakeholders and many other actors in the global community the complexities influencing the future of Arctic shipping and marine operations. The scenarios approach facilitated unconstrained thinking and identified the many plausible linkages of the Arctic to the global economic system. The AMSA scenarios work was influential in the Arctic ministers' approval of the framework set of AMSA recommendations that are being implemented today to enhance Arctic marine safety and environmental protection.

The International Polar year 2007-2008; the Arctic human health legacy.

PubMed

Parkinson, Alan J

2007-01-01

Life expectancy in Arctic populations has greatly improved over the last 50 years. Much of this improvement can be attributed health research that has resulted in a reduction in morbidity and mortality from infectious diseases, such as tuberculosis, and the vaccine-preventable diseases of childhood. However, despite these improvements in health indicators of Arctic residents, life expectancy and infant mortality remain higher in indigenous Arctic residents in the US Arctic, northern Canada, and Greenland when compared to Arctic residents of Nordic countries. The International Polar Year (IPY) represents a unique opportunity to focus world attention on Arctic human health and to further stimulate Circumpolar cooperation on emerging Arctic human health concerns. The Arctic Human Health Initiative (AHHI) is an Arctic Council IPY initiative that aims to build and expand on existing Arctic Council and International Union for Circumpolar Health (IUCH) human health research activities. The human health legacy of the IPY will be increased visibility of the human health concerns of Arctic communities, revitalization of cooperative Arctic human health research focused on those concerns, the development of health policies based on research findings, and the subsequent implementation of appropriate interventions, prevention and control measures at the community level.

33 CFR 80.115 - Portland Head, ME to Cape Ann, MA.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Portland Head, ME to Cape Ann, MA. 80.115 Section 80.115 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY..., MA. (a) Except inside lines specifically described in this section, the 72 COLREGS shall apply on the...

33 CFR 80.115 - Portland Head, ME to Cape Ann, MA.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Portland Head, ME to Cape Ann, MA. 80.115 Section 80.115 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY..., MA. (a) Except inside lines specifically described in this section, the 72 COLREGS shall apply on the...

33 CFR 80.115 - Portland Head, ME to Cape Ann, MA.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Portland Head, ME to Cape Ann, MA. 80.115 Section 80.115 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY..., MA. (a) Except inside lines specifically described in this section, the 72 COLREGS shall apply on the...

33 CFR 80.115 - Portland Head, ME to Cape Ann, MA.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Portland Head, ME to Cape Ann, MA. 80.115 Section 80.115 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY..., MA. (a) Except inside lines specifically described in this section, the 72 COLREGS shall apply on the...

33 CFR 80.115 - Portland Head, ME to Cape Ann, MA.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Portland Head, ME to Cape Ann, MA. 80.115 Section 80.115 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY..., MA. (a) Except inside lines specifically described in this section, the 72 COLREGS shall apply on the...

Development and Testing of The Lunar Resource Prospector Drill

NASA Astrophysics Data System (ADS)

Zacny, K.; Paulsen, G.; Kleinhenz, J.; Smith, J. T.; Quinn, J.

2017-12-01

The goal of the Lunar Resource Prospector (RP) mission is to capture and identify volatiles species within the top one meter layer of the lunar surface. The RP drill has been designed to 1. Generate cuttings and place them on the surface for analysis by the Near InfraRed Volatiles Spectrometer Subsystem (NIRVSS), and 2. Capture cuttings and transfer them to the Oxygen and Volatile Extraction Node (OVEN) coupled with the Lunar Advanced Volatiles Analysis (LAVA) subsystem. The RP drill is based on the TRL4 Mars Icebreaker drill and TRL5 LITA drill developed for capturing samples of ice and ice cemented ground on Mars, and represents over a decade of technology development effort. The TRL6 RP drill weighs approximately 15 kg and is rated at just over 500 Watt. The drill consists of: 1. Rotary-Percussive Drill Head, 2. Sampling Auger, 3. Brushing Station, 4. Feed Stage, and 5. Deployment Stage. To reduce sample handling complexity, the drill auger is designed to capture cuttings as opposed to cores. High sampling efficiency is possible through a dual design of the auger. The lower section has deep and low pitch flutes for retaining of cuttings. The upper section has been designed to efficiently move the cuttings out of the hole. The drill uses a "bite" sampling approach where samples are captured in 10 cm depth intervals. The first generation, TRL4 Icebreaker drill was tested in Mars chamber as well as in Antarctica and the Arctic. It demonstrated drilling at 1-1-100-100 level (1 meter in 1 hour with 100 Watt and 100 N Weight on Bit) in ice, ice cemented ground, soil, and rocks. The second generation, TRL5 LITA drill was deployed on a Carnegie Mellon University rover, called Zoe, and tested in Atacama, Antarctica, the Arctic, and Greenland. The tests demonstrated fully autonomous sample acquisition and delivery to a carousel. The modified LITA drill was tested in NASA GRC's lunar vacuum chamber at <10^-5 torr and <200 K. It demonstrated successful capture and transfer of volatile rich frozen samples to a crucible for analysis. The modified LITA drill has also been successfully vibration tested at NASA KSC. The drill was integrated with RP rover at NASA JSC and successfully tested in a lab and in the field, as well as on a large vibration table and steep slope. The latest TRL6 RP drill is currently undergoing testing at NASA GRC lunar chamber facilities.

Cross-sectional anatomy, computed tomography and magnetic resonance imaging of the head of common dolphin (Delphinus delphis) and striped dolphin (Stenella coeruleoalba).

PubMed

Alonso-Farré, J M; Gonzalo-Orden, M; Barreiro-Vázquez, J D; Barreiro-Lois, A; André, M; Morell, M; Llarena-Reino, M; Monreal-Pawlowsky, T; Degollada, E

2015-02-01

Computed tomography (CT) and low-field magnetic resonance imaging (MRI) were used to scan seven by-caught dolphin cadavers, belonging to two species: four common dolphins (Delphinus delphis) and three striped dolphins (Stenella coeruleoalba). CT and MRI were obtained with the animals in ventral recumbency. After the imaging procedures, six dolphins were frozen at -20°C and sliced in the same position they were examined. Not only CT and MRI scans, but also cross sections of the heads were obtained in three body planes: transverse (slices of 1 cm thickness) in three dolphins, sagittal (5 cm thickness) in two dolphins and dorsal (5 cm thickness) in two dolphins. Relevant anatomical structures were identified and labelled on each cross section, obtaining a comprehensive bi-dimensional topographical anatomy guide of the main features of the common and the striped dolphin head. Furthermore, the anatomical cross sections were compared with their corresponding CT and MRI images, allowing an imaging identification of most of the anatomical features. CT scans produced an excellent definition of the bony and air-filled structures, while MRI allowed us to successfully identify most of the soft tissue structures in the dolphin's head. This paper provides a detailed anatomical description of the head structures of common and striped dolphins and compares anatomical cross sections with CT and MRI scans, becoming a reference guide for the interpretation of imaging studies. © 2014 Blackwell Verlag GmbH.

29 CFR 1910.135 - Head protection.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 29 Labor 5 2012-07-01 2012-07-01 false Head protection. 1910.135 Section 1910.135 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR OCCUPATIONAL SAFETY AND HEALTH STANDARDS Personal Protective Equipment § 1910.135 Head protection. (a) General...

33 CFR 142.30 - Head protection.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Head protection. 142.30 Section 142.30 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head...

33 CFR 142.30 - Head protection.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Head protection. 142.30 Section 142.30 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OUTER CONTINENTAL SHELF ACTIVITIES WORKPLACE SAFETY AND HEALTH Personal Protective Equipment § 142.30 Head...

A "good practice" approach to the quality and consistency of morphological examination of the internal head structures of the term rabbit fetus.

PubMed

French, Julian M

2014-07-01

Variation in the interpretation of the regulatory guidelines has resulted in a diversity of techniques employed to examine the internal structures of the foetal rabbit head. Examination of the foetal rabbit brain, using a single transverse section as the sole technique, is considered not to be sufficiently thorough to be regarded as an adequate examination method. It is not compliant with published EPA and OECD guidelines covering required examination of the internal head structures, nor is it considered to conform to the spirit of the safety assessment required by the ICH guideline. Fixation of approximately half of the heads in each litter to allow the examination of multiple transverse sections enables the major structures within the head to be assessed effectively. This method is compliant with current guidelines, represents "good practice" and should be consistently adopted for the examination of the internal head structures of the term rabbit foetus. Copyright © 2014 Elsevier Inc. All rights reserved.

Simulation of the modern arctic climate by the NCAR CCM1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bromwich, D.H.; Tzeng, R.Y.; Parish, T.R.

The NCAR CCM1's simulation of the modern arctic climate is evaluated by comparing a five-year seasonal cycle simulation with the ECMWF global analyses. The sea level pressure (SLP), storm tracks, vertical cross section of height, 500-hPa height, total energy budget, and moisture budget are analyzed to investigate the biases in the simulated arctic climate. The results show that the model simulates anomalously low SLP, too much activity, and anomalously strong baroclinicity to the west of Greenland and vice versa to the east of Greenland. This bias is mainly attributed to the model's topographic representation of Greenland. First, the broadened Greenlandmore » topography in the model distorts the path of cyclone waves over the North Atlantic Ocean. Second, the model oversimulates the ridge over Greenland, which intensifies its blocking effect and steers the cyclone waves clockwise around it and hence produces an artificial [open quotes]circum-Greenland[close quotes] trough. These biases are significantly alleviated when the horizontal resolution increases to T42. Over the Arctic basin, the modal simulates large amounts of low-level (stratus) clouds in winter and almost no stratus in summer, which is opposite to the observations. This bias is mainly due to the location of the simulated SLP features and the negative anomaly of storm activity, which prevent the transport of moisture into this region during summer but favor this transport in winter. 26 refs., 14 figs., 42 tabs.« less

The Arctic zone: possibilities and risks of development

NASA Astrophysics Data System (ADS)

Sentsov, A.; Bolsunovskaya, Y.; Melnikovich, E.

2016-09-01

The authors analyze the Arctic region innovative possibilities from the perspective of political ideology and strategy. The Arctic region with its natural resources and high economic potential attracts many companies and it has become an important area of transnational development. At present, the Arctic region development is of great importance in terms of natural resource management and political system development. However, the most important development issue in the Arctic is a great risk of different countries’ competing interests in economic, political, and legal context. These are challenges for international partnership creating in the Arctic zone, Russian future model developing for the Arctic, and recognition of the Arctic as an important resource for the Russians. The Russian economic, military, and political expansion in the Arctic region has the potential to strengthen the national positions. The authors present interesting options for minimizing and eliminating political risks during the Arctic territories development and define an effective future planning model for the Russian Arctic.

The Arctic Visiting Speakers Program

NASA Astrophysics Data System (ADS)

Wiggins, H. V.; Fahnestock, J.

2013-12-01

The Arctic Visiting Speakers Program (AVS) is a program of the Arctic Research Consortium of the U.S. (ARCUS) and funded by the National Science Foundation. AVS provides small grants to researchers and other Arctic experts to travel and share their knowledge in communities where they might not otherwise connect. The program aims to: initiate and encourage arctic science education in communities with little exposure to arctic research; increase collaboration among the arctic research community; nurture communication between arctic researchers and community residents; and foster arctic science education at the local level. Individuals, community organizations, and academic organizations can apply to host a speaker. Speakers cover a wide range of arctic topics and can address a variety of audiences including K-12 students, graduate and undergraduate students, and the general public. Preference is given to tours that reach broad and varied audiences, especially those targeted to underserved populations. Between October 2000 and July 2013, AVS supported 114 tours spanning 9 different countries, including tours in 23 U.S. states. Tours over the past three and a half years have connected Arctic experts with over 6,600 audience members. Post-tour evaluations show that AVS consistently rates high for broadening interest and understanding of arctic issues. AVS provides a case study for how face-to-face interactions between arctic scientists and general audiences can produce high-impact results. Further information can be found at: http://www.arcus.org/arctic-visiting-speakers.

The Inuit (Eskimo) of Canada.

ERIC Educational Resources Information Center

Creery, Ian

This report examines the history of the colonization of Arctic Canada and the efforts of its 25,000 Inuit residents to decolonize themselves. Initial sections outline the origins and early history of the Inuit; characteristics of Inuit culture, family life, and spirituality; the effects of whaling and the fur trade; and the movement of the Inuit…

Close Encounters with Deadly Dangers: Riveting Reads and Classroom Ideas.

ERIC Educational Resources Information Center

Haven, Kendall

This book presents 15 tales that bring the animal world into the classroom. The stories in this book are divided into two sections: stories from aquatic ecosystems (both fresh- and saltwater systems), and from terrestrial systems, including desert, meadow, woodland, mountain, Arctic tundra, savanna, pine forest, and jungle ecosystems. All predator…

Images

Science.gov Websites

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Polycyclic aromatic hydrocarbon-DNA adducts in Beluga whales from the Arctic

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mathieu, A.; Payne, J.F.; Fancey, L.L.

1997-09-01

The Arctic is still relatively pristine in nature, but it is also vulnerable to pollution because contaminants originating from midlatitudes are transported to the Arctic by atmospheric processes, ocean currents, and river. Recognition of this fact of Arctic vulnerability has resulted in a Declaration on the Protection of the Arctic Environment by eight Arctic countries. A manifest aim of this declaration is to develop an Arctic Monitoring and Assessment Program. We report here on the presence of measurable levels of polycyclic aromatic hydrocarbon-DNA adducts, including relatively high levels in Arctic beluga (Delphinapterus leucas). These results lend support to the valuemore » of developing biological assessment programs for Arctic wildlife. 15 refs., 1 tab.« less

Atmospheric Sb in the Arctic during the past 16,000 years: Responses to climate change and human impacts

NASA Astrophysics Data System (ADS)

Krachler, Michael; Zheng, Jiancheng; Fisher, David; Shotyk, William

2008-03-01

Applying strict clean room procedures and sector field inductively coupled plasma mass spectrometry (ICP-MS) methods, concentrations of Sb and Sc were determined in 57 sections of a 170.6-m-long ice core drilled on Devon Island, Arctic Canada, in 1999, providing a record of atmospheric Sb extending back 15,800 years. Natural background concentrations of Sb and Sc established during the period between 1300 years BP and 10,590 years BP averaged 0.08 ± 0.03 pg/g (N = 18) and 0.44 ± 0.20 pg/g (N = 17), respectively. Scandium, a conservative reference element, was used as a surrogate for mineral dust inputs. The Sb/Sc ratio of 0.13 ± 0.07 in these ancient ice samples is comparable to the corresponding ratio of 0.09 ± 0.03 in peat samples from Switzerland from circa 6000 to 9000 years BP, indicating that this natural background ratio might have a much broader validity. The natural background flux of Sb (0.7 ± 0.5 ng/m2/a) in the Arctic was approximately 500 times lower than that established in central Europe using peat cores. For comparison with background values, modern Sb fluxes calculated using 45 samples from a 5-m snow pit dug on Devon Island in 2004, reflecting 10 years of snow accumulation, yielded an average deposition rate of 340 ± 270 ng/m2/a (range: 20-1240 ng/m2/a) with pronounced accumulation of Sb during winter periods when air masses reaching the Arctic predominantly come from Eurasia. These data reveal that approximately 99.8% of the Sb deposited in the Arctic today originates from anthropogenic activities. Modern Sb enrichment factors averaged 25 (range: 8-121). The ice core provides evidence of Sb contamination dating from Phoenician/Greek, Roman, and medieval lead mining and smelting in Europe. Moreover, the ice core data indicate that anthropogenic sources of Sb have continuously dominated the atmospheric inputs to the Arctic for at least 700 years.

The Age of the Arctic.

ERIC Educational Resources Information Center

Young, Oran R.

1986-01-01

Examines trends related to exploration in the Arctic by considering: (1) technology and military strategies; (2) foreign policy and the Arctic; (3) Arctic industrialization; (4) the Arctic policy agenda; and (5) recent United States initiatives in this region. (JN)

Arctic tipping points in an Earth system perspective.

PubMed

Wassmann, Paul; Lenton, Timothy M

2012-02-01

We provide an introduction to the volume The Arctic in the Earth System perspective: the role of tipping points. The terms tipping point and tipping element are described and their role in current science, general debates, and the Arctic are elucidated. From a wider perspective, the volume focuses upon the role of humans in the Arctic component of the Earth system and in particular the envelope for human existence, the Arctic ecosystems. The Arctic climate tipping elements, the tipping elements in Arctic ecosystems and societies, and the challenges of governance and anticipation are illuminated through short summaries of eight publications that derive from the Arctic Frontiers conference in 2011 and the EU FP7 project Arctic Tipping Points. Then some ideas based upon resilience thinking are developed to show how wise system management could ease pressures on Arctic systems in order to keep them away from tipping points.

45 CFR 1306.22 - Volunteers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 4 2012-10-01 2012-10-01 false Volunteers. 1306.22 Section 1306.22 Public Welfare... STAFFING REQUIREMENTS AND PROGRAM OPTIONS Head Start Program Staffing Requirements § 1306.22 Volunteers. (a) Head Start programs must use volunteers to the fullest extent possible. Head Start grantees must...

45 CFR 1306.22 - Volunteers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 4 2013-10-01 2013-10-01 false Volunteers. 1306.22 Section 1306.22 Public Welfare... STAFFING REQUIREMENTS AND PROGRAM OPTIONS Head Start Program Staffing Requirements § 1306.22 Volunteers. (a) Head Start programs must use volunteers to the fullest extent possible. Head Start grantees must...

45 CFR 1306.22 - Volunteers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Volunteers. 1306.22 Section 1306.22 Public Welfare... STAFFING REQUIREMENTS AND PROGRAM OPTIONS Head Start Program Staffing Requirements § 1306.22 Volunteers. (a) Head Start programs must use volunteers to the fullest extent possible. Head Start grantees must...

45 CFR 1306.22 - Volunteers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Volunteers. 1306.22 Section 1306.22 Public Welfare... STAFFING REQUIREMENTS AND PROGRAM OPTIONS Head Start Program Staffing Requirements § 1306.22 Volunteers. (a) Head Start programs must use volunteers to the fullest extent possible. Head Start grantees must...

45 CFR 1306.22 - Volunteers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 4 2014-10-01 2014-10-01 false Volunteers. 1306.22 Section 1306.22 Public Welfare... STAFFING REQUIREMENTS AND PROGRAM OPTIONS Head Start Program Staffing Requirements § 1306.22 Volunteers. (a) Head Start programs must use volunteers to the fullest extent possible. Head Start grantees must...

21 CFR 892.1920 - Radiographic head holder.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic head holder. 892.1920 Section 892.1920 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1920 Radiographic head holder. (a...

The Arctic Research Consortium of the United States (ARCUS)

NASA Astrophysics Data System (ADS)

Fox, S. E.; Wiggins, H. V.; Creek, K. R.

2012-12-01

The Arctic Research Consortium of the United States (ARCUS) is a nonprofit membership organization composed of universities and institutions that have a substantial commitment to research in the Arctic. Founded in 1988 to serve as a forum for advancing interdisciplinary studies of the Arctic, ARCUS synthesizes and disseminates scientific information on arctic research and educates scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS works closely with national and international stakeholders in advancing science planning and educational activities across disciplinary and organizational boundaries. Examples of ARCUS projects include: - Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. - Sea Ice for Walrus Outlook - a resource for Alaska Native subsistence hunters, coastal communities, and others that provides weekly reports with information on sea ice conditions relevant to walrus in Alaska waters. - PolarTREC (Teachers and Researchers Exploring and Collaborating) - a program for K-12 educators and researchers to work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. - ArcticInfo mailing list, Witness the Arctic newsletter, and the Arctic Calendar - communication tools for the arctic community to keep apprised of relevant news, meetings, and announcements. - Project Office for the Study of Environmental Arctic Change (SEARCH) program, which aims to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. More information about these and other ARCUS activities can be found at the ARCUS website at: http://www.arcus.org.

The Arctic Research Consortium of the United States (ARCUS)

NASA Astrophysics Data System (ADS)

Creek, K. R.; Fox, S. E.

2013-12-01

The Arctic Research Consortium of the United States (ARCUS) is a nonprofit membership organization composed of universities and institutions that have a substantial commitment to research in the Arctic. Founded in 1988 to serve as a forum for advancing interdisciplinary studies of the Arctic, ARCUS synthesizes and disseminates scientific information on arctic research and educates scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS works closely with national and international stakeholders in advancing science planning and educational activities across disciplinary and organizational boundaries. Examples of ARCUS projects include: - Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. - Sea Ice for Walrus Outlook - a resource for Alaska Native subsistence hunters, coastal communities, and others that provides weekly reports with information on sea ice conditions relevant to walrus in Alaska waters. - PolarTREC (Teachers and Researchers Exploring and Collaborating) - a program for K-12 educators and researchers to work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. - ArcticInfo mailing list, Witness the Arctic newsletter, and the Arctic Calendar - communication tools for the arctic community to keep apprised of relevant news, meetings, and announcements. - Project Office for the Study of Environmental Arctic Change (SEARCH) program, which aims to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. More information about these and other ARCUS activities can be found at the ARCUS website at: http://www.arcus.org.

The Arctic Research Consortium of the United States (ARCUS)

NASA Astrophysics Data System (ADS)

Fox, S. E.; Wiggins, H. V.

2011-12-01

The Arctic Research Consortium of the United States (ARCUS) is a nonprofit membership organization composed of universities and institutions that have a substantial commitment to research in the Arctic. ARCUS was formed in 1988 to serve as a forum for planning, facilitating, coordinating, and implementing interdisciplinary studies of the Arctic; to act as a synthesizer and disseminator of scientific information on arctic research; and to educate scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS, in collaboration with the broader science community, relevant agencies and organizations, and other stakeholders, coordinates science planning and educational activities across disciplinary and organizational boundaries. Examples of ARCUS projects include: - Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. - Sea Ice for Walrus Outlook - a resource for Alaska Native subsistence hunters, coastal communities, and others that provides weekly reports with information on sea ice conditions relevant to walrus in Alaska waters. - PolarTREC (Teachers and Researchers Exploring and Collaborating) - a program whereby K-12 educators and researchers work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. - ArcticInfo mailing list, Witness the Arctic newsletter, and the Arctic Calendar - communication tools for the arctic science community to keep apprised of relevant news, meetings, and announcements. - Coordination for the Study of Environmental Arctic Change (SEARCH) program, which aims to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic.

The first paleomagnetic data on dolerites from Jeannette Island (New Siberian Islands, Arctic)

NASA Astrophysics Data System (ADS)

Zhdanova, A. I.; Metelkin, D. V.; Vernikovsky, V. A.; Matushkin, N. Yu.

2016-06-01

The first paleomagnetic data on dolerite dikes from the volcanogenic-sedimentary section of Jeannette Island (De Long Archipelago, New Siberian Islands) are discussed. The petromagnetic data and results of the baked contact and fold tests are used to substantiate the nature of the characteristic magnetization component, which in combination with the 40Ar/39Ar dates implies its likely Late Precambrian-Early Paleozoic age. The calculated paleomagnetic pole makes it possible to extend the trajectory of the apparent polar movement for the New Siberian Islands block and confirms the assumption that this structural element of the Arctic shelf evolved as a terrane. Two variants of paleotectonic interpretation of the obtained data and their consistency with the available data on the geology and tectonics of the New Siberian Islands are considered.

Water temperature variability within an Arctic stream; analysis and implications

NASA Astrophysics Data System (ADS)

Mellor, C. J.; Hannah, D. M.; Milner, A. M.

2009-04-01

Arctic climate warming occurred at twice the global average over the last century and air temperature is predicted to increase by 7.5°C by 2099. Arctic river systems are hypothesized to be particularly vulnerable to warming due to their dependence on cryospheric water sources and thermal sensitivity of biotic communities. However, research is very limited on hydroecological response of Arctic rivers to a changing climate. This paper addresses this research gap and aims to investigate links between thermal dynamics and benthic communities for a river basin in Swedish Lappland. The Kårsavagge is located ~200 km north of the Arctic Circle and contains a small temperate glacier and two lakes. The Kårsa River drains into the Abisko River (~ 25 km from the valley head). The region experiences marked seasonality with average monthly air temperature ranging from +10 to -10°C. In June 2008, three gauging stations (1 - close to glacier snout, 2 - above first major extra glacial tributary and 3 - between the lakes and confluence with the Abisko river) were installed to record water temperature, riverbed temperature (at 0.05m, 0.20m and 0.40m depth), electrical conductivity, river stage, precipitation and turbidity. On top of these, twenty loggers recorded water temperature between gauging stations and across a braided reach located ~ 1.5km downstream of the glacier snout. Diurnal water temperature cycles were found at all sites; but average temperature increased downstream from 1.7°C near the glacier snout to 10.6°C before the Abisko River confluence. Sites immediately downstream of the lakes displayed moderated thermal variability. Bed temperatures in the upper catchment (lower) were higher (lower) and less variable that temperatures in the overlying water column. The degree of parity between water column and stream bed temperatures varied among sites with site 3 showing the greatest difference and site 2 showing the least. This implies a variable degree of connectivity between the water column and bed sediments and/or variation in the extent and source water of upwelling. Average temperature across the braided reach ranged from 2.8°C in the main glacier fed (kryal) channel to 8.8°C in a snowmelt (nival) channel sourced from north-facing slopes, reflecting the differential impact of solar heating on water from these two distinct sources. Chironomidae (non-biting midges) dominated the benthic communities in the upper catchment where maximum water temperature did not exceed 4.4°C. As distance from the glacier and water temperature increases other taxa appear (e.g. Plecoptera, Simulidae), with species richness and diversity peaking between the two lakes. Longitudinal changes in thermal regime are associated with shifts in the benthic invertebrate community. Work is ongoing to evaluate whether the observed lateral variation, which is close to that observed down the 25km longitudinal profile has similar implications. This lateral variability may be important in providing thermal refugia and therefore increasing biota diversity in the upper catchment. This work has highlighted the potential extent of longitudinal, vertical and lateral temperature variation within Arctic river systems. In combination with invertebrate distribution this could be used to identify communities at high risk from changes in thermal regime and further, identify species which can act as indicators of the changing Arctic climate.

High mountain origin, phylogenetics, evolution, and niche conservatism of arctic lineages in the hemiparasitic genus Pedicularis (Orobanchaceae).

PubMed

Tkach, Natalia; Ree, Richard H; Kuss, Patrick; Röser, Martin; Hoffmann, Matthias H

2014-07-01

The origin of the arctic flora covering the northernmost treeless areas is still poorly understood. Arctic plants may have evolved in situ or immigrated from the adjacent ecosystems. Frequently arctic species have disjunctive distributions between the Arctic and high mountain systems of the temperate zone. This pattern may result from long distance dispersal or from glacial plant migrations and extinctions of intermediate populations. The hemiparasitic genus Pedicularis is represented in the Arctic by c. 28 taxa and ranks among the six most species-rich vascular plant genera of this region. In this study, we test the hypothesis that these lineages evolved from predecessors occurring in northern temperate mountain ranges, many of which are current centers of diversity for the genus. We generated a nuclear ribosomal and chloroplast DNA phylogeny including almost all of the arctic taxa and nearly half of the genus as a whole. The arctic taxa of Pedicularis evolved 12-14 times independently and are mostly nested in lineages that otherwise occur in the high mountains of Eurasia and North America. It appears that only three arctic lineages arose from the present-day center of diversity of the genus, in the Hengduan Mountains and Himalayas. Two lineages are probably of lowland origin. Arctic taxa of Pedicularis show considerable niche conservatism with respect to soil moisture and grow predominantly in moist to wet soils. The studied characteristics of ecology, morphology, and chromosome numbers of arctic Pedicularis show a heterogeneous pattern of evolution. The directions of morphological changes among the arctic lineages show opposing trends. Arctic taxa are chiefly diploid, the few tetraploid chromosome numbers of the genus were recorded only for arctic taxa. Five arctic Pedicularis are annuals or biennials, life forms otherwise rare in the Arctic. Other genera of the Orobanchaceae consist also of an elevated number of short-lived species, thus hemiparasitism may favor this life form in the Arctic. Copyright © 2014 Elsevier Inc. All rights reserved.

Identifying Priorities for International Arctic Research and Policy

NASA Astrophysics Data System (ADS)

Rachold, V.; Hik, D.; Barr, S.

2015-12-01

The International Arctic Science Committee (IASC) is a non-governmental, international scientific organization, founded in 1990 by representatives of national scientific organizations of the eight Arctic countries - Canada, Denmark, Finland, Iceland, Norway, Russia (at that time Union of Soviet Socialist Republics), Sweden and the United States of America. Over the past 25 years, IASC has evolved into the leading international science organization of the North and its membership today includes 23 countries involved in all aspects of Arctic research, including 15 non-Arctic countries (Austria, China, the Czech Republic, France, Germany, India, Italy, Japan, the Netherlands, Poland, Portugal, South Korea, Spain, Switzerland and the UK). The Founding Articles committed IASC to pursue a mission of encouraging and facilitating cooperation in all aspects of Arctic research, in all countries engaged in Arctic research and in all areas of the Arctic region. IASC promotes and supports leading-edge multi-disciplinary research in order to foster a greater scientific understanding of the Arctic region and its role in the Earth system. IASC has organized three forward-looking conferences focused on international and interdisciplinary perspectives for advancing Arctic research cooperation and applications of Arctic knowledge. Indeed, the IASC Founding Articles call for IASC to host these conferences periodically in order to "review the status of Arctic science, provide scientific and technical advice, and promote cooperation and links with other national and international organizations." Through its members, including national science organizations and funding agencies from all countries engaged in Arctic research, IASC is uniquely placed to undertake this task. As an accredited observer on the Arctic Council, IASC is also in the position to introduce the outcome of its science planning efforts into the Arctićs main political body and to liaise with the Arctic Council Permanent Participants. This paper presents an overview of IASC´s efforts and achievements in terms of identifying Arctic research priorities and providing scientific expertise to policy makers and people who live in or near the Arctic.

46 CFR 7.70 - Folly Island, SC to Hilton Head Island, SC.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Folly Island, SC to Hilton Head Island, SC. 7.70 Section... BOUNDARY LINES Atlantic Coast § 7.70 Folly Island, SC to Hilton Head Island, SC. (a) A line drawn from the...′ W. (Port Royal Sound Lighted Whistle Buoy “2PR”); thence to the easternmost extremity of Hilton Head...

Role of Greenland meltwater in the changing Arctic

NASA Astrophysics Data System (ADS)

Dukhovskoy, Dmitry; Proshutinsky, Andrey; Timmermans, Mary-Louise; Myers, Paul; Platov, Gennady; Bamber, Jonathan; Curry, Beth; Somavilla, Raquel

2016-04-01

Observational data show that the Arctic ocean-ice-atmosphere system has been changing over the last two decades. Arctic change is manifest in the atypical behavior of the climate indices in the 21st century. Before the 2000s, these indices characterized the quasi-decadal variability of the Arctic climate related to different circulation regimes. Between 1948 and 1996, the Arctic atmospheric circulation alternated between anticyclonic circulation regimes and cyclonic circulation regimes with a period of 10-15 years. Since 1997, however, the Arctic has been dominated by an anticyclonic regime. Previous studies indicate that in the 20th century, freshwater and heat exchange between the Arctic Ocean and the sub-Arctic seas were self-regulated and their interactions were realized via quasi-decadal climate oscillations. What physical processes in the Arctic Ocean - sub-Arctic ocean-ice-atmosphere system are responsible for the observed changes in Arctic climate variability? The presented work is motivated by our hypothesis that in the 21st century, these quasi-decadal oscillations have been interrupted as a result of an additional freshwater source associated with Greenland Ice Sheet melt. Accelerating since the early 1990s, the Greenland Ice Sheet mass loss exerts a significant impact on thermohaline processes in the sub-Arctic seas. Surplus Greenland freshwater, the amount of which is about a third of the freshwater volume fluxed into the region during the 1970s Great Salinity Anomaly event, can spread and accumulate in the sub-Arctic seas influencing convective processes there. It is not clear, however, whether Greenland freshwater can propagate into the interior convective regions in the Labrador Sea and the Nordic Seas. In order to investigate the fate and pathways of Greenland freshwater in the sub-Arctic seas and to determine how and at what rate Greenland freshwater propagates into the convective regions, several numerical experiments using a passive tracer to track propagation of Greenland freshwater have been conducted as a part of the Forum for Arctic Ocean Modeling and Observational Synthesis effort. The presentation discusses the role of Greenland meltwater in the Arctic environment and how this can explain observed cessation of the quasi-decadal Arctic variability. The rate and pathways of Greenland meltwater in the sub-Arctic seas derived from the coordinated model experiments are analyzed. The presented study discusses a possible scenario of the Arctic in the future. It is argued that Greenland meltwater being accumulated in the sub-Arctic seas since the 1990s can trigger a negative feedback mechanism that may impede or even reverse processes of Arctic warming observed in the 21st century.

[Caesarean section with vacuum extraction of the head].

PubMed

Dimitrov, A; Pavlova, E; Krŭsteva, K; Nikolov, A

2008-01-01

The aim of the study is to investigate the benefits and the limits in using the soft cup vacuum extractor on the fetal scalp during the caesarean section. The prospective study includes 19 cases of caesarean sections (group A), with vacuum assisted delivery using the soft cup vacuum extractor on the fetal scalp (diameter 6 cm) and 25 cases (group B) of caesarean sections with usual, manual extraction of the head assisted by fundal compression. All of the patients had undergone a planned caesarean section on term in absence of uterine activity and preserved amniotic membranes. Our results doesn't show differences in the Apgar score on the first and 5-th minute in the newborns of the two groups. The duration of the scalp traction was significantly shorter (30 +/- 4 sec) in comparison to the classical manual extraction (53 +/- 21 sec). The mean duration for applying the vacuum cup was 10 sec and 25 sec for tractions. The total blood loose and total duration of the caesarean sections were shorter than in the control group. The applied traction with the vacuum cup was sufficient for head extraction and there was no need for additional fundal compression. In conclusion we consider that the extraction of the fetal head in high position in caesarean section with vacuum extractor is an easy, non traumatic and rapid method which can put away the need of rough and prolonged fundal compression and its consequences.

21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Neurosurgical head holder (skull clamp). 882.4460 Section 882.4460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4460 Neurosurgical head...

49 CFR 179.400-7 - Tank heads.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 3 2012-10-01 2012-10-01 false Tank heads. 179.400-7 Section 179.400-7... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-7 Tank heads. (a...

49 CFR 179.400-7 - Tank heads.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 3 2013-10-01 2013-10-01 false Tank heads. 179.400-7 Section 179.400-7... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-7 Tank heads. (a...

49 CFR 179.400-7 - Tank heads.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Tank heads. 179.400-7 Section 179.400-7... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-7 Tank heads. (a...

49 CFR 179.220-8 - Tank heads.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Tank heads. 179.220-8 Section 179.220-8... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS SPECIFICATIONS FOR TANK CARS Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-8 Tank heads. (a) Tank...

49 CFR 179.400-7 - Tank heads.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 3 2014-10-01 2014-10-01 false Tank heads. 179.400-7 Section 179.400-7... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) SPECIFICATIONS FOR TANK CARS Specification for Cryogenic Liquid Tank Car Tanks and Seamless Steel Tanks (Classes DOT-113 and 107A) § 179.400-7 Tank heads. (a...

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

14 CFR 97.5 - Bearings, courses, tracks, headings, radials, miles.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., radials, miles. 97.5 Section 97.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF... Bearings, courses, tracks, headings, radials, miles. (a) All bearings, courses, tracks, headings, and... visibility values are stated in statute miles. All other mileages are stated in nautical miles. [Doc. No. 561...

49 CFR 572.17 - Neck.

Code of Federal Regulations, 2012 CFR

2012-10-01

... (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline a... distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at time T as...

49 CFR 572.7 - Neck.

Code of Federal Regulations, 2014 CFR

2014-10-01

... paragraph (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline... the straight line distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at...

49 CFR 572.17 - Neck.

Code of Federal Regulations, 2014 CFR

2014-10-01

... (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline a... distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at time T as...

49 CFR 572.17 - Neck.

Code of Federal Regulations, 2013 CFR

2013-10-01

... (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline a... distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at time T as...

49 CFR 572.17 - Neck.

Code of Federal Regulations, 2010 CFR

2010-10-01

... (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline a... distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at time T as...

49 CFR 572.17 - Neck.

Code of Federal Regulations, 2011 CFR

2011-10-01

... (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline a... distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at time T as...

49 CFR 572.7 - Neck.

Code of Federal Regulations, 2012 CFR

2012-10-01

... paragraph (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline... the straight line distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at...

49 CFR 572.7 - Neck.

Code of Federal Regulations, 2013 CFR

2013-10-01

... paragraph (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline... the straight line distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at...

49 CFR 572.7 - Neck.

Code of Federal Regulations, 2010 CFR

2010-10-01

... paragraph (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline... the straight line distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at...

49 CFR 572.7 - Neck.

Code of Federal Regulations, 2011 CFR

2011-10-01

... paragraph (c) of this section, the head shall rotate in reference to the pendulum's longitudinal centerline... the straight line distance between (1) the position relative to the pendulum arm of the head center of gravity at time zero, and (2) the position relative to the pendulum arm of the head center of gravity at...

48 CFR 702.170-10 - Head of the contracting activity.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Head of the contracting activity. 702.170-10 Section 702.170-10 Federal Acquisition Regulations System AGENCY FOR INTERNATIONAL DEVELOPMENT GENERAL DEFINITIONS OF WORDS AND TERMS Definitions 702.170-10 Head of the contracting activity. (a...

Split spline screw

NASA Technical Reports Server (NTRS)

Vranish, John M. (Inventor)

1993-01-01

A split spline screw type payload fastener assembly, including three identical male and female type split spline sections, is discussed. The male spline sections are formed on the head of a male type spline driver. Each of the split male type spline sections has an outwardly projecting load baring segment including a convex upper surface which is adapted to engage a complementary concave surface of a female spline receptor in the form of a hollow bolt head. Additionally, the male spline section also includes a horizontal spline releasing segment and a spline tightening segment below each load bearing segment. The spline tightening segment consists of a vertical web of constant thickness. The web has at least one flat vertical wall surface which is designed to contact a generally flat vertically extending wall surface tab of the bolt head. Mutual interlocking and unlocking of the male and female splines results upon clockwise and counter clockwise turning of the driver element.

Arctic rabies--a review.

PubMed

Mørk, Torill; Prestrud, Pål

2004-01-01

Rabies seems to persist throughout most arctic regions, and the northern parts of Norway, Sweden and Finland, is the only part of the Arctic where rabies has not been diagnosed in recent time. The arctic fox is the main host, and the same arctic virus variant seems to infect the arctic fox throughout the range of this species. The epidemiology of rabies seems to have certain common characteristics in arctic regions, but main questions such as the maintenance and spread of the disease remains largely unknown. The virus has spread and initiated new epidemics also in other species such as the red fox and the racoon dog. Large land areas and cold climate complicate the control of the disease, but experimental oral vaccination of arctic foxes has been successful. This article summarises the current knowledge and the typical characteristics of arctic rabies including its distribution and epidemiology.

Behavioral interactions of penned red and arctic foxes

USGS Publications Warehouse

Rudzinski, D.R.; Graves, H.B.; Sargeant, A.B.; Storm, G.L.

1982-01-01

Expansion of the geographical distribution of red foxes (Vulpes vulpes) into the far north tundra region may lead to competition between arctic (Alopex lagopus) and red foxes for space and resources. Behavioral interactions between red and arctic foxes were evaluated during 9 trials conducted in a 4.05-ha enclosure near Woodworth, North Dakota. Each trial consisted of introducing a male-female pair of arctic foxes into the enclosure and allowing them to acclimate for approximately a week before releasing a female red fox into the enclosure, followed by her mate a few days later. In 8 of 9 trials, red foxes were dominant over arctic foxes during encounters. Activity of the arctic foxes decreased upon addition of red foxes. Arctic foxes tried unsuccessfully to defend preferred den, resting, and feeding areas. Even though the outcome of competition between red and arctic foxes in the Arctic is uncertain, the more aggressive red fox can dominate arctic foxes in direct competition for den sites and other limited resources.

Global warming and effects on the Arctic fox.

PubMed

Fuglei, Eva; Ims, Rolf Anker

2008-01-01

We predict the effect of global warming on the arctic fox, the only endemic terrestrial predatory mammals in the arctic region. We emphasize the difference between coastal and inland arctic fox populations. Inland foxes rely on peak abundance of lemming prey to sustain viable populations. In the short-term, warmer winters result in missed lemming peak years and reduced opportunities for successful arctic fox breeding. In the long-term, however, warmer climate will increase plant productivity and more herbivore prey for competitive dominant predators moving in from the south. The red fox has already intruded the arctic region and caused a retreat of the southern limit of arctic fox distribution range. Coastal arctic foxes, which rely on the richer and temporally stable marine subsidies, will be less prone to climate-induced resource limitations. Indeed, arctic islands, becoming protected from southern species invasions as the extent of sea ice is decreasing, may become the last refuges for coastal populations of Arctic foxes.

Relative sensitivity of Arctic species to physically and chemically dispersed oil determined from three hydrocarbon measures of aquatic toxicity.

PubMed

Bejarano, Adriana C; Gardiner, William W; Barron, Mace G; Word, Jack Q

2017-09-15

The risks to Arctic species from oil releases is a global concern, but their sensitivity to chemically dispersed oil has not been assessed using a curated and standardized dataset from spiked declining tests. Species sensitivity to dispersed oil was determined by their position within species sensitivity distributions (SSDs) using three measures of hydrocarbon toxicity: total petroleum hydrocarbons (TPH), polycyclic aromatic hydrocarbon (PAHs), and naphthalenes. Comparisons of SSDs with Arctic/sub-Arctic versus non-Arctic species, and across SSDs of compositionally similar oils, showed that Arctic and non-Arctic species have comparable sensitivities even with the variability introduced by combining data across studies and oils. Regardless of hydrocarbon measure, hazard concentrations across SSDs were protective of sensitive Arctic species. While the sensitivities of Arctic species to oil exposures resemble those of commonly tested species, PAH-based toxicity data are needed for a greater species diversity including sensitive Arctic species. Copyright © 2017 Elsevier Ltd. All rights reserved.

Levels and trends of contaminants in humans of the Arctic.

PubMed

Gibson, Jennifer; Adlard, Bryan; Olafsdottir, Kristin; Sandanger, Torkjel Manning; Odland, Jon Øyvind

2016-01-01

The Arctic Monitoring and Assessment Programme (AMAP) is one of the six working groups established under the Arctic Council. AMAP is tasked with monitoring the levels of contaminants present in the Arctic environment and people as well as assessing their effects on a continuous basis, and reporting these results regularly. Most of the presented data have been collected over the last 20 years and are from all eight Arctic countries. Levels of contaminants appear to be declining in some of the monitored Arctic populations, but it is not consistent across the Arctic. Most Arctic populations continue to experience elevated levels of these contaminants compared to other populations monitored globally. There are certain contaminants, such as perfluorinated compounds and polybrominated diphenyl ethers, which are still increasing in Arctic populations. These contaminants require more investigation to find out the predominant and important sources of exposure, and whether they are being transported to the Arctic through long-range transport in the environment.

Levels and trends of contaminants in humans of the Arctic

PubMed Central

Gibson, Jennifer; Adlard, Bryan; Olafsdottir, Kristin; Sandanger, Torkjel Manning; Odland, Jon Øyvind

2016-01-01

The Arctic Monitoring and Assessment Programme (AMAP) is one of the six working groups established under the Arctic Council. AMAP is tasked with monitoring the levels of contaminants present in the Arctic environment and people as well as assessing their effects on a continuous basis, and reporting these results regularly. Most of the presented data have been collected over the last 20 years and are from all eight Arctic countries. Levels of contaminants appear to be declining in some of the monitored Arctic populations, but it is not consistent across the Arctic. Most Arctic populations continue to experience elevated levels of these contaminants compared to other populations monitored globally. There are certain contaminants, such as perfluorinated compounds and polybrominated diphenyl ethers, which are still increasing in Arctic populations. These contaminants require more investigation to find out the predominant and important sources of exposure, and whether they are being transported to the Arctic through long-range transport in the environment. PMID:27974136

Arctic potential - Could more structured view improve the understanding of Arctic business opportunities?

NASA Astrophysics Data System (ADS)

Hintsala, Henna; Niemelä, Sami; Tervonen, Pekka

2016-09-01

The increasing interest towards the Arctic has been witnessed during the past decades. However, the commonly shared definitions of the Arctic key concepts have not yet penetrated national and international arenas for political and economic decision making. The lack of jointly defined framework has made different analyses related to the Arctic quite limited considering the magnitude of economic potential embedded in Arctic. This paper is built on the key findings of two separate, yet connected projects carried out in the Oulu region, Finland. In this paper's approach, the Arctic context has been defined as a composition of three overlapping layers. The first layer is the phenomenological approach to define the Arctic region. The second layer is the strategy-level analysis to define different Arctic paths as well as a national level description of a roadmap to Arctic specialization. The third layer is the operationalization of the first two layers to define the Arctic business context and business opportunities. The studied case from Oulu region indicates that alternative futures for the Arctic competences and business activities are in resemblance with only two of the four identified strategic pathways. Introduction of other pathways to regional level actors as credible and attractive options would require additional, systematic efforts.

Sulfate Aerosol in the Arctic: Source Attribution and Radiative Forcing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Yang; Wang, Hailong; Smith, Steven J.

Source attributions of Arctic sulfate and its direct radiative effect for 2010–2014 are quantified in this study using the Community Earth System Model (CESM) equipped with an explicit sulfur source-tagging technique. Regions that have high emissions and/or are near/within the Arctic present relatively large contributions to Arctic sulfate burden, with the largest contribution from sources in East Asia (27%). East Asia and South Asia together have the largest contributions to Arctic sulfate concentrations at 9–12 km, whereas sources within or near the Arctic account largely below 2 km. For remote sources with strong emissions, their contributions to Arctic sulfate burdenmore » are primarily driven by meteorology, while contributions of sources within or near the Arctic are dominated by their emission strength. The sulfate direct radiative effect (DRE) is –0.080 W m-2 at the Arctic surface, offsetting the net warming effect from the combination of in-snow heating and DRE cooling from black carbon. East Asia, Arctic local and Russia/Belarus/Ukraine sources contribute –0.017, –0.016 and –0.014 W m-2, respectively, to Arctic sulfate DRE. A 20% reduction in anthropogenic SO2 emissions leads to a net increase of +0.013 W m-2 forcing at the Arctic surface. These results indicate that a joint reduction in BC emissions could prevent possible Arctic warming from future reductions in SO2 emissions. Sulfate DRE efficiency calculations suggest that short transport pathways together with meteorology favoring long sulfate lifetimes make certain sources more efficient in influencing the Arctic sulfate DRE.« less

Health aspects of Arctic exploration – Alaska’s medical history based on the research files of Dr. Robert Fortuine

PubMed Central

Murray, Kathleen

2013-01-01

Background Robert Fortuine provided basic medical care to Alaska Native people, chronicled the Health Aspects of Arctic Exploration and through a number of influential publications, was the first to thoroughly document and analyse Alaska’s Medical History. This overview of his published work will provide the reader with a detailed overview, so that they can begin to explore Dr. Fortuine’s many published works in more detail. Objective This review will explore Alaska’s Medical History and the Health Aspects of Arctic Exploration through the research files and the 10 most significant publications of Dr. Robert Fortuine. Design Review of Dr. Fortuine’s major works and the master bibliography has over 3,000 references and 81 subjects. The master bibliography is a merger of 55 separate bibliographies, which provides a wealth of bibliographic information. This paper will describe his 10 most significant publications, 2 of which began as a journal issue. Results Dr. Fortuine was a prolific writer throughout his career, publishing 134 articles and books. He wrote papers and books on Alaska’s medical history, tuberculosis and health care delivery from Russian–America through the Public Health Service efforts in the territory and then the State of Alaska. The master bibliography has over 3,000 references and 81 subjects. This list has a significant number of entries for tuberculosis with almost one-third of the entries including this heading. Others dwell on the history of “pre-contact” health, the history of Alaska Native health care, the history of the Alaska Department of Health, especially the tuberculosis programme, the role of the US Public Health Service and traditional medicine. He completely reviewed every Governors’ and the US Surgeon General’s reports in regard to Alaska content. This paper describes his 10 most significant publications. Conclusions Robert Fortuine’s published works offer a wealth of information and insight into Alaska’s Medical History and the Health Aspects of Arctic Exploration. As is probably true for many historians, he began small, creating a bibliography and adapting a talk before tackling his first full-length book. Readers who sample his many works will be enriched and enlightened. PMID:23967418

Acculturation and self-rated health among Arctic indigenous peoples: a population-based cross-sectional study.

PubMed

Eliassen, Bent-Martin; Braaten, Tonje; Melhus, Marita; Hansen, Ketil Lenert; Broderstad, Ann Ragnhild

2012-11-05

Acculturation is for indigenous peoples related to the process of colonisation over centuries as well as the on-going social transition experienced in the Arctic today. Changing living conditions and lifestyle affect health in numerous ways in Arctic indigenous populations. Self-rated health (SRH) is a relevant variable in primary health care and in general public health assessments and monitoring. Exploring the relationship between acculturation and SRH in indigenous populations having experienced great societal and cultural change is thus of great importance. The principal method in the Survey of Living Conditions in the Arctic (SLiCA) was standardised face-to-face interviews using a questionnaire. Very high overall participation rates of 83% were obtained in Greenland and Alaska, whilst a more conventional rate of 57% was achieved in Norway. Acculturation was conceptualised as certain traditional subsistence activities being of lesser importance for people's ethnic identity, and poorer spoken indigenous language ability (SILA). Acculturation was included in six separate gender- and country-specific ordinal logistic regressions to assess qualitative effects on SRH. Multivariable analyses showed that acculturation significantly predicted poorer SRH in Greenland. An increased subsistence score gave an OR of 2.32 (P<0.001) for reporting poorer SRH among Greenlandic men, while an increased score for Greenlandic women generated an OR of 1.71 (P=0.01). Poorer SILA generated an OR of 1.59 in men (p=0.03). In Alaska, no evidence of acculturation effects was detected among Iñupiaq men. Among Iñupiaq women, an increased subsistence score represented an increased odds of 73% (p=0.026) for reporting poorer SRH. No significant effects of acculturation on SRH were detected in Norway. This study shows that aggregate acculturation is a strong risk factor for poorer SRH among the Kalaallit of Greenland and female Iñupiat of Alaska, but our cross-sectional study design does not allow any conclusion with regard to causality. Limitations with regard to wording, categorisations, assumed cultural differences in the conceptualisation of SRH, and confounding effects of health care use, SES and discrimination, make it difficult to appropriately assess how strong this effect is though.

Ecosystem dynamics of the Pacific-influenced Northern Bering and Chukchi Seas in the Amerasian Arctic

NASA Astrophysics Data System (ADS)

Grebmeier, Jacqueline M.; Cooper, Lee W.; Feder, Howard M.; Sirenko, Boris I.

2006-10-01

The shallow continental shelves and slope of the Amerasian Arctic are strongly influenced by nutrient-rich Pacific waters advected over the shelves from the northern Bering Sea into the Arctic Ocean. These high-latitude shelf systems are highly productive both as the ice melts and during the open-water period. The duration and extent of seasonal sea ice, seawater temperature and water mass structure are critical controls on water column production, organic carbon cycling and pelagic-benthic coupling. Short food chains and shallow depths are characteristic of high productivity areas in this region, so changes in lower trophic levels can impact higher trophic organisms rapidly, including pelagic- and benthic-feeding marine mammals and seabirds. Subsistence harvesting of many of these animals is locally important for human consumption. The vulnerability of the ecosystem to environmental change is thought to be high, particularly as sea ice extent declines and seawater warms. In this review, we focus on ecosystem dynamics in the northern Bering and Chukchi Seas, with a more limited discussion of the adjoining Pacific-influenced eastern section of the East Siberian Sea and the western section of the Beaufort Sea. Both primary and secondary production are enhanced in specific regions that we discuss here, with the northern Bering and Chukchi Seas sustaining some of the highest water column production and benthic faunal soft-bottom biomass in the world ocean. In addition, these organic carbon-rich Pacific waters are periodically advected into low productivity regions of the nearshore northern Bering, Chukchi and Beaufort Seas off Alaska and sometimes into the East Siberian Sea, all of which have lower productivity on an annual basis. Thus, these near shore areas are intimately tied to nutrients and advected particulate organic carbon from the Pacific influenced Bering Shelf-Anadyr water. Given the short food chains and dependence of many apex predators on sea ice, recent reductions in sea ice in the Pacific-influenced sector of the Arctic have the potential to cause an ecosystem reorganization that may alter this benthic-oriented system to one more dominated by pelagic processes.

Geology and physiography of the continental margin north of Alaska and implications for the origin of the Canada Basin

USGS Publications Warehouse

Grantz, Arthur; Eittreim, Stephen L.; Whitney, O.T.

1979-01-01

The continental margin north of Alaska is of Atlantic type. It began to form probably in Early Jurassic time but possibly in middle Early Cretaceous time, when the oceanic Canada Basin of the Arctic Ocean is thought to have opened by rifting about a pole of rotation near the Mackenzie Delta. Offsets of the rift along two fracture zones are thought to have divided the Alaskan margin into three sectors of contrasting structure and stratigraphy. In the Barter Island sector on the east and the Chukchi sector on the west the rift was closer to the present northern Alaska mainland than in the Barrow sector, which lies between them. In the Barter Island and Chukchi sectors the continental shelf is underlain by prisms of clastic sedimentary rocks that are inferred to include thick sections of Jurassic and Neocomian (lower Lower Cretaceous) strata of southern provenance. In the intervening Barrow sector the shelf is underlain by relatively thin sections of Jurassic and Neocomian strata derived from northern sources that now lie beneath the outer continental shelf. The rifted continental margin is overlain by a prograded prism of Albian (upper Lower Cretaceous) to Tertiary clastic sedimentary rocks that comprises the continental terrace of the western Beaufort and northern Chukchi Seas. On the south the prism is bounded by Barrow arch, which is a hingeline between the northward-tilted basement surface beneath the continental shelf of the western Beaufort Sea and the southward-tilted Arctic Platform of northern Alaska. The Arctic platform is overlain by shelf clastic and carbonate strata of Mississippian to Cretaceous age, and by Jurassic and Cretaceous clastic strata of the Colville foredeep. Both the Arctic platform and Colville foredeep sequences extend from northern Alaska beneath the northern Chukchi Sea. At Herald fault zone in the central Chukchi Sea they are overthrust by more strongly deformed Cretaceous to Paleozoic sedimentary rocks of Herald arch, which trends northwest from Cape Lisburne. Hope basin, an extensional intracontinental sedimentary basin of Tertiary age, underlies the Chukchi Sea south of Herald arch.

Earnings Profiles of Department Heads: Comparing Cross-Sectional and Panel Models.

ERIC Educational Resources Information Center

Ragan, James F., Jr.; Rehman, Qazi Najeeb

1996-01-01

A cross-sectional study of 842 faculty who served as department heads between 1965-92 was compared with 170 in a panel study for whom earnings were estimated using a personal effects model. The average chair received a 12% wage premium for administrative service. Skill depreciation was most severe and wage growth most adversely affected in the…

System Control Facilities: Head-Ends and Central Processors. A Survey of Technical Requirements for Broadband Cable Teleservices; Volume Four.

ERIC Educational Resources Information Center

Smith, Ernest K.; And Others

The system control facilities in broadband communication systems are discussed in this report. These facilities consist of head-ends and central processors. The first section summarizes technical problems and needs, and the second offers a cursory overview of systems, along with an incidental mention of processors. Section 3 looks at the question…

21 CFR 184.1979a - Reduced lactose whey.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Action” under the heading “Fat,” or in section 16.199 (dry sample), entitled “Fat in Dried Milk (45...,” or in section 16.196 (dry sample), entitled “Ash—Official Final Action” under the heading “Dried Milk, Nonfat Dry Milk, and Malted Milk.” (iv) Lactose content, not more than 60 percent—as determined by the...

Fossil organic matter characteristics in permafrost deposits of the northeast Siberian Arctic

Treesearch

Lutz Schirrmeister; Guido Grosse; Sebastian Wetterich; Pier Paul Overduin; Jens Straub; Edward A.G. Schuur; Hans-Wolfgang Hubberton

2011-01-01

Permafrost deposits constitute a large organic carbon pool highly vulnerable to degradation and potential carbon release due to global warming. Permafrost sections along coastal and river bank exposures in NE Siberia were studied for organic matter (OM) characteristics and ice content. OM stored in Quaternary permafrost grew, accumulated, froze, partly decomposed, and...

36 CFR 13.1006 - Customary trade.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 1 2012-07-01 2012-07-01 false Customary trade. 13.1006 Section 13.1006 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and Preserve § 13.1006 Customary trade. In the Gates of the...

36 CFR 13.1006 - Customary trade.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 1 2013-07-01 2013-07-01 false Customary trade. 13.1006 Section 13.1006 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR NATIONAL PARK SYSTEM UNITS IN ALASKA Special Regulations-Gates of the Arctic National Park and Preserve § 13.1006 Customary trade. In the Gates of the...

NATO’s Future Role in the Arctic

DTIC Science & Technology

2016-05-01

iv Global Climate Change and Arctic Geopolitics............................. Error! Bookmark not defined. Russian Claims to the Arctic...13 1 Global Climate Change and Arctic Geopolitics Global climate change has a profound...explaining the effect of climate change in the Arctic and the consequences on regional security. Issues regarding territorial sovereignty will be

Explore Arctic Health.

PubMed

Lebow, Mahria

2014-04-01

The Arctic Health web site is a portal to Arctic-specific, health related content. The site provides expertly organized and annotated resources pertinent to northern peoples and places, including health information, research publications and environmental information. This site also features the Arctic Health Publications Database, which indexes an array of Arctic-related resources.

PAST Gateways (Palaeo-Arctic Spatial and Temporal Gateways): Introduction and overview

NASA Astrophysics Data System (ADS)

Ó Cofaigh, Colm; Briner, Jason P.; Kirchner, Nina; Lucchi, Renata G.; Meyer, Hanno; Kaufman, Darrell S.

2016-09-01

This special issue relates to the Second International Conference of the PAST Gateways (Palaeo-Arctic Spatial and Temporal Gateways) network which was held in Trieste, Italy in 2014. Twenty five papers are included and they address topics under four main themes: (1) The growth and decay of Arctic ice sheets; (2) Arctic sea ice and palaeoceanography; (3) Terrestrial Arctic environments and permafrost change; and (4) Holocene Arctic environmental change. Geographically the focus is circum-Arctic; the special issue includes detailed regional studies from Greenland, Scandinavia, Russia, and Arctic North America and the adjoining seas, as well as a series of synthesis-type, review papers on Fennoscandian Ice Sheet deglaciation and Holocene Arctic palaeo-climate change. The methodologies employed are diverse and include marine sediment core and geophysical investigations, terrestrial glacial geology and geomorphology, isotopic analysis of ground ice, palaeo-ecological analysis of lacustrine and terrestrial sedimentary archives, geochronology and numerical ice sheet modeling.

Arctic Rabies – A Review

PubMed Central

Mørk, Torill; Prestrud, Pål

2004-01-01

Rabies seems to persist throughout most arctic regions, and the northern parts of Norway, Sweden and Finland, is the only part of the Arctic where rabies has not been diagnosed in recent time. The arctic fox is the main host, and the same arctic virus variant seems to infect the arctic fox throughout the range of this species. The epidemiology of rabies seems to have certain common characteristics in arctic regions, but main questions such as the maintenance and spread of the disease remains largely unknown. The virus has spread and initiated new epidemics also in other species such as the red fox and the racoon dog. Large land areas and cold climate complicate the control of the disease, but experimental oral vaccination of arctic foxes has been successful. This article summarises the current knowledge and the typical characteristics of arctic rabies including its distribution and epidemiology. PMID:15535081

Study of Environmental Arctic Change (SEARCH): Scientific Understanding of Arctic Environmental Change to Help Society Understand and Respond to a Rapidly Changing Arctic.

NASA Astrophysics Data System (ADS)

Wiggins, H. V.; Myers, B.

2015-12-01

The Study of Environmental Arctic Change (SEARCH) is a U.S. program with a mission to provide a foundation of Arctic change science through collaboration with the research community, funding agencies, and other stakeholders. To achieve this mission, SEARCH: Generates and synthesizes research findings and promotes Arctic science and scientific discovery across disciplines and among agencies. Identifies emerging issues in Arctic environmental change. Provides scientific information to Arctic stakeholders, policy-makers, and the public to help them understand and respond to arctic environmental change. Facilitates research activities across local-to-global scales, with an emphasis on addressing needs of decision-makers. Collaborates with national and international science programs integral to SEARCH goals. This poster presentation will present SEARCH activities and plans, highlighting those focused on providing information for decision-makers. http://www.arcus.org/search

Growing Land-Sea Temperature Contrast and the Intensification of Arctic Cyclones

NASA Astrophysics Data System (ADS)

Day, Jonathan J.; Hodges, Kevin I.

2018-04-01

Cyclones play an important role in the coupled dynamics of the Arctic climate system on a range of time scales. Modeling studies suggest that storminess will increase in Arctic summer due to enhanced land-sea thermal contrast along the Arctic coastline, in a region known as the Arctic Frontal Zone (AFZ). However, the climate models used in these studies are poor at reproducing the present-day Arctic summer cyclone climatology and so their projections of Arctic cyclones and related quantities, such as sea ice, may not be reliable. In this study we perform composite analysis of Arctic cyclone statistics using AFZ variability as an analog for climate change. High AFZ years are characterized both by increased cyclone frequency and dynamical intensity, compared to low years. Importantly, the size of the response in this analog suggests that General Circulation Models may underestimate the response of Arctic cyclones to climate change, given a similar change in baroclinicity.

Climate related trends and meteorological conditions in European Arctic region - Porsanger fjord, Norway

NASA Astrophysics Data System (ADS)

Cieszyńska, Agata; Stramska, Małgorzata

2017-04-01

Climate change has significant effect on the Arctic environment, where global trends are amplified. In this study, we have focused on the Porsanger fjord, located in European Arctic in the coastal region of the Barents Sea. We have analyzed climate related trends and meteorological condititions in the area of interest. Meteorological data included wind speed and direction, air temperature (AT) and precipitation from Era-Interim reanalysis (1986-2015) and local observations (1996-2015) from Lakselv (L, fjord's head area) and Honningsvaag (H - fjord's exit area). Our results confirm that this region is undergoing climate change related warming, which is indicated by rising air temperatures. Based on long-term reanalysis data, estimated trends for air temperature (AT) in Porsanger fjord are: 0.0536 °C year-1 at fjord's exit and 0.0428 °C year-1 at fjord's head. The results show that climate change does not seem to have a significant effect on long-term changes of wind speed and precipitation in the Porsanger fjord. Statistical analysis underlined significant spatial variability of meteorological conditions inside the fjord. For example, there are large differences in the annual cycle of AT with monthly mean January and July values of -8.4 and 12.6 °C in L and -2.5 and 10.1 °C in H. Dominant wind directions in Lakselv are S and SSE, while in Honningsvaag S and SSW directions prevail. Strong wind events (above 12 m s-1) are more frequent in H than in L. Annual cycle is characterized by stronger winds in winter and seasonality of wind direction. Precipitation for a given location can change by about 50% between years and varies spatially. Synoptic scale and within day variability are extremely intense in the area of interest. Air temperature and wind speed and direction can change dramatically in hours. In addition, regular patterns of the daily cycle of AT have different intensity in L and H. It is interesting to note that in spring/summer season, the daily cycle of air temperature difference between L and H is also strong and has an influence on winds. Estimates of land-originated water discharge (derived from the E-Hype model) show seasonal cycle with the maximum runoff in late spring/early summer. The main features of climate related trends and the effects of oceanic/continental interactions, presented in this study, shape the environment of the fjord and are possible to be analogous in other Norwegian fjords with comparable geographical location. This work was funded by the Norway Grants (NCBR contract No. 201985, project NORDFLUX). Partial support for MS comes from the Institute of Oceanology (IO PAN).

Observational and Modeling Studies of Mixed-Phase Arctic Stratus: Results From M-PACE and Future Investigations as a Part of SEARCH

NASA Astrophysics Data System (ADS)

de Boer, G.; Eloranta, E. W.; Tripoli, G. J.; Hashino, T.

2005-12-01

A combination of unique observational and modeling tools is being utilized at the University of Wisconsin-Madison to investigate mixed-phase Arctic stratus formation and evolution, and aerosol influence on these processes. The combination of detailed measurements and advanced simulation techniques provides increased insight into processes governing the existence of these cloud structures. Simulations are completed using the Univ. of Wisconsin Non-Hydrostatic Modeling System (UW-NMS). The NMS is fully scalable, and currently being updated to include the Spectral Habitat Ice Prediction System (SHIPS). This new form of microphysics is built on interacting predictive systems for ice and liquid hydrometeors, and aerosols. The hydrometeor size spectra evolve through a modified spectral approach. No a-priori assumptions are made about ice characteristics such as habit, size and density. Instead, they evolve freely. The Univ. of Wisconsin Arctic High-Spectral Resolution Lidar (UW-AHSRL) was designed for long-term unattended Arctic operation and features unique measurement capabilities. Utilizing a molecular reference channel, the AHSRL provides absolutely calibrated measurements of aerosol backscatter cross-section, polarization, and optical depth, in addition to traditional lidar backscatter profiles. Algorithms utilizing AHSRL data in conjunction with millimeter radar data determine microphysical properties such as particle equivalent radius, and potentially liquid and ice water content. The AHSRL was deployed to Barrow, AK as part of M-PACE and is currently located in Eureka, Canada for the SEARCH campaign. Both of these locations host a NOAA Millimeter Wave Cloud Radar, aiding in the implementation of the above-mentioned algorithms. The AHSRL, combined with additional cloud and aerosol measurement instrumentation at these Arctic locations, provides an expansive source of mixed-phase cloud data to be used individually and as validation for UW-NMS simulations. We will outline current work being completed at the Univ. of Wisconsin, as well as present results from M-PACE simulations and data analysis and preliminary SEARCH measurements.

Retractable tool bit having latch type catch mechanism

NASA Technical Reports Server (NTRS)

Voellmer, George (Inventor)

1993-01-01

A retractable tool bit assembly for a tool such as an allen key is presented. The assembly includes one or more spring loaded nestable or telescoping tubular sections together with a catch mechanism for capturing and holding the tool in its retracted position. The catch mechanism consists of a latch mechanism located in a base section and which engages a conically shaped tool head located at the inner end of the tool. The tool head adjoins an eccentric oval type neck portion which extends to a rear lip of the tool head. The latch mechanism releases when the ovular neck portion rotates about the catch members upon actuation of a rotary tool drive motor. When released, all the telescoping sections and the tool extends fully outward to a use position.

A New Method for Carbon Isotopic Analysis of Nanogram Quantities of Carbon from Dissolved Chitin Using A Spooling-wire Microcombustion Interface

NASA Astrophysics Data System (ADS)

Zhao, Y.; Nelson, D. M.; Clegg, B. F.; Berry, J.; Hu, F.

2016-12-01

δ13C analysis of specific taxa or compounds is commonly used for investigating past environmental change, including methane dynamics in lakes. However, most analytical methods require large sample sizes, prohibiting routine analysis of fossils of individual taxa found in sediment deposits. For example, 10-100 individual head capsules of fossil midges are required for δ13C analysis using an elemental analyzer (EA) interfaced with an isotope-ratio mass spectrometer (IRMS). Here we present a new method that uses a spooling-wire microcombustion (SWiM) device interfaced with an IRMS for measuring δ13C values of carbon dissolved from individual head capsules of chitinous aquatic zooplankton. We extracted chitin (a major biochemical component of insect exoskeleton) from modern midge material obtained from four commercial suppliers. We first assessed the effects of sample treatments on carbon yields and δ13C values of dissolved chitin by varying the concentration of HCl used for dissolution, the duration of reaction in HCl, and the temperature of dissolution. We then investigated potential fractionation of carbon isotopes associated with chitin dissolution, by comparing δ13C values of dissolved chitin obtained via SWiM-IRMS with those from untreated head capsules obtained via a EA-IRMS. The average δ13C values of untreated head capsules varied between -25.1 and -30.1‰. Higher acid concentrations and temperatures, as well as longer reaction times, increased dissolution of carbon from the head capsules and the precision of δ13C values. For example, carbon yields from reaction of head capsules with 6N HCl at 25°C increased from 1 to 3 Vs as reaction times increased from 1 to 24 hours. Acid concentration and reaction time had the greatest influence on carbon yields and isotopic precision. The δ13C values of dissolved chitin mirrored the δ13C values of untreated head capsules with minimal offset of absolute values, which suggests no systematic fractionation associated with dissolution. Overall, these results indicate that carbon isotopic analysis of dissolved chitin using the SWiM-IRMS system offers a reliable new method to determine taxa-specific δ13C values for chitinous aquatic zooplankton. In ongoing work, we are applying this tool to reconstruct past methane dynamics in Arctic lakes during the Holocene.

Next generation in-situ optical Raman sensor for seawater investigations

NASA Astrophysics Data System (ADS)

Kolomijeca, A.; Kwon, Y.-H.; Ahmad, H.; Kronfeldt, H.-D.

2012-04-01

We introduce the next generation of optical sensors based on a combination of surfaced enhanced Raman scattering (SERS) and shifted excitation Raman difference spectroscopy (SERDS) suited for investigations of tiny concentrations of pollutions in the seawater. First field measurements were carried out in the Arctic area which is of global interest since it is more affected by global warming caused climatic changes than any other areas of our planet and it is a recipient for many toxic organic pollutants. A significant long-range atmospheric transport of pollutants to Svalbard is mainly originated from industrialized countries in Europe and North America during the last decades. Therefore, the main interest is to investigate the Arctic water column and also the sediments. Standard chemical methods for water/sediment analysis are extremely accurate but complex and time-consuming. The primary objective of our study was to develop a fast response in-situ optical sensor for easy to use and quick analysis. The system comprises several components: a handheld measurement head containing a 671 nm microsystem diode laser and the Raman optical bench, a laser driver electronics board, a custom-designed miniature spectrometer with an optical resolution of 8 cm-1 and a netbook to control the spectrometer as well as for data evaluation. We introduced for the first time the portable Raman sensor system on an Artic sea-trial during a three week cruise on board of the James Clark Ross research vessel in August 2011. Numerous Raman and SERS measurements followed by SERDS evaluations were taken around locations 78° N and 9° E. Different SERS substrates developed for SERS measurements in sea-water were tested for their capability to detect different substances (PAHs) in the water down to very small (nmol/l) concentrations. Stability tests of the substrates were carried out also for the applicability of our system e.g. on a mooring. Details of the in-situ Raman sensor were presented together with the measurements results from the Arctic area.

45 CFR 1306.32 - Center-based program option.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Center-based program option. 1306.32 Section 1306... START PROGRAM HEAD START STAFFING REQUIREMENTS AND PROGRAM OPTIONS Head Start Program Options § 1306.32 Center-based program option. (a) Class size. (1) Head Start classes must be staffed by a teacher and an...

45 CFR 2554.9 - Who is the Corporation's authority head?

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Who is the Corporation's authority head? 2554.9 Section 2554.9 Public Welfare Regulations Relating to Public Welfare (Continued) CORPORATION FOR NATIONAL... Complaint § 2554.9 Who is the Corporation's authority head? The Corporation's “authority head” is the Chief...

45 CFR 79.39 - Appeal to authority head.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Appeal to authority head. 79.39 Section 79.39 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL ADMINISTRATION PROGRAM FRAUD CIVIL REMEDIES § 79.39 Appeal to authority head. (a) Any defendant who has filed a timely answer and who is...

6 CFR 13.39 - Appeal to Authority Head.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 6 Domestic Security 1 2010-01-01 2010-01-01 false Appeal to Authority Head. 13.39 Section 13.39 Domestic Security DEPARTMENT OF HOMELAND SECURITY, OFFICE OF THE SECRETARY PROGRAM FRAUD CIVIL REMEDIES § 13.39 Appeal to Authority Head. (a) Any Defendant who has served a timely answer and who is...

45 CFR 1305.5 - Recruitment of children.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 4 2014-10-01 2014-10-01 false Recruitment of children. 1305.5 Section 1305.5..., DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START... of children. (a) In order to reach those most in need of Head Start services, each Head Start grantee...

45 CFR 1305.5 - Recruitment of children.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 4 2013-10-01 2013-10-01 false Recruitment of children. 1305.5 Section 1305.5..., DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START... of children. (a) In order to reach those most in need of Head Start services, each Head Start grantee...

45 CFR 1305.5 - Recruitment of children.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 4 2012-10-01 2012-10-01 false Recruitment of children. 1305.5 Section 1305.5..., DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START... of children. (a) In order to reach those most in need of Head Start services, each Head Start grantee...

45 CFR 1305.5 - Recruitment of children.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 4 2011-10-01 2011-10-01 false Recruitment of children. 1305.5 Section 1305.5..., DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START... of children. (a) In order to reach those most in need of Head Start services, each Head Start grantee...

45 CFR 1305.5 - Recruitment of children.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 4 2010-10-01 2010-10-01 false Recruitment of children. 1305.5 Section 1305.5..., DEPARTMENT OF HEALTH AND HUMAN SERVICES THE ADMINISTRATION FOR CHILDREN, YOUTH AND FAMILIES, HEAD START... of children. (a) In order to reach those most in need of Head Start services, each Head Start grantee...

33 CFR 100.105 - Head of the Connecticut Regatta.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Head of the Connecticut Regatta. 100.105 Section 100.105 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.105 Head of the Connecticut Regatta...

Love Your Resource Neighbor: A Guide to Resource Collaboration in Head Start.

ERIC Educational Resources Information Center

Chapel Hill Training-Outreach Project, NC.

A product of a May 1976 conference on Head Start's collaboration with other agencies, the guide presents information on providing services to preschool handicapped children and their families. The first section discusses the development of the Kentucky State Advisory Council to Head Start's Program for Exceptional Children. Reviewed in the second…

49 CFR 236.565 - Provision made for preventing operation of pneumatic brake-applying apparatus by double-heading...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Provision made for preventing operation of pneumatic brake-applying apparatus by double-heading cock; requirement. 236.565 Section 236.565... preventing operation of pneumatic brake-applying apparatus by double-heading cock; requirement. Where...

49 CFR 236.565 - Provision made for preventing operation of pneumatic brake-applying apparatus by double-heading...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Provision made for preventing operation of pneumatic brake-applying apparatus by double-heading cock; requirement. 236.565 Section 236.565... preventing operation of pneumatic brake-applying apparatus by double-heading cock; requirement. Where...

31 CFR 7.3 - Responsibilities of heads of offices.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Responsibilities of heads of offices. 7.3 Section 7.3 Money and Finance: Treasury Office of the Secretary of the Treasury EMPLOYEE... and work assignments. (c) Heads of bureaus or offices, after such examination and investigation as may...

Potential for an Arctic-breeding migratory bird to adjust spring migration phenology to Arctic amplification.

PubMed

Lameris, Thomas K; Scholten, Ilse; Bauer, Silke; Cobben, Marleen M P; Ens, Bruno J; Nolet, Bart A

2017-10-01

Arctic amplification, the accelerated climate warming in the polar regions, is causing a more rapid advancement of the onset of spring in the Arctic than in temperate regions. Consequently, the arrival of many migratory birds in the Arctic is thought to become increasingly mismatched with the onset of local spring, consequently reducing individual fitness and potentially even population levels. We used a dynamic state variable model to study whether Arctic long-distance migrants can advance their migratory schedules under climate warming scenarios which include Arctic amplification, and whether such an advancement is constrained by fuel accumulation or the ability to anticipate climatic changes. Our model predicts that barnacle geese Branta leucopsis suffer from considerably reduced reproductive success with increasing Arctic amplification through mistimed arrival, when they cannot anticipate a more rapid progress of Arctic spring from their wintering grounds. When geese are able to anticipate a more rapid progress of Arctic spring, they are predicted to advance their spring arrival under Arctic amplification up to 44 days without any reproductive costs in terms of optimal condition or timing of breeding. Negative effects of mistimed arrival on reproduction are predicted to be somewhat mitigated by increasing summer length under warming in the Arctic, as late arriving geese can still breed successfully. We conclude that adaptation to Arctic amplification may rather be constrained by the (un)predictability of changes in the Arctic spring than by the time available for fuel accumulation. Social migrants like geese tend to have a high behavioural plasticity regarding stopover site choice and migration schedule, giving them the potential to adapt to future climate changes on their flyway. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Climate Change, Globalization and Geopolitics in the New Maritime Arctic

NASA Astrophysics Data System (ADS)

Brigham, L. W.

2011-12-01

Early in the 21st century a confluence of climate change, globalization and geopolitics is shaping the future of the maritime Arctic. This nexus is also fostering greater linkage of the Arctic to the rest of the planet. Arctic sea ice is undergoing a historic transformation of thinning, extent reduction in all seasons, and reduction in the area of multiyear ice in the central Arctic Ocean. Global Climate Model simulations of Arctic sea ice indicate multiyear ice could disappear by 2030 for a short period of time each summer. These physical changes invite greater marine access, longer seasons of navigation, and potential, summer trans-Arctic voyages. As a result, enhanced marine safety, environmental protection, and maritime security measures are under development. Coupled with climate change as a key driver of regional change is the current and future integration of the Arctic's natural wealth with global markets (oil, gas and hard minerals). Abundant freshwater in the Arctic could also be a future commodity of value. Recent events such as drilling for hydrocarbons off Greenland's west coast and the summer marine transport of natural resources from the Russian Arctic to China across the top of Eurasia are indicators of greater global economic ties to the Arctic. Plausible Arctic futures indicate continued integration with global issues and increased complexity of a range of regional economic, security and environmental challenges.

Sensitivity of Arctic carbon in a changing climate

Treesearch

A. David McGuire; Henry P. Huntington; Simon Wilson

2009-01-01

The Arctic has been warming rapidly in the past few decades. A key question is how that warming will affect the cycling of carbon (C) in the Arctic system. At present, the Arctic is a global sink for C. If that changes and the Arctic becomes a carbon source, global climate warming may speed up.

THE US MERCURY EMISSION INVENTORY FOR THE ARCTIC COUNCIL ACTION PLAN

EPA Science Inventory

The Arctic Council, having agreed to act to reduce exposures to a number of priority pollutants in the Arctic region, has initiated a mercury project via the Arctic Council Action Plan (ACAP). The project is led by the Danish EPA with a Steering Group from all eight Arctic count...

THE US MERCURY EMISSION INVENTORY FOR THE ARCTIC COUNCIL ACTION PLAN

EPA Science Inventory

The Arctic Council, having agreed to act to reduce exposures to a number of priority pollutants in the Arctic region, has initiated a mercury project via the Arctic Council Plan (ACAP). The project is being led by the Danish EPA with a Steering Group from all eight Arctic coun...

77 FR 31677 - Request for Public Comment on Interagency Arctic Research Policy Committee (IARPC) Arctic...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-29

... OFFICE OF SCIENCE AND TECHNOLOGY POLICY Request for Public Comment on Interagency Arctic Research Policy Committee (IARPC) Arctic Research Plan: FY2013-2017 May 22, 2012. ACTION: Request for public comment. SUMMARY: The Arctic Research and Policy Act of 1984 (ARPA), Public Law 98-373, established the...

76 FR 61074 - Reports and Updates on Arctic Research Programs and Projects; Meetings

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-03

... UNITED STATES ARCTIC RESEARCH COMMISSION Reports and Updates on Arctic Research Programs and Projects; Meetings Notice is hereby given that the US Arctic Research Commission will hold its 96th meeting... about topics of interest related to research activities in the Arctic. 96th Meeting Schedule: Wed., Oct...

Children and Youth of the Arctic: A Critical Challenge of Sustainable Development.

ERIC Educational Resources Information Center

Simon, Mary

1998-01-01

Argues for a children and youth agenda as part of the Arctic Council's overall agenda, to include profiling the health of Arctic children; assessing health and developmental impacts of pollution and environmental threats on Arctic children; developing sustainable employment opportunities for Arctic youth; and expanding distance education, with a…

Ice-Free Arctic Ocean?

ERIC Educational Resources Information Center

Science Teacher, 2005

2005-01-01

The current warming trends in the Arctic may shove the Arctic system into a seasonally ice-free state not seen for more than one million years, according to a new report. The melting is accelerating, and researchers were unable to identify any natural processes that might slow the deicing of the Arctic. "What really makes the Arctic different…

Seasonal Clear-Sky Flux and Cloud Radiative Effect Anomalies in the Arctic Atmospheric Column Associated with the Arctic Oscillation and Arctic Dipole

NASA Technical Reports Server (NTRS)

Hegyi, Bradley M.; Taylor, Patrick C.

2017-01-01

The impact of the Arctic Oscillation (AO) and Arctic Dipole (AD) on the radiative flux into the Arctic mean atmospheric column is quantified. 3-month-averaged AO and AD indices are regressed with corresponding surface and top-of-atmosphere (TOA) fluxes from the CERES-SFC and CERES-TOA EBAF datasets over the period 2000-2014. An increase in clear-sky fluxes into the Arctic mean atmospheric column during fall is the largest net flux anomaly associated with AO, primarily driven by a positive net longwave flux anomaly (i.e. increase of net flux into the atmospheric column) at the surface. A decrease in the Arctic mean atmospheric column cloud radiative effect during winter and spring is the largest flux anomaly associated with AD, primarily driven by a change in the longwave cloud radiative effect at the surface. These prominent responses to AO and AD are widely distributed across the ice-covered Arctic, suggesting that the physical process or processes that bring about the flux change associated with AO and AD are distributed throughout the Arctic.

Arctic Research Plan: FY2017-2021

USGS Publications Warehouse

Starkweather, Sandy; Jeffries, Martin O; Stephenson, Simon; Anderson, Rebecca D.; Jones, Benjamin M.; Loehman, Rachel A.; von Biela, Vanessa R.

2016-01-01

The United States is an Arctic nation—Americans depend on the Arctic for biodiversity and climate regulation and for natural resources. America’s Arctic—Alaska—is at the forefront of rapid climate, environmental, and socio-economic changes that are testing the resilience and sustainability of communities and ecosystems. Research to increase fundamental understanding of these changes is needed to inform sound, science-based decision- and policy-making and to develop appropriate solutions for Alaska and the Arctic region as a whole. Created by an Act of Congress in 1984, and since 2010 a subcommittee of the National Science and Technology Council (NSTC) in the Executive Office of the President, the Interagency Arctic Research Policy Committee (IARPC) plays a critical role in advancing scientific knowledge and understanding of the changing Arctic and its impacts far beyond the boundaries of the Arctic. Comprising 14 Federal agencies, offices, and departments, IARPC is responsible for the implementation of a 5-year Arctic Research Plan in consultation with the U.S. Arctic Research Commission, the Governor of the State of Alaska, residents of the Arctic, the private sector, and public interest groups.

Coordinating for Arctic Conservation: Implementing Integrated Arctic Biodiversity Monitoring, Data Management and Reporting

NASA Astrophysics Data System (ADS)

Gill, M.; Svoboda, M.

2012-12-01

Arctic ecosystems and the biodiversity they support are experiencing growing pressure from various stressors (e.g. development, climate change, contaminants, etc.) while established research and monitoring programs remain largely uncoordinated, lacking the ability to effectively monitor, understand and report on biodiversity trends at the circumpolar scale. The maintenance of healthy arctic ecosystems is a global imperative as the Arctic plays a critical role in the Earth's physical, chemical and biological balance. A coordinated and comprehensive effort for monitoring arctic ecosystems is needed to facilitate effective and timely conservation and adaptation actions. The Arctic's size and complexity represents a significant challenge towards detecting and attributing important biodiversity trends. This demands a scaled, pan-arctic, ecosystem-based approach that not only identifies trends in biodiversity, but also identifies underlying causes. It is critical that this information be made available to generate effective strategies for adapting to changes now taking place in the Arctic—a process that ultimately depends on rigorous, integrated, and efficient monitoring programs that have the power to detect change within a "management" time frame. To meet these challenges and in response to the Arctic Climate Impact Assessment's recommendation to expand and enhance arctic biodiversity monitoring, the Conservation of Arctic Flora and Fauna (CAFF) Working Group of the Arctic Council launched the Circumpolar Biodiversity Monitoring Program (CBMP). The CBMP is led by Environment Canada on behalf of Canada and the Arctic Council. The CBMP is working with over 60 global partners to expand, integrate and enhance existing arctic biodiversity research and monitoring efforts to facilitate more rapid detection, communication and response to significant trends and pressures. Towards this end, the CBMP has established three Expert Monitoring Groups representing major Arctic themes (Marine, Freshwater, and Terrestrial). Each group, representing a diversity of disciplines, is tasked with developing and implementing pan-arctic integrated biodiversity monitoring plans for the Arctic's ecosystems. To facilitate effective reporting and data management, the CBMP is developing a suite of indices and indicators and a web-based data portal that will be used to report on the current state of arctic biodiversity at various scales and levels of detail to suit a wide range of audiences (e.g. local Arctic communities, regional and national governments and the Convention on Biological Diversity). The current and planned CBMP biodiversity monitoring underpins these indicators and indices. The presentation will highlight the CBMP approach and provide some examples of how integrated monitoring, data management and reporting are leading to more informed decision-making.

The Sea Ice for Walrus Outlook: A collaboration between scientific and Indigenous communities to support safety and food security in a changing Arctic

NASA Astrophysics Data System (ADS)

Sheffield Guy, L.; Wiggins, H. V.; Schreck, M. B.; Metcalf, V. K.

2017-12-01

The Sea Ice for Walrus Outlook (SIWO) provides Alaskan Native subsistence walrus hunters and Bering Strait coastal communities with weekly reports on spring sea ice and weather conditions to promote hunter safety, food security, and preservation of cultural heritage. These reports integrate scientific and Indigenous knowledge into a co-produced tool that is used by both local and scientific communities. SIWO is a team effort led by the Arctic Research Consortium of the U.S. (ARCUS, with funding from NSF Arctic Sciences Section), with the Eskimo Walrus Commission, National Weather Service - Alaska Sea Ice Program, University of Alaska Fairbanks - International Arctic Research Center, and local observers. For each weekly outlook, the National Weather Service provides location-specific weather and sea ice forecasts and regional satellite imagery. Local observations of sea ice, weather, and hunting conditions are provided by observers from five Alaskan communities in the Bering Strait region: Wales, Shishmaref, Nome, Gambell, and Savoonga. These observations typically include a written description of conditions accompanied by photographs of sea ice or subsistence activities. Outlooks are easily accessible and provide a platform for sharing of knowledge among hunters in neighboring communities. The opportunity to contribute is open, and Indigenous language and terms are encouraged. These observations from local hunters and community members also provide a valuable tool for validation of weather forecasts, satellite products, and other information for scientists. This presentation will discuss the process, products, and mutually beneficial outcomes of the Sea Ice for Walrus Outlook.

GLORIA observations of de-/nitrification during the Arctic winter 2015/16 POLSTRACC campaign

NASA Astrophysics Data System (ADS)

Braun, Marleen; Woiwode, Wolfgang; Höpfner, Michael; Johansson, Sören; Friedl-Vallon, Felix; Oelhaf, Hermann; Preusse, Peter; Ungermann, Jörn; Grooß, Jens-Uwe; Jurkat, Tina; Khosrawi, Farahnaz; Kirner, Ole; Marsing, Andreas; Sinnhuber, Björn-Martin; Voigt, Christiane; Ziereis, Helmut; Orphal, Johannes

2017-04-01

Denitrification, the condensation and sedimentation of HNO3-containing particles in the winter stratosphere at high latitudes, is an important process affecting the deactivation of ozone-depleting halogen species. It modulates the vertical partitioning of chemically active NOy and the vertical redistribution of HNO3 can affect low stratospheric altitudes under sufficiently cold conditions. The capability of associated nitrification to disturb the NOy budget of the climate-relevant lowermost stratosphere (LMS) has hardly been investigated in detail and represents a challenge for model simulations. The Arctic winter 2015/16 was characterized by exceptionally cold stratospheric temperatures and widespread polar stratospheric clouds (PSCs) that were observed from mid-December 2015 until the end of February 2016 down to the LMS. Observations by the GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) spectrometer during the POLSTRACC (Polar Stratosphere in a Changing Climate) aircraft mission allow us to study the development of nitrification of the Arctic LMS during and after the 2015/16 PSC period with high vertical resolution. The vertical cross-sections of HNO3 distribution along the HALO (High Altitude and LOng range research aircraft) flight tracks derived from GLORIA observations show the result of significant vertical redistribution of NOy with strong nitrification of up to 6 ppbv in the LMS. We compare the results of the GLORIA observations with simulations by the state-of-the-art chemical-transport model CLaMS and the climate-chemistry model EMAC and discuss the capability of these models to reproduce nitrification of the Arctic LMS.

Along-slope variability of barotropic transport in the Nordic Seas: Simplified dynamics tested against observations

NASA Astrophysics Data System (ADS)

Aaboe, S.; NøSt, O. A.; Hansen, E.

2009-03-01

The present study combines simple geostrophic considerations and observational data to examine the along-slope evolution of the barotropic transport following the continental slope in the Nordic Seas and Arctic Ocean. Following geostrophic theory, the transport evolution is calculated from bottom densities in five different transects within the Nordic Seas. This theoretically predicted transport evolution is compared with transports estimated directly from velocity measurements. Between the Faroe-Shetland Channel and the Svinøy section off southern Norway, across the Fram Strait (below 800 m), and between the Fram Strait and the Greenland Sea the agreement is generally good between geostrophic theory and observations. This indicates that many aspects of the barotropic flow in these regions are captured by geostrophic dynamics. Between the eastern and western Fram Strait above 800 m and between Svinøy and the eastern Fram Strait the observed flow fields differ to a large extent from the flow field predicted by geostrophic dynamics, indicating that ageostrophic dynamics play a more important role in these regions. The barotropic transport differences between the eastern and western Fram Strait contain information about the barotropic transport evolution along the entire Arctic continental slope. The good agreement between observations and theory across the strait (below 800 m) therefore indicates that the flow along the deeper part of the Arctic continental slope is well described by geostrophic dynamics. According to our results, the noticeably more baroclinic nature of the flow in the western Fram Strait, compared with the eastern strait, can then be ascribed to water mass modifications along the Arctic continental slope.

Beyond Thin Ice: Co-Communicating the Many Arctics

NASA Astrophysics Data System (ADS)

Druckenmiller, M. L.; Francis, J. A.; Huntington, H.

2015-12-01

Science communication, typically defined as informing non-expert communities of societally relevant science, is persuaded by the magnitude and pace of scientific discoveries, as well as the urgency of societal issues wherein science may inform decisions. Perhaps nowhere is the connection between these facets stronger than in the marine and coastal Arctic where environmental change is driving advancements in our understanding of natural and socio-ecological systems while paving the way for a new assortment of arctic stakeholders, who generally lack adequate operational knowledge. As such, the Arctic provides opportunity to advance the role of science communication into a collaborative process of engagement and co-communication. To date, the communication of arctic change falls within four primary genres, each with particular audiences in mind. The New Arctic communicates an arctic of new stakeholders scampering to take advantage of unprecedented access. The Global Arctic conveys the Arctic's importance to the rest of the world, primarily as a regulator of lower-latitude climate and weather. The Intra-connected Arctic emphasizes the increasing awareness of the interplay between system components, such as between sea ice loss and marine food webs. The Transforming Arctic communicates the region's trajectory relative to the historical Arctic, acknowledging the impacts on indigenous peoples. The broad societal consensus on climate change in the Arctic as compared to other regions in the world underscores the opportunity for co-communication. Seizing this opportunity requires the science community's engagement with stakeholders and indigenous peoples to construct environmental change narratives that are meaningful to climate responses relative to non-ecological priorities (e.g., infrastructure, food availability, employment, or language). Co-communication fosters opportunities for new methods of and audiences for communication, the co-production of new interdisciplinary knowledge and cross-epistemological perspectives, and direct feedback to the science community regarding the societal implications of future research. Currently, the Study for Environmental Arctic Change (SEARCH) is developing this necessary cadre of co-communicators of marine and coastal arctic change.

The Arctic Research Consortium of the United States (ARCUS)

NASA Astrophysics Data System (ADS)

Wiggins, H. V.; Warnick, W. K.

2008-12-01

The Arctic Research Consortium of the United States (ARCUS) is a nonprofit membership organization composed of universities and institutions that have a substantial commitment to research in the Arctic. ARCUS was formed in 1988 to serve as a forum for planning, facilitating, coordinating, and implementing interdisciplinary studies of the Arctic; to act as a synthesizer and disseminator of scientific information on arctic research; and to educate scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS, in collaboration with the broader science community, relevant agencies and organizations, and other stakeholders, coordinates science planning and educational activities across disciplinary and organizational boundaries. Examples of current ARCUS science planning activities include: serving as the project office for the multi- agency Study of Environmental Arctic Change (SEARCH) program, providing support to the related Bering Ecosystem Study (BEST), and serving as the Science Management Office for the National Science Foundation (NSF) Arctic System Science (ARCSS) Program. ARCUS" central educational activity is PolarTREC (Teachers and Researchers Exploring and Collaborating), an International Polar Year (IPY) program whereby K-12 educators and researchers work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. Additional science planning, educational, information, and outreach activities include, among many others, the Witness the Arctic newsletter, the Arctic Visiting Speakers" Series, the ArcticInfo listserve, the Internet Media Archive (IMA), and the annual Arctic Forum conference. More information about these and other ARCUS activities can be found at the ARCUS website at: http://www.arcus.org.

The Arctic Research Consortium of the United States

NASA Astrophysics Data System (ADS)

Warnick, W. K.; Wiggins, H. V.

2007-12-01

The Arctic Research Consortium of the United States (ARCUS) is a nonprofit membership organization composed of universities and institutions that have a substantial commitment to research in the Arctic. ARCUS was formed in 1988 to serve as a forum for planning, facilitating, coordinating, and implementing interdisciplinary studies of the Arctic; to act as a synthesizer and disseminator of scientific information on arctic research; and to educate scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS, in collaboration with the broad science community, relevant agencies and organizations, and other stakeholders, coordinates science planning and educational activities across disciplinary and organizational boundaries. Examples of current ARCUS science planning activities include: serving as the project office for the multi-agency Study of Environmental Arctic Change (SEARCH) program and providing support to the related Bering Ecosystem Study (BEST), and serving as the Science Management Office for the National Science Foundation (NSF) Arctic System Science (ARCSS) Program. ARCUS' central educational activity is PolarTREC (Teachers and Researchers Exploring and Collaborating), an International Polar Year (IPY) program whereby K-12 educators and researchers work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. Additional science planning, educational, information, and outreach activities include the Witness the Arctic newsletter, the Arctic Visiting Speakers' Series, the ArcticInfo listserve, the Internet Media Archive (IMA), the annual Arctic Forum conference, and many others. More information about these and other ARCUS activities can be found at the ARCUS website at www.arcus.org.

The Arctic Research Consortium of the United States (ARCUS)

NASA Astrophysics Data System (ADS)

Creek, K. R.; Fox, S. E.; Wiggins, H. V.

2010-12-01

The Arctic Research Consortium of the United States (ARCUS) is a nonprofit membership organization composed of universities and institutions that have a substantial commitment to research in the Arctic. ARCUS was formed in 1988 to serve as a forum for planning, facilitating, coordinating, and implementing interdisciplinary studies of the Arctic; to act as a synthesizer and disseminator of scientific information on arctic research; and to educate scientists and the general public about the needs and opportunities for research in the Arctic. ARCUS, in collaboration with the broader science community, relevant agencies and organizations, and other stakeholders, coordinates science planning and educational activities across disciplinary and organizational boundaries. Examples of current ARCUS science planning activities include: serving as the project office for the multi-agency Study of Environmental Arctic Change (SEARCH) program, providing support to the related Bering Ecosystem Study (BEST), and serving as the Science Management Office for the National Science Foundation (NSF) Arctic System Science (ARCSS) Program. ARCUS’ central educational activity is PolarTREC (Teachers and Researchers Exploring and Collaborating), an International Polar Year (IPY) program whereby K-12 educators and researchers work together in hands-on field experiences in the Arctic and Antarctic to advance polar science education. Additional science planning, educational, information, and outreach activities include, among many others, the Witness the Arctic newsletter, the Arctic Visiting Speakers’ Series, the ArcticInfo listserve, the Internet Media Archive (IMA), and the annual Arctic Forum conference. More information about these and other ARCUS activities can be found at the ARCUS website at: http://www.arcus.org.

The High Arctic Large Igneous Province Mantle Plume caused uplift of Arctic Canada

NASA Astrophysics Data System (ADS)

Galloway, Jennifer; Ernst, Richard; Hadlari, Thomas

2016-04-01

The Sverdrup Basin is an east-west-trending extensional sedimentary basin underlying the northern Canadian Arctic Archipelago. The tectonic history of the basin began with Carboniferous-Early Permian rifting followed by thermal subsidence with minor tectonism. Tectonic activity rejuvenated in the Hauterivian-Aptian by renewed rifting and extension. Strata were deformed by diapiric structures that developed during episodic flow of Carboniferous evaporites during the Mesozoic and the basin contains igneous components associated with the High Arctic Large Igneous Province (HALIP). HALIP was a widespread event emplaced in multiple pulses spanning ca. 180 to 80 Ma, with igneous rocks on Svalbard, Franz Josef Island, New Siberian Islands, and also in the Sverdrup Basin on Ellef Ringnes, Axel Heiberg, and Ellesmere islands. Broadly contemporaneous igneous activity across this broad Arctic region along with a reconstructed giant radiating dyke swarm suggests that HALIP is a manifestation of large mantle plume activity probably centred near the Alpha Ridge. Significant surface uplift associated with the rise of a mantle plume is predicted to start ~10-20 my prior to the generation of flood basalt magmatism and to vary in shape and size subsequently throughout the LIP event (1,2,3) Initial uplift is due to dynamical support associated with the top of the ascending plume reaching a depth of about 1000 km, and with continued ascent the uplift topography broadens. Additional effects (erosion of the ductile lithosphere and thermal expansion caused by longer-term heating of the mechanical lithosphere) also affect the shape of the uplift. Topographic uplift can be between 1 to 4 km depending on various factors and may be followed by subsidence as the plume head decays or become permanent due to magmatic underplating. In the High Arctic, field and geochronological data from HALIP relevant to the timing of uplift, deformation, and volcanism are few. Here we present new evidence based on stratigraphic correlation that show thinning of strata in the northeastern part of the basin. The Isachsen Formation (Valanginian or Hauterivian to late Aptian) is a sandstone unit with interbeds of mudstone, coal, volcanic, and volcaniclastic/tuffaceous rocks attributed to HALIP. Isachsen Formation has a fairly consistent thickness over most of the Sverdrup Basin, ranging from ~120 m at basin margins to 1370 m on western Axel Heiberg Island but is generally > 400 m thick, even over the large salt domes that rose almost to the surface immediately prior to its deposition. The thickness of the formation decreases from over 400 m thick at Ellef Ringnes Island and southern Axel Heiberg Island to less than 120 m across a broad area of central Ellesmere Island. We interpret NE thinning of these strata to be the result of topographic uplift associated with initial mantle plume activity of HALIP. However, the rejuvenation of Sverdrup Basin formation (nearer the plume centre) in the Hauterivian-Aptian reflects complexities in the uplift pattern. References: 1-Griffiths, R.W. and Campbell, I.H. 1991 JGR 96: 18295-18310. 2-Campbell, I.H. 2007. Chem. Geol., 241: 153-176. 3-Ernst, 2014. LIPs. Cambridge U. Press, 653 p.

Connecting Arctic Research Across Boundaries through the Arctic Research Consortium of the United States (ARCUS)

NASA Astrophysics Data System (ADS)

Rich, R. H.; Myers, B.; Wiggins, H. V.; Zolkos, J.

2017-12-01

The complexities inherent in Arctic research demand a unique focus on making connections across the boundaries of discipline, institution, sector, geography, knowledge system, and culture. Since 1988, ARCUS has been working to bridge these gaps through communication, coordination, and collaboration. Recently, we have worked with partners to create a synthesis of the Arctic system, to explore the connectivity across the Arctic research community and how to strengthen it, to enable the community to have an effective voice in research funding policy, to implement a system for Arctic research community knowledge management, to bridge between global Sea Ice Prediction Network researchers and the science needs of coastal Alaska communities through the Sea Ice for Walrus Outlook, to strengthen ties between Polar researchers and educators, and to provide essential intangible infrastructure that enables cost-effective and productive research across boundaries. Employing expertise in managing for collaboration and interdisciplinarity, ARCUS complements and enables the work of its members, who constitute the Arctic research community and its key stakeholders. As a member-driven organization, everything that ARCUS does is achieved through partnership, with strong volunteer leadership of each activity. Key organizational partners in the United States include the U.S. Arctic Research Commission, Interagency Arctic Research Policy Committee, National Academy of Sciences Polar Research Board, and the North Slope Science Initiative. Internationally, ARCUS maintains strong bilateral connections with similarly focused groups in each Arctic country (and those interested in the Arctic), as well as with multinational organizations including the International Arctic Science Committee, the Association of Polar Early Career Educators, the University of the Arctic, and the Arctic Institute of North America. Currently, ARCUS is applying the best practices of the science of team science, expanding awareness of Arctic research in Washington, DC and in Alaska, and working to expand the base of support for Arctic research during this time of challenged U.S. federal research funding. The presentation will highlight our latest work to promote synthesis and systems thinking and make valuable connections.

Redefining U.S. Arctic Strategy

DTIC Science & Technology

2015-05-15

responsibility shifts 21 Barno, David and Nora Bensahel. The Anti-Access Challenge you’re not thinking...International Affairs 85, no. 6 (2009). 38 Barno, David and Nora Bensahel. THE ANTI-ACCESS CHALLENGE YOU’RE NOT THINKING ABOUT, 05 May 2015...and Rescue in the Arctic, 22 June 2011. Arctic Council Secretariat. About the Arctic Council, Arctic Council, 2011. Barno, David and Nora

The Climate Science Special Report: Arctic Changes and their Effect on Alaska and the Rest of the United States

NASA Astrophysics Data System (ADS)

Taylor, P. C.

2017-12-01

Rapid and visible climate change is happening across the Arctic, outpacing global change. Annual average near-surface air temperatures across the Arctic are increasing at more than twice the rate of global average surface temperature. In addition to surface temperature, all components of the Arctic climate system are responding in kind, including sea ice, mountain glaciers and the Greenland Ice sheet, snow cover, and permafrost. Many of these changes with a discernable anthropogenic imprint. While Arctic climate change may seem physically remote to those living in other regions of the planet, Arctic climate change can affect the global climate influencing sea level, the carbon cycle, and potentially atmospheric and oceanic circulation patterns. As an Arctic nation, United States' adaptation, mitigation, and policy decisions depend on projections of future Alaskan and Arctic climate. This chapter of the Climate Science Special Report documents significant scientific progress and knowledge about how the Alaskan and Arctic climate has changed and will continue to change.

A quantitative assessment of Arctic shipping in 2010–2014

PubMed Central

Eguíluz, Victor M.; Fernández-Gracia, Juan; Irigoien, Xabier; Duarte, Carlos M.

2016-01-01

Rapid loss of sea ice is opening up the Arctic Ocean to shipping, a practice that is forecasted to increase rapidly by 2050 when many models predict that the Arctic Ocean will largely be free of ice toward the end of summer. These forecasts carry considerable uncertainty because Arctic shipping was previously considered too sparse to allow for adequate validation. Here, we provide quantitative evidence that the extent of Arctic shipping in the period 2011–2014 is already significant and that it is concentrated (i) in the Norwegian and Barents Seas, and (ii) predominantly accessed via the Northeast and Northwest Passages. Thick ice along the forecasted direct trans-Arctic route was still present in 2014, preventing transit. Although Arctic shipping remains constrained by the extent of ice coverage, during every September, this coverage is at a minimum, allowing the highest levels of shipping activity. Access to Arctic resources, particularly fisheries, is the most important driver of Arctic shipping thus far. PMID:27477878

SEARCH: Study of Environmental Arctic Change-A System-scale, Cross-disciplinary Arctic Research Program

NASA Astrophysics Data System (ADS)

Wiggins, H. V.; Eicken, H.; Fox, S. E.; Search Science Steering Committee

2011-12-01

SEARCH is an interdisciplinary and interagency program that works with academic and government agency scientists to plan, conduct, and synthesize studies of arctic change. The vision of SEARCH is to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. Towards this end, SEARCH: (1) Generates and synthesizes research findings and promotes arctic science and scientific discovery across disciplines and among agencies. (2) Identifies emerging issues in arctic environmental change. (3) Provides information resources to arctic stakeholders, policy-makers, and the public to help them respond to arctic environmental change. (4) Coordinates with national arctic science programs integral to SEARCH goals. (5) Facilitates research activities across local-to-global scales with stakeholder concerns incorporated from the start of the planning process. (6) Represents the U.S. arctic environmental change science community in international and global change research initiatives. Examples of specific SEARCH activities include: (1) Arctic Observing Network (AON) - a system of atmospheric, land- and ocean-based environmental monitoring capabilities that will significantly advance our observations of arctic environmental conditions. (2) Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. (3) Sea Ice for Walrus Outlook - a resource for Alaska Native subsistence hunters, coastal communities, and others that provides weekly reports with information on sea ice conditions relevant to walrus in Alaska waters. (4) Developing recommendations for an interagency "Understanding Arctic Change" program. In addition to the above activities, SEARCH is also currently undertaking a strategic planning process to define priority goals and objectives for the next 3-5 years. SEARCH is guided by a Science Steering Committee and several panels and working groups, with broad representation of the research community. SEARCH is sponsored by eight U.S. agencies, including: the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA), the Department of Defense (DOD), the Department of Energy (DOE), the Department of the Interior (DOI), the Smithsonian Institution, and the U.S. Department of Agriculture (USDA). The U.S. Arctic Research Commission participates as an agency observer. For further information, please visit the website: http://www.arcus.org/search or contact: Helen V. Wiggins: helen@arcus.org, SEARCH Project Office, Arctic Research Consortium of the U.S. (ARCUS).

Arctic: A Friend Acting Strangely

Science.gov Websites

frequent. Explore the Arctic's changing climate. Discover what these changes mean for the Arctic, its warming in the Arctic by exploring how changes have been observed and documented by scientists and polar

Connecting Ocean Heat Transport Changes from the Midlatitudes to the Arctic Ocean

NASA Astrophysics Data System (ADS)

Hezel, P.; Nummelin, A.; Li, C.

2017-12-01

Under greenhouse warming, climate models simulate a weakening of the Atlantic Meridional Overturning Circulation and the associated ocean heat transport at midlatitudes but an increase in the ocean heat transport to the Arctic Ocean. These opposing trends lead to what could appear to be a discrepancy in the reported ocean contribution to Arctic amplification. This study clarifies how ocean heat transport affects Arctic climate under strong greenhouse warming using a set of the 21st century simulations performed within the Coupled Model Intercomparison Project. The results suggest that a future reduction in subpolar ocean heat loss enhances ocean heat transport to the Arctic Ocean, driving an increase in Arctic Ocean heat content and contributing to the intermodel spread in Arctic amplification. The results caution against extrapolating the forced oceanic signal from the midlatitudes to the Arctic.

Arctic climate tipping points.

PubMed

Lenton, Timothy M

2012-02-01

There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the Arctic are briefly reviewed. Then, the current behaviour of a range of Arctic systems is summarised. Looking ahead, a range of potential tipping phenomena are described. This leads to a revised and expanded list of potential Arctic climate tipping elements, whose likelihood is assessed, in terms of how much warming will be required to tip them. Finally, the available responses are considered, especially the prospects for avoiding Arctic climate tipping points.

Arctic Research NASA's Cryospheric Sciences Program

NASA Technical Reports Server (NTRS)

Waleed, Abdalati; Zukor, Dorothy J. (Technical Monitor)

2001-01-01

Much of NASA's Arctic Research is run through its Cryospheric Sciences Program. Arctic research efforts to date have focused primarily on investigations of the mass balance of the largest Arctic land-ice masses and the mechanisms that control it, interactions among sea ice, polar oceans, and the polar atmosphere, atmospheric processes in the polar regions, energy exchanges in the Arctic. All of these efforts have been focused on characterizing, understanding, and predicting, changes in the Arctic. NASA's unique vantage from space provides an important perspective for the study of these large scale processes, while detailed process information is obtained through targeted in situ field and airborne campaigns and models. An overview of NASA investigations in the Arctic will be presented demonstrating how the synthesis of space-based technology, and these complementary components have advanced our understanding of physical processes in the Arctic.

Promoting Knowledge to Action through the Study of Environmental Arctic Change (SEARCH) Program

NASA Astrophysics Data System (ADS)

Myers, B.; Wiggins, H. V.

2016-12-01

The Study of Environmental Arctic Change (SEARCH) is a multi-institutional collaborative U.S. program that advances scientific knowledge to inform societal responses to Arctic change. Currently, SEARCH focuses on how diminishing Arctic sea ice, thawing permafrost, and shrinking land ice impact both Arctic and global systems. Emphasizing "knowledge to action", SEARCH promotes collaborative research, synthesizes research findings, and broadly communicates the resulting knowledge to Arctic researchers, stakeholders, policy-makers, and the public. This poster presentation will highlight recent program products and findings; best practices and challenges for managing a distributed, interdisciplinary program; and plans for cross-disciplinary working groups focused on Arctic coastal erosion, synthesis of methane budgets, and development of Arctic scenarios. A specific focus will include how members of the broader research community can participate in SEARCH activities. http://www.arcus.org/search

Promoting Mental Health. Training Guides for the Head Start Learning Community.

ERIC Educational Resources Information Center

Bowman (James) Associates, San Francisco, CA.

This training guide is intended to help Head Start staff promote mental health for all members of the Head Start Community, by means of activities that build skills in creating responsive, respectful relationships with co-workers, parents, and children. The guide has five working sections, the first three of which are training modules. Each of the…

A Guide for Local Nutrition Consultants on the Nutrition Component of Head Start Programs.

ERIC Educational Resources Information Center

Administration for Children, Youth, and Families (DHHS), Washington, DC. Head Start Bureau.

This handbook has been prepared as a guide for the nutritionist providing services to Head Start and other preschool day care programs. Introductory sections describe Project Head Start; the program's major components and aspects of the program; center-based, home-based, child and family development, and Child Development Associate (CDA) programs;…

41 CFR 102-74.340 - Who is responsible for monitoring and controlling areas designated for smoking by an agency head...

Code of Federal Regulations, 2010 CFR

2010-07-01

... with proper signage? 102-74.340 Section 102-74.340 Public Contracts and Property Management Federal... designated for smoking by an agency head and for identifying those areas with proper signage? Agency heads... smoking and identifying these areas with proper signage. Suitable, uniform signs reading “Designated...

41 CFR 102-74.340 - Who is responsible for monitoring and controlling areas designated for smoking by an agency head...

Code of Federal Regulations, 2011 CFR

2011-01-01

... with proper signage? 102-74.340 Section 102-74.340 Public Contracts and Property Management Federal... designated for smoking by an agency head and for identifying those areas with proper signage? Agency heads... smoking and identifying these areas with proper signage. Suitable, uniform signs reading “Designated...

41 CFR 102-74.340 - Who is responsible for monitoring and controlling areas designated for smoking by an agency head...

Code of Federal Regulations, 2013 CFR

2013-07-01

... with proper signage? 102-74.340 Section 102-74.340 Public Contracts and Property Management Federal... designated for smoking by an agency head and for identifying those areas with proper signage? Agency heads... smoking and identifying these areas with proper signage. Suitable, uniform signs reading “Designated...

41 CFR 102-74.340 - Who is responsible for monitoring and controlling areas designated for smoking by an agency head...

Code of Federal Regulations, 2014 CFR

2014-01-01

... with proper signage? 102-74.340 Section 102-74.340 Public Contracts and Property Management Federal... designated for smoking by an agency head and for identifying those areas with proper signage? Agency heads... smoking and identifying these areas with proper signage. Suitable, uniform signs reading “Designated...

41 CFR 102-74.340 - Who is responsible for monitoring and controlling areas designated for smoking by an agency head...

Code of Federal Regulations, 2012 CFR

2012-01-01

... with proper signage? 102-74.340 Section 102-74.340 Public Contracts and Property Management Federal... designated for smoking by an agency head and for identifying those areas with proper signage? Agency heads... smoking and identifying these areas with proper signage. Suitable, uniform signs reading “Designated...

Development of pan-Arctic database for river chemistry

USGS Publications Warehouse

McClelland, J.W.; Holmes, R.M.; Peterson, B.J.; Amon, R.; Brabets, T.; Cooper, L.; Gibson, J.; Gordeev, V.V.; Guay, C.; Milburn, D.; Staples, R.; Raymond, P.A.; Shiklomanov, I.; Striegl, Robert G.; Zhulidov, A.; Gurtovaya, T.; Zimov, S.

2008-01-01

More than 10% of all continental runoff flows into the Arctic Ocean. This runoff is a dominant feature of the Arctic Ocean with respect to water column structure and circulation. Yet understanding of the chemical characteristics of runoff from the pan-Arctic watershed is surprisingly limited. The Pan- Arctic River Transport of Nutrients, Organic Matter, and Suspended Sediments ( PARTNERS) project was initiated in 2002 to help remedy this deficit, and an extraordinary data set has emerged over the past few years as a result of the effort. This data set is publicly available through the Cooperative Arctic Data and Information Service (CADIS) of the Arctic Observing Network (AON). Details about data access are provided below.

Dynamical mechanisms of Arctic amplification.

PubMed

Dethloff, Klaus; Handorf, Dörthe; Jaiser, Ralf; Rinke, Annette; Klinghammer, Pia

2018-05-12

The Arctic has become a hot spot of climate change, but the nonlinear interactions between regional and global scales in the coupled climate system responsible for Arctic amplification are not well understood and insufficiently described in climate models. Here, we compare reanalysis data with model simulations for low and high Arctic sea ice conditions to identify model biases with respect to atmospheric Arctic-mid-latitude linkages. We show that an appropriate description of Arctic sea ice forcing is able to reproduce the observed winter cooling in mid-latitudes as result of improved tropospheric-stratospheric planetary wave propagation triggering a negative phase of the Arctic Oscillation/North Atlantic Oscillation in late winter. © 2018 New York Academy of Sciences.

Freshwater Export from the Arctic Ocean and its Downstream Effect on Labrador Sea Deep Convection in a High-Resolution Numerical Model

DTIC Science & Technology

2010-12-01

Arctic has been observed in the northern Canadian Arctic Archipelago ( Bourke and McLaren 1992). There, thick multiyear ice of Arctic origin encounters...Affairs, 87(2), 63-77. 172 Bourke , R. H., and A. S. McLaren, 1992: Contour mapping of Arctic Basin ice draft and roughness parameters. J. Geophys

Application of Network Analysis to Identify and Map Relationships between Information Systems in the context of Arctic Sustainability

NASA Astrophysics Data System (ADS)

Kontar, Y. Y.

2017-12-01

The Arctic Council is an intergovernmental forum promoting cooperation, coordination and interaction among the Arctic States and indigenous communities on issues of sustainable development and environmental protection in the North. The work of the Council is primarily carried out by six Working Groups: Arctic Contaminants Action Program, Arctic Monitoring and Assessment Programme, Conservation of Arctic Flora and Fauna, Emergency Prevention, Preparedness and Response, Protection of the Arctic Marine Environment, and Sustainable Development Working Group. The Working Groups are composed of researchers and representatives from government agencies. Each Working Group issues numerous scientific assessments and reports on a broad field of subjects, from climate change to emergency response in the Arctic. A key goal of these publications is to contribute to policy-making in the Arctic. Complex networks of information systems and the connections between the diverse elements within the systems have been identified via network analysis. This allowed to distinguish data sources that were used in the composition of the primary publications of the Working Groups. Next step is to implement network analysis to identify and map the relationships between the Working Groups and policy makers in the Arctic.

4D Arctic: A Glimpse into the Structure and Evolution of the Arctic in the Light of New Geophysical Maps, Plate Tectonics and Tomographic Models.

PubMed

Gaina, Carmen; Medvedev, Sergei; Torsvik, Trond H; Koulakov, Ivan; Werner, Stephanie C

Knowledge about the Arctic tectonic structure has changed in the last decade as a large number of new datasets have been collected and systematized. Here, we review the most updated, publicly available Circum-Arctic digital compilations of magnetic and gravity data together with new models of the Arctic's crust. Available tomographic models have also been scrutinized and evaluated for their potential to reveal the deeper structure of the Arctic region. Although the age and opening mechanisms of the Amerasia Basin are still difficult to establish in detail, interpreted subducted slabs that reside in the High Arctic's lower mantle point to one or two episodes of subduction that consumed crust of possibly Late Cretaceous-Jurassic age. The origin of major igneous activity during the Cretaceous in the central Arctic (the Alpha-Mendeleev Ridge) and in the proximity of rifted margins (the so-called High Arctic Large Igneous Province-HALIP) is still debated. Models of global plate circuits and the connection with the deep mantle are used here to re-evaluate a possible link between Arctic volcanism and mantle plumes.

Multidecadal trends in aerosol radiative forcing over the Arctic: Contribution of changes in anthropogenic aerosol to Arctic warming since 1980

NASA Astrophysics Data System (ADS)

Breider, Thomas J.; Mickley, Loretta J.; Jacob, Daniel J.; Ge, Cui; Wang, Jun; Payer Sulprizio, Melissa; Croft, Betty; Ridley, David A.; McConnell, Joseph R.; Sharma, Sangeeta; Husain, Liaquat; Dutkiewicz, Vincent A.; Eleftheriadis, Konstantinos; Skov, Henrik; Hopke, Phillip K.

2017-03-01

Arctic observations show large decreases in the concentrations of sulfate and black carbon (BC) aerosols since the early 1980s. These near-term climate-forcing pollutants perturb the radiative balance of the atmosphere and may have played an important role in recent Arctic warming. We use the GEOS-Chem global chemical transport model to construct a 3-D representation of Arctic aerosols that is generally consistent with observations and their trends from 1980 to 2010. Observations at Arctic surface sites show significant decreases in sulfate and BC mass concentrations of 2-3% per year. We find that anthropogenic aerosols yield a negative forcing over the Arctic, with an average 2005-2010 Arctic shortwave radiative forcing (RF) of -0.19 ± 0.05 W m-2 at the top of atmosphere (TOA). Anthropogenic sulfate in our study yields more strongly negative forcings over the Arctic troposphere in spring (-1.17 ± 0.10 W m-2) than previously reported. From 1980 to 2010, TOA negative RF by Arctic aerosol declined, from -0.67 ± 0.06 W m-2 to -0.19 ± 0.05 W m-2, yielding a net TOA RF of +0.48 ± 0.06 W m-2. The net positive RF is due almost entirely to decreases in anthropogenic sulfate loading over the Arctic. We estimate that 1980-2010 trends in aerosol-radiation interactions over the Arctic and Northern Hemisphere midlatitudes have contributed a net warming at the Arctic surface of +0.27 ± 0.04 K, roughly one quarter of the observed warming. Our study does not consider BC emissions from gas flaring nor the regional climate response to aerosol-cloud interactions or BC deposition on snow.

SEARCH: Study of Environmental Arctic Change—A System-scale, Cross-disciplinary Arctic Research Program

NASA Astrophysics Data System (ADS)

Wiggins, H. V.; Eicken, H.; Fox, S. E.

2012-12-01

SEARCH is an interdisciplinary and interagency program that works with academic and government agency scientists to plan, conduct, and synthesize studies of arctic change. The vision of SEARCH is to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. Towards this end, SEARCH: 1. Generates and synthesizes research findings and promotes arctic science and scientific discovery across disciplines and among agencies. 2. Identifies emerging issues in arctic environmental change. 3. Provides information resources to arctic stakeholders, policy-makers, and the public to help them respond to arctic environmental change. 4. Coordinates with national arctic science programs integral to SEARCH goals. 5. Facilitates research activities across local-to-global scales with stakeholder concerns incorporated from the start of the planning process. 6. Represents the U.S. arctic environmental change science community in international and global change research initiatives. Specific current activities include: Arctic Observing Network (AON) - coordinating a system of atmospheric, land- and ocean-based environmental monitoring capabilities that will significantly advance our observations of arctic environmental conditions. Arctic Sea Ice Outlook ¬- an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. Sea Ice for Walrus Outlook - a resource for Alaska Native subsistence hunters, coastal communities, and others that provides weekly reports with information on sea ice conditions relevant to walrus in Alaska waters. In April, the SEARCH Science Steering Committee (SSC) released a set of draft 5-year goals and objectives for review by the broader arctic science community. The goals and objectives will direct the SEARCH program in the next five years. The draft SEARCH goals focus on four areas: ice-diminished Arctic Ocean, warming permafrost, land ice and sea level, and societal and policy implications. Together, the goals will provide significant insight into arctic system change as a whole. The SEARCH SSC will release the goals in their revised form and then work closely with agency representatives to implement the goals through research opportunities and community activities. SEARCH is guided by a Science Steering Committee and several panels and working groups, with broad representation of the research community. SEARCH is sponsored by eight U.S. agencies, including: the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA), the Department of Defense (DOD), the Department of Energy (DOE), the Department of the Interior (DOI), the Smithsonian Institution, and the U.S. Department of Agriculture (USDA). The U.S. Arctic Research Commission participates as an agency observer. For further information, please visit the website: http://www.arcus.org/search or contact: Helen V. Wiggins: helen@arcus.org, SEARCH Project Office, Arctic Research Consortium of the U.S. (ARCUS).

[Experimental study on vascular bundle implantation combined with cellular transplantation in treating rabbit femoral head necrosis].

PubMed

Chen, Shuang-Tao; Zhang, Wei-Ping; Liu, Chang-An; Wang, Jun-Jiang; Song, Heng-Yi; Chai, Zhi-wen

2013-03-01

To discuss the feasibility of vascular bundle implantation combined with allogeneic bone marrow stromal cells (BMSCs) transplantation in treating rabbit femoral head osteonecrosis and bone defect, in order to explore a new method for the treatment of femoral head necrosis. Thirty-six New Zealand rabbits were randomly divided into three groups,with 12 rabbits in each group. Bilateral femoral heads of the rabbits were studied in the experiment. The models were made by liquid nitrogen frozen, and the femoral heads were drilled to cause bone defect. Group A was the control group,group B was stem cells transplantaion group of allograft marrow stromal,and group C was stem cells transplantation group of allograft marrow stromal combined with vascular bundle implantation. Three rabbits of each group were sacrificed respectively at 2, 4, 8, 12 weeks after operation. All specimens of the femoral heads were sliced for HE staining. Furthermore ,vascular density and the percentage of new bone trabecula of femoral head coronary section in defect area were measured and analyzed statistically. In group C,new bone trabecula and original micrangium formed at the 2nd week after operation; new bone trabecula was lamellar and interlaced with abundant micrangium at the 8th week;at the 12th week,the broadened,coarsened bone trabecula lined up regularly,and the mature bone trabecula and new marrow were visible. At the 2nd week after operation,there was no statistical significance in the percentage of new bone trabecula of femoral head coronary section in defect area between group B and C. While at 4, 8, 12 week after operation, vascular density and the percentage of new bone trabecula of femoral head coronary section in defect area of group C was higher than that of group B. Allogeneic bone marrow stromal cells cultured in vivo can form new bone trabecula, and can be applied to allotransplant. Vascular bundle implanted into the bone defect area of femoral head necrosis could improve blood supply, and promote the formation of bone trabecula.

Annotated bibliography on soil erosion and erosion control in subarctic and high-latitude regions of North America.

Treesearch

C.W. Slaughter; J.W. Aldrich

1989-01-01

This annotated bibliography emphasizes the physical processes of upland soil erosion, prediction of soil erosion and sediment yield, and erosion control. The bibliography is divided into two sections: (1) references specific to Alaska, the Arctic and subarctic, and similar high-latitude settings; and (2) references relevant to understanding erosion, sediment production...

The Effects of Environmental Change on an Arctic Native Community: Evaluation Using Local Cultural Perceptions

ERIC Educational Resources Information Center

McBeath, Jerry; Shepro, Carl E.

2007-01-01

This article presents the research conducted by the authors in an Inupiat Eskimo village on the Alaska North Slope and describes the research in two substantive parts. In the first section, the authors present what subsistence hunters and fishers observed concerning changes to seas, lands, and inland lakes and rivers. Then, they mention changes of…

Impact of future Arctic shipping on high-latitude black carbon deposition (Invited)

NASA Astrophysics Data System (ADS)

Corbett, J. J.; Browse, J.; Carslaw, K. S.; Schmidt, A.

2013-12-01

The retreat of Arctic sea-ice has led to renewed calls to exploit Arctic shipping routes. The diversion of ship traffic through the Arctic will shorten shipping routes and possibly reduce global shipping emissions. However, deposition of black carbon (BC) aerosol emitted by additional Arctic ships could cause a reduction in the albedo of snow and ice, accelerating snow-melt and sea-ice loss. We use recently compiled Arctic shipping emission inventories for 2004 and 2050 together with a global aerosol microphysics model GLOMAP coupled to the chemical transport model TOMCAT to quantify the contribution of future Arctic shipping to high-latitude BC deposition. Emission rates of SOx (SO2 and SO4) and particulate matter (PM) were estimated for 2050 under both business-as-usual and high-growth scenarios. BC particles are assumed to be water-insoluble at emission but can become active in cloud drop formation through soluble material accumulation. After BC particles become cloud-active they are more efficiently wet scavenged, which accounts for 80% of modeled BC deposition. Current-day Arctic shipping contributes 0.3% to the BC mass deposited north of 60N (250 Gg). About 50% of modelled BC deposition is on open ocean, suggesting that current Arctic ship traffic may not significantly contribute to BC deposition on central Arctic sea ice. However, 6 - 8% of deposited BC on the west coast of Greenland originates from local ship traffic. Moreover, in-Arctic shipping contributes some 32% to high-latitude ship-sourced deposition despite accounting for less than 1.0% of global shipping emissions. This suggests that control of in-Arctic shipping BC emissions could yield greater decrease in high-latitude BC deposition than a similar control strategy applied only to the extra-Arctic shipping industry. Arctic shipping in 2050 will contribute less than 1% to the total BC deposition north of 60N due to the much greater relative contribution of BC transported from non-shipping sources at lower-latitudes (with a maximum of about 5%, considering upper bound estimates for transport). In the BAU and HiG scenarios, the total BC deposition averaged north of 60N from Arctic shipping remains small, increasing to only 0.4% and 0.7%, respectively. Several mitigation strategies confirmed that extra-Arctic sources other than shipping contribute significantly more to BC deposition than Arctic shipping, and that regulation solely aimed at the Arctic shipping industry is an insufficient control on high-latitude BC deposition. An exception is the impact of local shipping near the vulnerable Greenland ice-sheet. Over Greenland the deposited BC mass attributable to high-growth shipping emissions in 2050 is significantly higher (10-15%) than over Arctic sea-ice. The increase in local BC deposition over Greenland can be mitigated by a 10% decrease in North American BC emissions, but additional controls over distant stationary sources should be considered alongside international agreements controlling shipping emissions to achieve desired Arctic BC deposition reductions.

Future scientific drilling in the Arctic Ocean: Key objectives, areas, and strategies

NASA Astrophysics Data System (ADS)

Stein, R.; Coakley, B.; Mikkelsen, N.; O'Regan, M.; Ruppel, C.

2012-04-01

In spite of the critical role of the Arctic Ocean in climate evolution, our understanding of the short- and long-term paleoceanographic and paleoclimatic history through late Mesozoic-Cenozoic times, as well as its plate-tectonic evolution, remains behind that from the other world's oceans. This lack of knowledge is mainly caused by the major technological/logistic problems in reaching this permanently ice-covered region with normal research vessels and in retrieving long and undisturbed sediment cores. With the Arctic Coring Expedition - ACEX (or IODP Expedition 302), the first Mission Specific Platform (MSP) expedition within IODP, a new era in Arctic research began (Backman, Moran, Mayer, McInroy et al., 2006). ACEX proved that, with an intensive ice-management strategy, successful scientific drilling in the permanently ice-covered central Arctic Ocean is possible. ACEX is certainly a milestone in Arctic Ocean research, but - of course - further drilling activities are needed in this poorly studied ocean. Furthermore, despite the success of ACEX fundamental questions related to the long- and short-term climate history of the Arctic Ocean during Mesozoic-Cenozoic times remain unanswered. This is partly due to poor core recovery during ACEX and, especially, because of a major mid-Cenozoic hiatus in this single record. Since ACEX, a series of workshops were held to develop a scientific drilling strategy for investigating the tectonic and paleoceanographic history of the Arctic Ocean and its role in influencing the global climate system: - "Arctic Ocean History: From Speculation to Reality" (Bremerhaven/Germany, November 2008); - "Overcoming barriers to Arctic Ocean scientific drilling: the site survey challenge" (Copenhagen/Denmark, November 2011); - Circum-Arctic shelf/upper continental slope scientific drilling workshop on "Catching Climate Change in Progress" (San Francisco/USA, December 2011); - "Coordinated Scientific Drilling in the Beaufort Sea: Addressing Past, Present and Future Changes in Arctic Terrestrial and Marine Systems" (Kananaskis, Alberta/Canada, February 2012). During these workshops, key areas and key scientific themes as well as drilling and site-survey strategies were discussed. Major scientific themes for future Arctic drilling will include: - The Arctic Ocean during the transition from greenhouse to icehouse conditions and millennial scale climate changes; - Physical and chemical changes of the evolving Polar Ocean and Arctic gateways; - Impact of Pleistocene/Holocene warming and sea-level rise on upper continental slope and shelf gas hydrates and on shelf permafrost; - Land-ocean interactions; - Tectonic evolution and birth of the Arctic Ocean basin: Arctic ridges, sea floor spreading and global lithosphere processes. When thinking about future Arctic drilling, it should be clearly emphasized that for the precise planning of future Arctic Ocean drilling campaigns, including site selection, evaluation of proposed drill sites for safety and environmental protection, etc., comprehensive site survey data are needed first. This means that the development of a detailed site survey strategy is a major challenge for the coming years. Here, an overview of perspectives and plans for future Arctic Ocean drilling will be presented.

Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability

NASA Astrophysics Data System (ADS)

Tokinaga, Hiroki; Xie, Shang-Ping; Mukougawa, Hitoshi

2017-06-01

With amplified warming and record sea ice loss, the Arctic is the canary of global warming. The historical Arctic warming is poorly understood, limiting our confidence in model projections. Specifically, Arctic surface air temperature increased rapidly over the early 20th century, at rates comparable to those of recent decades despite much weaker greenhouse gas forcing. Here, we show that the concurrent phase shift of Pacific and Atlantic interdecadal variability modes is the major driver for the rapid early 20th-century Arctic warming. Atmospheric model simulations successfully reproduce the early Arctic warming when the interdecadal variability of sea surface temperature (SST) is properly prescribed. The early 20th-century Arctic warming is associated with positive SST anomalies over the tropical and North Atlantic and a Pacific SST pattern reminiscent of the positive phase of the Pacific decadal oscillation. Atmospheric circulation changes are important for the early 20th-century Arctic warming. The equatorial Pacific warming deepens the Aleutian low, advecting warm air into the North American Arctic. The extratropical North Atlantic and North Pacific SST warming strengthens surface westerly winds over northern Eurasia, intensifying the warming there. Coupled ocean-atmosphere simulations support the constructive intensification of Arctic warming by a concurrent, negative-to-positive phase shift of the Pacific and Atlantic interdecadal modes. Our results aid attributing the historical Arctic warming and thereby constrain the amplified warming projected for this important region.

Challenges of climate change: an Arctic perspective.

PubMed

Corell, Robert W

2006-06-01

Climate change is being experienced particularly intensely in the Arctic. Arctic average temperature has risen at almost twice the rate as that of the rest of the world in the past few decades. Widespread melting of glaciers and sea ice and rising permafrost temperatures present additional evidence of strong Arctic warming. These changes in the Arctic provide an early indication of the environmental and societal significance of global consequences. The Arctic also provides important natural resources to the rest of the world (such as oil, gas, and fish) that will be affected by climate change, and the melting of Arctic glaciers is one of the factors contributing to sea level rise around the globe. An acceleration of these climatic trends is projected to occur during this century, due to ongoing increases in concentrations of greenhouse gases in the Earth's atmosphere. These Arctic changes will, in turn, impact the planet as a whole.

Simulation of the modern arctic climate by the NCAR CCM1

NASA Technical Reports Server (NTRS)

Bromwich, David H.; Tzeng, Ren-Yow; Parish, Thomas, R.

1994-01-01

The National Center of Atmospheric Research (NCAR) Community Climate Model Version 1 (CCM1's) simulation of the modern arctic climate is evaluated by comparing a five-year seasonal cycle simulation with the European Center for Medium-Range Weather Forecasts (ECMWF) global analyses. The sea level pressure (SLP), storm tracks, vertical cross section of height, 500-hPa height, total energy budget, and moisture budget are analyzed to investigate the biases in the simulated arctic climate. The results show that the model simulates anomalously low SLP, too much storm activity, and anomalously strong baroclinicity to the west of Greenland and vice versa to the east of Greenland. This bias is mainly attributed to the model's topographic representation of Greenland. First, the broadened Greenland topography in the model distorts the path of cyclone waves over the North Atlantic Ocean. Second, the model oversimulates the ridge over Greenland, which intensifies its blocking effect and steers the cyclone waves clockwise around it and hence produces an artificial circum-Greenland trough. These biases are significantly alleviated when the horizontal resolution increases to T42. Over the Arctic basin, the model simulates large amounts of low-level (stratus) clouds in winter and almost no stratus in summer, which is opposite to the observations. This bias is mainly due to the location of the simulated SLP features and the negative anomaly of storm activity, which prevent the transport of moisture into this region during summer but favor this transport in winter. The moisture budget analysis shows that the model's net annual precipitation (P-E) between 70 deg N and the North Pole is 6.6 times larger than the observations and the model transports six times more moisture into this region. The bias in the advection term is attributed to the positive moisture fixer scheme and the distorted flow pattern. However, the excessive moisture transport into the Arctic basin does not solely result from the advection term. The contribution by the moisture fixer is as large as from advection. By contrast, the semi-Lagrangian transport scheme used in the CCM2 significantly improves the moisture simulation for this region; however, globally the error is as serious as for the positive moisture fixer scheme. Finally, because the model has such serious problems in simulating the present arctic climate, its simulations of past and future climate change for this region are questionable.

Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland

PubMed Central

Hanke, Dennis; Freuling, Conrad M.; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R.; Bøtner, Anette; Mettenleiter, Thomas C.; Beer, Martin; Rasmussen, Thomas B.; Müller, Thomas F.; Höper, Dirk

2016-01-01

There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1–4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I – 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure in Greenland arctic foxes based on mitochondrial sequences, but provided no evidence for independent isolated evolutionary development of RABV in different arctic fox lineages. These data are invaluable to support future initiatives for arctic fox rabies control and elimination in Greenland. PMID:27459154

Spatio-temporal Analysis of the Genetic Diversity of Arctic Rabies Viruses and Their Reservoir Hosts in Greenland.

PubMed

Hanke, Dennis; Freuling, Conrad M; Fischer, Susanne; Hueffer, Karsten; Hundertmark, Kris; Nadin-Davis, Susan; Marston, Denise; Fooks, Anthony R; Bøtner, Anette; Mettenleiter, Thomas C; Beer, Martin; Rasmussen, Thomas B; Müller, Thomas F; Höper, Dirk

2016-07-01

There has been limited knowledge on spatio-temporal epidemiology of zoonotic arctic fox rabies among countries bordering the Arctic, in particular Greenland. Previous molecular epidemiological studies have suggested the occurrence of one particular arctic rabies virus (RABV) lineage (arctic-3), but have been limited by a low number of available samples preventing in-depth high resolution phylogenetic analysis of RABVs at that time. However, an improved knowledge of the evolution, at a molecular level, of the circulating RABVs and a better understanding of the historical perspective of the disease in Greenland is necessary for better direct control measures on the island. These issues have been addressed by investigating the spatio-temporal genetic diversity of arctic RABVs and their reservoir host, the arctic fox, in Greenland using both full and partial genome sequences. Using a unique set of 79 arctic RABV full genome sequences from Greenland, Canada, USA (Alaska) and Russia obtained between 1977 and 2014, a description of the historic context in relation to the genetic diversity of currently circulating RABV in Greenland and neighboring Canadian Northern territories has been provided. The phylogenetic analysis confirmed delineation into four major arctic RABV lineages (arctic 1-4) with viruses from Greenland exclusively grouping into the circumpolar arctic-3 lineage. High resolution analysis enabled distinction of seven geographically distinct subclades (3.I - 3.VII) with two subclades containing viruses from both Greenland and Canada. By combining analysis of full length RABV genome sequences and host derived sequences encoding mitochondrial proteins obtained simultaneously from brain tissues of 49 arctic foxes, the interaction of viruses and their hosts was explored in detail. Such an approach can serve as a blueprint for analysis of infectious disease dynamics and virus-host interdependencies. The results showed a fine-scale spatial population structure in Greenland arctic foxes based on mitochondrial sequences, but provided no evidence for independent isolated evolutionary development of RABV in different arctic fox lineages. These data are invaluable to support future initiatives for arctic fox rabies control and elimination in Greenland.

Computed tomographic anatomy of the heads of blue-and-gold macaws (Ara ararauna), African grey parrots (Psittacus erithacus), and monk parakeets (Myiopsitta monachus).

PubMed

Veladiano, Irene A; Banzato, Tommaso; Bellini, Luca; Montani, Alessandro; Catania, Salvatore; Zotti, Alessandro

2016-12-01

OBJECTIVE To create an atlas of the normal CT anatomy of the head of blue-and-gold macaws (Ara ararauna), African grey parrots (Psittacus erithacus), and monk parakeets (Myiopsitta monachus). ANIMALS 3 blue-and-gold macaws, 5 African grey parrots, and 6 monk parakeets and cadavers of 4 adult blue-and-gold macaws, 4 adult African grey parrots, and 7 monk parakeets. PROCEDURES Contrast-enhanced CT imaging of the head of the live birds was performed with a 4-multidetector-row CT scanner. Cadaveric specimens were stored at -20°C until completely frozen, and each head was then sliced at 5-mm intervals to create reference cross sections. Frozen cross sections were cleaned with water and photographed on both sides. Anatomic structures within each head were identified with the aid of the available literature, labeled first on anatomic photographs, and then matched to and labeled on corresponding CT images. The best CT reconstruction filter, window width, and window level for obtaining diagnostic images of each structure were also identified. RESULTS Most of the clinically relevant structures of the head were identified in both the cross-sectional photographs and corresponding CT images. Optimal visibility of the bony structures was achieved via CT with a standard soft tissue filter and pulmonary window. The use of contrast medium allowed a thorough evaluation of the soft tissues. CONCLUSIONS AND CLINICAL RELEVANCE The labeled CT images and photographs of anatomic structures of the heads of common pet parrot species created in this study may be useful as an atlas to aid interpretation of images obtained with any imaging modality.

Relative Distribution of Quadriceps Head Anatomical Cross-Sectional Areas and Volumes – Sensitivity to Pain and to Training Intervention

PubMed Central

Sattler, M; Dannhauer, T; Ring-Dimitriou, S; Sänger, AM; Wirth, W; Hudelmaier, M; Eckstein, F

2014-01-01

SUMMARY Introduction Quadriceps heads are important in biomechanical stabilization and in the pathogenesis osteoarthritis of the knee. This is the first study to explore the relative distribution of quadriceps head anatomical cross-sectional areas (ACSA) and volumes, and their response to pain and to training intervention. Methods The relative proportions of quadriceps heads were determined in 48 Osteoarthritis Initiative participants with unilateral pain (65% women; age 45–78y). Quadriceps head volumes were also measured in 35 untrained women (45–55y) before and after 12 week training intervention. Cross-sectional areas of the vastus medialis (VM), inter-medius (VIM), and lateralis (VL), and of the rectus femoris (RF) were determined from axial T1-weighted MR images. Results The proportion of the VM on the total quadriceps ACSA increased from proximal to distal. The difference in quadriceps ACSA of painful (vs. pain-free) limbs was −5.4% for the VM (p<0.001), −6.8% for the VL (p<0.01), −2.8% for the VIM (p=0.06), and +3.4% for the RF (p=0.67) but the VM/VL ratio was not significantly altered. The muscle volume increase during training intervention was +4.2% (p<0.05) for VM, +1.3% for VL, +2.0% for VIM (p<0.05) and +1.6% for RF. Conclusion The proportion of quadriceps head relative to total muscle ACSA and volume depends on the anatomical level studied. The results suggest that there may be a differential response of the quadriceps heads to pain-induced atrophy and to training-related hypertrophy. Studies in larger samples are needed to ascertain whether the observed differences in response to pain and training are statistically and clinically significant. PMID:25153247

Comparing growth rates of Arctic Cod Boreogadus saida across the Chukchi and Beaufort Seas

NASA Astrophysics Data System (ADS)

Frothingham, A. M.; Norcross, B.

2016-02-01

Dramatic changes to the Arctic have highlighted the need for a greater understanding of the present ecosystem. Arctic Cod, Boreogadus saida, commonly dominate fish assemblages in the Arctic region and inhabit two geographically unique seas in the U.S. Due to the importance of Arctic Cod in the Arctic food web, establishing current benchmark information such as growth rates, will provide a better understanding as to how the species will adapt to the effects of climate change. To investigate differences in Arctic Cod life history across nearly 1500 km of vital habitat, growth rates were examined using a von Bertalanffy growth equation. Arctic Cod were collected from 2009 to 2014 from the Chukchi and Beaufort seas. Arctic Cod collected from the Chukchi Sea had an overall smaller maximum achievable length (210 mm) compared to the Beaufort Sea (253 mm) despite a larger sample size in the Chukchi Sea (n=1569) than the Beaufort Sea (n=1140). Growth rates indicated faster growth in the Chukchi Sea (K =0.33) than in the Beaufort Sea (K= 0.29). Arctic Cod collected from the Chukchi Sea had similar achievable maximum lengths throughout, but those collected from the southern Chukchi Sea grew at faster rates (K=0.45).Arctic Cod in the eastern Beaufort Sea region had a higher overall maximum achievable length (243 mm) than in the western Beaufort Sea region (186 mm). Knowledge about contemporary growth rates of Arctic Cod in the Chukchi and Beaufort Seas can be used in future comparisons to evaluate potential effects of increasing climate change and anthropogenic influences.

Arctic tundra greening and browning (2007-2013) based on satellite-observed solar-induced fluorescence data

NASA Astrophysics Data System (ADS)

Fu, D.; Su, F.; Wang, J.

2017-12-01

More accurate evaluation of the state of Arctic tundra vegetation is important for our understanding of Arctic and global systems. Arctic tundra greening has been reported, increasing vegetation cover and productivity in many regions, but browning has been also reported, based on satellite-observed Normalized Difference Vegetation Index (NDVI) from 2011 until recently. Here we demonstrate a satellite-based method of estimating tundra greenness trend. A more direct indicator of greenness (spatially downscaling solar-induced fluorescence, SIF) was used to analyze the spatial and temporal patterns of Arctic tundra greenness trends based on ordinary least square regression (2007-2013). Meanwhile, two other greenness indices were used for the comparison, which were two NDVI products: GIMMS NDVI3g, and MOD13Q1 Collection 6. Generally, the Arctic tundra was not consistently greening, browning also existed. For the spatial trends, the results showed that most parts of the Arctic tundra below 75ºN was browning (-0.0098 mW/m2/sr/nm/year) using SIF, whereas spatially heterogeneous trends (greening or browning) were obtained based on the two NDVI products. For the temporal trends, the greenness value of Eurasia Arctic tundra is higher than Northern America and the whole Arctic tundra for the three greenness indices. From 2010, the Arctic tundra was greening based on MOD13Q1, whereas is browning using GIMMS NDVI3g. However, the Arctic tundra was obviously browning using SIF data. This study demonstrates a way of investigating the variation of Arctic tundra vegetation via new satellite-observed data.

Variations in freshwater pathways from the Arctic Ocean into the North Atlantic Ocean

NASA Astrophysics Data System (ADS)

Wang, Zeliang; Hamilton, James; Su, Jie

2017-06-01

Understanding the mechanisms that drive exchanges between the Arctic Ocean and adjacent oceans is critical to building our knowledge of how the Arctic is reacting to a warming climate, and how potential changes in Arctic Ocean freshwater export may impact the AMOC (Atlantic Meridional Overturning Circulation). Here, freshwater pathways from the Arctic Ocean to the North Atlantic are investigated using a 1 degree global model. An EOF analysis of modeled sea surface height (SSH) demonstrates that while the second mode accounts for only 15% of the variability, the associated geostrophic currents are strongly correlated with freshwater exports through CAA (Canadian Arctic Archipelago; r = 0.75), Nares Strait (r = 0.77) and Fram Strait (r = -0.60). Separation of sea level into contributing parts allows us to show that the EOF1 is primarily a barotropic mode reflecting variability in bottom pressure equivalent sea level, while the EOF2 mode reflects changes in steric height in the Arctic Basin. This second mode is linked to momentum wind driven surface current, and dominates the Arctic Ocean freshwater exports. Both the Arctic Oscillation and Arctic Dipole atmospheric indices are shown to be linked to Arctic Ocean freshwater exports, with the forcing associated with the Arctic Dipole reflecting the out-of-phase relationship between transports through the CAA and those through Fram Strait. Finally, observed freshwater transport variation through the CAA is found to be strongly correlated with tide gauge data from the Beaufort Sea coast (r = 0.81), and with the EOF2 mode of GRACE bottom pressure data (r = 0.85) on inter-annual timescales.

Survival of ship biofouling assemblages during and after voyages to the Canadian Arctic.

PubMed

Chan, Farrah T; MacIsaac, Hugh J; Bailey, Sarah A

2016-01-01

Human-mediated vectors often inadvertently translocate species assemblages to new environments. Examining the dynamics of entrained species assemblages during transport can provide insights into the introduction risk associated with these vectors. Ship biofouling is a major transport vector of nonindigenous species in coastal ecosystems globally, yet its magnitude in the Arctic is poorly understood. To determine whether biofouling organisms on ships can survive passages in Arctic waters, we examined how biofouling assemblage structure changed before, during, and after eight round-trip military voyages from temperate to Arctic ports in Canada. Species richness first decreased (~70% loss) and then recovered (~27% loss compared to the original assemblages), as ships travelled to and from the Arctic, respectively, whereas total abundance typically declined over time (~55% total loss). Biofouling community structure differed significantly before and during Arctic transits as well as between those sampled during and after voyages. Assemblage structure varied across different parts of the hull; however, temporal changes were independent of hull location, suggesting that niche areas did not provide protection for biofouling organisms against adverse conditions in the Arctic. Biofouling algae appear to be more tolerant of transport conditions during Arctic voyages than are mobile, sessile, and sedentary invertebrates. Our results suggest that biofouling assemblages on ships generally have poor survivorship during Arctic voyages. Nonetheless, some potential for transporting nonindigenous species to the Arctic via ship biofouling remains, as at least six taxa new to the Canadian Arctic, including a nonindigenous cirripede, appeared to have survived transits from temperate to Arctic ports.

Arctic marine fishes and their fisheries in light of global change

PubMed Central

Christiansen, Jørgen S; Mecklenburg, Catherine W; Karamushko, Oleg V

2014-01-01

In light of ocean warming and loss of Arctic sea ice, harvested marine fishes of boreal origin (and their fisheries) move poleward into yet unexploited parts of the Arctic seas. Industrial fisheries, already in place on many Arctic shelves, will radically affect the local fish species as they turn up as unprecedented bycatch. Arctic marine fishes are indispensable to ecosystem structuring and functioning, but they are still beyond credible assessment due to lack of basic biological data. The time for conservation actions is now, and precautionary management practices by the Arctic coastal states are needed to mitigate the impact of industrial fisheries in Arctic waters. We outline four possible conservation actions: scientific credibility, ‘green technology’, legitimate management and overarching coordination. PMID:24105993

Effects of Arctic geoengineering on precipitation in the tropical monsoon regions

NASA Astrophysics Data System (ADS)

Nalam, Aditya; Bala, Govindasamy; Modak, Angshuman

2017-07-01

Arctic geoengineering wherein sunlight absorption is reduced only in the Arctic has been suggested as a remedial measure to counteract the on-going rapid climate change in the Arctic. Several modeling studies have shown that Arctic geoengineering can minimize Arctic warming but will shift the Inter-tropical Convergence Zone (ITCZ) southward, unless offset by comparable geoengineering in the Southern Hemisphere. In this study, we investigate and quantify the implications of this ITCZ shift due to Arctic geoengineering for the global monsoon regions using the Community Atmosphere Model version 4 coupled to a slab ocean model. A doubling of CO2 from pre-industrial levels leads to a warming of 6 K in the Arctic region and precipitation in the monsoon regions increases by up to 15%. In our Arctic geoengineering simulation which illustrates a plausible latitudinal distribution of the reduction in sunlight, an addition of sulfate aerosols (11 Mt) in the Arctic stratosphere nearly offsets the Arctic warming due to CO2 doubling but this shifts the ITCZ southward by 1.5° relative to the pre-industrial climate. The combined effect from this shift and the residual CO2-induced climate change in the tropics is a decrease/increase in annual mean precipitation in the Northern Hemisphere/Southern Hemisphere monsoon regions by up to -12/+17%. Polar geoengineering where sulfate aerosols are prescribed in both the Arctic (10 Mt) and Antarctic (8 Mt) nearly offsets the ITCZ shift due to Arctic geoengineering, but there is still a residual precipitation increase (up to 7%) in most monsoon regions associated with the residual CO2 induced warming in the tropics. The ITCZ shift due to our Global geoengineering simulation, where aerosols (20 Mt) are prescribed uniformly around the globe, is much smaller and the precipitation changes in most monsoon regions are within ±2% as the residual CO2-induced warming in the tropics is also much less than in Arctic and Polar geoengineering. Further, global geoengineering nearly offsets the Arctic warming. Based on our results we infer that Arctic geoengineering leads to ITCZ shift and leaves residual CO2 induced warming in the tropics resulting in substantial precipitation decreases (increases) in the Northern (Southern) hemisphere monsoon regions.

SEARCH: Study of Environmental Arctic Change--A System-scale, Cross-disciplinary Arctic Research Program

NASA Astrophysics Data System (ADS)

Shnoro, R. S.; Eicken, H.; Francis, J. A.; Scambos, T. A.; Schuur, E. A.; Straneo, F.; Wiggins, H. V.

2013-12-01

SEARCH is an interdisciplinary, interagency program that works with academic and government agency scientists and stakeholders to plan, conduct, and synthesize studies of Arctic change. Over the past three years, SEARCH has developed a new vision and mission, a set of prioritized cross-disciplinary 5-year goals, an integrated set of activities, and an organizational structure. The vision of SEARCH is to provide scientific understanding of arctic environmental change to help society understand and respond to a rapidly changing Arctic. SEARCH's 5-year science goals include: 1. Improve understanding, advance prediction, and explore consequences of changing Arctic sea ice. 2. Document and understand how degradation of near-surface permafrost will affect Arctic and global systems. 3. Improve predictions of future land-ice loss and impacts on sea level. 4. Analyze societal and policy implications of Arctic environmental change. Action Teams organized around each of the 5-year goals will serve as standing groups responsible for implementing specific goal activities. Members will be drawn from academia, different agencies and stakeholders, with a range of disciplinary backgrounds and perspectives. 'Arctic Futures 2050' scenarios tasks will describe plausible future states of the arctic system based on recent trajectories and projected changes. These scenarios will combine a range of data including climate model output, paleo-data, results from data synthesis and systems modeling, as well as expert scientific and traditional knowledge. Current activities include: - Arctic Observing Network (AON) - coordinating a system of atmospheric, land- and ocean-based environmental monitoring capabilities that will significantly advance our observations of arctic environmental conditions. - Arctic Sea Ice Outlook - an international effort that provides monthly summer reports synthesizing community estimates of the expected sea ice minimum. A newly-launched Sea Ice Prediction Network will create a network of scientists and stakeholders to generate, assess and communicate Arctic seasonal sea ice forecasts. - Collaboration with the Interagency Arctic Research Policy Committee (IARPC) to implement mutual science goals. SEARCH is sponsored by 8 U.S. agencies, including: the National Science Foundation, the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Defense, the Department of Energy, the Department of the Interior, the Smithsonian Institution, and the U.S. Department of Agriculture. The U.S. Arctic Research Commission participates as an observer. For more information: http://www.arcus.org/search.

Arctic circulation regimes

PubMed Central

Proshutinsky, Andrey; Dukhovskoy, Dmitry; Timmermans, Mary-Louise; Krishfield, Richard; Bamber, Jonathan L.

2015-01-01

Between 1948 and 1996, mean annual environmental parameters in the Arctic experienced a well-pronounced decadal variability with two basic circulation patterns: cyclonic and anticyclonic alternating at 5 to 7 year intervals. During cyclonic regimes, low sea-level atmospheric pressure (SLP) dominated over the Arctic Ocean driving sea ice and the upper ocean counterclockwise; the Arctic atmosphere was relatively warm and humid, and freshwater flux from the Arctic Ocean towards the subarctic seas was intensified. By contrast, during anticylonic circulation regimes, high SLP dominated driving sea ice and the upper ocean clockwise. Meanwhile, the atmosphere was cold and dry and the freshwater flux from the Arctic to the subarctic seas was reduced. Since 1997, however, the Arctic system has been under the influence of an anticyclonic circulation regime (17 years) with a set of environmental parameters that are atypical for this regime. We discuss a hypothesis explaining the causes and mechanisms regulating the intensity and duration of Arctic circulation regimes, and speculate how changes in freshwater fluxes from the Arctic Ocean and Greenland impact environmental conditions and interrupt their decadal variability. PMID:26347536

Fresh Water Content Variability in the Arctic Ocean

NASA Technical Reports Server (NTRS)

Hakkinen, Sirpa; Proshutinsky, Andrey

2003-01-01

Arctic Ocean model simulations have revealed that the Arctic Ocean has a basin wide oscillation with cyclonic and anticyclonic circulation anomalies (Arctic Ocean Oscillation; AOO) which has a prominent decadal variability. This study explores how the simulated AOO affects the Arctic Ocean stratification and its relationship to the sea ice cover variations. The simulation uses the Princeton Ocean Model coupled to sea ice. The surface forcing is based on NCEP-NCAR Reanalysis and its climatology, of which the latter is used to force the model spin-up phase. Our focus is to investigate the competition between ocean dynamics and ice formation/melt on the Arctic basin-wide fresh water balance. We find that changes in the Atlantic water inflow can explain almost all of the simulated fresh water anomalies in the main Arctic basin. The Atlantic water inflow anomalies are an essential part of AOO, which is the wind driven barotropic response to the Arctic Oscillation (AO). The baroclinic response to AO, such as Ekman pumping in the Beaufort Gyre, and ice meldfreeze anomalies in response to AO are less significant considering the whole Arctic fresh water balance.

Gender specific reproductive strategies of an arctic key species (Boreogadus saida) and implications of climate change.

PubMed

Nahrgang, Jasmine; Varpe, Oystein; Korshunova, Ekaterina; Murzina, Svetlana; Hallanger, Ingeborg G; Vieweg, Ireen; Berge, Jørgen

2014-01-01

The Arctic climate is changing at an unprecedented rate. What consequences this may have on the Arctic marine ecosystem depends to a large degree on how its species will respond both directly to elevated temperatures and more indirectly through ecological interactions. But despite an alarming recent warming of the Arctic with accompanying sea ice loss, reports evaluating ecological impacts of climate change in the Arctic remain sparse. Here, based upon a large-scale field study, we present basic new knowledge regarding the life history traits for one of the most important species in the entire Arctic, the polar cod (Boreogadus saida). Furthermore, by comparing regions of contrasting climatic influence (domains), we present evidence as to how its growth and reproductive success is impaired in the warmer of the two domains. As the future Arctic is predicted to resemble today's Atlantic domains, we forecast changes in growth and life history characteristics of polar cod that will lead to alteration of its role as an Arctic keystone species. This will in turn affect community dynamics and energy transfer in the entire Arctic food chain.

Heading-vector navigation based on head-direction cells and path integration.

PubMed

Kubie, John L; Fenton, André A

2009-05-01

Insect navigation is guided by heading vectors that are computed by path integration. Mammalian navigation models, on the other hand, are typically based on map-like place representations provided by hippocampal place cells. Such models compute optimal routes as a continuous series of locations that connect the current location to a goal. We propose a "heading-vector" model in which head-direction cells or their derivatives serve both as key elements in constructing the optimal route and as the straight-line guidance during route execution. The model is based on a memory structure termed the "shortcut matrix," which is constructed during the initial exploration of an environment when a set of shortcut vectors between sequential pairs of visited waypoint locations is stored. A mechanism is proposed for calculating and storing these vectors that relies on a hypothesized cell type termed an "accumulating head-direction cell." Following exploration, shortcut vectors connecting all pairs of waypoint locations are computed by vector arithmetic and stored in the shortcut matrix. On re-entry, when local view or place representations query the shortcut matrix with a current waypoint and goal, a shortcut trajectory is retrieved. Since the trajectory direction is in head-direction compass coordinates, navigation is accomplished by tracking the firing of head-direction cells that are tuned to the heading angle. Section 1 of the manuscript describes the properties of accumulating head-direction cells. It then shows how accumulating head-direction cells can store local vectors and perform vector arithmetic to perform path-integration-based homing. Section 2 describes the construction and use of the shortcut matrix for computing direct paths between any pair of locations that have been registered in the shortcut matrix. In the discussion, we analyze the advantages of heading-based navigation over map-based navigation. Finally, we survey behavioral evidence that nonhippocampal, heading-based navigation is used in small mammals and humans. Copyright 2008 Wiley-Liss, Inc.

7 CFR 868.311 - Grades and grade requirements for the class Second Head Milled Rice. (See also § 868.315.)

Code of Federal Regulations, 2011 CFR

2011-01-01

... Head Milled Rice. (See also § 868.315.) 868.311 Section 868.311 Agriculture Regulations of the... COMMODITIES United States Standards for Milled Rice Principles Governing Application of Standards § 868.311 Grades and grade requirements for the class Second Head Milled Rice. (See also § 868.315.) Grades, Grade...

7 CFR 868.311 - Grades and grade requirements for the class Second Head Milled Rice. (See also § 868.315.)

Code of Federal Regulations, 2010 CFR

2010-01-01

... Head Milled Rice. (See also § 868.315.) 868.311 Section 868.311 Agriculture Regulations of the... COMMODITIES United States Standards for Milled Rice Principles Governing Application of Standards § 868.311 Grades and grade requirements for the class Second Head Milled Rice. (See also § 868.315.) Grades, Grade...

Decomposing of Socioeconomic Inequality in Mental Health: A Cross-Sectional Study into Female-Headed Households.

PubMed

Veisani, Yousef; Delpisheh, Ali

2015-01-01

Connection between socioeconomic statuses and mental health has been reported already. Accordingly, mental health asymmetrically is distributed in society; therefore, people with disadvantaged condition suffer from inconsistent burden of mental disorders. In this study, we aimed to understand the determinants of socioeconomic inequality of mental health in the female-headed households and decomposed contributions of socioeconomic determinants in mental health. In this cross-sectional study, 787 female-headed households were enrolled using systematic random sampling in 2014. Data were taken from the household assets survey and a self-administered 28 item General Health Questionnaire (GHQ-28) as a screening tool for detection of possible cases of mental disorders. Inequality was measured by concentration index (CI) and as decomposing contribution in inequality. All analyses were performed by standard statistical software Stata 11.2. The overall CI for mental health in the female-headed households was -0.049 (95% CI: -0.072, 0.025). The highly positive contributors for inequality in mental health in the female-headed households were age (34%) and poor household economic status (22%). Socioeconomic inequalities exist in mental health into female-headed households and mental health problems more prevalent in women with lower socioeconomic status.

Review of technology for Arctic offshore oil and gas recovery. Appendices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sackinger, W. M.

1980-06-06

This volume contains appendices of the following: US Geological Survey Arctic operating orders, 1979; Det Noske Vertas', rules for the design, construction and inspection of offshore technology, 1977; Alaska Oil and Gas Association, industry research projects, March 1980; Arctic Petroleum Operator's Association, industry research projects, January 1980; selected additional Arctic offshore bibliography on sea ice, icebreakers, Arctic seafloor conditions, ice-structures, frost heave and structure icing.

Circumpolar Arctic vegetation: a hierarchic review and roadmap toward an internationally consistent approach to survey, archive and classify tundra plot data

Treesearch

D A Walker; F J A Daniels; I Alsos; U S Bhatt; A L Breen; M Buchhorn; H Bultmann; L A Druckenmiller; M E Edwards; D Ehrich; H E Epstein; William Gould; R A Ims; H Meltofte; M K Raynolds; J Sibik; S S Talbot; P J Webber

2016-01-01

Satellite-derived remote-sensing products are providing a modern circumpolar perspective of Arctic vegetation and its changes, but this new view is dependent on a long heritage of ground-based observations in the Arctic. Several products of the Conservation of Arctic Flora and Fauna are key to our current understanding.Wereview aspects of the PanArctic Flora, the...

An analysis of the carbon balance of the Arctic Basin from 1997 to 2006

Treesearch

A.D. McGuire; D.J. Hayes; D.W. Kicklighter; M. Manizza; Q. Zhuang; M. Chen; M.J. Follows; K.R. Gurney; J.W. McClelland; J.M. Melillo; B.J. Peterson; R.G. Prinn

2010-01-01

This study used several model-based tools to analyze the dynamics of the Arctic Basin between 1997 and 2006 as a linked system of land-ocean-atmosphere C exchange. The analysis estimates that terrestrial areas of the Arctic Basin lost 62.9 Tg C yr-1 and that the Arctic Ocean gained 94.1 Tg C yr-1. Arctic lands and oceans...

Introduction to the 2008 Circum-Arctic Resource Appraisal (CARA) professional paper

USGS Publications Warehouse

Gautier, Donald L.; Moore, Thomas E.; Moore, Thomas E.; Gautier, D.L.

2017-11-15

The amount of yet-to-find oil and gas in the high northern latitudes is one of the great uncertainties of future energy supply. The possibility of extensive new petroleum developments in the Arctic Ocean is of interest to the Arctic nations, to petroleum companies, and to those concerned with the delicate and changing Arctic environment. The U.S. Geological Survey (USGS) 2008 Circum-Arctic Resource Appraisal (CARA) had the express purpose of conducting a geologically based assessment of undiscovered petroleum north of the Arctic Circle, thereby providing an initial evaluation of resource potential. 

Results of an Arctic Council survey on water and sanitation services in the Arctic.

PubMed

Bressler, Jonathan M; Hennessy, Thomas W

2018-12-01

As part of a project endorsed by the Arctic Council's Sustainable Development Working Group (SDWG), a survey was conducted to describe the current status of water, sanitation and hygiene (WASH) services in the Arctic region. The English language internet-based survey was open from April to September, 2016 and drew 142 respondents from seven Arctic nations. Respondents provided information on access to WASH services, notification requirements for water-related infectious diseases, and examples of environmental- or climate-change related events that impact the provision of WASH services. Many remote Arctic and sub-Arctic residents lack WASH services, and these disparities are often not reflected in national summary data. Environmental changes impacting WASH services were reported by respondents in every Arctic nation. Participants at an international conference co-sponsored by SDWG reviewed these results and provided suggestions for next steps to improve health of Arctic residents through improved access to water and sanitation services. Suggestions included ongoing reporting on WASH service availability in underserved populations to measure progress towards UN Sustainable Development Goal #6; evaluations of the health and economic consequences of disparities in WASH services; and Arctic-specific forums to share innovations in WASH technology, improved management and operations, and adaptation strategies for environmental or climate change.

Results of an Arctic Council survey on water and sanitation services in the Arctic

PubMed Central

Bressler, Jonathan M.; Hennessy, Thomas W.

2018-01-01

ABSTRACT As part of a project endorsed by the Arctic Council’s Sustainable Development Working Group (SDWG), a survey was conducted to describe the current status of water, sanitation and hygiene (WASH) services in the Arctic region. The English language internet-based survey was open from April to September, 2016 and drew 142 respondents from seven Arctic nations. Respondents provided information on access to WASH services, notification requirements for water-related infectious diseases, and examples of environmental- or climate-change related events that impact the provision of WASH services. Many remote Arctic and sub-Arctic residents lack WASH services, and these disparities are often not reflected in national summary data. Environmental changes impacting WASH services were reported by respondents in every Arctic nation. Participants at an international conference co-sponsored by SDWG reviewed these results and provided suggestions for next steps to improve health of Arctic residents through improved access to water and sanitation services. Suggestions included ongoing reporting on WASH service availability in underserved populations to measure progress towards UN Sustainable Development Goal #6; evaluations of the health and economic consequences of disparities in WASH services; and Arctic-specific forums to share innovations in WASH technology, improved management and operations, and adaptation strategies for environmental or climate change. PMID:29383987

Early 20th Century Arctic Warming Intensified by Pacific and Atlantic Multidecadal Variability

NASA Astrophysics Data System (ADS)

Tokinaga, H.; Xie, S. P.; Mukougawa, H.

2017-12-01

We investigate the influence of Pacific and Atlantic multidecadal variability on the Arctic temperature, with a particular focus on the early 20th century Arctic warming. Arctic surface air temperature increased rapidly over the early 20th century, at rates comparable to those of recent decades despite much weaker greenhouse gas forcing than at present. We find that the concurrent phase shift of Pacific and Atlantic multidecadal variability is the major driver for the early 20th century Arctic warming. Atmospheric model simulations reproduce the early Arctic warming when the interdecadal variability of sea surface temperature (SST) is properly prescribed. The early Arctic warming is associated with the cold-to-warm phase shifts of Atlantic and Pacific multidecadal variability modes, a SST pattern reminiscent of the positive phase of the Pacific decadal and Atlantic multidecadal oscillations. The extratropical North Atlantic and North Pacific SST warming strengthens surface westerly winds over northern Eurasia, intensifying the warming there. The equatorial Pacific warming deepens the Aleutian low, advecting warm air to the North American Arctic. Coupled ocean-atmosphere simulations support the constructive intensification of Arctic warming by a concurrent, cold-to-warm phase shift of the Pacific and Atlantic multidecadal variability. Our results aid attributing the historical Arctic warming and thereby constrain the amplified warming projected for this important region.

Abnormal Winter Melting of the Arctic Sea Ice Cap Observed by the Spaceborne Passive Microwave Sensors

NASA Astrophysics Data System (ADS)

Lee, Seongsuk; Yi, Yu

2016-12-01

The spatial size and variation of Arctic sea ice play an important role in Earth’s climate system. These are affected by conditions in the polar atmosphere and Arctic sea temperatures. The Arctic sea ice concentration is calculated from brightness temperature data derived from the Defense Meteorological Satellite program (DMSP) F13 Special Sensor Microwave/Imagers (SSMI) and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS) sensors. Many previous studies point to significant reductions in sea ice and their causes. We investigated the variability of Arctic sea ice using the daily sea ice concentration data from passive microwave observations to identify the sea ice melting regions near the Arctic polar ice cap. We discovered the abnormal melting of the Arctic sea ice near the North Pole during the summer and the winter. This phenomenon is hard to explain only surface air temperature or solar heating as suggested by recent studies. We propose a hypothesis explaining this phenomenon. The heat from the deep sea in Arctic Ocean ridges and/ or the hydrothermal vents might be contributing to the melting of Arctic sea ice. This hypothesis could be verified by the observation of warm water column structure below the melting or thinning arctic sea ice through the project such as Coriolis dataset for reanalysis (CORA).

Integrating Research on Global Climate Change and Human Use of the Oceans: a Geospatial Method for Daily Monitoring of Sea Ice and Ship Traffic in the Arctic

NASA Astrophysics Data System (ADS)

Eucker, W.; McGillivary, P. A.

2012-12-01

One apparent consequence of global climate change has been a decrease in the extent and thickness of Arctic sea ice more rapidly than models have predicted, while Arctic ship traffic has likewise increased beyond economic predictions. To ensure representative observations of changing climate conditions and human use of the Arctic Ocean, we concluded a method of tracking daily changes in both sea ice and shipping in the Arctic Ocean was needed. Such a process improves the availability of sea ice data for navigational safety and allows future developments to be monitored for understanding of ice and shipping in relation to policy decisions appropriate to optimize sustainable use of a changing Arctic Ocean. The impetus for this work was the 2009 Arctic Marine Shipping Assessment (AMSA) which provided baseline data on Arctic ship traffic. AMSA was based on responses from circumpolar countries, was manpower intensive, and took years to compile. A more timely method of monitoring human use of the Arctic Ocean was needed. To address this, a method of monitoring sea ice on a scale relevant to ship-navigation (<10km) was developed and implemented in conjunction with arctic ship tracking using S-AIS (Satellite Automatic Identification Systems). S-AIS is internationally required on ships over a certain size, which includes most commercial vessels in the Arctic Ocean. Daily AIS and sea ice observations were chosen for this study. Results of this method of geospatial analysis of the entire arctic are presented for a year long period from April 1, 2010 to March 31, 2011. This confirmed the dominance of European Arctic ship traffic. Arctic shipping is maximal during August and diminishes in September with a minimum in winter, although some shipping continues year-round in perennially ice-free areas. Data are analyzed for the four principal arctic quadrants around the North Pole by season for number and nationality of vessels. The goal of this study was not merely to monitor ship traffic and ice conditions concurrently, but also to demonstrate a new method of ocean monitoring based on daily assimilation, data fusion, and integrated visualization of satellite ice remote sensing data and S-AIS ship data. In the future, as Arctic ship traffic and cryosphere sea ice cover variability are both expected to increase, this method can provide near real-time physical data on global climate change and human dimensions of ocean use of to guide policies addressing arctic resource management, Search and Rescue (SAR) operations, oil spill response, and issues such as ship noise impacts on marine mammals, and whale-ship collision avoidance. An internationally agreed implementation of this methodology would benefit ships operating in the Arctic and advance sustainable use of the Arctic Ocean.

Knowledge and application of correct car seat head restraint usage among chiropractic college interns: a cross-sectional study.

PubMed

Taylor, John Am; Burke, Jeanmarie; Gavencak, John; Panwar, Pervinder

2005-03-01

Cervical spine injuries sustained in rear-end crashes cost at least $7 billion in insurance claims annually in the United States alone. When positioned correctly, head restraint systems have been proven effective in reducing the risk of whiplash associated disorders. Chiropractors should be knowledgeable about the correct use of head restraint systems to educate their patients and thereby prevent or minimize such injuries. The primary objective of this study was to determine the prevalence of correct positioning of car seat head restraints among the interns at our institution. The secondary objective was to determine the same chiropractic interns' knowledge of the correct positioning of car seat head restraints. It was hypothesized that 100 percent of interns would have their head restraint correctly positioned within an acceptable range and that all interns would possess the knowledge to instruct patients in the correct positioning of head restraints. Cross-sectional study of a convenient sample of 30 chiropractic interns from one institution. Interns driving into the parking lot of our health center were asked to volunteer to have measurements taken and to complete a survey. Vertical and horizontal positions of the head restraint were measured using a beam compass. A survey was administered to determine knowledge of correct head restraint position. The results were recorded, entered into a spreadsheet, and analyzed. 13.3 percent of subjects knew the recommended vertical distance and only 20 percent of subjects knew the recommended horizontal distance. Chi Square analyses substantiated that the majority of subjects were unaware of guidelines set forth by the National Highway Traffic Safety Administration (NHTSA) for the correct positioning of the head restraint (chi(2) (vertical) = 16.13, chi(2) (horizontal) = 10.80, p <.05). Only 6.7 percent of the subjects positioned their head restraint at the vertical distance of 6 cm or less (p <.05). However, 60 percent of the subjects positioned their head restraint at the recommended horizontal distance of 7 cm or less, but this was no different than could be expected by chance alone (p >.05). Interestingly, the 13.3 percent of the subjects who were aware of the vertical plane recommendations did not correctly position their own head restraint in the vertical plane. Similarly, only half of the subjects who were aware of the horizontal plane recommendations correctly positioned their head restraint in the horizontal plane. The data suggest that chance alone could account for the correct positioning of the head restraint in our subjects. The results of this cross-sectional study raise concerns about chiropractic intern knowledge and application of correct head restraint positioning. The importance of chiropractors informing patients of the correct head restraint position should be emphasized in chiropractic education to help minimize or prevent injury in patients involved in motor vehicle collisions.

Early 20th-century Arctic warming intensified by Pacific and Atlantic multidecadal variability

PubMed Central

Tokinaga, Hiroki; Xie, Shang-Ping; Mukougawa, Hitoshi

2017-01-01

With amplified warming and record sea ice loss, the Arctic is the canary of global warming. The historical Arctic warming is poorly understood, limiting our confidence in model projections. Specifically, Arctic surface air temperature increased rapidly over the early 20th century, at rates comparable to those of recent decades despite much weaker greenhouse gas forcing. Here, we show that the concurrent phase shift of Pacific and Atlantic interdecadal variability modes is the major driver for the rapid early 20th-century Arctic warming. Atmospheric model simulations successfully reproduce the early Arctic warming when the interdecadal variability of sea surface temperature (SST) is properly prescribed. The early 20th-century Arctic warming is associated with positive SST anomalies over the tropical and North Atlantic and a Pacific SST pattern reminiscent of the positive phase of the Pacific decadal oscillation. Atmospheric circulation changes are important for the early 20th-century Arctic warming. The equatorial Pacific warming deepens the Aleutian low, advecting warm air into the North American Arctic. The extratropical North Atlantic and North Pacific SST warming strengthens surface westerly winds over northern Eurasia, intensifying the warming there. Coupled ocean–atmosphere simulations support the constructive intensification of Arctic warming by a concurrent, negative-to-positive phase shift of the Pacific and Atlantic interdecadal modes. Our results aid attributing the historical Arctic warming and thereby constrain the amplified warming projected for this important region. PMID:28559341

Trends in the Diversity, Distribution and Life History Strategy of Arctic Hydrozoa (Cnidaria)

PubMed Central

Ronowicz, Marta; Kukliński, Piotr; Mapstone, Gillian M.

2015-01-01

This is the first attempt to compile a comprehensive and updated species list for Hydrozoa in the Arctic, encompassing both hydroid and medusa stages and including Siphonophorae. We address the hypothesis that the presence of a pelagic stage (holo- or meroplanktonic) was not necessary to successfully recolonize the Arctic by Hydrozoa after the Last Glacial Maximum. Presence-absence data of Hydrozoa in the Arctic were prepared on the basis of historical and present-day literature. The Arctic was divided into ecoregions. Species were grouped into distributional categories according to their worldwide occurrences. Each species was classified according to life history strategy. The similarity of species composition among regions was calculated with the Bray-Curtis index. Average and variation in taxonomic distinctness were used to measure diversity at the taxonomic level. A total of 268 species were recorded. Arctic-boreal species were the most common and dominated each studied region. Nineteen percent of species were restricted to the Arctic. There was a predominance of benthic species over holo- and meroplanktonic species. Arctic, Arctic-Boreal and Boreal species were mostly benthic, while widely distributed species more frequently possessed a pelagic stage. Our results support hypothesis that the presence of a pelagic stage (holo- or meroplanktonic) was not necessary to successfully recolonize the Arctic. The predominance of benthic Hydrozoa suggests that the Arctic could have been colonised after the Last Glacial Maximum by hydroids rafting on floating substrata or recolonising from glacial refugia. PMID:25793294

Trends in the diversity, distribution and life history strategy of Arctic Hydrozoa (Cnidaria).

PubMed

Ronowicz, Marta; Kukliński, Piotr; Mapstone, Gillian M

2015-01-01

This is the first attempt to compile a comprehensive and updated species list for Hydrozoa in the Arctic, encompassing both hydroid and medusa stages and including Siphonophorae. We address the hypothesis that the presence of a pelagic stage (holo- or meroplanktonic) was not necessary to successfully recolonize the Arctic by Hydrozoa after the Last Glacial Maximum. Presence-absence data of Hydrozoa in the Arctic were prepared on the basis of historical and present-day literature. The Arctic was divided into ecoregions. Species were grouped into distributional categories according to their worldwide occurrences. Each species was classified according to life history strategy. The similarity of species composition among regions was calculated with the Bray-Curtis index. Average and variation in taxonomic distinctness were used to measure diversity at the taxonomic level. A total of 268 species were recorded. Arctic-boreal species were the most common and dominated each studied region. Nineteen percent of species were restricted to the Arctic. There was a predominance of benthic species over holo- and meroplanktonic species. Arctic, Arctic-Boreal and Boreal species were mostly benthic, while widely distributed species more frequently possessed a pelagic stage. Our results support hypothesis that the presence of a pelagic stage (holo- or meroplanktonic) was not necessary to successfully recolonize the Arctic. The predominance of benthic Hydrozoa suggests that the Arctic could have been colonised after the Last Glacial Maximum by hydroids rafting on floating substrata or recolonising from glacial refugia.

Concentration data and dimensionality in groundwater models: evaluation using inverse modelling

USGS Publications Warehouse

Barlebo, H.C.; Hill, M.C.; Rosbjerg, D.; Jensen, K.H.

1998-01-01

A three-dimensional inverse groundwater flow and transport model that fits hydraulic-head and concentration data simultaneously using nonlinear regression is presented and applied to a layered sand and silt groundwater system beneath the Grindsted Landfill in Denmark. The aquifer is composed of rather homogeneous hydrogeologic layers. Two issues common to groundwater flow and transport modelling are investigated: 1) The accuracy of simulated concentrations in the case of calibration with head data alone; and 2) The advantages and disadvantages of using a two-dimensional cross-sectional model instead of a three-dimensional model to simulate contaminant transport when the source is at the land surface. Results show that using only hydraulic heads in the nonlinear regression produces a simulated plume that is profoundly different from what is obtained in a calibration using both hydraulic-head and concentration data. The present study provides a well-documented example of the differences that can occur. Representing the system as a two-dimensional cross-section obviously omits some of the system dynamics. It was, however, possible to obtain a simulated plume cross-section that matched the actual plume cross-section well. The two-dimensional model execution times were about a seventh of those for the three-dimensional model, but some difficulties were encountered in representing the spatially variable source concentrations and less precise simulated concentrations were calculated by the two-dimensional model compared to the three-dimensional model. Summed up, the present study indicates that three dimensional modelling using both hydraulic heads and concentrations in the calibration should be preferred in the considered type of transport studies.

75 FR 58350 - Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-24

... UNITED STATES ARCTIC RESEARCH COMMISSION Meeting Notice is hereby given that the U.S. Arctic... reports. (4) Discussion and presentations concerning Arctic research activities. The focus of the meeting will be reports and updates on programs and research projects affecting the Arctic. If you plan to...

Prevalence of seizures in cats after head trauma.

PubMed

Grohmann, Kristina S; Schmidt, Martin J; Moritz, Andreas; Kramer, Martin

2012-12-01

To determine the prevalence of seizures in cats after head trauma. Retrospective cross-sectional study. 52 cats with head trauma. Information was obtained from medical records of cats with head trauma and via telephone interviews of owners at least 2 years after cats had head trauma. Severity of head trauma in cats was classified with the modified Glasgow coma scale (mGCS), and the association between scores and development of seizures was determined. 9 cats had moderate head trauma (mGCS score, 9 to 14), and 43 cats had mild head trauma (mGCS score, 15 to 18). None of the cats developed seizures during the follow-up period (≥ 2 years after head injury). The calculated 95% confidence interval for prevalence of seizures in cats after head injury was 0% to 5.6%. There was no significant relationship between severity of head trauma and the risk of seizures in cats. Results indicated the probability that cats with mild to moderate head trauma would develop posttraumatic seizures was low. However, clinicians should monitor cats with a history of head trauma for development of secondary epilepsy.

49 CFR 572.32 - Head.

Code of Federal Regulations, 2011 CFR

2011-10-01

... midsagittal plane is vertical. EC01AU91.162 (4) Drop the head from the specified height by means that ensure... dropped from a height of 14.8 inches in accordance with paragraph (c) of this section, the peak resultant...

49 CFR 572.32 - Head.

Code of Federal Regulations, 2013 CFR

2013-10-01

... midsagittal plane is vertical. EC01AU91.162 (4) Drop the head from the specified height by means that ensure... dropped from a height of 14.8 inches in accordance with paragraph (c) of this section, the peak resultant...

Multinational Experiment 7. Maritime Security Region: The Arctic

DTIC Science & Technology

2013-07-08

Russia. Marine Resources The Arctic Ocean is home to countless species from microscopic plankton to gigantic whales . Large-scale commercial...Arctic is a circumpolar region that encompasses both marine and land masses and includes the Arctic Ocean and its seas that cover more than 30...and does not rise on the day of the winter solstice. The Arctic Ocean is the world’s smallest and shallowest, with an average depth of roughly a

Biological Environmental Arctic Project (BEAP) Preliminary Data (Arctic West Summer 1986 Cruise).

DTIC Science & Technology

1986-11-01

predictive model of bioluminescence in near-surface arctic waters . Data were collected during Arctic West Summer 1986 from USCG POLAR STAR (WAGB 10). . %. J...2 20ODISTRIBUTION AVAILABILIT "Y OF ABSTRACT 21 ABSTRACT SECURITY CLASSIFICATION C]UNCLASSIFIED UNLIMITED SAME AS RPT C] DTIC USERS UNCLASSIFIED David...correlates for a predictive model of bioluminescence in near-surface arctic waters . - In previous years, these measurements were conducted from the USCG

Distribution of Aerosols in the Arctic as Observed by CALIOP

NASA Astrophysics Data System (ADS)

Winker, D.; Kittaka, C.

2007-12-01

The Arctic climate is now recognized to be uniquely sensitive to atmospheric perturbations. Pollution aerosols and smoke from boreal fires have potentially important impacts on Arctic climate but there are many uncertainties. Aerosol in the Arctic, generally referred to as "Arctic haze", has been studied with great interest for over thirty years. Much has been learned about the composition and sources of the haze yet our knowledge is largely based on long term measurements at a very few widely dispersed sites, augmented by modeling activities and occasional field campaigns. Transport pathways from source regions into the Arctic are not well understood. Emission patterns have changed over the last several decades, but the impact of this on concentrations and distribution of Arctic haze are understood only in the crudest sense. Due to poor lighting conditions, extended periods of darkness, and surfaces covered by snow and ice, satellite sensors have been unable to provide much information on Arctic haze to date. The CALIPSO satellite carries CALIOP, a two-wavelength polarization lidar, optimized for profiling clouds and aerosols. CALIOP has been acquiring global observations since June 2006 and provides our first opportunity to observe the distribution and seasonal variation of aerosol in the Arctic. The Arctic is characterized by the prevalence of optically thin ice clouds and clouds composed of supercooled water, often occurring in the same atmospheric column along with aerosol. CALIOP depolarization signals are used to discriminate Arctic haze from optically thin cirrus and diamond dust. Two-wavelength returns aid in the discrimination of aerosol and optically thin water cloud. Results of initial analyses of CALIOP aerosol observations in the Arctic will be presented. This work is a preliminary analysis in support of the NASA Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign planned for April 2008.

Higher incidence of nasopharyngeal carcinoma in some regions in the world confers for interplay between genetic factors and external stimuli.

PubMed

Roy Chattopadhyay, Nabanita; Das, Piyanki; Chatterjee, Koustav; Choudhuri, Tathagata

2017-01-01

Nasopharyngeal carcinoma (NPC) is a rare variety of head and neck cancers. The risk factors include three major causes: genetic factors, viral infection, and environmental and dietary factors. The types of NPC show strong ethnic and geographic variations. The keratinizing and non-keratinizing types are prevalent in the lower incidence regions like North America and Europe; whereas the undifferentiated type is mostly found in the regions with higher incidences like China, North Africa, Arctic, and Nagaland of North-East India. These suggest a possible major role of the internal genetic factors for generation and promotion of this disease. Viral infections might accelerate the process of carcinogenesis by helping in cellular proliferation and loss of apoptosis. Diet and other environmental factors promote these neoplastic processes and further progression of the disease occurs.

75 FR 79334 - Meeting Notice

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-20

... ARCTIC RESEARCH COMMISSION Meeting Notice Notice is hereby given that the U.S. Arctic Research...) Discussion and presentations concerning Arctic research activities. The focus of the meeting will be reports and updates on programs and research projects affecting the Arctic. If you plan to attend this meeting...

The impact of lower sea-ice extent on Arctic greenhouse-gas exchange

USGS Publications Warehouse

Parmentier, Frans-Jan W.; Christensen, Torben R.; Sørensen, Lise Lotte; Rysgaard, Søren; McGuire, A. David; Miller, Paul A.; Walker, Donald A.

2013-01-01

In September 2012, Arctic sea-ice extent plummeted to a new record low: two times lower than the 1979–2000 average. Often, record lows in sea-ice cover are hailed as an example of climate change impacts in the Arctic. Less apparent, however, are the implications of reduced sea-ice cover in the Arctic Ocean for marine–atmosphere CO2 exchange. Sea-ice decline has been connected to increasing air temperatures at high latitudes. Temperature is a key controlling factor in the terrestrial exchange of CO2 and methane, and therefore the greenhouse-gas balance of the Arctic. Despite the large potential for feedbacks, many studies do not connect the diminishing sea-ice extent with changes in the interaction of the marine and terrestrial Arctic with the atmosphere. In this Review, we assess how current understanding of the Arctic Ocean and high-latitude ecosystems can be used to predict the impact of a lower sea-ice cover on Arctic greenhouse-gas exchange.

Contribution of Arctic seabird-colony ammonia to atmospheric particles and cloud-albedo radiative effect

NASA Astrophysics Data System (ADS)

Croft, B.; Wentworth, G. R.; Martin, R. V.; Leaitch, W. R.; Murphy, J. G.; Murphy, B. N.; Kodros, J. K.; Abbatt, J. P. D.; Pierce, J. R.

2016-11-01

The Arctic region is vulnerable to climate change and able to affect global climate. The summertime Arctic atmosphere is pristine and strongly influenced by natural regional emissions, which have poorly understood climate impacts related to atmospheric particles and clouds. Here we show that ammonia from seabird-colony guano is a key factor contributing to bursts of newly formed particles, which are observed every summer in the near-surface atmosphere at Alert, Nunavut, Canada. Our chemical-transport model simulations indicate that the pan-Arctic seabird-influenced particles can grow by sulfuric acid and organic vapour condensation to diameters sufficiently large to promote pan-Arctic cloud-droplet formation in the clean Arctic summertime. We calculate that the resultant cooling tendencies could be large (about -0.5 W m-2 pan-Arctic-mean cooling), exceeding -1 W m-2 near the largest seabird colonies due to the effects of seabird-influenced particles on cloud albedo. These coupled ecological-chemical processes may be susceptible to Arctic warming and industrialization.

Dynamical amplification of Arctic and global warming

NASA Astrophysics Data System (ADS)

Alekseev, Genrikh; Ivanov, Nikolai; Kharlanenkova, Natalia; Kuzmina, Svetlana; Bobylev, Leonid; Gnatiuk, Natalia; Urazgildeeva, Aleksandra

2015-04-01

The Arctic is coupled with global climate system by the atmosphere and ocean circulation that provides a major contribution to the Arctic energy budget. Therefore increase of meridional heat transport under global warming can impact on its Arctic amplification. Contribution of heat transport to the recent warming in the Arctic, Northern Hemisphere and the globe are estimated on base of reanalysis data, global climate model data and proposed special index. It is shown that significant part of linear trend during last four decades in average surface air temperature in these areas can be attributed to dynamical amplification. This attribution keeps until 400 mb height with progressive decreasing. The Arctic warming is amplified also due to an increase of humidity and cloudiness in the Arctic atmosphere that follow meridional transport gain. From October to January the Arctic warming trends are amplified as a result of ice edge retreat from the Siberian and Alaska coast and the heating of expanded volume of sea water. This investigation is supported with RFBR project 15-05-03512.

Contribution of Arctic seabird-colony ammonia to atmospheric particles and cloud-albedo radiative effect.

PubMed

Croft, B; Wentworth, G R; Martin, R V; Leaitch, W R; Murphy, J G; Murphy, B N; Kodros, J K; Abbatt, J P D; Pierce, J R

2016-11-15

The Arctic region is vulnerable to climate change and able to affect global climate. The summertime Arctic atmosphere is pristine and strongly influenced by natural regional emissions, which have poorly understood climate impacts related to atmospheric particles and clouds. Here we show that ammonia from seabird-colony guano is a key factor contributing to bursts of newly formed particles, which are observed every summer in the near-surface atmosphere at Alert, Nunavut, Canada. Our chemical-transport model simulations indicate that the pan-Arctic seabird-influenced particles can grow by sulfuric acid and organic vapour condensation to diameters sufficiently large to promote pan-Arctic cloud-droplet formation in the clean Arctic summertime. We calculate that the resultant cooling tendencies could be large (about -0.5 W m -2 pan-Arctic-mean cooling), exceeding -1 W m -2 near the largest seabird colonies due to the effects of seabird-influenced particles on cloud albedo. These coupled ecological-chemical processes may be susceptible to Arctic warming and industrialization.

Twentieth century bipolar seesaw of the Arctic and Antarctic surface air temperatures

NASA Astrophysics Data System (ADS)

Chylek, Petr; Folland, Chris K.; Lesins, Glen; Dubey, Manvendra K.

2010-04-01

Understanding the phase relationship between climate changes in the Arctic and Antarctic regions is essential for our understanding of the dynamics of the Earth's climate system. In this paper we show that the 20th century de-trended Arctic and Antarctic temperatures vary in anti-phase seesaw pattern - when the Arctic warms the Antarctica cools and visa versa. This is the first time that a bi-polar seesaw pattern has been identified in the 20th century Arctic and Antarctic temperature records. The Arctic (Antarctic) de-trended temperatures are highly correlated (anti-correlated) with the Atlantic Multi-decadal Oscillation (AMO) index suggesting the Atlantic Ocean as a possible link between the climate variability of the Arctic and Antarctic regions. Recent accelerated warming of the Arctic results from a positive reinforcement of the linear warming trend (due to an increasing concentration of greenhouse gases and other possible forcings) by the warming phase of the multidecadal climate variability (due to fluctuations of the Atlantic Ocean circulation).

Integrated regional changes in arctic climate feedbacks: Implications for the global climate system

USGS Publications Warehouse

McGuire, A.D.; Chapin, F. S.; Walsh, J.E.; Wirth, C.; ,

2006-01-01

The Arctic is a key part of the global climate system because the net positive energy input to the tropics must ultimately be resolved through substantial energy losses in high-latitude regions. The Arctic influences the global climate system through both positive and negative feedbacks that involve physical, ecological, and human systems of the Arctic. The balance of evidence suggests that positive feedbacks to global warming will likely dominate in the Arctic during the next 50 to 100 years. However, the negative feedbacks associated with changing the freshwater balance of the Arctic Ocean might abruptly launch the planet into another glacial period on longer timescales. In light of uncertainties and the vulnerabilities of the climate system to responses in the Arctic, it is important that we improve our understanding of how integrated regional changes in the Arctic will likely influence the evolution of the global climate system. Copyright ?? 2006 by Annual Reviews. All rights reserved.

The Arctic-Subarctic Sea Ice System is Entering a Seasonal Regime: Implications for Future Arctic Amplication

NASA Astrophysics Data System (ADS)

Haine, T. W. N.; Martin, T.

2017-12-01

The loss of Arctic sea ice is a conspicuous example of climate change. Climate models project ice-free conditions during summer this century under realistic emission scenarios, reflecting the increase in seasonality in ice cover. To quantify the increased seasonality in the Arctic-Subarctic sea ice system, we define a non-dimensional seasonality number for sea ice extent, area, and volume from satellite data and realistic coupled climate models. We show that the Arctic-Subarctic, i.e. the northern hemisphere, sea ice now exhibits similar levels of seasonality to the Antarctic, which is in a seasonal regime without significant change since satellite observations began in 1979. Realistic climate models suggest that this transition to the seasonal regime is being accompanied by a maximum in Arctic amplification, which is the faster warming of Arctic latitudes compared to the global mean, in the 2010s. The strong link points to a peak in sea-ice-related feedbacks that occurs long before the Arctic becomes ice-free in summer.

The Impact of Transported Pollution on Arctic Climate

NASA Astrophysics Data System (ADS)

Quinn, P.; Stohl, A.; Arneth, A.; Berntsen, T.; Burkhart, J. F.; Flanner, M. G.; Kupiainen, K.; Shepherd, M.; Shevchenko, V. P.; Skov, H.; Vestreng, V.

2011-12-01

Arctic temperatures have increased at almost twice the global average rate over the past 100 years. Warming in the Arctic has been accompanied by an earlier onset of spring melt, a lengthening of the melt season, changes in the mass balance of the Greenland ice sheet, and a decrease in sea ice extent. Short-lived, climate warming pollutants such as black carbon (BC) have recently gained attention as a target for immediate mitigation of Arctic warming in addition to reductions in long lived greenhouse gases. Model calculations indicate that BC increases surface temperatures within the Arctic primarily through deposition on snow and ice surfaces with a resulting decrease in surface albedo and increase in absorbed solar radiation. In 2009, the Arctic Monitoring and Assessment Program (AMAP) established an Expert Group on BC with the goal of identifying source regions and energy sectors that have the largest impact on Arctic climate. Here we present the results of this work and investigate links between mid-latitude pollutants and Arctic climate.

The Importance of Habit Evolution for Maintaining Supercooled Liquid in Arctic Clouds

NASA Astrophysics Data System (ADS)

Sulia, K. J.; Harrington, J. Y.

2010-12-01

Low-level clouds cover large sections of the Arctic for much of the year, and these clouds are generally composed of supercooled liquid and contain regions of ice. These supercooled liquid clouds can persist for long periods of time with a large spatial extent. What are not well understood are the mechanisms whereby these clouds are able to maintain a supercooled liquid state rather than dissipating through the Bergeron mechanism, or the process by which ice crystals grow at the expense of liquid drops, with ice precipitation leading to cloud dissipation. Most prior research has focused on ice nucleation as providing a critical, first-order control on the glaciation rates of supercooled Arctic clouds. Ice nucleation is critical for its control over ice concentration, which then feeds into liquid depletion through its influence on the total ice mass growth rates. In addition, ice particle habit evolution can also strongly affect ice mass; however, the vapor growth rates based on habit evolution are routinely ignored in most mixed-phase methods. Most prior studies assume simple shapes or spheres as a proxy for ice habits. Recent studies have suggested that these simplified methods produce large uncertainties in estimates of the vapor growth rates, and hence the rate of glaciation, in supercooled clouds. Our studies show that these uncertainties are due to the inability of most models to predict ice particle aspect ratio. We therefore present results that help clarify the influence of ice habit on glaciation. We show that habit prediction is critical for estimates of glaciation in supercooled clouds, and that this is most important when ice concentrations are relatively low, as they appear to be in the Arctic.

Remote Sensing, Modeling, and In-Situ Measurements to Study the Spring and Summer Thermal Regime of the Kuparuk River, Northern Alaska

NASA Astrophysics Data System (ADS)

Floyd, A.; Liljedahl, A. K.; Gens, R.; Prakash, A.; Mann, D. H.

2011-12-01

A combined use of remote sensing techniques, modeling and in-situ measurements is a pragmatic approach to study arctic hydrology, given the vastness, complexity, and logistical challenges posed by most arctic watersheds. Remote sensing techniques can provide tools to assess the geospatial variations that form the integrated response of a river system and therefore provide important details to study climate change effects on the remote arctic environment. The proposed study tests the applicability of remote sensing and modeling techniques to map, monitor and compare river temperatures and river break-up in the coastal and foothill sections of the Kuparak River, which is an intensely studied watershed. We co-registered about hundred synthetic aperture radar (SAR) images from RADARSAT-1, ERS-1 and ERS-2 satellites, acquired during the months of May through July for a period between 1999 and 2010. Co-registration involved a Fast Fourier Transform (FFT) match of amplitude images. The offsets were then applied to the radiometrically corrected SAR images, converted to dB values, to generate an image stack. We applied a mask to extract pixels representing only the river, and used an adaptive threshold to delineate open water from frozen areas. The variation in river break-up can be bracketed by defining open vs. frozen river conditions. Summer river surface water temperatures will be simulated through the well-established HEC-RAS hydrologic software package and validated with field measurements. The three-pronged approach of using remote sensing, modeling and field measurements demonstrated in this study can be adapted to work for other watersheds across the Arctic.

Detecting and Understanding Changing Arctic Carbon Emissions

NASA Astrophysics Data System (ADS)

Bruhwiler, L.

2017-12-01

Warming in the Arctic has proceeded faster than anyplace on Earth. Our current understanding of biogeochemistry suggests that we can expect feedbacks between climate and carbon in the Arctic. Changes in terrestrial fluxes of carbon can be expected as the Arctic warms, and the vast stores of organic carbon frozen in Arctic soils could be mobilized to the atmosphere, with possible significant impacts on global climate. Quantifying trends in Arctic carbon exchanges is important for policymaking because greater reductions in anthropogenic emissions may be required to meet climate goals. Observations of greenhouse gases in the Arctic and globally have been collected for several decades. Analysis of this data does not currently support significantly changed Arctic emissions of CH4, however it is difficult to detect changes in Arctic emissions because of transport from lower latitudes and large inter-annual variability. Unfortunately, current space-based remote sensing systems have limitations at Arctic latitudes. Modeling systems can help untangle the Arctic budget of greenhouse gases, but they are dependent on underlying prior fluxes, wetland distributions and global anthropogenic emissions. Also, atmospheric transport models may have significant biases and errors. For example, unrealistic near-surface stability can lead to underestimation of emissions in atmospheric inversions. We discuss our current understanding of the Arctic carbon budget from both top-down and bottom-up approaches. We show that current atmospheric inversions agree well on the CH4 budget. On the other hand, bottom-up models vary widely in their predictions of natural emissions, with some models predicting emissions too large to be accommodated by the budget implied by global observations. Large emissions from the shallow Arctic ocean are also inconsistent with atmospheric observations. We also discuss the sensitivity of the current atmospheric network to what is likely small, gradual increases in emissions over time by examining modeled and observed spatial and seasonal variability. An issue we will consider is whether well-mixed background atmospheric records are more likely to detect changing Arctic emissions compared to stronger, but more variable signal from local sources.

Arctic System Science: Meeting Earth System and Social Impact Challenges through Integrative Approaches and Synthesis

NASA Astrophysics Data System (ADS)

Vorosmarty, C. J.; Hinzman, L. D.; Rawlins, M. A.; Serreze, M. C.; Francis, J. A.; Liljedahl, A. K.; McDonald, K. C.; Piasecki, M.; Rich, R. H.; Holland, M. M.

2017-12-01

The Arctic is an integral part of the Earth system where multiple interactions unite its natural and human elements. Recent observations show the Arctic to be experiencing rapid and amplified signatures of global climate change. At the same time, the Arctic system's response to this broader forcing has itself become a central research topic, given its potential role as a critical throttle on future planetary dynamics. Changes are already impacting life systems and economic prosperity and continued change is expected to bear major implications far outside the region. We also have entered an era when environmental management, traditionally local in scope, must confront regional, whole biome, and pan-Arctic biogeophysical challenges. While challenges may appear to operate in isolation, they emerge within the context of an evolving, integrated Arctic system defined by interactions among natural and social sub-systems. Clearly, new efforts aimed at community planning, industrial development, and infrastructure construction must consider this multiplicity of interacting processes. We recently organized an "Arctic System Synthesis Workshop Series" supported by the Arctic Systems Science Program of NSF and devoted to exploring approaches capable of uncovering the systems-level behavior in both the natural and social sciences domains. The series featured two topical meetings. The first identified the sources responsible for extreme climate events in the Arctic. The second focused on multiple "currencies" within the system (i.e., water, energy, carbon, nutrients) and how they interact to produce systems-level behaviors. More than 40 experts participated, drawn from the ranks of Arctic natural and social sciences. We report here on the workshop series consensus report, which identifies a broad array of topics. Principal among these are a consideration of why study the Arctic as a system, as well as an articulation of the major systems-level approaches to support basic as well as policy-relevant research on the Arctic. Two examples of these approaches are given with respect to extremes (exposure, impacts and reverberations within and outside of the Arctic) and currencies (their role in "uniting" the Arctic as an interacting system). We will also review some proposed programmatic elements to support this new science.

Temporal and Longitudinal Mercury Trends in Burbot (Lota lota) in the Russian Arctic.

PubMed

Pelletier, Alexander R; Castello, Leandro; Zhulidov, Alexander V; Gurtovaya, Tatiana Yu; Robarts, Richard D; Holmes, Robert M; Zhulidov, Daniel A; Spencer, Robert G M

2017-11-21

Current understanding of mercury (Hg) dynamics in the Arctic is hampered by a lack of data in the Russian Arctic region, which comprises about half of the entire Arctic watershed. This study quantified temporal and longitudinal trends in total mercury (THg) concentrations in burbot (Lota lota) in eight rivers of the Russian Arctic between 1980 and 2001, encompassing an expanse of 118 degrees of longitude. Burbot THg concentrations declined by an average of 2.6% annually across all eight rivers during the study period, decreasing by 39% from 0.171 μg g -1 wet weight (w.w.) in 1980 to 0.104 μg g -1 w.w. in 2001. THg concentrations in burbot also declined by an average of 1.8% per 10° of longitude from west to east across the study area between 1988 and 2001. These results, in combination with those of previous studies, suggest that Hg trends in Arctic freshwater fishes before 2001 were spatially and temporally heterogeneous, as those in the North American Arctic were mostly increasing while those in the Russian Arctic were mostly decreasing. It is suggested that Hg trends in Arctic animals may be influenced by both depositional and postdepositional processes.

Enhanced Arctic Amplification Began at the Mid-Brunhes Event ~400,000 years ago.

PubMed

Cronin, T M; Dwyer, G S; Caverly, E K; Farmer, J; DeNinno, L H; Rodriguez-Lazaro, J; Gemery, L

2017-11-03

Arctic Ocean temperatures influence ecosystems, sea ice, species diversity, biogeochemical cycling, seafloor methane stability, deep-sea circulation, and CO 2 cycling. Today's Arctic Ocean and surrounding regions are undergoing climatic changes often attributed to "Arctic amplification" - that is, amplified warming in Arctic regions due to sea-ice loss and other processes, relative to global mean temperature. However, the long-term evolution of Arctic amplification is poorly constrained due to lack of continuous sediment proxy records of Arctic Ocean temperature, sea ice cover and circulation. Here we present reconstructions of Arctic Ocean intermediate depth water (AIW) temperatures and sea-ice cover spanning the last ~ 1.5 million years (Ma) of orbitally-paced glacial/interglacial cycles (GIC). Using Mg/Ca paleothermometry of the ostracode Krithe and sea-ice planktic and benthic indicator species, we suggest that the Mid-Brunhes Event (MBE), a major climate transition ~ 400-350 ka, involved fundamental changes in AIW temperature and sea-ice variability. Enhanced Arctic amplification at the MBE suggests a major climate threshold was reached at ~ 400 ka involving Atlantic Meridional Overturning Circulation (AMOC), inflowing warm Atlantic Layer water, ice sheet, sea-ice and ice-shelf feedbacks, and sensitivity to higher post-MBE interglacial CO 2 concentrations.

Gender Specific Reproductive Strategies of an Arctic Key Species (Boreogadus saida) and Implications of Climate Change

PubMed Central

Nahrgang, Jasmine; Varpe, Øystein; Korshunova, Ekaterina; Murzina, Svetlana; Hallanger, Ingeborg G.; Vieweg, Ireen; Berge, Jørgen

2014-01-01

The Arctic climate is changing at an unprecedented rate. What consequences this may have on the Arctic marine ecosystem depends to a large degree on how its species will respond both directly to elevated temperatures and more indirectly through ecological interactions. But despite an alarming recent warming of the Arctic with accompanying sea ice loss, reports evaluating ecological impacts of climate change in the Arctic remain sparse. Here, based upon a large-scale field study, we present basic new knowledge regarding the life history traits for one of the most important species in the entire Arctic, the polar cod (Boreogadus saida). Furthermore, by comparing regions of contrasting climatic influence (domains), we present evidence as to how its growth and reproductive success is impaired in the warmer of the two domains. As the future Arctic is predicted to resemble today's Atlantic domains, we forecast changes in growth and life history characteristics of polar cod that will lead to alteration of its role as an Arctic keystone species. This will in turn affect community dynamics and energy transfer in the entire Arctic food chain. PMID:24871481

The Regional Influence of the Arctic Oscillation and Arctic Dipole on the Wintertime Arctic Surface Radiation Budget and Sea Ice Growth

NASA Technical Reports Server (NTRS)

Hegyi, Bradley M.; Taylor, Patrick C.

2017-01-01

An analysis of 2000-2015 monthly Clouds and the Earth's Radiant Energy System-Energy Balanced and Filled (CERES-EBAF) and Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA2) data reveals statistically significant fall and wintertime relationships between Arctic surface longwave (LW) radiative flux anomalies and the Arctic Oscillation (AO) and Arctic Dipole (AD). Signifying a substantial regional imprint, a negative AD index corresponds with positive downwelling clear-sky LW flux anomalies (greater than10W m(exp -2)) north of western Eurasia (0 deg E-120 deg E) and reduced sea ice growth in the Barents and Kara Seas in November-February. Conversely, a positive AO index coincides with negative clear-sky LW flux anomalies and minimal sea ice growth change in October-November across the Arctic. Increased (decreased) atmospheric temperature and water vapor coincide with the largest positive (negative) clear-sky flux anomalies. Positive surface LW cloud radiative effect anomalies also accompany the negative AD index in December-February. The results highlight a potential pathway by which Arctic atmospheric variability influences the regional surface radiation budget over areas of Arctic sea ice growth.

Observational determination of albedo decrease caused by vanishing Arctic sea ice.

PubMed

Pistone, Kristina; Eisenman, Ian; Ramanathan, V

2014-03-04

The decline of Arctic sea ice has been documented in over 30 y of satellite passive microwave observations. The resulting darkening of the Arctic and its amplification of global warming was hypothesized almost 50 y ago but has yet to be verified with direct observations. This study uses satellite radiation budget measurements along with satellite microwave sea ice data to document the Arctic-wide decrease in planetary albedo and its amplifying effect on the warming. The analysis reveals a striking relationship between planetary albedo and sea ice cover, quantities inferred from two independent satellite instruments. We find that the Arctic planetary albedo has decreased from 0.52 to 0.48 between 1979 and 2011, corresponding to an additional 6.4 ± 0.9 W/m(2) of solar energy input into the Arctic Ocean region since 1979. Averaged over the globe, this albedo decrease corresponds to a forcing that is 25% as large as that due to the change in CO2 during this period, considerably larger than expectations from models and other less direct recent estimates. Changes in cloudiness appear to play a negligible role in observed Arctic darkening, thus reducing the possibility of Arctic cloud albedo feedbacks mitigating future Arctic warming.

Observed Changes at the Surface of the Arctic Ocean

NASA Astrophysics Data System (ADS)

Ortmeyer, M.; Rigor, I.

2004-12-01

The Arctic has long been considered a harbinger of global climate change since simulations with global climate models predict that if the concentration of CO2 in the atmosphere doubles, the Arctic would warm by more than 5°C, compared to a warming of 2°C for subpolar regions (Manabe et al., 1991). And indeed, studies of the observational records show polar amplification of the warming trends (e.g. Serreze and Francis, 2004). These temperature trends are accompanied by myriad concurrent changes in Arctic climate. One of the first indicators of Arctic climate change was found by Walsh et al. (1996) using sea level pressure (SLP) data from the International Arctic Buoy Programme (IABP, http://iabp.apl.washington.edu). In this study, they showed that SLP over the Arctic Ocean decreased by over 4 hPa from 1979 - 1994. The decreases in SLP (winds) over the Arctic Ocean, forced changes in the circulation of sea ice and the surface ocean currents such that the Beaufort Gyre is reduced in size and speed (e.g. Rigor et al., 2002). Data from the IABP has also been assimilated into the global surface air temperature (SAT) climatologies (e.g. Jones et al. 1999), and the IABP SAT analysis shows that the temperature trends noted over land extend out over the Arctic Ocean. Specifically, Rigor et al. (2000) found warming trends in SAT over the Arctic Ocean during win¬ter and spring, with values as high as 2°C/decade in the eastern Arctic during spring. It should be noted that many of the changes in Arctic climate were first observed or explained using data from the IABP. The observations from IABP have been one of the cornerstones for environmental forecasting and studies of climate and climate change. These changes have a profound impact on wildlife and people. Many species and cultures depend on the sea ice for habitat and subsistence. Thus, monitoring the Arctic Ocean is crucial not only for our ability to detect climate change, but also to improve our understanding of the Arctic and global climate system, and for forecasting weather and sea ice conditions. The IABP provides the longest continuing record of observations for the Arctic Ocean.

Join This Cool Club!

ERIC Educational Resources Information Center

Novelli, Joan

1995-01-01

Students can study the Arctic by creating Arctic clubs, using modems to communicate with students nationwide who are following International Arctic Project (IAP) explorers. The article describes the IAP, explains how to form a club, and discusses issues that clubs can tackle, for example, pollution, Arctic animals, natural resources, and the…

Was the Eocene Arctic a Source Area for Exotic Plants and Mammals? (Invited)

NASA Astrophysics Data System (ADS)

Eberle, J. J.; Harrington, G. J.; Fricke, H. C.; Humphrey, J.; Hackett, L.; Newbrey, M.; Hutchison, J. H.

2010-12-01

Today’s High Arctic is undergoing rapid warming, but the impact on its animal and plant communities is not clear. As a deep time analog to better understand and predict the impacts of global warming on the Arctic biota, early Eocene (52-53 Ma) rocks on Ellesmere Island, Nunavut in Canada’s High Arctic (~79°N latitude) preserve evidence of diverse terrestrial ecosystems that supported dense forests inhabited by turtles, alligators, snakes, primates, tapirs, brontotheres, and hippo-like Coryphodon. The fossil localities were just a few degrees further south and still well above the Arctic Circle during the early Eocene; consequently, the biota experienced months of continuous sunlight as well as darkness, the Arctic summer and winter, respectively. The flora and fauna of the early Eocene Arctic imply warmer, wetter conditions than at present, and recently published analyses of biogenic phosphate from fossil fish, turtle, and mammal estimate warm summers (19 - 20 C) and mild, above-freezing winters. In general, temperature estimates for the early Eocene Arctic can be compared to those found today in temperate rainforests in the Pacific Northwest of the United States. The early Eocene Arctic mammalian fauna shares most genera with coeval mid-latitude faunas thousands of kilometers to the south in the US Western Interior, and several genera also are shared with Europe and Asia. Recent analyses suggest that the large herbivores such as hippo-like Coryphodon were year-round inhabitants in the Eocene Arctic forests. Although several of the Eocene Arctic mammalian taxa are hypothesized to have originated in either mid-latitude North America or Asia, the earlier occurrence of certain clades (e.g., tapirs) in the Arctic raises the possibility of a northern high-latitude origin. Analysis of the early Eocene Arctic palynoflora indicates comparable richness to early Eocene plant communities in the US Western Interior, but nearly 50% of its species (mostly angiosperms) are not found in correlative strata of either mid-latitude North America or Europe. Either the Arctic region is a source of some evolutionary novelty, or alternatively it recruited plants directly from Asia. In sum, although the Arctic was undoubtedly en route for terrestrial plants and animals dispersing across Holarctic continents during parts of the Paleogene, evidence from both the Eocene plant and vertebrate communities on Ellesmere Island indicates the Arctic must also be evaluated as a potential source area for exotic taxa.

Arctic Ocean Sedimentary Cover Structure, Based on 2D MCS Seismic Data.

NASA Astrophysics Data System (ADS)

Kireev, A.; Kaminsky, V.; Poselov, V.; Poselova, L.; Kaminsky, D.

2016-12-01

In 2016 the Russian Federation has submitted its partial revised Submission for establishment of the OLCS (outer limit of the continental shelf) in the Arctic Ocean. In order to prepare the Submission, in 2005 - 2014 the Russian organizations carried out a wide range of geological and geophysical studies, so that today over 23000 km of MCS lines and 4000 km of deep seismic sounding are accomplished. For correct time/depth conversion of seismic sections obtained with a short streamer in difficult ice conditions wide-angle reflection/refraction seismic sonobuoy soundings were used. All of these seismic data were used to refine the stratigraphy model, to identify sedimentary complexes and to estimate the total thickness of the sedimentary cover. Seismic stratigraphy model was successively determined for the Cenozoic and pre-Cenozoic parts of the sedimentary section and was based on correlation of the Russian MCS data and seismic data documented by boreholes. Cenozoic part of the sedimentary cover is based on correlation of the Russian MCS data and AWI91090 section calibrated by ACEX-2004 boreholes on the Lomonosov Ridge for Amerasia basin and by correlation of onlap contacts onto oceanic crust with defined magnetic anomalies for Eurasia basin. Pre-Cenozoic part of the sedimentary cover is based on tracing major unconformities from boreholes on the Chukchi shelf (Crackerjack, Klondike, Popcorn) to the North-Chuckchi Trough and further to the Mendeleev Rise as well as to the Vilkitsky Trough and the adjacent Podvodnikov Basin. Six main unconformities were traced: regional unconformity (RU), Eocene unconformity (EoU) (for Eurasia basin only), post-Campanian unconformity (pCU), Brookian (BU - base of the Lower Brookian unit), Lower Cretaceous (LCU) and Jurassic (JU - top of the Upper Ellesmerian unit). The final step in our research was to generalize all seismic surveys (top of acoustic basement correlation data) and bathymetry data in the sedimentary cover thickness map of the Arctic Ocean and adjacent Eurasian shelf, on which the structural prolongation of the shallow shelf into deep-water is obviously seen.

New insights into the Weichselian environment and climate of the East Siberian Arctic, derived from fossil insects, plants, and mammals

NASA Astrophysics Data System (ADS)

Sher, A. V.; Kuzmina, S. A.; Kuznetsova, T. V.; Sulerzhitsky, L. D.

2005-03-01

Multidisciplinary study of a key section on the Laptev Sea Coast (Bykovsky Peninsula, east Lena Delta) in 1998-2001 provides the most complete record of Middle and Late Weichselian environments in the East Siberian Arctic. The 40-m high Mamontovy Khayata cliff is a typical Ice Complex section built of icy silts with a network of large syngenetic polygonal ice wedges, and is richly fossiliferous. In combination with pollen, plant macrofossil and mammal fossils, a sequence of ca 70 insect samples provides a new interpretation of the environment and climate of the area between ca 50 and 12 ka. The large number of radiocarbon dates from the section, together with an extensive 14C database on mammal bones, allows chronological correlation of the various proxies. The Bykovsky record shows how climate change, and the Last Glacial Maximum in particular, affected terrestrial organisms such as insects and large grazing mammals. Both during the presumed "Karginsky Interstadial" (MIS 3) and the Sartanian Glacial (MIS 2), the vegetation remained a mosaic arctic grassland with relatively high diversity of grasses and herbs and dominance of xeric habitats: the tundra-steppe type. This biome was supported by a constantly very continental climate, caused by low sea level and enormous extension of shelf land. Variations within the broad pattern were caused mainly by fluctuations in summer temperature, related to global trends but overprinted by the effect of continentality. No major changes in humidity were observed nor were advances of modern-type forest or forest-tundra recorded, suggesting a major revision of the "Karginsky Interstadial" paradigm. The changing subtypes of the tundra-steppe environment were persistently favourable for mammalian grazers, which inhabited the shelf lowlands throughout the studied period. Mammal population numbers were lowered during the LGM, especially toward its end, and then flourished in a short, but impressive peak in the latest Weichselian, just before the collapse of the tundra-steppe biome. Throughout MIS 3 and MIS 2, the climate remained very favourable for the aggradation of permafrost. No events of regional permafrost degradation were observed in the continuous Bykovsky sequence until the very end of the Pleistocene.

Arctic Security Considerations and the U.S. Navy’s Roadmap for the Arctic

DTIC Science & Technology

2010-01-01

observed in the sea, in the air, and on land. Indigenous Arctic people are facing relocation and loss of communities as sea-ice melt causes increased...sea-ice melting associated with global climate change has caused leadersfrom the United States and the international community to reconsider the...of the Navy as a valued partner by the joint, interagency, and international communities . THE CHANGING ARCTIC ENVIRONMENT The Arctic has long been a

Head-on crashes on two-way interurban roads: a public health concern in road safety.

PubMed

Olabarria, Marta; Santamariña-Rubio, Elena; Marí-Dell'Olmo, Marc; Gotsens, Mercè; Novoa, Ana M; Borrell, Carme; Pérez, Katherine

2015-09-01

To describe the magnitude and characteristics of crashes and drivers involved in head-on crashes on two-way interurban roads in Spain between 2007 and 2012, and to identify the factors associated with the likelihood of head-on crashes on these roads compared with other types of crash. A cross-sectional study was conducted using the National Crash Register. The dependent variables were head-on crashes with injury (yes/no) and drivers involved in head-on crashes (yes/no). Factors associated with head-on crashes and with being a driver involved in a head-on crash versus other types of crash were studied using a multivariate robust Poisson regression model to estimate proportion ratios (PR) and confidence intervals (95% CI). There were 9,192 head-on crashes on two-way Spanish interurban roads. A total of 15,412 men and 3,862 women drivers were involved. Compared with other types of crash, head-on collisions were more likely on roads 7 m or more wide, on road sections with curves, narrowings or drop changes, on wet or snowy surfaces, and in twilight conditions. Transgressions committed by drivers involved in head-on crashes were driving in the opposite direction and incorrectly overtaking another vehicle. Factors associated with a lower probability of head-on crashes were the existence of medians (PR=0.57; 95%CI: 0.48-0.68) and a paved shoulder of less than 1.5 meters (PR=0.81; 95%CI: 0.77-0.86) or from 1.5 to 2.45 meters (PR=0.90; 95%CI: 0.84-0.96). This study allowed the characterization of crashes and drivers involved in head-on crashes on two-way interurban roads. The lower probability observed on roads with median strips point to these measures as an effective way to reduce these collisions. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Live from the Arctic

NASA Astrophysics Data System (ADS)

Warnick, W. K.; Haines-Stiles, G.; Warburton, J.; Sunwood, K.

2003-12-01

For reasons of geography and geophysics, the poles of our planet, the Arctic and Antarctica, are places where climate change appears first: they are global canaries in the mine shaft. But while Antarctica (its penguins and ozone hole, for example) has been relatively well-documented in recent books, TV programs and journalism, the far North has received somewhat less attention. This project builds on and advances what has been done to date to share the people, places, and stories of the North with all Americans through multiple media, over several years. In a collaborative project between the Arctic Research Consortium of the United States (ARCUS) and PASSPORT TO KNOWLEDGE, Live from the Arctic will bring the Arctic environment to the public through a series of primetime broadcasts, live and taped programming, interactive virtual field trips, and webcasts. The five-year project will culminate during the 2007-2008 International Polar Year (IPY). Live from the Arctic will: A. Promote global understanding about the value and world -wide significance of the Arctic, B. Bring cutting-edge research to both non-formal and formal education communities, C. Provide opportunities for collaboration between arctic scientists, arctic communities, and the general public. Content will focus on the following four themes. 1. Pan-Arctic Changes and Impacts on Land (i.e. snow cover; permafrost; glaciers; hydrology; species composition, distribution, and abundance; subsistence harvesting) 2. Pan-Arctic Changes and Impacts in the Sea (i.e. salinity, temperature, currents, nutrients, sea ice, marine ecosystems (including people, marine mammals and fisheries) 3. Pan-Arctic Changes and Impacts in the Atmosphere (i.e. precipitation and evaporation; effects on humans and their communities) 4. Global Perspectives (i.e. effects on humans and communities, impacts to rest of the world) In The Earth is Faster Now, a recent collection of comments by members of indigenous arctic peoples, arctic residents speak in eloquent terms of the changes they see around them, manifested in new patterns of vegetation, the melting of permafrost and the absence of game species that used to be abundant. Meanwhile, new satellites and more sophisticated sensors on the ground and in the ice, add scientific testimony that seems to support and even extend native perceptions. Live from the Arctic will unify both perspectives, and use todays most powerful and effective communications media to connect young people and general audiences all across America to researchers and communities living and working in the Arctic. During IPY there will be a level of interest in the Polar regions unprecedented in a generation. Live from the Arctic offers unique resources to satisfy that curiosity, and encourage active participation and engagement in understanding some of Earths most significant peoples, places and rapidly changing conditions.

Arctic science input wanted

NASA Astrophysics Data System (ADS)

The Arctic Research and Policy Act (Eos, June 26, 1984, p. 412) was signed into law by President Ronald Reagan this past July. One of its objectives is to develop a 5-year research plan for the Arctic. A request for input to this plan is being issued this week to nearly 500 people in science, engineering, and industry.To promote Arctic research and to recommend research policy in the Arctic, the new law establishes a five-member Arctic Research Commission, to be appointed by the President, and establishes an Interagency Arctic Research Policy Committee, to be composed of representatives from nearly a dozen agencies having interests in the region. The commission will make policy recommendations, and the interagency committee will implement those recommendations. The National Science Foundation (NSF) has been designated as the lead agency of the interagency committee.

Does Arctic governance hold the key to achieving climate policy targets?

NASA Astrophysics Data System (ADS)

Forbis, Robert, Jr.; Hayhoe, Katharine

2018-02-01

Arctic feedbacks are increasingly viewed as the wild card in the climate system; but their most unpredictable and potentially dangerous aspect may lie in the human, rather than the physical, response to a warming climate. If Arctic policy is driven by agendas based on domestic resource development, the ensuing oil and gas extraction will ensure the failure of the Paris Agreement. If Arctic energy policy can be framed by the Arctic Council, however, its environmental agenda and fragmented governance structure offers the scientific community a fighting chance to determine the region’s energy future. Connecting Arctic climate science to resource economics via its unique governance structure is one of the most powerful ways the scientific community can protect the Arctic region’s environmental, cultural, and scientific resources, and influence international energy and climate policy.

Arctic marine fishes and their fisheries in light of global change.

PubMed

Christiansen, Jørgen S; Mecklenburg, Catherine W; Karamushko, Oleg V

2014-02-01

In light of ocean warming and loss of Arctic sea ice, harvested marine fishes of boreal origin (and their fisheries) move poleward into yet unexploited parts of the Arctic seas. Industrial fisheries, already in place on many Arctic shelves, will radically affect the local fish species as they turn up as unprecedented bycatch. Arctic marine fishes are indispensable to ecosystem structuring and functioning, but they are still beyond credible assessment due to lack of basic biological data. The time for conservation actions is now, and precautionary management practices by the Arctic coastal states are needed to mitigate the impact of industrial fisheries in Arctic waters. We outline four possible conservation actions: scientific credibility, 'green technology', legitimate management and overarching coordination. © 2013 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

Islandinium minutum subsp. barbatum subsp. nov. (Dinoflagellata), a New Organic-Walled Dinoflagellate Cyst from the Western Arctic: Morphology, Phylogenetic Position Based on SSU rDNA and LSU rDNA, and Distribution.

PubMed

Potvin, Éric; Kim, So-Young; Yang, Eun Jin; Head, Martin J; Kim, Hyun-Cheol; Nam, Seung-Il; Yim, Joung Han; Kang, Sung-Ho

2018-03-25

A study of modern sediment from the Western Arctic has revealed the presence of a distinctive brown-colored cyst with a spherical central body bearing unbranched processes that are usually solid with a small basal pericoel. Distinctive barbs project from some processes, and process tips are usually minutely expanded into conjoined barbs. The archeopyle is apical and saphopylic. This cyst corresponds to Islandinium? cezare morphotype 2 of Head et al. (2001, J. Quat. Sci., 16:621). Phylogenetic analyses based on the small and large subunit rRNA genes infer close relationship with Islandinium minutum, the type of which is that of the genus. Re-examination of specimens of I. minutum reveals the presence of minute barbs on its processes, but differences with Islandinium? cezare morphotype 2 remain based on size, process distribution, and barb development. Furthermore, the internal transcribed spacer shows I. minutum to be distinct from this morphotype. On the basis of these small but discrete differences, we propose the new subspecies Islandinium minutum subsp. barbatum subsp. nov. Molecular sequencing of other cysts encountered, namely Echinidinium karaense, an unidentified flattened cyst, and "Polykrikos quadratus", places them in the Monovela clade, the latter showing greater morphological variability than previously thought. © 2018 The Author(s) Journal of Eukaryotic Microbiology © 2018 International Society of Protistologists.

Surveillance of infectious diseases in the Arctic.

PubMed

Bruce, M; Zulz, T; Koch, A

2016-08-01

This study reviews how social and environmental issues affect health in Arctic populations and describes infectious disease surveillance in Arctic Nations with a special focus on the activities of the International Circumpolar Surveillance (ICS) project. We reviewed the literature over the past 2 decades looking at Arctic living conditions and their effects on health and Arctic surveillance for infectious diseases. In regards to other regions worldwide, the Arctic climate and environment are extreme. Arctic and sub-Arctic populations live in markedly different social and physical environments compared to those of their more southern dwelling counterparts. A cold northern climate means people spending more time indoors, amplifying the effects of household crowding, smoking and inadequate ventilation on the person-to-person spread of infectious diseases. The spread of zoonotic infections north as the climate warms, emergence of antibiotic resistance among bacterial pathogens, the re-emergence of tuberculosis, the entrance of HIV into Arctic communities, the specter of pandemic influenza or the sudden emergence and introduction of new viral pathogens pose new challenges to residents, governments and public health authorities of all Arctic countries. ICS is a network of hospitals, public health agencies, and reference laboratories throughout the Arctic working together for the purposes of collecting, comparing and sharing of uniform laboratory and epidemiological data on infectious diseases of concern and assisting in the formulation of prevention and control strategies (Fig. 1). In addition, circumpolar infectious disease research workgroups and sentinel surveillance systems for bacterial and viral pathogens exist. The ICS system is a successful example of collaborative surveillance and research in an extreme environment. Published by Elsevier Ltd.

Potential impacts of the Arctic on interannual and interdecadal summer precipitation over China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Yuefeng; Leung, Lai-Yung R.

2013-02-01

After the end of the 1970s, there has been a tendency for enhanced summer precipitation over South China and the Yangtze River valley and drought over North China and Northeastern China. Coincidentally, Arctic ice concentration has decreased since the late 1970s, with larger reduction in summer than spring. However, the Arctic warming is more significant in spring than summer, suggesting that spring Arctic conditions could be more important in their remote impacts. This study investigates the potential impacts of the Arctic on summer precipitation in China. The leading spatial patterns and time coefficients of the unfiltered, interannual, and interdecadal precipitationmore » (1960-2008) modes were analyzed and compared using empirical orthogonal function (EOF) analysis, which shows that the first three EOFs can capture the principal precipitation patterns (northern, central and southern patterns) over eastern China. Regression of the Arctic spring and summer temperature onto the time coefficients of the leading interannual and interdecadal precipitation modes shows that interdecadal summer precipitation in China is related to the Arctic spring warming, but the relationship with Arctic summer temperature is weak. Moreover, no notable relationships were found between the first three modes of interannual precipitation and Arctic spring or summer temperatures. Finally, correlations between summer precipitation and the Arctic Oscillation (AO) index from January to August were investigated, which indicate that summer precipitation in China correlates with AO only to some extent. Overall, this study suggests important relationships between the Arctic spring temperature and summer precipitation over China at the interdecadal time scale.« less

Status and trends in Arctic biodiversity - Synthesis: implications for conservation

USDA-ARS?s Scientific Manuscript database

Arctic biodiversity – the multitude of species and ecosystems in the land north of the tree line together with the Arctic Ocean and adjacent seas – is an irreplaceable cultural, aesthetic, scientific, ecological, economic and spiritual asset. For Arctic peoples, biodiversity has been the very basis ...

78 FR 52941 - Cooperative Research and Development Agreement: Next Generation Arctic Navigational Safety...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-27

... Development Agreement: Next Generation Arctic Navigational Safety Information System AGENCY: Coast Guard, DHS... technology approach to the ``Next Generation Arctic Maritime Navigational Safety Information System,'' which... their voyage risks, as they transit the remote and hostile waters of the U.S. Arctic Exclusive Economic...

Oceanographic Aspects of Recent Changes in the Arctic

NASA Astrophysics Data System (ADS)

Morison, J. H.

2002-12-01

In the Arctic recent decadal-scale changes have marked the atmosphere, ocean, and land. Connections between the oceanographic changes and large-scale atmospheric circulation changes are emerging. Surface atmospheric pressure has shown a declining trend over the Arctic. In the 1990s, the Arctic Ocean circulation took on a more cyclonic character, and the front separating Atlantic-derived waters of the Eurasian Basin and the Pacific-derived waters of the Canadian Basin shifted counterclockwise. The temperature of Atlantic water in the Arctic Ocean reached record levels. The cold halocline, which isolates the surface from the warm Atlantic water, grew thinner disappearing entirely from the Amundsen Basin at one point [Steele and Boyd, 1998]. Arctic sea ice extent has decreased 3% per decade since the 1970s [Parkinson et al., 1999]. Sea ice thickness over much of the Arctic decreased 43% between 1958-1976 and 1993-1997 [Rothrock et al., 1999]. Arctic ecosystems have responded to these changes. Sea ice studies in the late 1990s indicate that the sea ice algal species composition changed from decades before, with the species recently being characterized by more brackish and freshwater forms. Barents Sea fisheries have shifted north following reductions in ice extent. Pacific salmon species have been found entering rivers in the Arctic. There is evidence that this complex of pan-Arctic changes is connected with the rising trend in the Arctic Oscillation (AO) or Northern Hemisphere atmospheric polar vortex in the 1990s. Theoretical evidence that a positive trend in the AO index might be indicative of greenhouse warming raises the possibility that the recent complex of changes is an Arctic characteristic of global climate change. Also, the changes in ice cover manifest a connection between the complex of change and global climate through ice-albedo feedback, by which reductions in ice cover reduce the amount of sunlight reflected from the earth's surface. Another important climate feedback is that the changes in ocean circulation and ice production have increased the amount of relatively fresh surface water exported to the sub-Arctic Seas, increasing stratification there, and arguably reducing the strength of the global thermohaline circulation. Since the mid-1990s the strength of the Polar Vortex (AO) has relaxed partially toward earlier levels. Recent observations show that Arctic Ocean water mass structure has relaxed somewhat towards climatology near the surface but is still changing at depth. The cold halocline has recovered in some areas. This reinforces the notion that the changes in the Arctic are tied to the atmospheric circulation of the whole northern hemisphere. The events of the last 10-15 years suggest ways the Arctic environment may be an indicator and agent of climate change and highlight the importance of a systematic program to observe the changing Arctic. References Parkinson C. L., D. J. Cavalieri, P. Gloersen, H. J. Zwally, and J. C. Comiso, 1999, Arctic sea ice extents, areas, and trends, 1978-1996, J. Geophys. Res., 104, 20,387-20,856. Rothrock, D. A., Y. Yu, and G. A. Maykut, 1999, Thinning of the Arctic sea-ice cover, Geophys. Res. Lett., 26(23), 3469-3472. Steele, M., and T. Boyd, 1998, Retreat of the cold halocline layer in the Arctic Ocean, J. Geophys. Res., 103, 10,419-10,435.

ACEX: A First Look at Arctic Ocean Cenozoic History

NASA Astrophysics Data System (ADS)

Moran, K.; Backman, J.

2004-12-01

The first Integrated Ocean Drilling Program mission specificplatform expedition (ACEX - Arctic Coring Expedition) drilled and recovered core from five holes at four sites through Cenozoic sediments draping the crest of the Lomonosov Ridge in the central Arctic Ocean. Coring continued into the underlying Cretaceous sedimentary bedrock. Sites are located only a few nautical miles apart along a single seismic line (AWI-91090), showing an identical and coherent Cenozoic seismostratigraphy. Preliminary results from shipboard investigations of core-catcher-based bio- and lithostratigraphy, pore water analyses and core logger data describe a thick (~160 m) middle Miocene through Pleistocene sequence that shows large amplitude, cyclic variability in the density, magnetic susceptibility and acoustic velocity of the sediments. Sediments are largely carbonate free. Pleistocene sedimentation rates are close to 3 cm/ka, whereas Pliocene sediments are by-and-large missing. A sharp change in physical properties at ~200 m defines the transition into a 200+ m thick Paleogene sequence that is initially dominated by large numbers of dinoflagellate cysts. The early Miocene, Oligocene and late Eocene appear to be largely missing in a hiatus. However, a 32 m thick interval separates the overlying middle Miocene from the underlying middle Eocene and presumably preserves some of the early Neogene and late Paleogene sections. Dinoflagellate cysts, diatoms, ebridians and silicoflagellates are common to abundant in the middle Eocene section, which bottoms in a spectacular layer showing massive occurrences of glochidia and massulae (megaspores) of the freshwater hydropterid fern Azolla (duckweed) at the early/middle Eocene boundary (~306 m), suggesting strongly reduced surface water salinity or perhaps even a brief episode of fresh water conditions at the surface. Biosilica is not present prior to the late early Eocene (~320 m). The (sub-) tropical dinoflagellate species Apectodinium augustum occurs abundantly at around 380m in pyrite-rich mudstones, indicating that the Paleocene/Eocene boundary and the associated Carbon Isotope Excursion (CIE) interval were recovered, and that the Arctic Ocean experienced surface temperatures on the order of 20°C during the Paleocene Eocene Thermal Maximum (PETM). Benthic foraminifers indicate that the early Eocene through latest Paleocene sediments were deposited in shallow-marine, neritic to inner neritic, environments. The mudstone of late Paleocene age rests unconformably on Campanian marine sands, sandstone and mudstone.

Arctic Collaborative Environment: A New Multi-National Partnership for Arctic Science and Decision Support

NASA Technical Reports Server (NTRS)

Laymon, Charles A,; Kress, Martin P.; McCracken, Jeff E.; Spehn, Stephen L.; Tanner, Steve

2011-01-01

The Arctic Collaborative Environment (ACE) project is a new international partnership for information sharing to meet the challenges of addressing Arctic. The goal of ACE is to create an open source, web-based, multi-national monitoring, analysis, and visualization decision-support system for Arctic environmental assessment, management, and sustainability. This paper will describe the concept, system architecture, and data products that are being developed and disseminated among partners and independent users through remote access.

The International Arctic Buoy Programme (IABP): A Cornerstone of the Arctic Observing Network

DTIC Science & Technology

2008-09-01

SEP 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE The International Arctic Buoy Programme ( IABP ): A...Prescribed by ANSI Std Z39-18 The International Arctic Buoy Programme ( IABP ): A Cornerstone of the Arctic Observing Network Ignatius G. Rigor...changes in weather, climate and environment. It should be noted that many of these changes were first observed and studied using data from the IABP (http