Radar observations of magnetospheric activity during extremely quiet solar wind conditions

first_imgDuring a period of extremely quiet solar wind conditions from 8 to 10 March 1997, strong activity was observed by the Southern Hemisphere Auroral Radar Experiment Super Dual Auroral Radar Network radars in the Antarctic premidnight ionosphere. This activity took the form of quasiperiodic flow bursts with ionospheric drift velocities exceeding 2 km s−1. Data from the Satellite Experiments Simultaneous with Antarctic Measurements (SESAME) automated geophysical observatories in Antarctica and Defense Meteorological Satellite Program and Polar satellites are used with the radar data to study the convection flow in the southern polar ionosphere at the time of these flow bursts. The study shows that the bursts occurred with an approximate period of 12 min. Their direction was westward, and they were superimposed on a background westward flow. In the premidnight sector this is interpreted as a flow associated with dipolarization of the magnetotail tail field. There is a band of strong particle precipitation associated with the flow bursts. The location suggests that they occur deep in the magnetotail and cannot be associated with any lobe reconnection. They are at a latitude near the region where a viscously driven convection cell is expected to exist, and their sense is that of the return convection flow in such a cell. The results suggest that there is an internal magnetospheric mechanism for sporadic energy release in the magnetotail that need not be associated with changes in solar wind reconnection on the magnetopause.last_img read more


Male reproductive strategy and the importance of maternal status in the Antarctic fur seal Arctocephalus gazella

first_imgAlthough mammalian mating systems are classically characterized in terms of male competition and polygyny, it is becoming increasingly apparent that alternative male strategies and female choice may play important roles. For example, females who mate with males from a dominant dynasty risk producing inbred offspring. Many pinnipeds are highly polygynous, but in some species alternative male strategies such as aquatic mating appear to be important, even when behavioral observations suggest strong polygyny. Here, we analyze male reproductive success in the Antarctic fur seal Arctocephalus gazella, an otariid described behaviorally as being highly polygynous, by combining a microsatellite paternity analysis spanning seven consecutive breeding seasons with detailed behavioral data on both sexes. Territorial males fathered 59% of 660 pups analyzed from our study colony. Male reproductive skew was considerable, with a quarter of all paternities assigned to just 12 top individuals on a beach where mean annual pup production was 635. Most males were successful for only a single season, but those able to return over successive years enjoyed rapidly increasing success with each additional season of tenure. We found no evidence of alternative male reproductive tactics such as aquatic or sneaky terrestrial mating. However, paternity was strongly influenced by maternal status. Females observed on the beach without a pup were significantly less likely to conceive to a sampled territorial male than equivalent females that did pup. In addition, their pups carried combinations of paternal alleles that were less likely to be found on the study beach and exhibited lower levels of shared paternity. Thus, from a territorial male’s perspective, not all females offer equal opportunities for fertilization.last_img read more


Thermal reaction norms and the scale of temperature variation: latitudinal vulnerability of intertidal Nacellid limpets to climate change

first_imgThe thermal reaction norms of 4 closely related intertidal Nacellid limpets, Antarctic (Nacella concinna), New Zealand (Cellana ornata), Australia (C. tramoserica) and Singapore (C. radiata), were compared across environments with different temperature magnitude, variability and predictability, to test their relative vulnerability to different scales of climate warming. Lethal limits were measured alongside a newly developed metric of “duration tenacity”, which was tested at different temperatures to calculate the thermal reaction norm of limpet adductor muscle fatigue. Except in C. tramoserica which had a wide optimum range with two break points, duration tenacity did not follow a typical aerobic capacity curve but was best described by a single break point at an optimum temperature. Thermal reaction norms were shifted to warmer temperatures in warmer environments; the optimum temperature for tenacity (Topt) increased from 1.0°C (N. concinna) to 14.3°C (C. ornata) to 18.0°C (an average for the optimum range of C. tramoserica) to 27.6°C (C. radiata). The temperature limits for duration tenacity of the 4 species were most consistently correlated with both maximum sea surface temperature and summer maximum in situ habitat logger temperature. Tropical C. radiata, which lives in the least variable and most predictable environment, generally had the lowest warming tolerance and thermal safety margin (WT and TSM; respectively the thermal buffer of CTmax and Topt over habitat temperature). However, the two temperate species, C. ornata and C. tramoserica, which live in a variable and seasonally unpredictable microhabitat, had the lowest TSM relative to in situ logger temperature. N. concinna which lives in the most variable, but seasonally predictable microhabitat, generally had the highest TSMs. Intertidal animals live at the highly variable interface between terrestrial and marine biomes and even small changes in the magnitude and predictability of their environment could markedly influence their future distributions.last_img read more


Multicolony tracking reveals the winter distribution of a pelagic seabird on an ocean basin scale

first_imgAim: An understanding of the non-breeding distribution and ecology of migratory species is necessary for successful conservation. Many seabirds spend the non-breeding season far from land, and information on their distribution during this time is very limited. The black-legged kittiwake, Rissa tridactyla, is a widespread and numerous seabird in the North Atlantic and Pacific, but breeding populations throughout the Atlantic range have declined recently. To help understand the reasons for the declines, we tracked adults from colonies throughout the Atlantic range over the non-breeding season using light-based geolocation. Location: North Atlantic. Methods: Geolocation data loggers were deployed on breeding kittiwakes from 19 colonies in 2008 and 2009 and retrieved in 2009 and 2010. Data from 236 loggers were processed and plotted using GIS. Size and composition of wintering populations were estimated using information on breeding population size. Results: Most tracked birds spent the winter in the West Atlantic, between Newfoundland and the Mid-Atlantic Ridge, including in offshore, deep-water areas. Some birds (mainly local breeders) wintered in the North Sea and west of the British Isles. There was a large overlap in winter distributions of birds from different colonies, and colonies closer to each other showed larger overlap. We estimated that 80% of the 4.5 million adult kittiwakes in the Atlantic wintered west of the Mid-Atlantic Ridge, with only birds from Ireland and western Britain staying mainly on the European side. Main conclusions: The high degree of mixing in winter of kittiwakes breeding in various parts of the Atlantic range implies that the overall population could be sensitive to potentially deteriorating environmental conditions in the West Atlantic, e.g. owing to lack of food or pollution. Our approach to estimating the size and composition of wintering populations should contribute to improved management of birds faced with such challenges.last_img read more


Distribution of known macrozooplankton abundance and biomass in the global ocean

first_imgMacrozooplankton are an important link between higher and lower trophic levels in the oceans. They serve as the primary food for fish, reptiles, birds and mammals in some regions, and play a role in the export of carbon from the surface to the intermediate and deep ocean. Little, however, is known of their global distribution and biomass. Here we compiled a dataset of macrozooplankton abundance and biomass observations for the global ocean from a collection of four datasets. We harmonise the data to common units, calculate additional carbon biomass where possible, and bin the dataset in a global 1 × 1 degree grid. This dataset is part of a wider effort to provide a global picture of carbon biomass data for key plankton functional types, in particular to support the development of marine ecosystem models. Over 387 700 abundance data and 1330 carbon biomass data have been collected from pre-existing datasets. A further 34 938 abundance data were converted to carbon biomass data using species-specific length frequencies or using species-specific abundance to carbon biomass data. Depth-integrated values are used to calculate known epipelagic macrozooplankton biomass concentrations and global biomass. Global macrozooplankton biomass, to a depth of 350 m, has a mean of 8.4 μg C L−1, median of 0.2 μg C L−1 and a standard deviation of 63.5 μg C L−1. The global annual average estimate of macrozooplankton biomass in the top 350 m, based on the median value, is 0.02 Pg C. There are, however, limitations on the dataset; abundance observations have good coverage except in the South Pacific mid-latitudes, but biomass observation coverage is only good at high latitudes. Biomass is restricted to data that is originally given in carbon or to data that can be converted from abundance to carbon. Carbon conversions from abundance are restricted by the lack of information on the size of the organism and/or the absence of taxonomic information. Distribution patterns of global macrozooplankton biomass and statistical information about biomass concentrations may be used to validate biogeochemical and plankton functional type models.last_img read more


Utah Women’s Basketball Promotes Assistant Coach

first_imgMay 21, 2018 /Sports News – Local Utah Women’s Basketball Promotes Assistant Coach Brad James Tags: Emily Potter/Gavin Petersen/Lynne Roberts/Megan Huff/Pac 12/Pacific Tigers/Utah Women’s Basketball Written by FacebookTwitterLinkedInEmailSALT LAKE CITY-Monday, University of Utah women’s basketball head coach Lynne Roberts  confirmed the promotion of assistant head coach Gavin Petersen to associate head coach.Roberts extolled Petersen, saying “[Gavin] is a star in this profession and he plays such a significant role in our program.”Petersen has 16 years of Division I coaching experience and has spent four seasons with the Utes.  In Salt Lake City, Petersen has been part of a staff that has led the Utes to three consecutive postseason appearances and a pair of 18-win seasons.Petersen, a native of Honolulu, stated he feels privileged to be part of the Utes’ program and he is “humbled by this promotion.”Petersen has been instrumental in helping the Utes finish in the top half of the Pac-12 in field goal percentage defense the past two seasons as well as in the top three in defensive rebounds per game the past three seasons.During his tenure in Salt Lake City, Petersen has helped the Utes develop some of the top post players in the conference, including three-time all-Pac-12 selection Emily Potter and all-Pac-12 2018 1st team selection Megan Huff.This past season, the Utes were #30 in the NCAA (out of 351 Division I schools) in rebounding margin while Potter and Huff were each in the top 10 in the Pac-12 in rebounds per game.Prior to coming to the Utah women’s basketball program, Petersen spent two seasons at the University of the Pacific under Roberts, helping the Tigers to consecutive WNIT berths. He has also served as an assistant at Hawaii, Idaho and Idaho State, helping eight teams he coached reach the postseason.last_img read more


Diverse French team brings home World Cup championship

first_img FacebookTwitterLinkedInEmailShaun Botterill/Getty Images(PARIS) — The French are welcoming home their soccer heroes in Paris on Monday after becoming the 2018 World Cup champions. But what is notable about the squad isn’t just the goals they managed to rack up, but the diversity the players embody.Some 15 of the 23 members of France’s World Cup team are of African descent, with families hailing from places like the Democratic Republic of the Congo (formerly Zaire), Cameroon, Morocco, Angola, and Algeria. While 21 out of the 23 players were born in France, many come from immigrant families.Kylian Mbappe, 19, one of the star players of the World Cup, is part Cameroonian and part Algerian.One of France’s biggest goal scorers, Antoine Griezmann, is of German and Portuguese descent.“We are proud to represent the diversity of France,” French midfielder Blaise Matuidi said during a press conference before the World Cup final.France midfielder Paul Pogba, whose parents are from Guinea, responded to a question about the diversity of the French team last week as well.“France today is a France full of colors. There are people of many different origins, that’s what makes France so beautiful. We all feel French, we’re happy to wear this shirt,” Pogba said.France’s World Cup win comes a year after far-right leader Marine Le Pen reached the run-off stage in the French presidential election. Le Pen ran on an anti-immigration platform that found support in parts of French society. This diverse team’s victory contrasts with the struggle France has had in welcoming immigrants in recent years.Echoing the diversity of their football teams, thousands of people from all different backgrounds headed to the famous Champs Elysees Avenue in Paris Sunday night to celebrate the victory.Waving French flags and chanting “We are the champions,” supporters united in a party atmosphere throughout the night.It’s the second time in history that France has won the World Cup. The first time was in 1998.The World Cup winners were set to parade down the Champs Elysees Monday in front of thousands of supporters.The French team then heads to the presidential palace to meet French President Emmanuel Macron.Macron attended the final World Cup game in Moscow and celebrated the victory with the players in the locker room. He also thanked them in a tweet.While most of the celebrations in Paris were harmonious, there were small pockets of violence and conflict, with troublemakers throwing flares at police on Champs Elysees Avenue.French police responded using tear gas and water canons to disperse violent fans.More than 290 people were taken into custody in France last night, and 45 policemen were slightly injured during the clashes, according to the French interior minister.Copyright © 2018, ABC Radio. All rights reserved. Beau Lund July 16, 2018 /Sports News – National Diverse French team brings home World Cup championshipcenter_img Written bylast_img read more


Thieves break into Tampa Bay running back Peyton Barber’s car, steal playbook and other valuables

first_img FacebookTwitterLinkedInEmailiStock/artisteer(TAMPA BAY, Fla.) — Tampa Bay Buccaneers running back Peyton Barber is used to being on the run from defenders. He’s not used to thieves being on the run from him.Barber is now in that very position though, as police told Atlanta ABC affiliate WSB that someone broke into the NFL player’s SUV early Saturday and stole a tablet, which stores his team’s playbook. The thieves also took his passport, designer sunglasses and some clothing items, WSB reported.Barber is a native of Alpharetta, Georgia, a suburb north of Atlanta, and went to school at Auburn University. He’s played three years in the NFL and started all 16 games for the Buccaneers last season.Barber, who made $630,000 last season, was visiting a friend at the Post Alexander High Rise when the break-in occurred. The location is right in downtown Atlanta, across from LEGOLAND Discovery Center.When he returned to his Jeep on Saturday morning he found the door open and the items stolen.NFL teams guard their playbooks with extreme secrecy to prevent other teams from getting their hands on the details of their plays.Police told WSB surveillance footage shows five men breaking into several vehicles in the area, so it appears unlikely the thieves knew what they were taking. An investigation into the thefts is ongoing.Barber finished 2018 with 871 rushing yards on 234 carries. He has 10 career touchdowns.He is a restricted free agent in 2019, with free agency opening up on March 13.Copyright © 2019, ABC Radio. All rights reserved. Written by February 24, 2019 /Sports News – National Thieves break into Tampa Bay running back Peyton Barber’s car, steal playbook and other valuablescenter_img Beau Lundlast_img read more


Robinson’s INT sets up Toledo’s winning TD in 28-21 victory over BYU

first_img Tags: BYU Cougars Football/Kahlil Robinson/Toledo Rockets Written by FacebookTwitterLinkedInEmailTOLEDO, Ohio (AP) — Kahlil Robinson’s 40-yard interception return to the BYU 2-yard line in the final minute set up Shakif Seymour’s touchdown run to rally Toledo to a 28-21 victory on Saturday.Robinson’s pick of a Zach Wilson pass came immediately after BYU’s Chaz Ah You stripped the ball from Rockets running back Bryant Koback and recovered it at the Cougars 20.Koback’s 1-yard score tied the score at 21 early in the fourth quarter, capping a nine-play, 70-yard drive.With Wilson out of the game in the final minute, backup Jaren Hall directed the Cougars to the Toledo 32 before his pass went beyond the end zone on the game’s final play.BYU coach Kalani Sitake said after the game that Wilson suffered an injury to his throwing hand and expected the quarterback to miss some playing time.Mitchell Guadagni threw for 206 yards with a touchdown and an interception for Toledo (3-1), which has won three straight.Wilson was 22 of 38 for 315 yards and two scores, both to Aleva Hifo. Hifo caught five passes for 111 yards and two scores including a 75-yarder for BYU (2-3). September 28, 2019 /Sports News – Local Robinson’s INT sets up Toledo’s winning TD in 28-21 victory over BYU Associated Presslast_img read more


Pac-12 announces final weekend of games in football season; Utah hosts Washington State

first_img Written by FacebookTwitterLinkedInEmailSAN FRANCSICO (AP) — The Pac-12 Conference has set the schedule for its final weekend of football games.The conference announced Sunday its teams will play six games, including Washington at No. 16 Southern California in the Pac-12 championship game on Friday.Oregon will face No. 21 Colorado at Memorial Coliseum on Saturday. The winner of that game could slide into a rescheduled title game if the Trojans or Huskies are unable to play due to COVID-19 issues.Saturday’s games also include Washington State at Utah, Stanford at UCLA, and Arizona State at Oregon State. Arizona will face California at a site and time to be determined. Tags: Pac-12/Utah Utes Football Associated Press December 13, 2020 /Coronavirus (COVID-19) related news and sports stories, Sports News – Local Pac-12 announces final weekend of games in football season; Utah hosts Washington Statelast_img read more


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