Survey of upper band chorus and ECH waves: implications for the diffuse aurora

first_imgThe origin of the diffuse aurora has been a source of controversy for many years. More recently, the question has taken a new significance in view of the associated changes in atmospheric chemistry which may affect the middle atmosphere. Here, we use CRRES data to assess the importance of upper band chorus and electron cyclotron harmonic (ECH) waves in the production of the diffuse aurora. Both wave modes increase with increasing geomagnetic activity, suggesting they are related to periods of enhanced convection and/or substorm activity. They are confined to the near-equatorial region, which excludes the prenoon sector from the wave survey. During active conditions, intense ECH waves and upper band chorus, with amplitudes exceeding 1 mV m(-1), are observed in the region 4 < L < 7 from 2100 to 0600 MLT approximately 20% and 6% of the time, respectively. This suggests that both wave modes can put electrons on strong diffusion, but only during active conditions and not at all local times. Scattering rates fall below the strong diffusion limit at other times when the wave amplitudes are weaker. Fluxes of low energy electrons (100 eV < E < 30 keV) also increase with increasing geomagnetic activity in approximately the same region of geospace as the waves, suggesting that these electrons are responsible for the generation of the waves. The patterns of the upper band chorus, ECH waves, and low-energy electrons are similar to the global morphology of the diffuse aurora, suggesting that both wave modes play significant roles in the production of the diffuse aurora.last_img read more

Detection of fungal 18S rRNA sequences in conjunction with marine nematode 18S rRNA amplicons

first_imgFree-living nematodes constitute an important component of estuarine and marine benthic ecosystems. Some marine and soil nematodes are known to harbor microbes, including symbiotic bacteria and fungi, in their external cuticle as well as internally. While assessing diversity of marine nematodes from southwest England using molecular approaches, we found evidence of co-amplification of fungal 18S rRNA sequences in conjunction with nematode 18S rRNA sequences. Based on an 18S rRNA PCR-DGGE approach, 3 fungal clone types were detected alongside nematodes from 2 of 4 estuarine and marine sites in southwest England. At the phylogeny level, fungal clone type 1 belongs to Chaetothyriales while the other 2 clone types belong to Hypocreales. The fungal clones were co-amplified with specific marine nematode taxa indicating true ecological association rather than transient environmental contamination. The present study is the first to detect fungal 18S sequences in parallel with marine nematodes and opens up a new avenue of research for investigating ecological interactions between nematodes and fungi in the marine environment.last_img read more

Is there a distinct continental slope fauna in the Antarctic?

first_imgThe Antarctic continental slope spans the depths from the shelf break (usually between 500 and 1000 m) to not, vert, similar3000 m, is very steep, overlain by ‘warm’ (2–2.5 °C) Circumpolar Deep Water (CDW), and life there is poorly studied. This study investigates whether life on Antarctica’s continental slope is essentially an extension of the shelf or the abyssal fauna, a transition zone between these or clearly distinct in its own right. Using data from several cruises to the Weddell Sea and Scotia Sea, including the ANDEEP (ANtarctic benthic DEEP-sea biodiversity, colonisation history and recent community patterns) I–III, BIOPEARL (BIOdiversity, Phylogeny, Evolution and Adaptive Radiation of Life in Antarctica) 1 and EASIZ (Ecology of the Antarctic Sea Ice Zone) II cruises as well as current databases (SOMBASE, SCAR-MarBIN), four different taxa were selected (i.e. cheilostome bryozoans, isopod and ostracod crustaceans and echinoid echinoderms) and two areas, the Weddell Sea and the Scotia Sea, to examine faunal composition, richness and affinities. The answer has important ramifications to the link between physical oceanography and ecology, and the potential of the slope to act as a refuge and resupply zone to the shelf during glaciations. Benthic samples were collected using Agassiz trawl, epibenthic sledge and Rauschert sled. By bathymetric definition, these data suggest that despite eurybathy in some of the groups examined and apparent similarity of physical conditions in the Antarctic, the shelf, slope and abyssal faunas were clearly separated in the Weddell Sea. However, no such separation of faunas was apparent in the Scotia Sea (except in echinoids). Using a geomorphological definition of the slope, shelf-slope-abyss similarity only changed significantly in the bryozoans. Our results did not support the presence of a homogenous and unique Antarctic slope fauna despite a high number of species being restricted to the slope. However, it remains the case that there may be a unique Antarctic slope fauna, but the paucity of our samples could not demonstrate this in the Scotia Sea. It is very likely that various ecological and evolutionary factors (such as topography, water-mass and sediment characteristics, input of particulate organic carbon (POC) and glaciological history) drive slope distinctness. Isopods showed greatest species richness at slope depths, whereas bryozoans and ostracods were more speciose at shelf depths; however, significance varied across Weddell Sea and Scotia Sea and depending on bathymetric vs. geomorphological definitions. Whilst the slope may harbour some source populations for localised shelf recolonisation, the absence of many shelf species, genera and even families (in a poorly dispersing taxon) from the continental slope indicate that it was not a universal refuge for Antarctic shelf fauna.last_img read more

The discovery of new deep-sea hydrothermal vent communities in the Southern Ocean and implications for biogeography

first_imgSince the first discovery of deep-sea hydrothermal vents along the Galápagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8°C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than previously recognised.last_img read more

Landscape mapping at sub-Antarctic South Georgia provides a protocol for underpinning large-scale marine protected areas

first_imgGlobal biodiversity is in decline, with the marine environment experiencing significant and increasing anthropogenic pressures. In response marine protected areas (MPAs) have increasingly been adopted as the flagship approach to marine conservation, many covering enormous areas. At present, however, the lack of biological sampling makes prioritising which regions of the ocean to protect, especially over large spatial scales, particularly problematic. Here we present an interdisciplinary approach to marine landscape mapping at the sub-Antarctic island of South Georgia as an effective protocol for underpinning large-scale (105–106  km2) MPA designations. We have developed a new high-resolution (100 m) digital elevation model (DEM) of the region and integrated this DEM with bathymetry-derived parameters, modelled oceanographic data, and satellite primary productivity data. These interdisciplinary datasets were used to apply an objective statistical approach to hierarchically partition and map the benthic environment into physical habitats types. We assess the potential application of physical habitat classifications as proxies for biological structuring and the application of the landscape mapping for informing on marine spatial planninglast_img read more

AMPERE Polar Cap Boundaries

first_imgThe high-latitude atmosphere is a dynamic region with processes that respond to forcing from the Sun, magnetosphere, neutral atmosphere, and ionosphere. Historically, the dominance of magnetosphere–ionosphere interactions has motivated upper atmospheric studies to use magnetic coordinates when examining magnetosphere–ionosphere–thermosphere coupling processes. However, there are significant differences between the dominant interactions within the polar cap, auroral oval, and equatorward of the auroral oval. Organising data relative to these boundaries has been shown to improve climatological and statistical studies, but the process of doing so is complicated by the shifting nature of the auroral oval and the difficulty in measuring its poleward and equatorward boundaries.This study presents a new set of open–closed magnetic field line boundaries (OCBs) obtained from Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) magnetic perturbation data. AMPERE observations of field-aligned currents (FACs) are used to determine the location of the boundary between the Region 1 (R1) and Region 2 (R2) FAC systems. This current boundary is thought to typically lie a few degrees equatorward of the OCB, making it a good candidate for obtaining OCB locations. The AMPERE R1–R2 boundaries are compared to the Defense Meteorological Satellite Program Special Sensor J (DMSP SSJ) electron energy flux boundaries to test this hypothesis and determine the best estimate of the systematic offset between the R1–R2 boundary and the OCB as a function of magnetic local time. These calibrated boundaries, as well as OCBs obtained from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) observations, are validated using simultaneous observations of the convection reversal boundary measured by DMSP. The validation shows that the OCBs from IMAGE and AMPERE may be used together in statistical studies, providing the basis of a long-term data set that can be used to separate observations originating inside and outside of the polar cap.last_img read more

Tod Leiweke named CEO and president of Seattle Hockey

first_imgApril 11, 2018 /Sports News – National Tod Leiweke named CEO and president of Seattle Hockey FacebookTwitterLinkedInEmailOtto Greule Jr/Getty Images(SEATTLE) — As the Vegas Golden Knights get ready to host the Los Angeles Kings Wednesday in the first round of the Stanley Cup playoffs in their inaugural season, Seattle took the next step in getting an expansion team of its own.At a news conference Wednesday, Tod Leiweke was named the CEO and president of Seattle Hockey, the group authorized to redevelop KeyArena and bring an NHL team.  “One of the great things about Seattle is the community, and the community of teams is fanatsic,” Leiweke said.Leiweke, formally the CEO of the Tampa Bay Lightning, was most recently the COO of the National Football League before leaving in March.The project is already off to a great start, with 25,000 deposits for season tickets being placed in the first hour they were available back in March. The goal was 10,000, which was eclipsed in the first 12 minutes.“I’ve always believed in the fans in Seattle,” Leiweke said. “I’ve always believe they were different.”Leiweke’s brother, Tim, the CEO of Oak View Group, is partnered up with investment banker David Bonderman and Hollywood producer Jerry Bruckheimer to help make Seattle’s dream of bringing and NHL team there a reality.The Oak View Group put down a ten million dollar down payment to the NHL in February to be the team’s 32nd franchise. The NHL’s fee for Seattle to become a team is 650 million dollars, and the team hopes to be ready by the 2020-21 season.Leiweke wasted no time setting up the rivalry between Seattle and the cross-country rival Vancouver Canucks, either. We’re going to bring it,” he said. “The rivalry between these two great cities will be remarkable.”Seattle appears to be well ahead of schedule, considering when the Golden Knights ran a season-ticket drive it received 5,000 deposits in the first two days. Vegas also didn’t announce its CEO until a year before puck drop.Copyright © 2018, ABC Radio. All rights reserved. Written bycenter_img Beau Lundlast_img read more

Trump: NFL players who don’t stand for the national anthem ‘shouldn’t be in the country’

first_img Written by FacebookTwitterLinkedInEmailWin McNamee/Getty Images(WASHINGTON) — NFL players should “stand proudly” during the national anthem, President Donald Trump said after praising the league’s new rule banning players from kneeling on the field during the song.Trump criticized the league’s players who might challenge the rule and continue to kneel in protest, suggesting “maybe you shouldn’t be in the country.”“I don’t think people should be staying in locker rooms,” Trump said in an interview with Fox and Friends Thursday morning. “You have to stand proudly for the national anthem or you shouldn’t be playing. You shouldn’t be there. Maybe you shouldn’t be in the country. You have to stand proudly for the national anthem.”This is a developing story. Please check back for updates.Copyright © 2018, ABC Radio. All rights reserved. May 24, 2018 /Sports News – National Trump: NFL players who don’t stand for the national anthem ‘shouldn’t be in the country’center_img Beau Lundlast_img read more

Weber State Football Returns To Top 10

first_img FacebookTwitterLinkedInEmailOGDEN, Utah-Monday, Weber State football returned to the top 10 in both the FCS STATS and coaches polls.After a 14-6 win over #3 Eastern Washington, the Wildcats were ranked #7 in the FCS STATS poll and ninth in the AFCA FCS Coaches poll.The Wildcats, who are now 4-2 on the season and 2-1 in Big Sky Conference play, host the Montana State Bobcats Saturday at 4:00 pm at Stewart Stadium. Tags: AFCA FCS Coaches Poll/FCS STATS/Montana State Bobcats/Weber State Football October 15, 2018 /Sports News – Local Weber State Football Returns To Top 10 Brad James Written bylast_img read more

Tuttle, Constantine lift Weber State to 26-14 win

first_imgNovember 3, 2018 /Sports News – Local Tuttle, Constantine lift Weber State to 26-14 win Associated Press FacebookTwitterLinkedInEmailOGDEN, Utah (AP) — Jake Constantine passed for two touchdowns and Trey Tuttle added a pair of field goals and Weber State defeated Sacramento State 26-14 on Saturday to win its fourth straight and remain bunched among Big Sky Conference leaders.Tuttle kicked field goals of 42 and 35 yards in the first half, and Constantine threw a 20-yard scoring pass to Darryl Denby wide open in the end zone as the Wildcats (7-2, 5-1) built a 13-0 lead after a half.Weber State, ranked No. 5 in the FCS coaches poll, pushed the lead to 19-0 when Constantine connected with Rashid Shaheed from 20 early in the third quarter.Armon Bailey came untouched off the end to sack Constantine — his first career sack — and Leonard Hazewood IV picked the ball off the turf and returned it 33 yards for Sacramento State’s first touchdown. Hamish McClure added a 13-yard scramble in the final minute for the Hornets (2-7, 0-6). Written by Tags: Big Sky/Football/Jake Constantine/Trey Tuttle/Weber State Wildcatslast_img read more

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