first_imgThe responses of phytoplankton populations to seasonal changes in radiation flux in two Antarctic lakes with extensive winter ice-cover are described. A phytoplankton capable of photosynthesis was found throughout the year in both systems. During winter, low incident radiation combined with thick layers of snow and ice prevented in situ photosynthesis becoming detectable. The beginning of spring was marked by a reduction in snow cover which resulted in a considerable increase in surface penetrating radiation. Planktonic algae rapidly adapted to utilise these increased levels efficiently, though they still showed characteristics of strong shade adaptation. Loss of ice cover at the start of the short open water period further increased the radiation levels and a summer population developed which was much less shade adapted. Saturation and photoinhibition effects were widespread during this period as the algae proved unable to utilise high radiation levels efficiently. They were however effective at the radiation fluxes prevalent in the lower part of the rapidly circulating water columns.last_img read more

first_imgTemperature records in the Antarctic Peninsula have shown a climatic warming of 1.5°C over the past 30 years and a number of ice shelves have retreated. The most dramatic retreat has been that of Wordie Ice Shelf which has undergone a catastrophic disintegration since the 1960s. Understanding the cause and mechanism of the break-up may provide important clues to the fate of ice shelves farther south which, it has been suggested, help to stabilize the West Antarctic Ice Sheet. The break-up of Wordie Ice Shelf has been analysed using Landsat and SPOT imagery. These observations show that the relative contribution of the various input glaciers to the grounding line flux has not altered during the break-up. This means that the effect of the rapid and almost complete removal of the ice shelf has not been transmitted upstream and is not causing a rapid increase in velocities on the input glaciers. The volume of grounded ice in the catchment of Wordie Ice Shelf will thus, be largely unaffected by the break-up and there will be no significant contribution to sea level change. Since other ice shelves around the Antarctic Peninsula are also fed by relatively steep mountain glaciers the effect of the loss of the ice shelves on sea level would be likely to be similarly smalllast_img read more

first_imgThe fishery for Illex argentinus in the Southwest Atlantic is subject to large inter-annualvariability in recruitment strength. In this paper we attempt to build a predictive model using sea surfacetemperature (SST) to examine links between recruitment to the Falkland Islands fishery and environmentalvariability during the juvenile and adult life history stages. SST data from the National centerfor Atmospheric Research (NCAR) were found to be comparable with near-surface data derivedfrom in situ expendable bathy-thermograph (XBT) profiles in the southern Patagonian shelf. Variationin SST during the early life stages appears to be important in determining recruitment of I. argentin us.SST in the hatching grounds of the northern Patagonian shelf during the period of hatching (particularlyJune and July) was negatively correlated with catches in the fishery in the following season. SSTanomaly data from positions in the Pacific and Southwest Atlantic were used to examine teleconnectionsbetween these areas. Links were seen at a lag of 2 yr between the Pacific and southern Patagonianshelf, and at about 5 yr between the Pacific and northern Patagonian shelf. This is consistent withSST anomalies associated with El Niilo in the Pacific propagating around the globe via the AntarcticCircumpolar Wave (ACW). Predicting cold events via teleconnections between SST anomalies in thePacific and Atlantic would appear to have the potential to predict the recruitment strength of I. argentinusin the Southwest Atlantic.last_img read more

first_imgThe exceptional sea-ice retreat and advance that occurred in the Bellingshausen Sea, Antarctica during August 1993 was the largest such winter event in this sector of the Antarctic during the satellite era. The reasons for this fluctuation of ice are investigated using passive microwave satellite imagery, ice motion vectors derived from the satellite data, in-situ meteorological reports and near-surface winds and temperatures from the European Centre for Medium-range Weather Forecasts (ECMWF) numerical weather prediction model. The ice edge retreat of more than 400 km took place near 80degreesW from approximately 1-15 August, although the southward migration of the ice edge was not continuous and short periods of advance were also recorded. Between 16 August and 2 September there was almost continuous sea-ice recovery. The rate of change of the ice edge location during both the retreat and advance phases significantly exceeded the southward and northward velocity components of ice within the pack, pointing to the importance of ice production and melting during this event. During the month, markedly different air masses affected the area, resulting in temperature changes from +2degreesC to -21degreesC at the nearby Rothera station. ‘Bulk’ movement of the pack, and compaction and divergence of the sea ice, made a secondary, but still significant, contribution to the observed advance and retreat. The ice extent fluctuations were so extreme because strong meridional atmospheric flow was experienced in a sector of the Southern Ocean where relatively low ice concentrations were occurring. The very rapid ice retreat/advance was associated with pronounced low-high surface pressure anomaly couplets on either side of the Antarctic Peninsula.last_img read more

first_img[1] We examine 22 case studies of CRRES satellite observations of substorm-enhanced whistler-mode waves. These observations were made close to the geomagnetic equator and between 0200 and 0600 MLT. The frequency of the enhanced whistler-mode waves is seen to vary strongly with magnetic field strength, and for this reason we plot the data in terms of the equivalent parallel resonant energy of an electron in first-order cyclotron resonance with a wave of a given frequency. No consistent increase or decrease of the equivalent parallel resonant energy of the substorm-enhanced whistler-mode waves with time is seen; rather the typical behavior is that it remains constant with time. We interpret our findings in terms of the injected electron population and resonance ellipses in velocity space. Furthermore, we relate the findings of our study to observations of ducted waves seen on the ground as substorm chorus events (SCEs) and conclude that the frequency dispersion seen in SCEs is dominated by electric field effects.last_img read more

first_imgTrapped beneath the Antarctic ice sheet lie over 400 subglacial lakes, which are considered to be extreme, isolated, yet viable habitats for microbial life. The physical conditions within subglacial lakes are critical to evaluating how and where life may best exist. Here, we propose that Earth’s geothermal flux provides efficient stirring of Antarctic subglacial lake water. We demonstrate that most lakes are in a regime of vigorous turbulent vertical convection, enabling suspension of spherical particulates with diameters up to 36 micrometers. Thus, dynamic conditions support efficient mixing of nutrient- and oxygen-enriched meltwater derived from the overlying ice, which is essential for biome support within the water column. We caution that accreted ice analysis cannot always be used as a proxy for water sampling of lakes beneath a thin (<3.166 kilometers) ice cover, because a stable layer isolates the well-mixed bulk water from the ice-water interface where freezing may occur.last_img read more

first_img Written by Robert Lovell FacebookTwitterLinkedInEmail(Salt Lake City, UT)  —   The Bees were unable to protect an early lead as they fell to the Round Rock Express 10-5 at Smith’s Ballpark.After taking a 5-2 lead in the second inning the Bees yielded eight unanswered runs.  Parker Bridwell surrendered six runs across five innings to take the loss.The Bees fell to 35-and-24 and resume the series with Round Rock tonight. June 6, 2018 /Sports News – Local Bees fall to Round Rock Tags: Baseball/PCL/Salt Lake Beeslast_img read more

first_img Tags: Demario Warren/Jeff Tukuafu/Trever McFalls Written by FacebookTwitterLinkedInEmailCEDAR CITY, Utah-Thursday afternoon, Southern Utah University head football coach Demario Warren named Trever McFalls as the director of football operations for the program.Prior to his promotion, McFalls served as offensive assistant/team manager for the Thunderbirds and is also a former SUU football player.McFalls replaces Jeff Tukuafu in this position after he became the assistant athletic director for operations/facilities for SUU. Brad James July 12, 2018 /Sports News – Local Trever McFalls Named As SUU Director of Football Operationslast_img read more

first_img FacebookTwitterLinkedInEmailJoe Faraoni/ESPN Images(NEW YORK) — Former WNBA star Lisa Leslie took her talents to the small screen and made a guest appearance on an episode of ABC’s Speechless.In the episode, which aired on Dec. 14, Leslie played character Kenneth Clements’ sister.Watch a clip from her appearance on the sitcom below:Copyright © 2018, ABC Radio. All rights reserved. December 17, 2018 /Sports News – National Former WNBA star Lisa Leslie appears in ABC’s “Speechless” Beau Lundcenter_img Written bylast_img read more

first_img Brad James Written by Tags: Adam Pulsipher/Albertson’s Tackle Hunger/Boys & Girls Club/Famous Idaho Potato Bowl/Jamauri Bogan/Student-Athlete Advisory Committee/Treasure Valley FacebookTwitterLinkedInEmailBOISE, Idaho-Monday, The Famous Idaho Potato Bowl announced BYU linebacker Adam Pulsipher and Western Michigan tailback Jamauri Bogan as humanitarian award winners for their bowl game Friday at Albertson’s Stadium.The duo will be presented with their awards Monday at the conclusion of the Albertson’s Tackle Hunger Event at Boise’s Bishop Kelly High School.This event will see the Broncos and Cougars compete against each other to see which team can package the most meals in an hour.The meals will be distributed to families throughout the Treasure Valley area (western Idaho and eastern Oregon) for the next several months.Throughout his collegiate career, Pulsipher, a senior out of Temecula, Calif., has served others. In the Provo community, he dedicates time to tutor in multiple academic disciplines at the Boys & Girls Club and has organized hospital visits for his teammates.He serves as the co-chair of BYU’s Student-Athlete Advisory Committee as well. December 17, 2018 /Sports News – Local BYU Linebacker Adam Pulsipher Named Idaho Potato Bowl Humanitarian Award Winnerlast_img read more