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Sample records for antarctic ozone hole

  1. Antarctic Ozone Hole, 2000

    Science.gov (United States)

    2002-01-01

    Each spring the ozone layer over Antarctica nearly disappears, forming a 'hole' over the entire continent. The hole is created by the interaction of some man-made chemicals-freon, for example-with Antarctica's unique weather patterns and extremely cold temperatures. Ozone in the stratosphere absorbs ultraviolet radiation from the sun, thereby protecting living things. Since the ozone hole was discovered many of the chemicals that destroy ozone have been banned, but they will remain in the atmosphere for decades. In 2000, the ozone hole grew quicker than usual and exceptionally large. By the first week in September the hole was the largest ever-11.4 million square miles. The top image shows the average total column ozone values over Antarctica for September 2000. (Total column ozone is the amount of ozone from the ground to the top of the atmosphere. A relatively typical measurement of 300 Dobson Units is equivalent to a layer of ozone 0.12 inches thick on the Earth's surface. Levels below 220 Dobson Units are considered to be significant ozone depletion.) The record-breaking hole is likely the result of lower than average ozone levels during the Antarctic fall and winter, and exceptionally cold temperatures. In October, however (bottom image), the hole shrank dramatically, much more quickly than usual. By the end of October, the hole was only one-third of it's previous size. In a typical year, the ozone hole does not collapse until the end of November. NASA scientists were surprised by this early shrinking and speculate it is related to the region's weather. Global ozone levels are measured by the Total Ozone Mapping Spectrometer (TOMS). For more information about ozone, read the Earth Observatory's ozone fact sheet, view global ozone data and see these ozone images. Images by Greg Shirah, NASA GSFC Scientific Visualization Studio.

  2. The Antarctic ozone hole

    International Nuclear Information System (INIS)

    Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For the historical perspective, the events leading up to the discovery of the 'hole' are presented, as well as the response from the international community and the measures taken to protect the ozone layer now and into the future

  3. The Antarctic Ozone Hole

    Science.gov (United States)

    Jones, Anna E.

    2008-01-01

    Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For…

  4. The Antarctic Ozone Hole: An Update

    Science.gov (United States)

    Douglass, Anne R.; Newman, Paul A.; Solomon, Susan

    2014-01-01

    The stratospheric ozone hole, an annual occurrence during austral spring, is caused by heterogeneous conversion of hydrogen chloride and chlorine nitrate to chlorine radicals. These reactions take place of polar stratospheric cloud particles in the cold, isolate Antarctic winter vortex. The chlorine radicals participate in chemical reactions that rapidly deplete ozone when sunlight returns at the end of polar night. International agreements eliminated production of the culprit anthropogenic chlorofluorocarbons in the late 1990s, but due to their long stratospheric lifetime (50-100 years), the ozone hole will continue its annual appearance for years to come.

  5. Antarctic Ozone Hole on September 17, 2001

    Science.gov (United States)

    2002-01-01

    Satellite data show the area of this year's Antarctic ozone hole peaked at about 26 million square kilometers-roughly the size of North America-making the hole similar in size to those of the past three years, according to scientists from NASA and the National Oceanic and Atmospheric Administration (NOAA). Researchers have observed a leveling-off of the hole size and predict a slow recovery. Over the past several years the annual ozone hole over Antarctica has remained about the same in both its size and in the thickness of the ozone layer. 'This is consistent with human-produced chlorine compounds that destroy ozone reaching their peak concentrations in the atmosphere, leveling off, and now beginning a very slow decline,' said Samuel Oltmans of NOAA's Climate Monitoring and Diagnostics Laboratory, Boulder, Colo. In the near future-barring unusual events such as explosive volcanic eruptions-the severity of the ozone hole will likely remain similar to what has been seen in recent years, with year-to-year differences associated with meteorological variability. Over the longer term (30-50 years) the severity of the ozone hole in Antarctica is expected to decrease as chlorine levels in the atmosphere decline. The image above shows ozone levels on Spetember 17, 2001-the lowest levels observed this year. Dark blue colors correspond to the thinnest ozone, while light blue, green, and yellow pixels indicate progressively thicker ozone. For more information read: 2001 Ozone Hole About the Same Size as Past Three Years. Image courtesy Greg Shirah, GSFC Scientific Visualization Studio, based on data from the TOMS science team

  6. Estimating when the Antarctic Ozone Hole will Recover

    Science.gov (United States)

    Newman, Paul A.; Nash, Eric R.; Douglass, Anne R.; Nielsen, J. Eric; Pawson, Steven; Stolarski, Richard S.

    2007-01-01

    The Antarctic ozone hole develops each year and culminates by early spring (late September - early October). The severity of the hole has been assessed from satellites using the minimum total ozone value from the October monthly mean (depth of the hole) and by calculating the average area coverage during this September-October period. Profile information shows that ozone is completely destroyed in the 14-2 1 km layer by early October. Ozone is mainly destroyed by halogen (chlorine and bromine) catalytic cycles, and these losses are modulated by temperature variations. Because atmospheric halogen levels are responding to international a'greements that limit or phase out production, the amount of halogens in the stratosphere should decrease over the next few decades. Using projections of halogen levels combined with age-of-air estimates, we find that the ozone hole is recovering at an extremely slow rate and that large ozone holes will regularly recur over the next 2 decades. We estimate that the ozone hole will begin to show first signs of size decrease in about 2023, and the hole will fully recover to pre-1980 levels in approximately 2070. Estimates of the ozone hole's recovery from models reveal important differences that will be discussed.

  7. Measuring the Antarctic ozone hole with the new Ozone Mapping and Profiler Suite (OMPS)

    OpenAIRE

    Kramarova, N. A.; E. R. Nash; P. A. Newman; P. K. Bhartia; R. D. McPeters; D. F. Rault; Seftor, C. J.; P. Q. Xu; Labow, G. J.

    2014-01-01

    The new Ozone Mapping and Profiler Suite (OMPS), which launched on the Suomi National Polar-orbiting Partnership satellite in October 2011, gives a detailed view of the development of the Antarctic ozone hole and extends the long series of satellite ozone measurements that go back to the early 1970s. OMPS includes two modules – nadir and limb – to measure profile and total ozone concentrations. The new limb module is designed to measure the vertical profile of ozone between ...

  8. Unequivocal detection of ozone recovery in the Antarctic Ozone Hole through significant increases in atmospheric layers with minimum ozone

    Science.gov (United States)

    de Laat, Jos; van Weele, Michiel; van der A, Ronald

    2015-04-01

    An important new landmark in present day ozone research is presented through MLS satellite observations of significant ozone increases during the ozone hole season that are attributed unequivocally to declining ozone depleting substances. For many decades the Antarctic ozone hole has been the prime example of both the detrimental effects of human activities on our environment as well as how to construct effective and successful environmental policies. Nowadays atmospheric concentrations of ozone depleting substances are on the decline and first signs of recovery of stratospheric ozone and ozone in the Antarctic ozone hole have been observed. The claimed detection of significant recovery, however, is still subject of debate. In this talk we will discuss first current uncertainties in the assessment of ozone recovery in the Antarctic ozone hole by using multi-variate regression methods, and, secondly present an alternative approach to identify ozone hole recovery unequivocally. Even though multi-variate regression methods help to reduce uncertainties in estimates of ozone recovery, great care has to be taken in their application due to the existence of uncertainties and degrees of freedom in the choice of independent variables. We show that taking all uncertainties into account in the regressions the formal recovery of ozone in the Antarctic ozone hole cannot be established yet, though is likely before the end of the decade (before 2020). Rather than focusing on time and area averages of total ozone columns or ozone profiles, we argue that the time evolution of the probability distribution of vertically resolved ozone in the Antarctic ozone hole contains a better fingerprint for the detection of ozone recovery in the Antarctic ozone hole. The advantages of this method over more tradition methods of trend analyses based on spatio-temporal average ozone are discussed. The 10-year record of MLS satellite measurements of ozone in the Antarctic ozone hole shows a

  9. Chemistry and Dynamics of the Unusual 2015 Antarctic Ozone Hole

    Science.gov (United States)

    Braathen, Geir O.

    2016-04-01

    The Global Atmosphere Watch of the World Meteorological Organization includes several stations in Antarctica that keep a close eye on the ozone layer during the ozone hole season. Observations made during the unusually large ozone hole of 2015 will be compared to ozone holes from 2003 to 2014 and interpreted in light of the meteorological conditions. Satellite observations will be used to get a more general picture of the size and depth of the ozone hole and will also be used to calculate various metrics for ozone hole severity. In 2003, 2005 and 2006, the ozone hole was relatively large with more ozone loss than normal. This is in particular the case for 2006, which by most ozone hole metrics was the most severe ozone hole on record. On the other hand, the ozone holes of 2004, 2007, 2010 and 2012, 2013 and 2014 were less severe than normal, and only the very special ozone hole of 2002 had less ozone depletion when one regards the ozone holes of the last decade. The South Polar vortex of 2015 was unusually stable and long-lived, so ozone depletion lasted longer than seen in recent years. The ozone hole area, i.e. the area where total ozone is less that 220 DU, averaged over the worst 60 consecutive days was larger in 2015 than in any other year since the beginning of the ozone hole era in the early 1980s.

  10. Monitoring and future projections of the Antarctic Ozone Hole using the new Ozone Mapping and Profiler Suite (OMPS)

    Science.gov (United States)

    Kramarova, N. A.; Newman, P. A.; Nash, E. R.; Bhartia, P. K.; McPeters, R. D.; Rault, D. F.; Seftor, C. J.; Xu, P.

    2013-12-01

    Using the new Ozone Mapping and Profiler Suite (OMPS), launched October 2011 on board the Suomi National Polar-orbiting Partnership satellite, we have studied the structure and evolution of the 2012 and 2013 ozone holes. The 1st ozone hole observations by OMPS began in 2012. We quality check the OMPS measurements by comparing to other satellite instruments (Aura MLS, OMI and SBUV) and ozone sonde balloon measurements. The comparisons reveal that OMPS is producing excellent Antarctic ozone hole information, and, thus, OMPS data can be used to continue the historical record of Antarctic ozone observations. In 2012 the ozone hole developed quite normally in the August to-late September 2012 period, but disappeared much more rapidly during the late-September to November period than it would be expected in a normal year. This resulted in the second weakest ozone hole observed since 1988. Some have suggested that the rapid 2012 disappearance is evidence that the Montreal Protocol is working. However, the development of the ozone hole in August and September is largely driven by chlorine and bromine from human-produced compounds, and the normal development of the ozone hole in August-September 2012 suggests that chlorine and bromine levels were roughly the same as previous years. At the same time, observations from meteorological data show that there were stronger than average weather systems, faster warming during the September -November period, and stronger vertical motions, that led to a rapid decay of the 2012 ozone hole. Hence, the weak ozone hole of 2012 is not evidence that the Montreal Protocol has impacted the ozone hole. The characteristics of the 2013 ozone hole, as observed by OMPS, will also be shown in the presentation. Model predictions suggest that the ozone hole will begin showing signs of recovery in about 2018, and it will be fully recovered back to 1980 levels in about 2065. We will update projections of the ozone hole recovery using a parametric model

  11. Effects of injected ice particles in the lower stratosphere on the Antarctic ozone hole

    OpenAIRE

    Nagase, H.; Kinnison, D.; Petersen, A.; F. Vitt; Brasseur, G.

    2015-01-01

    The Antarctic ozone hole will continue to be observed in the next 35-50 years, although the emissions of chlorofluorocarbons (CFCs) have gradually been phased out during the last two decades. In this paper, we suggest a geo-engineering approach that will remove substantial amounts of hydrogen chloride (HCl) from the lower stratosphere in fall, and hence limit the formation of the Antarctic ozone hole in late winter and early spring. HCl will be removed by ice from the atmosphere at temperatur...

  12. The influence of cosmic rays on the size of the Antarctic Ozone Hole

    CERN Document Server

    Madrigal, M Alvarez; Velasco, V M

    2010-01-01

    The Antarctic region in which severe ozone depletion has taken place is known as the ozone hole. This region has two basic indicators: the area, where the ozone abundance is low (size), and the quantity of ozone mass deficit (depth). The energetic particles that penetrate deeply into the atmosphere and galactic cosmic rays (GCR) modify the ozone abundance in the stratosphere. With this research project, we are looking for evidence of a connection between variations in the cosmic ray flux and variations in the size of the ozone hole. In addition, we are looking for signs of the kind of processes that physically connect GCR fluxes with variations in the stratospheric ozone hole size (OHS) in the Antarctic region. With this goal in mind, we also analyze here the atmospheric temperature (AT) anomalies, which have often been linked with such variations. Using Morlet's wavelet spectral analysis to compute the coherence between two time series, we found that during the analyzed period (1982-2005), there existed a co...

  13. Effects of injected ice particles in the lower stratosphere on the Antarctic ozone hole

    Science.gov (United States)

    Nagase, H.; Kinnison, D. E.; Petersen, A. K.; Vitt, F.; Brasseur, G. P.

    2015-05-01

    The Antarctic ozone hole will continue to be observed in the next 35-50 years, although the emissions of chlorofluorocarbons (CFCs) have gradually been phased out during the last two decades. In this paper, we suggest a geo-engineering approach that will remove substantial amounts of hydrogen chloride (HCl) from the lower stratosphere in fall, and hence limit the formation of the Antarctic ozone hole in late winter and early spring. HCl will be removed by ice from the atmosphere at temperatures higher than the threshold under which polar stratospheric clouds (PSCs) are formed if sufficiently large amounts of ice are supplied to produce water saturation. A detailed chemical-climate numerical model is used to assess the expected efficiency of the proposed geo-engineering method, and specifically to calculate the removal of HCl by ice particles. The size of ice particles appears to be a key parameter: larger particles (with a radius between 10 and 100 µm) appear to be most efficient for removing HCl. Sensitivity studies lead to the conclusions that the ozone recovery is effective when ice particles are supplied during May and June in the latitude band ranging from 70°S to 90°S and in the altitude layer ranging from 10 to 26 km. It appears, therefore, that supplying ice particles to the Antarctic lower stratosphere could be effective in reducing the depth of the ozone hole. In addition, photodegradation of CFCs might be accelerated when ice is supplied due to enhanced vertical transport of this efficient greenhouse gas.

  14. Ozone Hole Over Antarctica

    Science.gov (United States)

    2002-01-01

    These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from 1979 to 1999. This 'ozone hole' has extended to cover an area as large as 10.5 million square miles in September 1998. The previous record of 10.0 million square miles was set in 1996. The Antarctic ozone hole develops each year between late August and early October. Regions with higher levels of ozone are shown in red. NASA and NOAA instruments have been measuring Antarctic ozone levels since the early 1970s. Large regions of depleted ozone began to develop over Antarctica in the early 1980s. Ozone holes of substantial size and depth are likely to continue to form during the next few years, scientists hope to see a reduction in ozone loss as levels of ozone-destroying CFCs (chlorofluorocarbons) are gradually reduced. Credit: Images by Greg Shirah, NASA Goddard Space Flight Center Scientific Visualization Studio

  15. The Antarctic Ice Sheet, Sea Ice, and the Ozone Hole: Satellite Observations of how they are Changing

    Science.gov (United States)

    Parkinson, Claire L.

    2012-01-01

    Antarctica is the Earth's coldest and highest continent and has major impacts on the climate and life of the south polar vicinity. It is covered almost entirely by the Earth's largest ice sheet by far, with a volume of ice so great that if all the Antarctic ice were to go into the ocean (as ice or liquid water), this would produce a global sea level rise of about 60 meters (197 feet). The continent is surrounded by sea ice that in the wintertime is even more expansive than the continent itself and in the summertime reduces to only about a sixth of its wintertime extent. Like the continent, the expansive sea ice cover has major impacts, reflecting the sun's radiation back to space, blocking exchanges between the ocean and the atmosphere, and providing a platform for some animal species while impeding other species. Far above the continent, the Antarctic ozone hole is a major atmospheric phenomenon recognized as human-caused and potentially quite serious to many different life forms. Satellites are providing us with remarkable information about the ice sheet, the sea ice, and the ozone hole. Satellite visible and radar imagery are providing views of the large scale structure of the ice sheet never seen before; satellite laser altimetry has produced detailed maps of the topography of the ice sheet; and an innovative gravity-measuring two-part satellite has allowed mapping of regions of mass loss and mass gain on the ice sheet. The surrounding sea ice cover has a satellite record that goes back to the 1970s, allowing trend studies that show a decreasing sea ice presence in the region of the Bellingshausen and Amundsen seas, to the west of the prominent Antarctic Peninsula, but increasing sea ice presence around much of the rest of the continent. Overall, sea ice extent around Antarctica has increased at an average rate of about 17,000 square kilometers per year since the late 1970s, as determined from satellite microwave data that can be collected under both light and

  16. 南极臭氧洞的发现、研究和启示%The Antarctic Ozone Hole and its Discovery, Research and Inspiration

    Institute of Scientific and Technical Information of China (English)

    陆龙骅

    2016-01-01

    回顾了南极臭氧洞的发现过程,评述了南极臭氧洞形成和发展的机制、以及南北极臭氧变化的差异,讨论了南极臭氧洞的发现和研究带来的启示。研究指出,目前只是在南极春季出现了臭氧洞,北极并没有出现过臭氧洞。在当前大气环境被污染的情况下,极地大气臭氧亏损的程度将更多地随大气环流,特别是极地涡旋中的低温状况而发生变化。%This study reviews the detection and the variety of the Antarctic ozone hole; the reason why the ozone hole is formed over the Antarctic is discussed, while the different patterns of the ozone variation over the Arctic and the Antarctic are outlined. It is also discussed the inspiration obtained throughout the detection and research of Antarctic ozone hole. It is pointed out that, currently, the ozone hole appears only in spring over the Antarctic and not appeared yet over the Arctic. Under the current atmospheric environment with the added pollution, the change of atmospheric ozone depletion over the Polar Regions will be more dependent on the atmospheric circulation, especially the low temperature in the polar vortex.

  17. UV spectral irradiance monitoring during the 1988 and 1989 Antarctic ozone holes

    Energy Technology Data Exchange (ETDEWEB)

    Booth, C.R.; Lucas, T.B.; Morrow, J.H.; Yeh, J. (Biospherical Instruments, Inc., San Diego, CA (United States))

    1990-01-09

    UV spectral irradiance incident at the United States bases at McMurdo, Palmer, and the South Pole, in Antarctica, and at an Argentina Laboratory in Ushuaia is being routinely monitored by the NSF UV Spectroradiometer Network. Coverage includes the 1988 and 1989 ozone hole seasons and show marked differences between these two years. Many different methods of assessing UV irradiance or exposure are found in the literature. The degree of contrast between the 1988 and 1989 seasons varies widely depending upon the UV assessment method chosen. Data will be presented describing how different assessment methods present this time series.

  18. Largest-ever Ozone Hole over Antarctica

    Science.gov (United States)

    2002-01-01

    A NASA instrument has detected an Antarctic ozone 'hole' (what scientists call an 'ozone depletion area') that is three times larger than the entire land mass of the United States-the largest such area ever observed. The 'hole' expanded to a record size of approximately 11 million square miles (28.3 million square kilometers) on Sept. 3, 2000. The previous record was approximately 10.5 million square miles (27.2 million square km) on Sept. 19, 1998. The ozone hole's size currently has stabilized, but the low levels in its interior continue to fall. The lowest readings in the ozone hole are typically observed in late September or early October each year. 'These observations reinforce concerns about the frailty of Earth's ozone layer. Although production of ozone-destroying gases has been curtailed under international agreements, concentrations of the gases in the stratosphere are only now reaching their peak. Due to their long persistence in the atmosphere, it will be many decades before the ozone hole is no longer an annual occurrence,' said Dr. Michael J. Kurylo, manager of the Upper Atmosphere Research Program, NASA Headquarters, Washington, DC. Ozone molecules, made up of three atoms of oxygen, comprise a thin layer of the atmosphere that absorbs harmful ultraviolet radiation from the Sun. Most atmospheric ozone is found between approximately six miles (9.5 km) and 18 miles (29 km) above the Earth's surface. Scientists continuing to investigate this enormous hole are somewhat surprised by its size. The reasons behind the dimensions involve both early-spring conditions, and an extremely intense Antarctic vortex. The Antarctic vortex is an upper-altitude stratospheric air current that sweeps around the Antarctic continent, confining the Antarctic ozone hole. 'Variations in the size of the ozone hole and of ozone depletion accompanying it from one year to the next are not unexpected,' said Dr. Jack Kaye, Office of Earth Sciences Research Director, NASA Headquarters

  19. The 1988 Antarctic ozone depletion - Comparison with previous year depletions

    Science.gov (United States)

    Schoeberl, Mark R.; Stolarski, Richard S.; Krueger, Arlin J.

    1989-01-01

    The 1988 spring Antarctic ozone depletion was observed by TOMS to be substantially smaller than in recent years. The minimum polar total ozone values declined only 15 percent during September 1988, compared to nearly 50 percent during September 1987. At southern midlatitudes, exceptionally high total ozone values were recorded beginning in July 1988. The total integrated southern hemispheric ozone increased rapidly during the Austral spring, approaching 1980 levels during October. The high midlatitude total ozone values were associated with a substantial increase in eddy activity as indicated by the standard deviation in total ozone in the zonal band 30-60 deg S. Mechanisms through which the increased midlatitude eddy activity could disrupt the formation of the Antarctic ozone hole are briefly discussed.

  20. Emergence of healing in the Antarctic ozone layer

    Science.gov (United States)

    Solomon, Susan; Ivy, Diane J.; Kinnison, Doug; Mills, Michael J.; Neely, Ryan R.; Schmidt, Anja

    2016-07-01

    Industrial chlorofluorocarbons that cause ozone depletion have been phased out under the Montreal Protocol. A chemically driven increase in polar ozone (or “healing”) is expected in response to this historic agreement. Observations and model calculations together indicate that healing of the Antarctic ozone layer has now begun to occur during the month of September. Fingerprints of September healing since 2000 include (i) increases in ozone column amounts, (ii) changes in the vertical profile of ozone concentration, and (iii) decreases in the areal extent of the ozone hole. Along with chemistry, dynamical and temperature changes have contributed to the healing but could represent feedbacks to chemistry. Volcanic eruptions have episodically interfered with healing, particularly during 2015, when a record October ozone hole occurred after the Calbuco eruption.

  1. Emergence of healing in the Antarctic ozone layer.

    Science.gov (United States)

    Solomon, Susan; Ivy, Diane J; Kinnison, Doug; Mills, Michael J; Neely, Ryan R; Schmidt, Anja

    2016-07-15

    Industrial chlorofluorocarbons that cause ozone depletion have been phased out under the Montreal Protocol. A chemically driven increase in polar ozone (or "healing") is expected in response to this historic agreement. Observations and model calculations together indicate that healing of the Antarctic ozone layer has now begun to occur during the month of September. Fingerprints of September healing since 2000 include (i) increases in ozone column amounts, (ii) changes in the vertical profile of ozone concentration, and (iii) decreases in the areal extent of the ozone hole. Along with chemistry, dynamical and temperature changes have contributed to the healing but could represent feedbacks to chemistry. Volcanic eruptions have episodically interfered with healing, particularly during 2015, when a record October ozone hole occurred after the Calbuco eruption. PMID:27365314

  2. Artificial ozone holes

    CERN Document Server

    Dolya, S N

    2014-01-01

    This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.

  3. The Antarctic ozone depletion caused by Erebus volcano gas emissions

    Science.gov (United States)

    Zuev, V. V.; Zueva, N. E.; Savelieva, E. S.; Gerasimov, V. V.

    2015-12-01

    Heterogeneous chemical reactions releasing photochemically active molecular chlorine play a key role in Antarctic stratospheric ozone destruction, resulting in the Antarctic ozone hole. Hydrogen chloride (HCl) is one of the principal components in these reactions on the surfaces of polar stratospheric clouds (PSCs). PSCs form during polar nights at extremely low temperatures (lower than -78 °C) mainly on sulfuric acid (H2SO4) aerosols, acting as condensation nuclei and formed from sulfur dioxide (SO2). However, the cause of HCl and H2SO4 high concentrations in the Antarctic stratosphere, leading to considerable springtime ozone depletion, is still not clear. Based on the NCEP/NCAR reanalysis data over the last 35 years and by using the NOAA HYSPLIT trajectory model, we show that Erebus volcano gas emissions (including HCl and SO2) can reach the Antarctic stratosphere via high-latitude cyclones with the annual average probability Pbarann. of at least ∼0.235 (23.5%). Depending on Erebus activity, this corresponds to additional annual stratospheric HCl mass of 1.0-14.3 kilotons (kt) and SO2 mass of 1.4-19.7 kt. Thus, Erebus volcano is the natural and powerful source of additional stratospheric HCl and SO2, and hence, the cause of the Antarctic ozone depletion, together with man-made chlorofluorocarbons.

  4. Fundamental differences between Arctic and Antarctic ozone depletion.

    Science.gov (United States)

    Solomon, Susan; Haskins, Jessica; Ivy, Diane J; Min, Flora

    2014-04-29

    Antarctic ozone depletion is associated with enhanced chlorine from anthropogenic chlorofluorocarbons and heterogeneous chemistry under cold conditions. The deep Antarctic "hole" contrasts with the generally weaker depletions observed in the warmer Arctic. An unusually cold Arctic stratospheric season occurred in 2011, raising the question of how the Arctic ozone chemistry in that year compares with others. We show that the averaged depletions near 20 km across the cold part of each pole are deeper in Antarctica than in the Arctic for all years, although 2011 Arctic values do rival those seen in less-depleted years in Antarctica. We focus not only on averages but also on extremes, to address whether or not Arctic ozone depletion can be as extreme as that observed in the Antarctic. This information provides unique insights into the contrasts between Arctic and Antarctic ozone chemistry. We show that extreme Antarctic ozone minima fall to or below 0.1 parts per million by volume (ppmv) at 18 and 20 km (about 70 and 50 mbar) whereas the lowest Arctic ozone values are about 0.5 ppmv at these altitudes. At a higher altitude of 24 km (30-mbar level), no Arctic data below about 2 ppmv have been observed, including in 2011, in contrast to values more than an order of magnitude lower in Antarctica. The data show that the lowest ozone values are associated with temperatures below -80 °C to -85 °C depending upon altitude, and are closely associated with reduced gaseous nitric acid concentrations due to uptake and/or sedimentation in polar stratospheric cloud particles. PMID:24733920

  5. Latest tendency in the Antarctic ozone longitudinal distribution

    Science.gov (United States)

    Milinevsky, Gennadi; Grytsai, Asen; Klekociuk, Andrew; Evtushevsky, Olexander

    2014-05-01

    Significant ozone depletion was observed within the southern polar vortex during spring in the 1980s - early 1990s. Later, a stabilization in total ozone levels and ozone hole area has been observed. Atmosphere models predict a consequent recovery of the Antarctic ozone. Nevertheless, identification of the long-term processes is complicated by high interannual variability hiding their general regularities. In particular, a large stratosphere warming in 2002 resulted in significant increase in total ozone levels. The Antarctic ozone hole is formed inside polar stratospheric vortex, which is under influence of large-scale planetary waves. The components of the quasi-stationary wave (QSW) in the spring Southern Hemisphere (SH) stratosphere is mainly contributed by zonal wave number 1 which in turn determines the location of the total ozone extremes in spring: QSW minimum (maximum) is located in the South Atlantic (Australian) sector. In our work the satellite data of TOMS/Nimbus-7, TOMS/Earth Probe and OMI/Aura (http://ozoneaq.gsfc.nasa.gov/) have been used to investigate longitudinal distribution of the total ozone in Antarctic region. The gap in these satellite observations (1993-1995) was filled by the Multi-Sensor Reanalysis data (http://www.temis.nl/). Ozone distribution in the SH high and mid latitudes 80-50S were analyzed for southern spring season including months from September to November. The zonal distribution is considered along seven latitude circles from 80S to 50S with step of five degrees. To distinguish long-term processes and to obtain a quasi-stationary pattern, daily September - November ozone was averaged. Our previous study demonstrated a systematic eastward shift of the QSW minimum region. In this study, we extended the analysis to 2013 and obtained new results that exhibited a probable cessation in that eastward shift. Polynomial fit for all chosen latitudes is even evidence of a change in the tendency to opposite. It more time needs to

  6. COMMENT ON AEROSOL EFFECT ON ANTARCTIC OZONE

    OpenAIRE

    イワサカ, ヤスノブ; Yasunobu, IWASAKA; Guang-Yu, SHI

    1987-01-01

    The structure of the aerosol layer disturbed by a cold air was suggested from the lidar measurements at Syowa Station (69°00′S, 39°35′E). The particle layer containing sublayers of spherical or nonspherical aerosols was frequently observed in Antarctic spring. It is a point one sholud not ignore when he discusses aerosol effects on "Antarctic ozone depletion" through radiative processes and heterogeneous chemical reactions.

  7. Ozone zonal asymmetry and planetary wave characterization during Antarctic spring

    Directory of Open Access Journals (Sweden)

    I. Ialongo

    2012-03-01

    Full Text Available A large zonal asymmetry of ozone has been observed over Antarctica during winter-spring, when the ozone hole develops. It is caused by a planetary wave-driven displacement of the polar vortex. The total ozone data by OMI (Ozone Monitoring Instrument and the ozone profiles by MLS (Microwave Limb Sounder and GOMOS (Global Ozone Monitoring by Occultation of Stars were analysed to characterize the ozone zonal asymmetry and the wave activity during Antarctic spring. Both total ozone and profile data have shown a persistent zonal asymmetry over the last years, which is usually observed from September to mid-December. The largest amplitudes of planetary waves at 65° S (the perturbations can achieve up to 50% of zonal mean values is observed in October. The wave activity is dominated by the quasi-stationary wave 1 component, while the wave 2 is mainly an eastward travelling wave. Wave numbers 1 and 2 generally explain more than the 90% of the ozone longitudinal variations. Both GOMOS and MLS ozone profile data show that ozone zonal asymmetry covers the whole stratosphere and extends up to the altitudes of 60–65 km. The wave amplitudes in ozone mixing ratio decay with altitude, with maxima (up to 50% below 30 km.

    The characterization of the ozone zonal asymmetry has become important in the climate research. The inclusion of the polar zonal asymmetry in the climate models is essential for an accurate estimation of the future temperature trends. This information might also be important for retrieval algorithms that rely on ozone a priori information.

  8. Quasi-biennial modulation of the Antarctic ozone depletion

    Science.gov (United States)

    Lait, Leslie R.; Schoeberl, Mark R.; Newman, Paul A.

    1989-01-01

    The quasi-biennial oscillation (QBO) in total ozone and temperature has been extracted from 9 years of Total Ozone Mapping Spectrometer (TOMS) observations and National Meteorological Center (NMC) analyses. Years in which QBO-related variations in the total ozone and temperature are positive are found to correspond to years with smaller September Antarctic total ozone hole decline rates and vice versa. The QBO appears to be responsible for September decline rate deviations up to 0.4 Dobson units (DU) per day. Also, the QBO at mid-latitudes appears to be better correlated with the 30-mbar tropical QBO winds than with those at 50 mbar. Possible mechanisms that would explain these phenomena are discussed.

  9. Observations of the 1995 ozone hole over Punta Arenas, Chile

    Science.gov (United States)

    Kirchhoff, V. W. J. H.; Sahai, Y.; Casiccia, C. A. R. S.; Zamorano, B. F.; Valderrama, V. V.

    1997-07-01

    We examine the appearance of the ozone hole over a populated area with more than 100,000 inhabitants. The largest population concentrations on the South American continent nearest the ozone hole region are Punta Arenas, Chile (53.0°S, 70.9°W) and Ushuaia, Argentina (54.5°S, 68.0°W), located close to the strait of Magallanes, opposite the Antarctic Peninsula. A special field mission was held in Punta Arenas, in September-October 1995 to investigate the vertical distribution of ozone during the appearance of the Antarctic ozone hole. Previous work has shown that the city of Punta Arenas is located at the edge of the hole area and is affected every year during a few days in the October period. The ozone trend near these locations is -0.5% per year using the yearly averages and -1.2% per year using the October means. This trend is 2 to 5 times larger than the global average. Several ozonesondes of the electrochemical concentration cell type were launched from Punta Arenas to determine the vertical distribution of ozone during "normal" and "perturbed" conditions. The ozone hole passed over Punta Arenas on October 12, 13 and 14, 1995. In addition to the sondes, which were launched once a day, ozone column amounts and UVB radiation were measured with a ground-based ozone Brewer spectrophotometer. The strongest ozone depletion over Punta Arenas in 1995 occurred on October 13, when the ozone column decreased from a "normal" value of about 325 Dobson Units (DU) to 200 DU; the vertical distribution of ozone on October 13 compared with October 6 shows depleted ozone roughly 50% less during hole conditions in the stratosphere. The UVB intensities have increased accordingly. The spectral ratio for October 13 to October 4 is 13 times larger at 297 nm.

  10. The effect of representing bromine from VSLS on the simulation and evolution of Antarctic ozone

    Science.gov (United States)

    Oman, Luke D.; Douglass, Anne R.; Salawitch, Ross J.; Canty, Timothy P.; Ziemke, Jerald R.; Manyin, Michael

    2016-09-01

    We use the Goddard Earth Observing System Chemistry-Climate Model, a contributor to both the 2010 and 2014 World Meteorological Organization Ozone Assessment Reports, to show that inclusion of 5 parts per trillion (ppt) of stratospheric bromine (Bry) from very short lived substances (VSLS) is responsible for about a decade delay in ozone hole recovery. These results partially explain the significantly later recovery of Antarctic ozone noted in the 2014 report, as bromine from VSLS was not included in the 2010 Assessment. We show multiple lines of evidence that simulations that account for VSLS Bry are in better agreement with both total column BrO and the seasonal evolution of Antarctic ozone reported by the Ozone Monitoring Instrument on NASA's Aura satellite. In addition, the near-zero ozone levels observed in the deep Antarctic lower stratospheric polar vortex are only reproduced in a simulation that includes this Bry source from VSLS.

  11. The Hole in the Ozone Layer.

    Science.gov (United States)

    Hamers, Jeanne S.; Jacob, Anthony T.

    This document contains information on the hole in the ozone layer. Topics discussed include properties of ozone, ozone in the atmosphere, chlorofluorocarbons, stratospheric ozone depletion, effects of ozone depletion on life, regulation of substances that deplete the ozone layer, alternatives to CFCs and Halons, and the future of the ozone layer.…

  12. Stratospheric warmings - The quasi-biennial oscillation Ozone Hole in the Antarctic but not the Arctic - Correlations between the Solar Cycle, Polar Temperatures, and an Equatorial Oscillation

    Energy Technology Data Exchange (ETDEWEB)

    Hoppe, Ulf-Peter

    2010-05-15

    This report is a tutorial and overview over some of the complex dynamic phenomena in the polar and equatorial stratosphere, and the unexpected correlation that exists between these and the solar cycle. Sudden stratospheric warmings (stratwarms) occur in the polar stratosphere in winter, but not equally distributed between the two hemispheres. As a result, the ozone hole in the springtime polar stratosphere is much more severe in the Southern Hemisphere than in the Northern Hemisphere. The Quasi-Biennial Oscillation (QBO) is a dynamic phenomenon of the equatorial stratosphere. Through processes not fully understood, the phase of the QBO (easterly or westerly) influences the onset of stratwarms. In addition, a correlation between the stratospheric winter temperature over the poles and the solar cycle has been found, but only if the datapoints are ordered by the phase of the QBO. - The best explanations and figures from four recent textbooks are selected, and abstracts of most relevant publications from the six last years are collected, with the most relevant portions for these subjects highlighted. - In addition to being basic science, the understanding of these phenomena is important in the context of the ozone hole, the greenhouse effect, as well as anthropogenic and natural climate change. (author)

  13. The stratospheric ozone hole a man-caused chemical instability

    CERN Document Server

    Crutzen, P J

    1997-01-01

    The discovery of the spring time stratospheric ozone hole by scientists of the British Antarctic Survey, led by Joe Farman, was one of the greatest surprises in the history of the atmospheric sciences and global change studies. After intensive research efforts by many international scientific teams it has clearly been demonstrated that the observed rapid ozone depletions are due to catalytic reactions involving CIO radicals, more than 80571130f which are produced by the photochemical breakdown of the industrial chlorofluorocarbon (CFC) gases. In this lecture I will present the course of events leading to the rapid ozone depletions. International agreements have been reached to forbid the production of the CFC gases. However, despite these measures, it will take almost 50 years before the ozone hole will have disappeared. I will also show that mankind has indeed been very lucky and that things could have been far worse.

  14. The Ozone and Ozone Hole%臭氧与臭氧洞

    Institute of Scientific and Technical Information of China (English)

    陆龙骅

    2012-01-01

    The unprecedented depletion of ozone over the Arctic in 2011 attracts the attentions of people to the ozone and ozone hole once more. This study reviews the history of the Antarctic ozone and its change. The reason how the ozone is produced over the Antarctic and the difference of the ozone changes over the Arctic and the Antarctic are discussed. It is pointed out that, currently, the ozone hole appears only in spring over the Antarctic and not over the Arctic. Under the current atmospheric environmental pollution, the change of atmospheric ozone depletion over the polar regions will be more dependent on the atmospheric circulation, especially the low temperature in the polar vortex. For protecting the Earth dwelled by human, the international society has made a great effort, and China also has made some contributions to it.%2011年空前的北极臭氧损耗,引发了人们对臭氧和臭氧洞的新关注.本文回顾了南极臭氧洞的由来及变化;讨论了南极臭氧洞产生的原因以及南北极臭氧变化的差异;指出目前只是在南极春季出现了臭氧洞,北极并没有出现过臭氧洞.在当前大气环境被污染的情况下,极地大气臭氧亏损的程度将更多地随大气环流,特别是极地涡旋中的低温状况而发生变化.人类只有一个地球,为保护大气臭氧层,国际社会做出了巨大的努力,中国也有自己的贡献.

  15. Brief communication "Stratospheric winds, transport barriers and the 2011 Arctic ozone hole"

    Directory of Open Access Journals (Sweden)

    M. J. Olascoaga

    2012-12-01

    Full Text Available The Arctic stratosphere throughout the late winter and early spring of 2011 was characterized by an unusually severe ozone loss, resulting in what has been described as an ozone hole. The 2011 ozone loss was made possible by unusually cold temperatures throughout the Arctic stratosphere. Here we consider the issue of what constitutes suitable environmental conditions for the formation and maintenance of a polar ozone hole. Our discussion focuses on the importance of the stratospheric wind field and, in particular, the importance of a high latitude zonal jet, which serves as a meridional transport barrier both prior to ozone hole formation and during the ozone hole maintenance phase. It is argued that stratospheric conditions in the boreal winter/spring of 2011 were highly unusual inasmuch as in that year Antarctic-like Lagrangian dynamics led to the formation of a boreal ozone hole.

  16. Antarctic springtime ozone depletion computed from temperature observations

    Science.gov (United States)

    Rosenfield, Joan E.; Schoeberl, Mark R.; Newman, Paul A.

    1988-01-01

    An observationally based, mechanistic dynamical model is used to simulate the decline of total ozone during September and October for the years 1979 through 1986. Vertical velocities derived from observed stratospheric temperature changes and computed radiative heating rates are used to advect an ozone mixing ratio profile during the Antarctic spring period. An early August 1982 Syowa balloonsonde ozone profile is used to initialize the computations. The model reasonably simulates the September and October changes in total ozone, considering the uncertainties in the observed data and the radiative heating. The simulated decline is found to be very sensitive to the choice of initial ozone profile and to small changes in the radiative heating. The results of this study suggest that the dynamical hypothesis of the Antarctic ozone depletion is both quantitatively credible and consistent with the observed temperature changes.

  17. The unusual persistence of an ozone hole over a southern mid-latitude station during the Antarctic spring 2009. A multi-instrument study

    Energy Technology Data Exchange (ETDEWEB)

    Wolfram, E.A.; Salvador, J.; Orte, F. [CEILAP-UNIDEF (MINDEF-CONICET), UMI-IFAECI-CNRS-3351, UMI3351, Villa Martelli (Argentina). Centro de Investigaciones en Laseres y Aplicaciones] [and others

    2012-07-01

    Record-low ozone column densities (with a minimum of 212 DU) persisted over three weeks at the Rio Gallegos NDACC (Network for the Detection of Atmospheric Composition Change) station (51.5 S, 69.3 W) in November 2009. Total ozone remained two standard deviations below the climatological mean for five consecutive days during this period. The statistical analysis of 30 years of satellite data from the Multi Sensor Reanalysis (MSR) database for Rio Gallegos revealed that such a long-lasting low-ozone episode is a rare occurrence. The event is examined using height-resolved ozone lidar measurements at Rio Gallegos, and observations from satellite and groundbased instruments. The computed relative difference between the measured total ozone and the climatological monthly mean shows reductions varying between 10 and 30% with an average decrease of 25 %. The mean absolute difference of total ozone column with respect to climatological monthly mean ozone column is around 75 DU. Extreme values of the UV index (UVI) were measured at the ground for this period, with the daily maximum UVI of around 13 on 15 and 28 November. The high-resolution MIMOSACHIM (Modelisation Isentrope du transport Meso-echelle de l'Ozone Stratospherique par Advection) model was used to interpret the ozone depletion event. An ozone decrease of about 2 ppmv was observed in mid-November at the 550 K isentropic level ({proportional_to}22 km). The position of Rio Gallegos relative to the polar vortex was classified using equivalent latitude maps. During the second week of November, the vortex was over the station at all isentropic levels, but after 20 November and until the end of the month, only the 10 lower levels in the stratosphere were affected by vortex overpasses with ozone poor air masses. A rapid recovery of the ozone column density was observed later, due to an ozone rich filament moving over Rio Gallegos between 18 and 24 km in the first two weeks of December 2009. (orig.)

  18. Ozone depletion - Ultraviolet radiation and phytoplankton biology in Antarctic waters

    Science.gov (United States)

    Smith, R. C.; Prezelin, B. B.; Baker, K. S.; Bidigare, R. R.; Boucher, N. P.; Coley, T.; Karentz, D.; Macintyre, S.; Matlick, H. A.; Menzies, D.

    1992-01-01

    The near-50-percent thinning of the stratospheric ozone layer over the Antarctic, with increased passage of mid-UV radiation to the surface of the Southern Ocean, has prompted concern over possible radiation damage to the near-surface phytoplankton communities that are the bases of Antarctic marine ecosystems. As the ozone layer thinned, a 6-week study of the marginal ice zone of the Bellingshousen Sea in the austral spring of 1990 noted sea-surface and depth-dependent ratios of mid-UV irradiance to total irradiance increased, and mid-UV inhibition of photosynthesis increased. A 6-12 percent reduction in primary production associated with ozone depletion was estimated to have occurred over the course of the present study.

  19. Antarctic winter mercury and ozone depletion events over sea ice

    Science.gov (United States)

    Nerentorp Mastromonaco, M.; Gårdfeldt, K.; Jourdain, B.; Abrahamsson, K.; Granfors, A.; Ahnoff, M.; Dommergue, A.; Méjean, G.; Jacobi, H.-W.

    2016-03-01

    During atmospheric mercury and ozone depletion events in the springtime in polar regions gaseous elemental mercury and ozone undergo rapid declines. Mercury is quickly transformed into oxidation products, which are subsequently removed by deposition. Here we show that such events also occur during Antarctic winter over sea ice areas, leading to additional deposition of mercury. Over four months in the Weddell Sea we measured gaseous elemental, oxidized, and particulate-bound mercury, as well as ozone in the troposphere and total and elemental mercury concentrations in snow, demonstrating a series of depletion and deposition events between July and September. The winter depletions in July were characterized by stronger correlations between mercury and ozone and larger formation of particulate-bound mercury in air compared to later spring events. It appears that light at large solar zenith angles is sufficient to initiate the photolytic formation of halogen radicals. We also propose a dark mechanism that could explain observed events in air masses coming from dark regions. Br2 that could be the main actor in dark conditions was possibly formed in high concentrations in the marine boundary layer in the dark. These high concentrations may also have caused the formation of high concentrations of CHBr3 and CH2I2 in the top layers of the Antarctic sea ice observed during winter. These new findings show that the extent of depletion events is larger than previously believed and that winter depletions result in additional deposition of mercury that could be transferred to marine and terrestrial ecosystems.

  20. Antarctic ozone variability inside the polar vortex estimated from balloon measurements

    Science.gov (United States)

    Parrondo, M. C.; Gil, M.; Yela, M.; Johnson, B. J.; Ochoa, H. A.

    2014-01-01

    Thirteen years of ozone soundings at the Antarctic Belgrano II station (78° S, 34.6° W) have been analysed to establish a climatology of stratospheric ozone and temperature over the area. The station is inside the polar vortex during the period of development of chemical ozone depletion. Weekly periodic profiles provide a suitable database for seasonal characterization of the evolution of stratospheric ozone, especially valuable during wintertime, when satellites and ground-based instruments based on solar radiation are not available. The work is focused on ozone loss rate variability (August-October) and its recovery (November-December) at different layers identified according to the severity of ozone loss. The time window selected for the calculations covers the phase of a quasi-linear ozone reduction, around day 220 (mid-August) to day 273 (end of September). Decrease of the total ozone column over Belgrano during spring is highly dependent on the meteorological conditions. Largest depletions (up to 59%) are reached in coldest years, while warm winters exhibit significantly lower ozone loss (20%). It has been found that about 11% of the total O3 loss, in the layer where maximum depletion occurs, takes place before sunlight has arrived, as a result of transport to Belgrano of air from a somewhat lower latitude, near the edge of the polar vortex, providing evidence of mixing inside the vortex. Spatial homogeneity of the vortex has been examined by comparing Belgrano results with those previously obtained for South Pole station (SPS) for the same altitude range and for 9 yr of overlapping data. Results show more than 25% higher ozone loss rate at SPS than at Belgrano. The behaviour can be explained taking into account (i) the transport to both stations of air from a somewhat lower latitude, near the edge of the polar vortex, where sunlight reappears sooner, resulting in earlier depletion of ozone, and (ii) the accumulated hours of sunlight, which become much

  1. [The retrieval of ozone column densities by passive differential optical absorption spectroscopy during summer at Zhongshan Station, Antarctic].

    Science.gov (United States)

    Luo, Yu-Han; Liu, Wen-Qing; Bian, Lin-Gen; Lu, Chang-Gui; Xie, Pin-Hua; Si, Fu-Qi; Sun, Li-Guang

    2011-02-01

    Daily ozone column densities were monitored by Passive DOAS (differential optical absorption spectroscopy) from December 10th, 2008 to Feb 19th, 2009 at Zhongshan Station, Antarctic (69 degrees 22'24" S, 76 degrees 22'14" E). Considering the absorption of O3, OClO, NO2, O4, BrO and the Ring effect, ozone slant column densities were retrieved using the zenith scattered sunlight as the light source. The results showed that there was no obvious "ozone hole" during the monitoring period, but ozone VCD (vertical column density) had greatly changed within short time scale, especially in middle December and early February. The analysis of passive DOAS and Brewer measurements of ozone VCD showed good agreement with the correlative coefficient of 0.863, while satellite board OMI measurements with the correlative coefficient of 0.840, which confirmed the validity of the monitoring of Passive DOAS. PMID:21510403

  2. Antarctic ozone variability inside the Polar Vortex estimated from balloon measurements

    Directory of Open Access Journals (Sweden)

    M. C. Parrondo

    2013-06-01

    Full Text Available 13 yr of ozonesoundings at the Antarctic Belgrano II station (78° S, 34.6° W have been analyzed to establish a climatology of stratospheric ozone and temperature over the area. The station is inside the polar vortex during the period of development of chemical ozone depletion. Weekly periodic profiles provide a suitable database for seasonal characterization of the evolution of stratospheric ozone, especially valuable during winter time when satellites and ground-based instruments based on solar radiation are lacking. The work is focused on ozone loss rate variability (August–October and its recovery (November–December at different layers identified according to the severity of ozone loss. The time window selected for the calculations covers the phase of a quasi-linear ozone reduction, about day 220 (mid August to day 273 (end of September. Decrease of the total ozone column over Belgrano during spring is highly dependent on the meteorological conditions. Largest depletions (up to 59% are reached in coldest years while warms winters exhibit significantly lower ozone loss (20%. It has been found that about 11% of the total O3 loss in the layer where maximum depletion occurs takes place before the sun has arrived as a result of transport of lower latitude air masses, providing evidence of mixing inside the vortex. Spatial homogeneity of the vortex has been examined by comparing Belgrano results with those previously obtained for South Pole Station (SPS for the same altitude range and for 9 yr of overlapping data. Unexpected results show more than 25% larger ozone loss rate at SPS than at Belgrano. It has been found that the accumulated hours of sunlight are the dominant factor driving the ozone loss rate. According to the variability of the ozone-hole recovery, a clear connection between the timing of the breakup of the vortex and the monthly ozone content was found. Minimum ozone concentration of 57 DU in the 12–24 km layer remained in

  3. Stratospheric ozone chemistry in the Antarctic: what determines the lowest ozone values reached and their recovery?

    Directory of Open Access Journals (Sweden)

    J.-U. Grooß

    2011-12-01

    Full Text Available Balloon-borne observations of ozone from the South Pole Station have been reported to reach ozone mixing ratios below the detection limit of about 10 ppbv at the 70 hPa level by late September. After reaching a minimum, ozone mixing ratios increase to above 1 ppmv on the 70 hPa level by late December. While the basic mechanisms causing the ozone hole have been known for more than 20 yr, the detailed chemical processes determining how low the local concentration can fall, and how it recovers from the minimum have not been explored so far. Both of these aspects are investigated here by analysing results from the Chemical Lagrangian Model of the Stratosphere (CLaMS. As ozone falls below about 0.5 ppmv, a balance is maintained by gas phase production of both HCl and HOCl followed by heterogeneous reaction between these two compounds in these simulations. Thereafter, a very rapid, irreversible chlorine deactivation into HCl can occur, either when ozone drops to values low enough for gas phase HCl production to exceed chlorine activation processes or when temperatures increase above the polar stratospheric cloud (PSC threshold. As a consequence, the timing and mixing ratio of the minimum ozone depends sensitively on model parameters, including the ozone initialisation. The subsequent ozone increase between October and December is linked mainly to photochemical ozone production, caused by oxygen photolysis and by the oxidation of carbon monoxide and methane.

  4. Antarctic ozone variability inside the polar vortex estimated from balloon measurements

    OpenAIRE

    Parrondo, M. C.; Gil, M.; M. Yela; B. J. Johnson; H. A. Ochoa

    2014-01-01

    Thirteen years of ozone soundings at the Antarctic Belgrano II station (78° S, 34.6° W) have been analysed to establish a climatology of stratospheric ozone and temperature over the area. The station is inside the polar vortex during the period of development of chemical ozone depletion. Weekly periodic profiles provide a suitable database for seasonal characterization of the evolution of stratospheric ozone, especially valuable during wintertime, when satellites and ground-...

  5. Evidence of the mid-latitude impact of Antarctic ozone depletion

    Science.gov (United States)

    Atkinson, Roger J.; Matthews, W. Andrew; Newman, Paul A.; Plumb, R. Alan

    1989-01-01

    Record low ozone values found over Australia and New Zealand during December 1987 following the record low Antarctic values of October 1987 are analyzed. The sudden decline of ozone amounts in midmonth rule out photochemical effects as a cause and permit the underlying processes to be investigated on a case study basis. Using data from ozone sondes, radiosondes, the Nimbus-7 total ozone mapping spectrometer, and meteorological analyses from the National Meteorological Center, it is argued that these low values resulted from transport of ozone-poor air from higher latitudes. Thus, it seems that the chemical destruction of ozone over Antarctica in early spring is having an impact on lower latitudes.

  6. Antarctic ozone variability inside the Polar Vortex estimated from balloon measurements

    OpenAIRE

    Parrondo, M. C.; Gil, M.; M. Yela; B. J. Johnson; H. A. Ochoa

    2013-01-01

    13 yr of ozonesoundings at the Antarctic Belgrano II station (78° S, 34.6° W) have been analyzed to establish a climatology of stratospheric ozone and temperature over the area. The station is inside the polar vortex during the period of development of chemical ozone depletion. Weekly periodic profiles provide a suitable database for seasonal characterization of the evolution of stratospheric ozone, especially valuable during winter time when satellites and ground-based instrum...

  7. Is the Ozone Hole over Your Classroom?

    Science.gov (United States)

    Cordero, Eugene C.

    2002-01-01

    Reports on a survey of first year university science students regarding their understanding of the ozone layer, ozone depletion, and the effect of ozone depletion on Australia. Suggests that better teaching resources for environmental issues such as ozone depletion and global warming are needed before improvements in student understanding can be…

  8. Antarctic network of lamp-calibrated multichannel radiometers for continuous ozone and uv radiation data

    OpenAIRE

    Redondas, A.; Torres, C.; O. Meinander; K. Lakkala; R. García; E. Cuevas; Ochoa, H.; Deferrari, G.; Díaz, S.

    2008-01-01

    Three NILU-UV multichannel radiometers have been installed in 1999 at the Argentinian sites of Ushuaia (54S), Marambio (64S) and Belgrano-II (77S) in order to continuously monitor UV radiation, photosynthetically active radiation and total ozone. The measurements were established by INM, Spain in collaboration with FMI, Finland, DNA-IAA, Argentina and CADIC, Argentina to observe and characterize the spatial and temporal evolution of ozone and ultraviolet radiation in the Antarctic region. Spe...

  9. DISC0VR, a unique tool to study the mechanisms that generate ozone mini-holes

    Science.gov (United States)

    Teitelbaum, H.

    2011-12-01

    An ozone mini-hole is a region of strongly depleted column total ozone amount, that can persist for several days. They are characterized by a rapid and small-scale decrease of columnar ozone and an equally rapid recovery after a few days. "Mini ozone holes" are frequently observed at northern hemisphere mid-latitudes in winter. They evolve rapidly and according to some authors, may originate because of northeast motions of air patches with low total ozone content. However, several other studies attribute the formation of ozone mini-holes to the uplift of air masses that decrease the ozone columnar content by simply decreasing the pressure thickness of the ozone layer, without changing the mixing ratio. According to these studies, the latter mechanism explains the main reduction of ozone that occurs between the tropopause and the ozone maximum during an ozone mini-hole event. Since ozone mini-holes cannot be the result of ozone chemical destruction, they should be the result of meteorological processes. In many cases the mini-holes move, the direction and speed of movement is of great importance for the study of the mechanism that causes the phenomenon. DISCOVR, because of its spatial resolution, continuous time coverage and its ability to detect ozone, can describe the irregularities of ozone and its displacement. Complemented by a method of tracing air mass trajectories (FLEXTRA) the DSCOVR observations will allow us to determine the mechanisms of ozone mini-holes formation.

  10. The Impact of Warm Pool El Nino Events on Antarctic Ozone

    Science.gov (United States)

    Hurwitz, Margaret M.; Newman, P. A.; Song, In-Sun; Frith, Stacey M.

    2011-01-01

    Warm pool El Nino (WPEN) events are characterized by positive sea surface temperature (SST) anomalies in the central equatorial Pacific in austral spring and summer. Previous work found an enhancement in planetary wave activity in the South Pacific in austral spring, and a warming of 3-5 K in the Antarctic lower stratosphere during austral summer, in WPEN events as compared with ENSO neutral. In this presentation, we show that weakening of the Antarctic vortex during WPEN affects the structure and magnitude of high-latitude total ozone. We use total ozone data from TOMS and OMI, as well as station data from Argentina and Antarctica, to identify shifts in the longitudinal location of the springtime ozone minimum from its climatological position. In addition, we examine the sensitivity of the WPEN-related ozone response to the phase of the quasi-biennial oscillation (QBO). We then compare the observed response to WPEN events with Goddard Earth Observing System chemistry-climate model, version 2 (GEOS V2 CCM) simulations. Two, 50-year time-slice simulations are forced by annually repeating SST and sea ice climatologies, one set representing observed WPEN events and the second set representing neutral ENSO events, in a present-day climate. By comparing the two simulations, we isolate the impact of WPEN events on lower stratospheric ozone, and furthermore, examine the sensitivity of the WPEN ozone response to the phase of the QBO.

  11. Surface ozone observations during voyages to the Arctic and Antarctic regions

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Surface ozone concentration and UV-B data between 75°N and 70°S were obtained aboard the Chinese polar scientific vessel "Xue-long" (Snow-Dragon) during the first voyage to the Arctic and the 16th to the Antarctic in 1999-2000. Analysis of these data presents that variations of the surface ozone concentration have small amplitude during voyages except the mid-latitude in the Northern Hemisphere. As a whole, average surface ozone concentration in the Northern Hemisphere is higher than that in the Southern, and high value occurred when the ship sailed close to the continents. The average diurnal variations of the surface ozone in the Northern Hemisphere are also higher compared to the southern counterparts, and high diurnal variations were found at low latitudes, and relative low level in the polar region.

  12. Estimation of Antarctic ozone loss from ground-based total column measurements

    Directory of Open Access Journals (Sweden)

    J. Kuttippurath

    2010-07-01

    Full Text Available The passive tracer method is used to estimate ozone loss from ground-based measurements in the Antarctic. A sensitivity study shows that the ozone depletion can be estimated within an accuracy of ~4%. The method is then applied to the ground-based observations from Arrival Heights, Belgrano, Concordia, Dumont d'Urville, Faraday, Halley, Marambio, Neumayer, Rothera, South Pole, Syowa, and Zhongshan for the diagnosis of ozone loss in the Antarctic. On average, the ten-day boxcar average of the vortex mean ozone column loss deduced from the ground-based stations was about 55±5% in 2005–2009. The ozone loss computed from the ground-based measurements is in very good agreement with those derived from satellite measurements (OMI and SCIAMACHY and model simulations (REPROBUS and SLIMCAT, where the differences are within ±3–5%.

    The historical ground-based total ozone observations in October show that the depletion started in the late 1970s, reached a maximum in the early 1990s and stabilised afterwards due to saturation. There is no indication of ozone recovery yet. At southern mid-latitudes, a reduction of 20–50% is observed for a few days in October–November at the newly installed Rio Gallegos station. Similar depletion of ozone is also observed episodically during the vortex overpasses at Kerguelen in October–November and at Macquarie Island in July–August of the recent winters. This illustrates the significance of measurements at the edges of Antarctica.

  13. Ozone Loss in the Antarctic Vortex Boundary Region from in situ Observations with the Geophysica Aircraft

    Science.gov (United States)

    Ivanova, E.; Volk, C. M.; Riediger, O.; Strunk, M.; Schmidt, U.; Ulanovsky, A.; Ravegnani, F.; Redaelli, G.

    2003-04-01

    We analyse the distribution of ozone depletion in the Antarctic vortex edge region from in situ measurements taken from the Russian high-altitude aircraft M-55 "Geophysica" during the APE-GAIA campaign (Airborne Polar Experiment - Geophysica Aircraft In Antarctica) based out of Ushuaia, Argentina (54° S) in September and October 1999. The University of Frankfurt's High Altitude Gas Analyzer (HAGAR) provided in situ measurements of N2O, CFC-12, CFC-11, halon-1211 every 90 s, SF6 every 45 s, and CO2 every 10 s. Ozone was measured at high resolution by the Fast Ozone Analyzer (FOZAN). During 5 southbound flights toward the Antarctic vortex the Geophysica penetrated the vortex edge at various potential temperatures between 380 K and 480 K and performed dives inside the vortex yielding vertical profiles in one case down to the tropopause. The amount of lost ozone in the measured air has been estimated from the deviations from the compact extra-vortex O3-N2O relationship. While nearly complete ozone loss is found only in air clearly inside the vortex, ozone loss up to 60% is routinely found in a transition region extending 5° northward from the edge delineated by sharp meridional tracer gradients. We investigate whether this transition region lies indeed outside the vortex by applying alternative methods for defining the vortex edge, including potential vorticity and a new method using the observed relation of N2O with potential temperature (Greenblatt et al., J. Geophys. Res., 2002). We also examine the correlations between O3, CO2, and N2O to investigate the possibility that the decreased ozone within the transition region is caused by outward mixing from the vortex core.

  14. Estimation of Antarctic ozone loss from Ground-based total column measurements

    Directory of Open Access Journals (Sweden)

    J. Kuttippurath

    2010-03-01

    Full Text Available The passive ozone method is used to estimate ozone loss from ground-based measurements in the Antarctic. A sensitivity study shows that the O3 loss can be estimated within an accuracy of ~4%. The method is then applied to the observations from Amundsen-Scott/South Pole, Arrival Heights, Belgrano, Concordia, Dumont d'Urville, Faraday, Halley, Marambio, Neumayer, Rothera, Syowa and Zhongshan for the diagnosis of ozone loss in the Antarctic. On average, the five-day running mean of the vortex averaged ozone column loss deduced from the ground-based stations shows about 53% in 2009, 59% in 2008, 55% in 2007, 56% in 2006 and 61% in 2005. The observed O3 loss and loss rates are in very good agreement with the satellite observations (Ozone Monitoring Instrument and Sciamachy and are well reproduced by the model (Reprobus and SLIMCAT calculations.

    The historical ground-based total ozone measurements show that the depletion started in the late 1970s, reached a maximum in the early 1990s, stabilising afterwards at this level until present, with the exception of 2002, the year of an early vortex break-up. There is no indication of significant recovery yet.

    At southern mid-latitudes, a total ozone reduction of 40–50% is observed at the newly installed station Rio Gallegos and 25–35% at Kerguelen in October–November of 2008–2009 and 2005–2009 (except 2008 respectively, and of 10–20% at Macquarie Island in July–August of 2006–2009. This illustrates the significance of measurements at the edges of Antarctica.

  15. What-ifs for a Northern ozone hole

    Energy Technology Data Exchange (ETDEWEB)

    Newman, A.

    1993-08-01

    Based on papers presented at a recent American Geophysical Union meeting in Baltimore, this article discusses various processes that could lead to further significant stratospheric ozone losses over northern latitudes. In southern high latitudes, ClO, formed when Cl atoms react with O[sub 3], persists into the spring and enters a photocatalytic cycle that regenerates ozone-destroying Cl atoms. Type II polar stratospheric clouds (PSCs) are believed to act as catalysts in this cycle. Although type II PSCs rarely form in the warmer Arctic stratosphere, it is possible that type I PSCs and sulfuric acid droplets may act as catalytic surfaces in this region. The arctic however, currently lacks a pronounced ozone hole, unlike Antartica. This is because in the Northern Hemisphere, large-scale tropospheric weather disturbances leak a portion of their energy to the less dense stratosphere. This indirectly leads to the descent of air over the Arctic region which produces compression heating of the polar cap and keeps the Arctic winter stratosphere warm enough to evade the cold temperatures that would produce widespread PSCs, and the associated significant ozone destruction. However, the greenhouse effect could lead to a cooler stratosphere containing more water and weaker tropospheric large-scale disturbances meaning colder Arctic winters. All these factors would contribute to greater PSC formation and the associated ozone destruction.

  16. Vertical structure of Antarctic tropospheric ozone depletion events: characteristics and broader implications

    Directory of Open Access Journals (Sweden)

    A. E. Jones

    2010-03-01

    Full Text Available The majority of tropospheric ozone depletion event (ODE studies have focussed on time-series measurements, with comparatively few studies of the vertical component. Those that exist have almost exclusively used free-flying balloon-borne ozonesondes and almost all have been conducted in the Arctic. Here we use measurements from two separate Antarctic field experiments to examine the vertical profile of ozone during Antarctic ODEs. We use tethersonde data to probe details in the lowest few hundred meters and find considerable structure in the profiles associated with complex atmospheric layering. The profiles were all measured at wind speeds less than 7 ms−1, and on each occasion the lowest inversion height lay between 10 m and 40 m. We also use data from a free-flying ozonesonde study to select events where ozone depletion was recorded at altitudes >1 km above ground level. Using ERA-40 meteorological charts, we find that on every occasion the high altitude depletion was preceded by an atmospheric low pressure system. An examination of limited published ozonesonde data from other Antarctic stations shows this to be a consistent feature. Given the link between BrO and ODEs, we also examine ground-based and satellite BrO measurements, and find a strong association between enhanced BrO and atmospheric low pressure systems. The results suggest that, in Antarctica, such depressions are responsible for driving high altitude ODEs and for generating the large-scale BrO clouds observed from satellites. In the Arctic, the prevailing meteorology differs from that in Antarctica, but we show that major low pressure systems in the Arctic, when they occur, can also generate BrO clouds. Such depressions thus appear to be fundamental when considering the broader influence of ODEs, particularly in Antarctica, such as halogen export and the radiative influence of ozone-depleted air masses.

  17. Vertical structure of Antarctic tropospheric ozone depletion events: characteristics and broader implications

    Directory of Open Access Journals (Sweden)

    A. E. Jones

    2010-08-01

    Full Text Available The majority of tropospheric ozone depletion event (ODE studies have focussed on time-series measurements, with comparatively few studies of the vertical component. Those that exist have almost exclusively used free-flying balloon-borne ozonesondes and almost all have been conducted in the Arctic. Here we use measurements from two separate Antarctic field experiments to examine the vertical profile of ozone during Antarctic ODEs. We use tethersonde data to probe details in the lowest few hundred meters and find considerable structure in the profiles associated with complex atmospheric layering. The profiles were all measured at wind speeds less than 7 ms−1, and on each occasion the lowest inversion height lay between 10 m and 40 m. We also use data from a free-flying ozonesonde study to select events where ozone depletion was recorded at altitudes >1 km above ground level. Using ERA-40 meteorological charts, we find that on every occasion the high altitude depletion was preceded by an atmospheric low pressure system. An examination of limited published ozonesonde data from other Antarctic stations shows this to be a consistent feature. Given the link between BrO and ODEs, we also examine ground-based and satellite BrO measurements and find a strong association between atmospheric low pressure systems and enhanced BrO that must arise in the troposphere. The results suggest that, in Antarctica, such depressions are responsible for driving high altitude ODEs and for generating the large-scale BrO clouds observed from satellites. In the Arctic, the prevailing meteorology differs from that in Antarctica, but, while a less common effect, major low pressure systems in the Arctic can also generate BrO clouds. Such depressions thus appear to be fundamental when considering the broader influence of ODEs, certainly in Antarctica, such as halogen export and the radiative influence of ozone-depleted air masses.

  18. Spatial variation of ozone depletion rates in the springtime Antarctic polar vortex

    Science.gov (United States)

    Yung, Yuk L.; Allen, Mark; Crisp, David; Zurek, Richard W.; Sander, Stanley P.

    1990-01-01

    An area-mapping technique, designed to filter out synoptic perturbations of the Antarctic polar vortex such as distortion or displacement away from the pole, was applied to the Nimbus-7 TOMS (Total Ozone Mapping Spectrometer) data. This procedure reveals the detailed morphology of the temporal evolution of column O3. The results for the austral spring of 1987 suggest the existence of a relatively stable collar region enclosing an interior that is undergoing large variations. A simplified photochemical model of O3 loss and the temporal evolution of the area-mapped polar O3 are used to constrain the chlorine monoxide (ClO) concentrations in the springtime Antarctic vortex. The O3 loss rates could be larger than deduced here because of underestimates of total O3 by TOMS near the terminator.

  19. Cosmic Rays, CFCs, Ozone Hole and Global Climate Change: Understandings from a Physicist

    CERN Document Server

    Lu, Qing-Bin

    2013-01-01

    This paper reviews observed data and uses simple physical models with few parameters to evaluate the underlying mechanisms for the ozone hole and recent global climate changes. The cosmic-ray-driven electron-induced-reaction (CRE) mechanism and the greenhouse effect of CFCs are first reviewed briefly. It is followed by statistical analyses of comprehensive measured datasets of quantities, including cosmic rays (CRs), total solar irradiance, sunspot number, halocarbons (CFCs, CCl4 and HCFCs), CO2, total O3, lower stratospheric temperatures and global surface temperatures, to examine natural and anthropogenic contributions to O3 loss and global climate change. For O3 depletion, new statistical analyses of the CRE equation with observed total O3 and stratospheric temperature data give high linear correlation coefficients >=0.92. After the removal of the CR effect, a pronounced recovery by 20~25% of the Antarctic O3 hole is found, while no recovery of O3 loss in mid-latitudes has been observed. This is consistent...

  20. A contribution toward understanding the biospherical significance of Antarctic ozone depletion

    Science.gov (United States)

    Lubin, Dan; Mitchell, Greg; Frederick, John E.; Alberts, Amy D.; Booth, C. R.; Lucas, Timothy; Neuschuler, David

    1992-01-01

    The paper presents and compares measurements of biologically active UV radiation made by the NSF scanning spectroradiometer (UV-monitor) at Palmer Station, Antarctica, during the Austral springs of 1988, 1989, and 1990. Column ozone abundance above Palmer Station is computed from these measurements using a multiple wavelength algorithm. Two contrasting action spectra are employed to estimate the biologically relevant dose from the spectral measurements: a standard weighting function for damage to DNA, and a new action spectrum representing the potential for photosynthesis inhibition in Antarctic phytoplankton. The former weights only UV-B wavelengths (280-320 nm) and gives the most weight to wavelengths shorter than 300 nm, while the latter includes large contributions out to 355 nm. Ozone abundances and dose-weighted irradiances provided by the NSF UV-monitor are used to derive the radiation amplification factors for both DNA- and phytoplankton-effective irradiance.

  1. Contribution of liquid, NAT and ice particles to chlorine activation and ozone depletion during Antarctic winter and spring

    Directory of Open Access Journals (Sweden)

    O. Kirner

    2014-06-01

    Full Text Available Heterogeneous reactions in the Antarctic stratosphere are the cause of chlorine activation and ozone depletion, but the relative roles of different types of PSCs in chlorine activation is an open question. We use multi-year simulations of the chemistry-climate model EMAC to investigate the impact that the various types of PSCs have on Antarctic chlorine activation and ozone loss. One standard and three sensitivity EMAC simulations have been performed. The results of these simulations show that the significance of heterogeneous reactions on NAT and ice particles, in comparison to liquid particles, is subordinate regarding chlorine activation and ozone depletion in Antarctic winter and spring. The heterogeneous chemistry on liquid particles is sufficient to activate at least 90% of the chlorine reservoir species. With the exception of the upper PSC regions between 10 and 30 hPa where temporarily the ice particles have a relevant contribution to the chlorine activation and during the initial PSC occurrence with short NAT contributions the liquid particles alone are sufficient to activate almost all of the available chlorine. In the model simulations heterogeneous chemistry on liquid particles is responsible for more than 90% of the ozone depletion in Antarctic spring. Only up to 5 DU of column ozone in high southern latitudes is depleted by chlorine activation due to additional heterogeneous chemistry on ice particles and less than 0.5 DU due to additional heterogeneous chemistry on NAT particles.

  2. Antarctic network of lamp-calibrated multichannel radiometers for continuous ozone and uv radiation data

    Science.gov (United States)

    Redondas, A.; Torres, C.; Meinander, O.; Lakkala, K.; García, R.; Cuevas, E.; Ochoa, H.; Deferrari, G.; Díaz, S.

    2008-02-01

    Three NILU-UV multichannel radiometers have been installed in 1999 at the Argentinian sites of Ushuaia (54S), Marambio (64S) and Belgrano-II (77S) in order to continuously monitor UV radiation, photosynthetically active radiation and total ozone. The measurements were established by INM, Spain in collaboration with FMI, Finland, DNA-IAA, Argentina and CADIC, Argentina to observe and characterize the spatial and temporal evolution of ozone and ultraviolet radiation in the Antarctic region. Special attention has been given to the quality control and quality assurance of the measurements under harsh climatological conditions. The ozone and UV time series of 2000-2006 were calibrated using a polynomial fit for lamp measurements performed every second week all year round. The gaps in these data are minimal, with almost no data missing, and the data products are available from http://www.polarvortex.org in near real time. The data products include the erythemally-weighted UV, UVB and UVA radiation, photosynthetically active radiation (PAR), total ozone (O3) and a cloud parameter (CLT). For UV data, dose rates as well as daily doses are available; from these the maximum measured UV indices (UVI), during 2000-2006, were 12.0, 9.7 and 8.1 at Ushuaia, Marambio and Belgrano-II, respectively.

  3. Antarctic network of lamp-calibrated multichannel radiometers for continuous ozone and uv radiation data

    Directory of Open Access Journals (Sweden)

    A. Redondas

    2008-02-01

    Full Text Available Three NILU-UV multichannel radiometers have been installed in 1999 at the Argentinian sites of Ushuaia (54S, Marambio (64S and Belgrano-II (77S in order to continuously monitor UV radiation, photosynthetically active radiation and total ozone. The measurements were established by INM, Spain in collaboration with FMI, Finland, DNA-IAA, Argentina and CADIC, Argentina to observe and characterize the spatial and temporal evolution of ozone and ultraviolet radiation in the Antarctic region. Special attention has been given to the quality control and quality assurance of the measurements under harsh climatological conditions. The ozone and UV time series of 2000–2006 were calibrated using a polynomial fit for lamp measurements performed every second week all year round. The gaps in these data are minimal, with almost no data missing, and the data products are available from http://www.polarvortex.org in near real time. The data products include the erythemally-weighted UV, UVB and UVA radiation, photosynthetically active radiation (PAR, total ozone (O3 and a cloud parameter (CLT. For UV data, dose rates as well as daily doses are available; from these the maximum measured UV indices (UVI, during 2000–2006, were 12.0, 9.7 and 8.1 at Ushuaia, Marambio and Belgrano-II, respectively.

  4. Depletion of stratospheric ozone over the Antarctic and Arctic : Responses of plants of polar terrestrial ecosystems to enhanced UV-B, an overview

    NARCIS (Netherlands)

    Rozema, Jelte; Boelen, Peter; Blokker, Peter

    2005-01-01

    Depletion of stratospheric ozone over the Antarctic has been re-occurring yearly since 1974, leading to enhanced UV-B radiation. Arctic ozone depletion has been observed since 1990. Ozone recovery has been predicted by 2050, but no signs of recovery occur. Here we review responses of polar plants to

  5. Polar stratospheric clouds and ozone depletion

    Science.gov (United States)

    Toon, Owen B.; Turco, Richard P.

    1991-01-01

    A review is presented of investigations into the correlation between the depletion of ozone and the formation of polar stratospheric clouds (PSCs). Satellite measurements from Nimbus 7 showed that over the years the depletion from austral spring to austral spring has generally worsened. Approximately 70 percent of the ozone above Antarctica, which equals about 3 percent of the earth's ozone, is lost during September and October. Various hypotheses for ozone depletion are discussed including the theory suggesting that chlorine compounds might be responsible for the ozone hole, whereby chlorine enters the atmosphere as a component of chlorofluorocarbons produced by humans. The three types of PSCs, nitric acid trihydrate, slowly cooling water-ice, and rapidly cooling water-ice clouds act as important components of the Antarctic ozone depletion. It is indicated that destruction of the ozone will be more severe each year for the next few decades, leading to a doubling in area of the Antarctic ozone hole.

  6. The two-timescale response of Antarctic sea-surface temperature and sea-ice cover to ozone depletion

    Science.gov (United States)

    Ferreira, D.; Marshall, J.; Hausmann, U.

    2015-12-01

    In recent modelling work, we showed that the response of Antarctic sea-surface temperature and sea-ice cover to abrupt ozone depletion has two phases: a fast inter-annual (~1-5y) adjustment in which the surface ocean cools and sea-ice cover increases, followed by a slower decadal trend leading to a warming of the surface ocean and a reduction of sea-ice cover. I will first summarize the dynamics behind the two-timescale response and how it can help reconcile diverging views on the relationship between ozone depletion and Antarctic sea ice changes. Using numerical experiments, I will then show that knowledge of the two-timescale response can be used to predict how the coupled climate responds to a time-varying ozone distribution, such as one of depletion and recovery. These ideas will then be used to evaluate how 1) ozone depletion might have contributed to recent observed decadal Antarctic sea-ice trends and 2) the ozone-driven signal can emerge from natural variability. Finally, implications for the ability of coupled climate models to reproduce observed sea-ice trends will be discussed.

  7. Antarctic ozone depletion chemistry - Reactions of N2O5 with H2O and HCl on ice surfaces

    Science.gov (United States)

    Tolbert, Margaret A.; Rossi, Michel J.; Golden, David M.

    1988-01-01

    In a study concerning Antarctic ozone depletion, reactions of dinitrogen pentoxide with water and hydrochloric acid were studied on ice surfaces in a Knudsen cell flow reactor. The N2O5 reacted on ice at 185 K to form condensed-phase nitric acid (HNO3). This reaction may provide a sink for odd nitrogen, NO(x), during the polar winter, a requirement in nearly all models of Antarctic ozone depletion. The reaction of N2O5 on HCl-ice surfaces at 185 K produced gaseous nitryl chloride (ClNO2) and condensed-phase HNO3 and proceeded until all of the HCl within the ice was depleted. The ClNO2 which did not react or condense on ice at 185 K, can be readily photolyzed in the Antarctic spring to form atomic chlorine for catalytic ozone destruction cycles. The other photolysis product, gaseous nitrogen dioxide may be important in the partitioning of NO(x) between gaseous and condensed phases in the Antarctic winter.

  8. Ozone mini-hole occurring over the Tibetan Plateau in December 2003

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    By analyzing the total ozone data from TOMS and ground-based observations, it is found that a large area with extremely low ozone occurred over the Tibetan Plateau during December 14-17, 2003. After correcting the bias in TOMS data, the area with the total ozone < 220 DU is found to be over 2500000 km2, and the minimum value is only 190 DU. It is the first time that an ozone mini-hole or an extremely low ozone event is found to occur over the Tibetan Plateau.

  9. Correction and Validation of Total Ozone Data Series From An Antarctic Multichannel Filter Radiometer Solar UV Network

    Science.gov (United States)

    Torres, C.; Redondas, A.; Cuevas, E.; Lakkala, K.; Taalas, P.

    The Antarctic Network of the MAR-Project (Measurement of Antarctic Radiance for monitoring the ozone layer) is the result of a co-operation among the Instituto Nacional de Meteorología (INM, Spain), Instituto Nacional de Técnica Aeroespacial (INTA, Spain), the Instituto Antártico Argentino - Dirección Nacional del Antártico (IAA/DNA), the Finnish Meteorological Institute (FMI), and the Centro Austral de Investigaciones Científicas (CADIC, Argentina). This network consists on three NILU-UV6 multichannel filter radiometers installed at the Argentinean Antarctic bases of Vicecomodoro Marambio and Belgrano II, and at the CADIC in Ushuaia, respectively. These instruments measure at five UV channels (305, 3120, 320, 340 and 380 nm) and PAR (400 - 700 nm). Quality control and quality assurance systems of the network give us information for irradiance correction. Quality control is based on the 2-week lamp tests performed at each station, and provides quantitative information about the stability of each instrument. Quality assurance, which is performed twice a year by the FMI, lies in inter-comparisons between the travelling reference instrument and the station instruments. These intercomparisons provide calibration coefficients for each channel. Ozone can be derived from the NILU-UV6 instruments using the 305 nm / 320 nm ratio. Ozone data series before and after irradiance correction are compared against independent ozone measurements from the TOMS, the Dobson and the UV-VIS instruments at the Ushuaia station.

  10. Dynamical contribution to formation of an ozone mini hole in the Northern Hemisphere in mid-winter

    OpenAIRE

    Iwao,Koki/Hirooka,Toshihiko

    2002-01-01

    Ozone mini holes are localized and transient (several days) column ozone amount depletion phenomena which often appear over northern Europe. In early February 1989, the extremely low ozone value of 172 DU was observed by Total Ozone Mapping Spectrometer observation. Quantitative analyses of this event using a forward and backward trajectory method show that the total ozone depletion is by uplift of air throughout the lower stratosphere, whereas the effect of horizontal advection of ozone-poor...

  11. The role of extraterrestrial particles in the formation of the ozone hole

    International Nuclear Information System (INIS)

    The object of Part I of this paper is to estimate the concentration of extraterrestrial particles in the ozone layer over South Pole, Antarctica, during zone hole formation. This estimate is based on an analysis of microscopic magnetic spherules collected in an extended program of atmospheric sampling. Spherules are shown to be of extraterrestrial origin and serve as markers for the larger class of less distinguished extraterrestrial particles. These particles settle to ground level as aggregates formed in a stratospheric ice crystal coalescence process. Specific spherules arrivals at ground level are strongly associated with apparent ozone depletion episodes during formation of the ozone hole. The origin of these spherules is a major stream of extraterrestrial particles independent of known meteor showers. The variability in its intensity from year to year corresponds to the variability in ozone depletion in the ozone hole itself. A quantitative theory based on these spherules arrivals and this coalescence process implies that the concentration of extraterrestrial particles at ozone hole formation lies between 500 and 2000/m3. A mechanism is proposed in Part II of this paper by which particle concentrations in this range are sufficient to produce the ozone hole

  12. Ozone, Iodine, and MSA - Case studies in Antarctic aerosol composition from the 2ODIAC Campaign

    Science.gov (United States)

    Giordano, M.; Kalnajs, L.; Deshler, T.; Davis, S. M.; Johnson, A.; Slater, A. G.; Goetz, J. D.; Mukherjee, A. D.; DeCarlo, P. F.

    2015-12-01

    Aerosol generation and transport over the Polar Regions, and especially Antarctica, remains a source of uncertainty for geophysical scientists. A characterization of aerosol sources, production, and lifecycle processes in the Polar Regions is required to better understand the polar atmosphere. In an attempt to better characterize Antarctic aerosol and trace gas interactions, the Two-Season, Ozone Depletion and Interaction with Aerosols Campaign (2ODIAC) was launched over the Austral Spring/Summer of 2014 and Austral Winter of 2015. One highlight of the campaign is the first ever deployment of a high-resolution aerosol mass spectrometer to Antarctica. In conjunction with trace gas, meteorology, and aerosol sizing measurements, this presentation will focus on case studies from the campaign relevant to the atmospheric science community. Questions about the role of iodine, MSA, and ozone depletion events in regards to aerosol composition will be examined. Specific attention will be paid to aerosol compositional changes before, during, and after particle bursts especially where changes in aerosol sulfate oxidation occurred (SO2 -> SO4)

  13. Ozone Layer Observations

    Science.gov (United States)

    McPeters, Richard; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV and SAGE (Stratospheric Aerosol and Gas Experiment) instruments for example, show that the largest changes are occurring in the lower stratosphere and upper troposphere. The goal of ozone measurement in the next decades will be to document the predicted recovery of the ozone layer as CFC (chlorofluorocarbon) levels decline. This will require a continuation of global measurements of total column ozone on a global basis, but using data from successor instruments to TOMS. Hyperspectral instruments capable of measuring in the UV will be needed for this purpose. Establishing the relative roles of chemistry and dynamics will require instruments to measure ozone in the troposphere and in the stratosphere with good vertical resolution. Instruments that can measure other chemicals important to ozone formation and destruction will also be needed.

  14. The Effects of Interactive Stratospheric Chemistry on Antarctic and Southern Ocean Climate Change in an AOGCM

    Science.gov (United States)

    Li, Feng; Newman, Paul; Pawson, Steven; Waugh, Darryn

    2014-01-01

    Stratospheric ozone depletion has played a dominant role in driving Antarctic climate change in the last decades. In order to capture the stratospheric ozone forcing, many coupled atmosphere-ocean general circulation models (AOGCMs) prescribe the Antarctic ozone hole using monthly and zonally averaged ozone field. However, the prescribed ozone hole has a high ozone bias and lacks zonal asymmetry. The impacts of these biases on model simulations, particularly on Southern Ocean and the Antarctic sea ice, are not well understood. The purpose of this study is to determine the effects of using interactive stratospheric chemistry instead of prescribed ozone on Antarctic and Southern Ocean climate change in an AOGCM. We compare two sets of ensemble simulations for the 1960-2010 period using different versions of the Goddard Earth Observing System 5 - AOGCM: one with interactive stratospheric chemistry, and the other with prescribed monthly and zonally averaged ozone and 6 other stratospheric radiative species calculated from the interactive chemistry simulations. Consistent with previous studies using prescribed sea surface temperatures and sea ice concentrations, the interactive chemistry runs simulate a deeper Antarctic ozone hole and consistently larger changes in surface pressure and winds than the prescribed ozone runs. The use of a coupled atmosphere-ocean model in this study enables us to determine the impact of these surface changes on Southern Ocean circulation and Antarctic sea ice. The larger surface wind trends in the interactive chemistry case lead to larger Southern Ocean circulation trends with stronger changes in northerly and westerly surface flow near the Antarctica continent and stronger upwelling near 60S. Using interactive chemistry also simulates a larger decrease of sea ice concentrations. Our results highlight the importance of using interactive chemistry in order to correctly capture the influences of stratospheric ozone depletion on climate

  15. The ozone hole and the 1995 Nobel prize in chemistry

    International Nuclear Information System (INIS)

    To mark to award of the 1995 Nobel Prize in chemistry to three world renowned atmospheric chemists, this paper recalls the history of scientific progress in stratospheric ozone chemistry. Then it summarizes current knowledge of ozone-layer depletion and its impact on climate, vegetation and human health. (author). 21 refs., 12 figs

  16. Australian Students' Appreciation of the Greenhouse Effect and the Ozone Hole.

    Science.gov (United States)

    Fisher, Brian

    1998-01-01

    Examines students' explanations of the greenhouse effect and the hole in the ozone layer, using a life-world and scientific dichotomy. Illuminates ideas often expressed in classrooms and sheds light on the progression in students' developing powers of explanation. Contains 17 references. (DDR)

  17. Quantification of relative contribution of Antarctic ozone depletion to increased austral extratropical precipitation during 1979-2013

    Science.gov (United States)

    Bai, Kaixu; Chang, Ni-Bin; Gao, Wei

    2016-02-01

    Attributing the observed climate changes to relevant forcing factors is critical to predicting future climate change scenarios. Precipitation observations in the Southern Hemisphere indicate an apparent moistening pattern over the extratropics during the time period 1979 to 2013. To investigate the predominant forcing factor in triggering such an observed wetting climate pattern, precipitation responses to four climatic forcing factors, including Antarctic ozone, water vapor, sea surface temperature (SST), and carbon dioxide, were assessed quantitatively in sequence through an inductive approach. Coupled time-space patterns between the observed austral extratropical precipitation and each climatic forcing factor were firstly diagnosed by using the maximum covariance analysis (MCA). With the derived time series from each coupled MCA modes, statistical relationships were established between extratropical precipitation variations and each climatic forcing factor by using the extreme learning machine. Based on these established statistical relationships, sensitivity tests were conducted to estimate precipitation responses to each climatic forcing factor quantitatively. Quantified differential contribution with respect to those climatic forcing factors may explain why the observed austral extratropical moistening pattern is primarily driven by the Antarctic ozone depletion, while mildly modulated by the cooling effect of equatorial Pacific SST and the increased greenhouse gases, respectively.

  18. Impact of Antarctic polar vortex occurrences on total ozone and UVB radiation at southern Argentinean and Antarctic stations during 1997-2003 period

    Science.gov (United States)

    PazmiñO, Andrea F.; Godin-Beekmann, Sophie; Ginzburg, MáXimo; Bekki, Slimane; Hauchecorne, Alain; Piacentini, RubéN. D.; Quel, Eduardo J.

    2005-02-01

    The evolution of total ozone and surface UV radiation over some stations in the southern region of South America and in Antarctica in relationship with polar vortex occurrences is analyzed using Total Ozone Mapping Spectrometer total ozone measurements and local surface UV data for the 1997-2003 period. The data are classified as a function of the position of the stations with respect to the polar vortex using equivalent latitude at 550 K isentropic level. The study of vortex occurrences showed that Ushuaia station (54.9°S) was located ˜40% of the cases in the edge of the vortex and 5% inside the vortex core during the winter-spring period. Concerning the Marambio (62.2°S) and Dumont d'Urville (66.4°S) stations, located on the shore of the Antarctic continent, the analysis shows a zonal asymmetry with respect to the center of the vortex. Marambio is located around 60% of the time inside the vortex, while Dumont d'Urville is predominantly at the edge of or outside the vortex. The evolution of the equivalent latitude of the stations in the anomalous 2002 winter presents a different behavior with respect to other years in the 1997-2003 period. The persistence of the vortex core above the stations is in average 1.8 days over Ushuaia and 7.1 days over Marambio in October during the 1997-2003 period with corresponding mean total ozone columns of 208.2 and 181.4 Dobson units, respectively. When the stations are inside the vortex, the total ozone columns are generally larger at Ushuaia than at Marambio in October during the 1997-2003 period. Finally, the impact of ozone-depleted air mass occurrences on ultraviolet radiation is evaluated by relating total ozone and UV erythemal dose measured at the stations. Twofold or threefold UV dose increases were reached in the 55°-65° southern latitude region during vortex overpasses, reaching maximum UV dose around 5 kJ/m2. The average increase of UV dose could be computed at the stations considered in the study when the

  19. Recent and Future Evolution of the Stratospheric Ozone Layer

    Science.gov (United States)

    Dameris, Martin; Loyola, Diego

    Since the early 1980s significant depletion of the ozone layer in the stratosphere, in other words the ozone hole, has been observed every year over the South Pole area in Antarctic spring. In the meantime destruction of stratospheric ozone has been detected globally. Emissions of man-made halogenated chemicals play a dominant role in ozone loss. Combined analyses of observations and numerical modeling help to understand the complex interplay of the dynamic and chemical processes involved. Evaluated models provide a base for predicting the future recovery of the ozone layer expected for the middle of this century.

  20. Stratospheric column NO2 anomalies over Russia related to the 2011 Arctic ozone hole

    Science.gov (United States)

    Aheyeva, Viktoryia; Gruzdev, Aleksandr; Elokhov, Aleksandr; Grishaev, Mikhail; Salnikova, Natalia

    2013-04-01

    We analyze data of spectrometric measurements of stratospheric column NO2 contents at mid- and high-latitude stations of Zvenigorod (55.7°N, Moscow region), Tomsk (56.5°N, West Siberia), and Zhigansk (66.8°N, East Siberia). Measurements are done in visual spectral range with zenith-viewing spectrometers during morning and evening twilights. Alongside column NO2 contents, vertical profiles of NO2 are retrieved at the Zvenigorod station. Zvenigorod and Zhigansk are the measurement stations within the Network for the Detection of Atmospheric Composition Change (NDACC). For interpretation of results of analysis of NO2 data, data of Ozone Monitoring Instrument measurements of total column ozone and rawinsonde data are also analyzed and back trajectories calculated with the help of HYSPLIT trajectory model are used. Significant negative anomalies in stratospheric NO2 columns accompanied by episodes of significant cooling of the stratosphere and decrease in total ozone were observed at the three stations in the winter-spring period of 2011. Trajectory analysis shows that the anomalies were caused by the transport of stratospheric air from the region of the ozone hole observed that season in the Arctic. Although negative NO2 anomalies due to the transport from the Arctic were also observed in some other years, the anomalies in 2011 have had record magnitudes. Analysis of NO2 vertical profiles at Zvenigorod shows that the NO2 anomaly in 2011 compared to other years anomalies was additionally contributed by the denitrification of the Arctic lower stratosphere. NO2 profiles show that a certain degree of the denitrification probably survived even after the ozone hole.

  1. Polar stratospheric ozone: interactions with climate change, results from the EU project RECONCILE, and the 2010/11 Arctic ozone hole

    Science.gov (United States)

    von Hobe, Marc

    2013-04-01

    One of the most profound and well known examples of human impacts on atmospheric chemistry is the so called ozone hole. During the second half of the 20th century, anthropogenic emissions of chlorofluorocarbons (CFCs) led to a significant increase in stratospheric chlorine levels and hence the rate of ozone removal by catalytic cycles involving chlorine. While CFCs were essentially banned by the 1987 Montreal Protocol and its subsequent amendments, and stratospheric chlorine levels have recently started to decline again, another anthropogenic influence may at least delay the recovery of the stratospheric ozone layer: climate change, with little doubt a result of human emissions of carbon dioxide and other greenhouse gases, has led to changes in stratospheric temperature and circulation. The large ozone losses that typically occur in polar regions in spring are particularly affected by these changes. Here, we give an overview of the ozone-climate interactions affecting polar stratospheric ozone loss, and present latest results from the international research project RECONCILE funded by the European Commission. Remaining open questions will be discussed including the possible impacts of recently suggested geoengineering concepts to artificially enhance the stratospheric aerosol loading. A special focus will also be put on the 2010/11 Arctic winter that saw the first Arctic Ozone hole, including an impact study on surface UV radiation in the densely populated northern mid-latitudes.

  2. Depletion of stratospheric ozone over the Antarctic and Arctic: Responses of plants of polar terrestrial ecosystems to enhanced UV-B, an overview

    Energy Technology Data Exchange (ETDEWEB)

    Rozema, Jelte [Department of Systems Ecology, Institute of Ecological Science, Climate Centre, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands)]. E-mail: jelte.rozema@ecology.falw.vu.nl; Boelen, Peter [Department of Systems Ecology, Institute of Ecological Science, Climate Centre, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands); Blokker, Peter [Department of Systems Ecology, Institute of Ecological Science, Climate Centre, Vrije Universiteit, De Boelelaan 1087, 1081 HV Amsterdam (Netherlands)

    2005-10-15

    Depletion of stratospheric ozone over the Antarctic has been re-occurring yearly since 1974, leading to enhanced UV-B radiation. Arctic ozone depletion has been observed since 1990. Ozone recovery has been predicted by 2050, but no signs of recovery occur. Here we review responses of polar plants to experimentally varied UV-B through supplementation or exclusion. In supplementation studies comparing ambient and above ambient UV-B, no effect on growth occurred. UV-B-induced DNA damage, as measured in polar bryophytes, is repaired overnight by photoreactivation. With UV exclusion, growth at near ambient may be less than at below ambient UV-B levels, which relates to the UV response curve of polar plants. UV-B screening foils also alter PAR, humidity, and temperature and interactions of UV with environmental factors may occur. Plant phenolics induced by solar UV-B, as in pollen, spores and lignin, may serve as a climate proxy for past UV. Since the Antarctic and Arctic terrestrial ecosystems differ essentially (e.g. higher species diversity and more trophic interactions in the Arctic), generalization of polar plant responses to UV-B needs caution. - Polar plant responses to UV-B may be different in the Arctic than Antarctic regions.

  3. Observations of chlorine monoxide over Scott Base, Antarctica, during the ozone hole, 1996-2005

    Science.gov (United States)

    Connor, Brian; Solomon, Philip; Barrett, James; Mooney, Thomas; Parrish, Alan

    2007-01-01

    We report observations of chlorine monoxide, ClO, in the lower stratosphere, made from Scott Base (77.85º S, 166.77º E) in springtime during each year, 1996-2005. The ClO amounts in the atmosphere are retrieved from remote measurements of microwave emission spectra. ClO column densities of up to about 2.5 × 1015 cm-2 are recorded during September, when chlorine is present in chemically active forms due to reactions on the surface of Polar Stratospheric Cloud (PSC) particles. Maximum mixing ratios of ClO are approximately 2 ppbv. The annual average of ClO column density during the activation period is anticorrelated with similar averages of ozone column measured at nearby Arrival Heights, with correlation coefficient of –0.81, and with averages of ozone mass integrated over the entire polar region, with similar correlation coefficients. There was a substantial decrease in ClO amounts during 2002-2004. There has been no systematic change in the timing of chlorine deactivation attributable to secular change in the Antarctic vortex

  4. Latitudinal UVR-PAR measurements in Argentina. Extent of the `ozone hole`

    Energy Technology Data Exchange (ETDEWEB)

    Orce, V. Luis [Instituto de Genetica y Biologia Molecular INGEBI-CONICET, Buenos Aires (Argentina); Helbling, E. Walter [Estacion de Fotobiologia Playa Union y Consejo Nacional de Investigaciones Cientificas y Tecnicas CONICET, Chubut (Argentina)

    1997-10-30

    The UVR-PAR Argentinean Monitoring Network started its operation in September 1994 recording ultraviolet (UVR) and Photosynthetic Available Radiation (PAR) at a frequency of once per minute, at four sites, throughout the entire year. Four spectroradiometers (GUV-511, Biospherical Instruments, Inc.) were installed at research centers separated by about 8-12 degrees of latitude, extending from the Subantarctic-Fueguian region to the Tropic of Capricorn. The instruments are located in populated areas ranging from 30,000 to 11 million people and with extremely different climate regimes and conditions of tropospheric pollution. Our ground-based data indicated that the irradiance increased steadily from south to north. This increase was also observed in the calculated daily doses of UV-B (280-320 nm); however, daily integrated values for UV-A (320-400 nm) and PAR (400-700 nm) were higher at mid-latitudes (Puerto Madryn, 4247`S). A similar south-to-north increase was evident in the ratio of the energy at 305 nm and 340 nm wavelengths (with low 305/340 ratios indicating high total ozone column concentration), with low values at Ushuaia (5501`S) and high values at Jujuy (2410`S). However, the 305/340 ratios increased significantly over their normal spring values at two sites, Ushuaia and Puerto Madryn, for variable time periods during October-December. Our data suggest that the ozone hole was over South America extending to about 38S for at least a week during October and about two weeks during November-December of the years of 1994 and 1995. However, it should be noted that the erythemal irradiance, in the area influenced by the ozone hole, was at all times lower than that in Buenos Aires and well below the value at Jujuy (tropical station). This study also indicates that when assessing the impact of solar UVR upon organisms, other variables such as cloud cover, solar zenith angle, day length, latitude, and atmospheric pollution should be considered in addition to total

  5. Latitudinal UVR-PAR measurements in Argentina: extent of the 'ozone hole'

    Science.gov (United States)

    Luis Orce, V.; Walter Helbling, E.

    1997-10-01

    The UVR-PAR Argentinean Monitoring Network started its operation in September 1994 recording ultraviolet (UVR) and Photosynthetic Available Radiation (PAR) at a frequency of once per minute, at four sites, throughout the entire year. Four spectroradiometers (GUV-511, Biospherical Instruments, Inc.) were installed at research centers separated by about 8-12 degrees of latitude, extending from the Subantarctic-Fueguian region to the Tropic of Capricorn. The instruments are located in populated areas ranging from 30,000 to 11 million people and with extremely different climate regimes and conditions of tropospheric pollution. Our ground-based data indicated that the irradiance increased steadily from south to north. This increase was also observed in the calculated daily doses of UV-B (280-320 nm); however, daily integrated values for UV-A (320-400 nm) and PAR (400-700 nm) were higher at mid-latitudes (Puerto Madryn, 42°47'S). A similar south-to-north increase was evident in the ratio of the energy at 305 nm and 340 nm wavelengths (with low 305/340 ratios indicating high total ozone column concentration), with low values at Ushuaia (55°01'S) and high values at Jujuy (24°10'S). However, the 305/340 ratios increased significantly over their normal spring values at two sites, Ushuaia and Puerto Madryn, for variable time periods during October-December. Our data suggest that the ozone hole was over South America extending to about 38°S for at least a week during October and about two weeks during November-December of the years of 1994 and 1995. However, it should be noted that the erythemal irradiance, in the area influenced by the ozone hole, was at all times lower than that in Buenos Aires and well below the value at Jujuy (tropical station). This study also indicates that when assessing the impact of solar UVR upon organisms, other variables such as cloud cover, solar zenith angle, day length, latitude, and atmospheric pollution should be considered in addition to

  6. Impact of Antarctic polar vortex occurrences on total ozone and UVB radiation at southern Argentinean and Antarctic stations during 1997–2003 period

    OpenAIRE

    Pazmiño, Andrea F.; Godin-Beekmann, Sophie; Ginzburg, Maximo; Bekki, Slimane; Hauchecorne, Alain; Piacentini, Ruben D.; Quel, Eduardo J

    2005-01-01

    International audience The evolution of total ozone and surface UV radiation over some stations in the southern region of South America and in Antarctica in relationship with polar vortex occurrences is analyzed using Total Ozone Mapping Spectrometer total ozone measurements and local surface UV data for the 1997–2003 period. The data are classified as a function of the position of the stations with respect to the polar vortex using equivalent latitude at 550 K isentropic level. The study ...

  7. Reductions of Antarctic ozone due to synergistic interactions of chlorine and bromine

    Science.gov (United States)

    Mcelroy, M. B.; Salawitch, R. J.; Wofsy, S. C.; Logan, J. A.

    1986-01-01

    The vertical column density of ozone observed in October over Antarctica has fallen precipitously over the past 10 yr. The concentration at Halley Bay (76 deg S, 27 deg W), expressed conventionally in Dobson units (DU), has dropped from about 300 DU in 1975 to less than 200 DU in 1984. Values in 1985 were even lower, comparable with the lowest values recorded anywhere on earth. It is suggested here that the loss of O3 in Antarctica may be attributed to catalysis of O3 recombination by a scheme in which the rate-limiting step is defined by the reaction of ClO + BrO - Cl + Br + O2. Concentrations of NO2 must be low and heterogeneous reactions involving particles in the polar stratospheric clouds must be an important element of the relevant chemistry. Industrial sources make important contributions to the contemporary budgets of both BrO and ClO and are likely to grow significantly in the future.

  8. Antarctic news clips, 1991

    Science.gov (United States)

    1991-08-01

    Published stories are presented that sample a year's news coverage of Antarctica. The intent is to provide the U.S. Antarctic Program participants with a digest of current issues as presented by a variety of writers and popular publications. The subject areas covered include the following: earth science; ice studies; stratospheric ozone; astrophysics; life science; operations; education; antarctic treaty issues; and tourism

  9. Late Cenozoic Climate History of the Ross Embayment from the AND-1B Drill Hole: Culmination of Three Decades of Antarctic Margin Drilling

    Science.gov (United States)

    Naish, T.R.; Powell, R.D.; Barrett, P.J.; Levy, R.H.; Henrys, S.; Wilson, G.S.; Krissek, L.A.; Niessen, F.; Pompilio, M.; Ross, J.; Scherer, R.; Talarico, F.; Pyne, A.; ,

    2007-01-01

    Because of the paucity of exposed rock, the direct physical record of Antarctic Cenozoic glacial history has become known only recently and then largely from offshore shelf basins through seismic surveys and drilling. The number of holes on the continental shelf has been small and largely confined to three areas (McMurdo Sound, Prydz Bay, and Antarctic Peninsula), but even in McMurdo Sound, where Oligocene and early Miocene strata are well cored, the late Cenozoic is poorly known and dated. The latest Antarctic geological drilling program, ANDRILL, successfully cored a 1285-m-long record of climate history spanning the last 13 m.y. from subsea-floor sediment beneath the McMurdo Ice Shelf (MIS), using drilling systems specially developed for operating through ice shelves. The cores provide the most complete Antarctic record to date of ice-sheet and climate fluctuations for this period of Earth’s history. The >60 cycles of advance and retreat of the grounded ice margin preserved in the AND-1B record the evolution of the Antarctic ice sheet since a profound global cooling step in deep-sea oxygen isotope records ~14 m.y.a. A feature of particular interest is a ~90-m-thick interval of diatomite deposited during the warm Pliocene and representing an extended period (~200,000 years) of locally open water, high phytoplankton productivity, and retreat of the glaciers on land.

  10. The ozone hole and the 1995 Nobel prize in chemistry; Trou d`ozone et Prix Nobel 1995 de chimie

    Energy Technology Data Exchange (ETDEWEB)

    Berger, A. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium). Inst. d`Astronomie et de Geophysique G. Lemaitre

    1996-03-01

    To mark to award of the 1995 Nobel Prize in chemistry to three world renowned atmospheric chemists, this paper recalls the history of scientific progress in stratospheric ozone chemistry. Then it summarizes current knowledge of ozone-layer depletion and its impact on climate, vegetation and human health. (author). 21 refs., 12 figs.

  11. 臭氧洞的形成、危害及对策%The Harms and Formation of the Hole in the Ozone Layer and the Necessary Aid for It

    Institute of Scientific and Technical Information of China (English)

    王若禹; 孙茜; 孙仁义

    2001-01-01

    A seasonal hole in the ozone layer was found over Antarctica more than 10 years ago . That was worrisome: Ozone between 10~30 miles up absorbs the sun's ultraviolet radiation, more of which would lead to cataracts, skin cancers and weaken immune systems in humans and other animals, and damage to plants. Data-gathering flights in Antarctic in 1987 made the connection between CFCs and ozone destruction all but certain. In dealing with the threat of the hole in the ozone layer, the world community and leaders of all nations are taking steps to find environmentally acceptable substitutes for CFCs in order to phase out all CFCs production as soon as possible.%十多年前在南极上空发现了臭氧洞. 位于10-30km高空的臭氧层能吸收太阳的紫外线辐射,过多的紫外辐射能引起人类和其他动物的白内障、皮肤癌并减弱其免疫功能,而且对植物也有损害. 1987年在南极地区进行的收集数据的飞行证明氟氯烃类物质与臭氧层破坏之间存在着联系几乎是确定无疑的. 为了解决臭氧洞的威胁问题,目前国际社会和各国领导人都正在采取措施寻求有利于环境的氟氯烃代用品,以便尽早停止全部氟氯烃类物质的生产.

  12. What would have happened to the ozone layer if chlorofluorocarbons (CFCs had not been regulated?

    Directory of Open Access Journals (Sweden)

    P. A. Newman

    2009-03-01

    Full Text Available Ozone depletion by chlorofluorocarbons (CFCs was first proposed by Molina and Rowland in their 1974 Nature paper. Since that time, the scientific connection between ozone losses and CFCs and other ozone depleting substances (ODSs has been firmly established with laboratory measurements, atmospheric observations, and modeling studies. This science research led to the implementation of international agreements that largely stopped the production of ODSs. In this study we use a fully-coupled radiation-chemical-dynamical model to simulate a future world where ODSs were never regulated and ODS production grew at an annual rate of 3%. In this "world avoided" simulation, 17% of the globally-averaged column ozone is destroyed by 2020, and 67% is destroyed by 2065 in comparison to 1980. Large ozone depletions in the polar region become year-round rather than just seasonal as is currently observed in the Antarctic ozone hole. Very large temperature decreases are observed in response to circulation changes and decreased shortwave radiation absorption by ozone. Ozone levels in the tropical lower stratosphere remain constant until about 2053 and then collapse to near zero by 2058 as a result of heterogeneous chemical processes (as currently observed in the Antarctic ozone hole. The tropical cooling that triggers the ozone collapse is caused by an increase of the tropical upwelling. In response to ozone changes, ultraviolet radiation increases, more than doubling the erythemal radiation in the northern summer midlatitudes by 2060.

  13. What would have happened to the ozone layer if chlorofluorocarbons (CFCs had not been regulated?

    Directory of Open Access Journals (Sweden)

    P. A. Newman

    2008-12-01

    Full Text Available Ozone depletion by chlorofluorocarbons (CFCs was first proposed by Molina and Rowland in their 1974 Nature paper. Since that time, the scientific connection between ozone losses and CFCs and other ozone depleting substances (ODSs has been firmly established with laboratory measurements, atmospheric observations, and modeling research. This science research led to the implementation of international agreements that largely stopped the production of ODSs. In this study we use a fully-coupled radiation-chemical-dynamical model to simulate a future world where ODSs were never regulated and ODS production grew at an annual rate of 3%. In this "world avoided" simulation, 17% of the globally-average column ozone is destroyed by 2020, and 67% is destroyed by 2065 in comparison to 1980. Large ozone depletions in the polar region become year-round rather than just seasonal as is currently observed in the Antarctic ozone hole. Very large temperature decreases are observed in response to circulation changes and decreased shortwave radiation absorption by ozone. Ozone levels in the tropical lower stratosphere remain constant until about 2053 and then collapse to near zero by 2058 as a result of heterogeneous chemical processes (as currently observed in the Antarctic ozone hole. The tropical cooling that triggers the ozone collapse is caused by an increase of the tropical upwelling. In response to ozone changes, ultraviolet radiation increases, more than doubling the erythemal radiation in the northern summer midlatitudes by 2060.

  14. What Would Have Happened to the Ozone Layer if Chlorofluorocarbons (CFCs) had not been Regulated?

    Science.gov (United States)

    Newman, Paul A.; Oman, L. D.; Douglass, A. R.; Fleming, E. L.; Frith, S. M.; Hurwitz, M. M.; Kawa, S. R.; Jackman, C. H.; Krotkov, N. A.; Nash, E. R.; Nielsen, J. E.; Pawson, S.; Stolarski, R. S.; Velders, G. J. M.

    2008-01-01

    Ozone depletion by chlorofluorocarbons (CFCs) was first proposed by Molina and Rowland in their 1974 Nature paper. Since that time, the sci entific connection between ozone losses and CFCs and other ozone depl eting substances (ODSs) has been firmly established with laboratory m easurements, atmospheric observations, and modeling research. This science research led to the implementation of international agreements t hat largely stopped the production of ODSs. In this study we use a fu lly-coupled radiation-chemical-dynamical model to simulate a future world where ODSs were never regulated and ODS production grew at an ann ual rate of 3%. In this "world avoided" simulation 1.7 % of the globa lly-average column ozone is destroyed by 2020, and 67% is destroyed b y 2065 in comparison to 1980. Large ozone depletions in the polar region become year-round rather than just seasonal as is currently observ ed in the Antarctic ozone hole. Very large temperature decreases are observed in response to circulation changes and decreased shortwave radiation absorption by ozone. Ozone levels in the tropical lower strat osphere remain constant until about 2053 and then collapse to near ze ro by 2058 as a result of heterogeneous chemical processes (as curren tly observed in the Antarctic ozone hole). The tropical cooling that triggers the ozone collapse is caused by an increase of the tropical upwelling. In response to ozone changes, ultraviolet radiation increa ses, more than doubling the erythemal radiation in the northern summer midlatitudes by 2060.

  15. The depletion of the stratospheric ozone layer

    International Nuclear Information System (INIS)

    The protection of the Earth's ozone layer is of the highest importance to mankind. The dangers of its destruction are by now well known. The depletion of that layer has reached record levels. The Antarctic ozone hole covered this year a record area. The ozone layer is predicted to begin recovery in the next one or two decades and should be restored to pre-1980 levels by 2050. This is the achievement of the regime established by the 1985 Vienna Convention for the Protection of the Ozone Layer and the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. The regime established by these two agreements has been revised, and made more effective in London (1990), Copenhagen (1992), Vienna (1995), and Beijing (1999)

  16. The potential for ozone depletion in the Arctic polar stratosphere

    Science.gov (United States)

    Brune, W. H.; Anderson, J. G.; Toohey, D. W.; Fahey, D. W.; Kawa, S. R.; Poole, L. R.

    1991-01-01

    The nature of the Arctic polar stratosphere is observed to be similar in many respects to that of the Antarctic polar stratosphere, where an ozone hole has been identified. Most of the available chlorine (CHl and ClONO2) was converted by reactions on polar stratospheric clouds to reactive ClO and Cl2O2 thoroughout the Arctic polar vortex before midwinter. Reactive nitrogen was converted to HNO3, and some, with spatial inhomogeneity, fell out of the stratosphere. These chemical changes ensured characteristic ozone losses of 10 to 15 percent at altitudes inside the polar vortex where polar stratospheric clouds had occurred. These local losses can translate into 5 to 8 percent losses in the vertical column abundance of ozone. As the amount of stratospheric chlorine inevitably increases by 50 percent over the next two decades, ozone losses recognizable as an ozone hole may well appear.

  17. Wind profile radar for study of Antarctic air circulation. Progetto di un radar 'wind-profiler' per lo studio della circolazione atmosferica antartica

    Energy Technology Data Exchange (ETDEWEB)

    Ragaini, E.; Sarango, M.F.; Vasquez, E.H.

    1992-10-01

    After a brief discussion of meteorological methods used in the Antarctic, the paper gives an outline of a coordinated international research project whose objective is to set up a wind profiler radar station that would give meteorologists information regarding Antarctic atmospheric dynamics useful in their investigation of the causes and effects of the hole in the ozone layer. The radar instrumentation is to provide continuous readings of wind velocity at varying altitudes above the polar continent.

  18. Stratospheric ozone depletion.

    Science.gov (United States)

    Rowland, F Sherwood

    2006-05-29

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290-320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime-the 'Antarctic ozone hole'. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  19. Evaluation of DNA dosimetry to assess ozone-mediated variability of biologically harmful radiation in Antarctica

    NARCIS (Netherlands)

    George, AL; Peat, HJ; Buma, AGJ

    2002-01-01

    In this study we investigated the use of a DNA dosimeter to accurately measure changes in ultraviolet B radiation (UVBR; 280-315 nm) under Antarctic ozone hole conditions. Naked DNA solution in quartz tubes was exposed to ambient solar radiation at Rothera Research Station, Antarctica, between Octob

  20. Scientific information and public opinion. Daily press analysis about ozone hole in the years 1996-1997

    International Nuclear Information System (INIS)

    One of ENEA's many activities consists in dealing with the analysis of information strategies. In this case the analysis concerns an environmental issue, the ozone hole which, in spite of the consideration given by the media, is not sufficiently highlighted, as well as in the case of climate changes issue. A survey of the coverage of four daily newspapers was realized; the time period covered by the analysis spans form January 1996 to December 1997, 77 articles in total. The newspapers involved are: La Repubblica, Il Corriere della Sera, L'Unita' on a national scale, and Il Resto del Carlino on a regional scale. The number of articles analyzed is divided as follows: 26 for the Repubblica, 24 for the Corriere della Sera, 21 for the Unita', 6 for the Resto del Carlino. The purpose of the work was to detect quality and quantity indicators of the Italian press about the ozone hole issue and possible environmental risks conveyed to the public, using the classical methods of the Content analysis. The analysis, carried out through a questionnaire realized for another research on climate change and daily press and appropriately readapted, consisted of 35 questions pointing out the fundamental characteristics of each article: (i) morphological characteristics; (ii) modalities describing the ozone hole; (iii) communication connotations

  1. In-situ measurements of chlorine activation, nitric acid redistribution and ozone depletion in the Antarctic lower vortex aboard the German research aircraft HALO during TACTS/ESMVal

    Science.gov (United States)

    Jurkat, Tina; Voigt, Christiane; Kaufmann, Stefan; Schlage, Romy; Gottschaldt, Klaus-Dirk; Ziereis, Helmut; Hoor, Peter; Bozem, Heiko; Müller, Stefan; Zahn, Andreas; Schlager, Hans; Oelhaf, Hermann; Sinnhuber, Björn-Martin; Dörnbrack, Andreas

    2016-04-01

    In-situ measurements of stratospheric chlorine compounds are rare and exhibit the potential to gain insight into small scale mixing processes where stratospheric air masses of different origin and history interact. In addition, the relationship with chemically stable trace gases helps to identify regions that have been modified by chemical processing on polar stratospheric clouds. To this end, in-situ measurements of ClONO2, HCl, HNO3, NOy, N2O and O3 have been performed in the Antarctic Polar Vortex in September 2012 aboard the German research aircraft HALO (High Altitude and Long Rang research aircraft) during the TACTS/ESMVal (Transport and Composition in the UTLS/Earth System Model Validation) mission. With take-off and landing in Capetown, HALO sampled vortex air with latitudes down to 65°S, at altitudes between 8 and 14.3 km and potential temperatures between 340 and 390 K. Before intering the vortex at 350 K potential temperature, HALO additionally sampled mid-latitude stratospheric air. The trace gas distributions at the edge of the Antarctic polar vortex show distinct signatures of processed upper stratospheric vortex air and chemically different lower stratospheric / upper tropospheric air. Diabatic descend of the vortex transports processed air into the lower stratosphere. Here small scale filaments of only a few kilometers extension form at the lower vortex boundary due to shear stress, ultimately leading to transport and irreversible mixing. Comparison of trace gas relationships with those at the beginning of the polar winter reveals substantial chlorine activation, ozone depletion de- and renitrification with high resolution. Furthermore, the measurements are compared to the chemistry climate models EMAC and supported by ECMWF analysis. Finally, we compare the Antarctic measurements with new measurements of ClONO2, HCl and HNO3 aboard HALO obtained during the Arctic mission POLSTRACC (POLar STratosphere in a Changing Climate) based in Kiruna (Sveden

  2. Detection and Attribution of the Recovery of Polar Ozone

    Science.gov (United States)

    Newman, Paul A.; Nash, E. R.; Douglass, A. R.; Nielsen, J. E.; Pawson, S.; Stolarski, R. S.

    2008-01-01

    The Antarctic ozone hole develops each year and culminates by early spring (late September - early October). The severity of the hole has been assessed from satellites using the minimum total ozone value from the October monthly mean (depth of the hole), calculating the average area coverage during this September-October period, and by estimating ozone mass deficit. Profile information shows that ozone is completely destroyed in the 14-2 1 km layer by early October. Ozone is mainly destroyed by halogen (chlorine and bromine) catalytic cycles, and these losses are modulated by temperature variations. Because atmospheric halogen levels are responding to international agreements that limit or phase out production, the amount of halogens in the stratosphere should decrease over the next few decades. Both models and projections of ozone depleting substances (ODSs) into the 21St century reveal that polar ozone levels should recover in the 2060- 2070 period. In this talk, we will review current projections of polar ozone recovery. Using models and ODs projections, we explore both the past, near future (2008-2025), and far future (> 2025) levels of polar ozone. Finally, we will discuss various factors that complicate recovery such as greenhouse gas changes (e.g., cooling in the upper stratosphere) and the acceleration of the Brewer-Dobson circulation.

  3. Device performance and lifetime of polymer:fullerene solar cells with UV-ozone-irradiated hole-collecting buffer layers.

    Science.gov (United States)

    Lee, Seungsoo; Nam, Sungho; Lee, Hyena; Kim, Hwajeong; Kim, Youngkyoo

    2011-11-18

    We report the influence of UV-ozone irradiation of the hole-collecting buffer layers on the performance and lifetime of polymer:fullerene solar cells. UV-ozone irradiation was targeted at the surface of the poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS) layers by varying the irradiation time up to 600 s. The change of the surface characteristics in the PEDOT:PSS after UV-ozone irradiation was measured by employing optical absorption spectroscopy, photoelectron yield spectroscopy, and contact angle measurements, while Raman and X-ray photoelectron spectroscopy techniques were introduced for more microscopic analysis. Results showed that the UV-ozone irradiation changed the chemical structure/composition of the surface of the PEDOT:PSS layers leading to the gradual increase of ionization potential with irradiation time in the presence of up-and-down variations in the contact angle (polarity). This surface property change was attributed to the formation of oxidative components, as evidenced by XPS and Auger electron images, which affected the sheet resistance of the PEDOT:PSS layers. Interestingly, device performance was slightly improved by short irradiation (up to 10 s), whereas it was gradually decreased by further irradiation. The short-duration illumination test showed that the lifetime of solar cells with the UV-ozone irradiated PEDOT:PSS layer was improved due to the protective role of the oxidative components formed upon UV-ozone irradiation against the attack of sulfonic acid groups in the PEDOT:PSS layer to the active layer.

  4. Heterogeneous reactions of N2O5 with H2O and HCl on ice surfaces - Implications for Antarctic ozone depletion

    Science.gov (United States)

    Leu, Ming-Taun

    1988-01-01

    This paper reports on the measurements of reaction probabilities for heterogeneous reaction of N2O5 with H2O and HCl on ice surfaces at 195 K, using a fast-flow reactor coupled with a quadrupole mass spectrometer. The reaction probability for N2O5 on pure-water ice was found to be 0.028 + or - 0.011, with nitric acid in the solid phase as the sole product. In the presence of HCl in ice, the probability of N2O5 reaction was enhanced (to 0.037); the reaction produced, besides solid-phase nitric acid, ClNO2 and ClONO which were released into the gas phase within a few milliseconds. The latter two compounds can be readily photolyzed in the austral spring to form active chlorine which would remove stratospheric ozone. It is suggested that, since the polar stratospheric clouds are believed to contain HCl-ice mixture on the surface, the reactions of N2O5 on H2O/HCl particles is a major factor in the Antarctic springtime ozone depletion.

  5. The search for signs of recovery of the ozone layer.

    Science.gov (United States)

    Weatherhead, Elizabeth C; Andersen, Signe Bech

    2006-05-01

    Evidence of mid-latitude ozone depletion and proof that the Antarctic ozone hole was caused by humans spurred policy makers from the late 1980s onwards to ratify the Montreal Protocol and subsequent treaties, legislating for reduced production of ozone-depleting substances. The case of anthropogenic ozone loss has often been cited since as a success story of international agreements in the regulation of environmental pollution. Although recent data suggest that total column ozone abundances have at least not decreased over the past eight years for most of the world, it is still uncertain whether this improvement is actually attributable to the observed decline in the amount of ozone-depleting substances in the Earth's atmosphere. The high natural variability in ozone abundances, due in part to the solar cycle as well as changes in transport and temperature, could override the relatively small changes expected from the recent decrease in ozone-depleting substances. Whatever the benefits of the Montreal agreement, recovery of ozone is likely to occur in a different atmospheric environment, with changes expected in atmospheric transport, temperature and important trace gases. It is therefore unlikely that ozone will stabilize at levels observed before 1980, when a decline in ozone concentrations was first observed. PMID:16672963

  6. Are we approaching an Arctic ozone hole; Gaar vi mot et arktisk ozonhull

    Energy Technology Data Exchange (ETDEWEB)

    Braathen, Geir [Norsk Inst. for Luftforskning, Kjeller (Norway)

    1999-04-01

    Observations during the last decade in the Arctic areas mainly made by satellite, on the ground and by probes and sensors in the stratosphere are presented. Future perspectives are deducted from the results. Factors that may influence the ozone layer negatively are: Emission rate of ozone destroying compounds, the rapidly increasing use of some substitutes, increased concentrations of steam from aeroplanes and increased amount of methane, decreasing temperature in the stratosphere due to increasing amounts of climatic gases, large volcanic eruptions and altered timing for the polar whirl dissolution. It is concluded that the ozone reduction will be larger than observed at present in the next 10 to 20 years.

  7. The Ozone Hole - from today's observations to long-term predictions

    Science.gov (United States)

    von Hobe, M.; Reconcile Science Team

    2010-12-01

    The effects of the Montreal Protocol will very likely result in ozone recovery during the next few decades. In the long run, climate change and possible geoengineering ventures to mitigate climate change may radically alter the temperature, circulation patterns and chemical composition in the stratosphere. To realistically predict the response of the ozone layer to these changes and the future evolution of Arctic ozone, a complete and correct representation of all relevant processes is necessary. Using a comprehensive approach of laboratory experiments, field observations, microphysical and chemical transport modeling as well as data assimilation, the EU project RECONCILE aims to produce reliable parameterizations of the key processes in Arctic stratospheric ozone depletion and bridge them to a large scale chemistry climate model (CCM). We will present a compact overview of the project activities and the highlights of the extensive field campaign with the high-flying aircraft M55-Geophysica from Kiruna, Sweden, in the cold Arctic winter 2009/10.

  8. Antarctic ecosystems as models for extraterrestrial surface habitats

    Science.gov (United States)

    Wynn-Williams, D. D.; Edwards, H. G. M.

    2000-09-01

    Surface habitats in Antarctic deserts are near the limits of life on Earth and resemble those hypothesized for early Mars. Cyanobacteria dominate the transient riverbeds, stromatolitic sediments in ice-covered lakes, and endolithic communities in translucent rock. There is still no direct evidence of photosynthetic life on early Mars, but cyanobacteria are amongst the earliest microbes detectable in the fossil record for analogous habitats on Earth. Key biomolecules persist in Antarctic microbial habitats, even after extinction by excessive low temperatures, desiccation and UV-B stress within the Ozone Hole. Pigments (or their fossil residues), such as chlorophyll and the UV-protectants scytonemin, carotene and quinones, are good biomarkers. To show not only their presence but also their micro-spatial distribution in situ, we describe the use of FT-Raman spectroscopy with 1064 nm excitation to avoid autofluorescence from the pigments. We report not only the diversity of biomolecules that we have diagnosed from their unique Raman spectra of Antarctic cyanobacterial communities, but also their functional stratification in endolithic communities. Our analyses of Antarctic habitats show the potential of this remote, non-intrusive technique to probe for buried biomolecules on future Mars missions and in Antarctic Lake Vostok, >4 km beneath the Central Ice Sheet, with implications for the putative analogous sub-ice ocean on Europa.

  9. From closing the atmospheric ozone hole to reducing climate change. Lessons learned.

    Science.gov (United States)

    Ewart, Gary W; Rom, William N; Braman, Sidney S; Pinkerton, Kent E

    2015-02-01

    Global warming presents U.S. and transnational leaders with enormous political and policy challenges. World leadership addressed a similar worldwide environmental challenge in the 1980s and 1990s when scientists advised that accelerating emission of man-made chlorofluorocarbons was depleting the ozone layer of the earth's atmosphere. The process that led to global agreement on reducing depletion of the ozone layer holds valuable lessons, and some ironies, for scientists and policy makers seeking now to address global climate change. By understanding the international treaty process, how science informed that process, and how the physician community played a constructive role in the transition away from commercial use of ozone-depleting gases three decades ago, environmental activists can better understand the challenges, opportunities, and potential solutions under current consideration in affecting global climate change. PMID:25706493

  10. Polar stratospheric clouds in the 1998-2003 Antarctic vortex: Microphysical modeling and Polar Ozone and Aerosol Measurement (POAM) III observations

    Science.gov (United States)

    Benson, C. M.; Drdla, K.; Nedoluha, G. E.; Shettle, E. P.; Alfred, J.; Hoppel, K. W.

    2006-09-01

    The Integrated Microphysics and Aerosol Chemistry on Trajectories (IMPACT) model is used to study polar stratospheric cloud (PSC) formation and evolution in the Antarctic vortex. The model is applied to individual air parcel trajectories driven by UK Met Office (UKMO) wind and temperature fields. The IMPACT model calculates the parcel microphysics, including the formation and sedimentation of ice, nitric acid trihydrate (NAT), sulfuric acid tetrahydrate (SAT), and supercooled ternary solution (STS) aerosols. Model results are validated by comparison with data obtained by the Polar Ozone and Aerosol Measurement (POAM) III solar occultation instrument and are examined for 6 years of POAM data (1998-2003). Comparisons of POAM water vapor and aerosol extinction measurements to the model results help to constrain three microphysical parameters influencing the formation and growth of both type I and type II PSCs. Principally, measurements of aerosol extinction prove to be valuable in differentiating model runs; the relationship of aerosol extinction to temperature is determined by the various particle types as they form and grow. Comparison of IMPACT calculations of this relationship to POAM measurements suggests that the initial fraction of nuclei available for heterogeneous NAT freezing is approximately 0.02% of all aerosols. Constraints are also placed on the accommodation coefficient of ice and the NAT-ice lattice compatibility. However, these two parameters have similar effects on the extinction-temperature relationship, and thus a range of values are permissible for each.

  11. Consequences of depletion of stratospheric ozone for terrestrial Antarctic ecosystems: the response of Deschampsia antarctica to enhanced UV-B radiation in a controlled environment

    NARCIS (Netherlands)

    Rozema, J.J.; Broekman, R.; Lud, D.; Huiskes, A.H.L.; Moerdijk-Poortvliet, T.C.W.; De Bakker, N.; Meijkamp, B.; Van Beem, A.

    2001-01-01

    Mini UV lamps were installed over antarctic plants at Leonie Island, Antarctic peninsula, and shoot length measurements of Deschampsia antarctica were performed during the austral summer January-February 1999. We studied the response of the antarctic hairgrass, Deschampsia antarctica to enhanced UV-

  12. Investigations of Stratosphere-Troposphere Exchange of Ozone Derived From MLS Observations

    Science.gov (United States)

    Olsen, M. A.; Schoeberl, M. R.; Ziemke, J. R.

    2006-12-01

    Daily high-resolution maps of stratospheric ozone have been constructed using observations by MLS combined with trajectory information. These fields are used to determine the extratropical stratosphere- troposphere exchange (STE) of ozone for the year 2005 using two diagnostic methods. The resulting two annual estimates compare well with past model- and observational-based estimates. Initial analyses of the seasonal characteristics indicate that significant STE of ozone in the polar regions occurs only during spring and early summer. We also examine evidence that the Antarctic ozone hole is responsible for a rapid decrease in the rate of ozone STE during the SH spring. Subtracting the high-resolution stratospheric ozone from OMI total column measurements creates a high- resolution tropospheric ozone residual (HTOR) product. The HTOR fields are compared to the spatial distribution of the ozone STE. We show that the mean tropospheric ozone maxima tend to occur near locations of significant ozone STE. This suggests that ozone transported from the stratosphere may be responsible for a significant fraction of the mean tropospheric ozone maxima.

  13. On Cosmic-Ray-Driven Electron Reaction Mechanism for Ozone Hole and Chlorofluorocarbon Mechanism for Global Climate Change

    CERN Document Server

    Lu, Qing-Bin

    2012-01-01

    Numerous laboratory measurements have provided a sound physical basis for the cosmic-ray driven electron-induced reaction (CRE) mechanism of halogen-containing molecules for the ozone hole. And observed spatial and time correlations between polar ozone loss or stratospheric cooling and cosmic rays have shown strong evidence of the CRE mechanism [Q.-B. Lu, Phys. Rep. 487, 141-167(2010)]. Chlorofluorocarbons (CFCs) were also long-known greenhouse gases but were thought to play only a minor role in climate change. However, recent observations have shown evidence of the saturation in greenhouse effect of non-CFC gases. A new evaluation has shown that halocarbons alone (mainly CFCs) could account for the rise of 0.5~0.6 deg C in global surface temperature since 1950, leading to the striking conclusion that not CO2 but CFCs were the major culprit for global warming in the late half of the 20th century [Q.-B. Lu, J. Cosmology 8, 1846-1862(2010)]. Surprizingly, a recent paper [J.-W. Grooss and R. Muller, Atmos. Envir...

  14. Stratospheric ozone depletion and future levels of atmospheric chlorine and bromine

    Science.gov (United States)

    Prather, Michael J.; Watson, Robert T.

    1990-01-01

    The rise in atmospheric chlorine levels caused by the emission of chlorofluorocarbons and other halocarbons is thought to be the main cause of the appearance of the Antarctic ozone 'hole' in the late 1970s, and the more modest ozone depletion observed over parts of the Northern Hemisphere. Atmospheric bromine, also associated with halocarbon emissions, is believed to contribute to ozone depletion. Over the next decade, further increases in these compounds are inevitable. Model calculations show that by the end of the next century, atmospheric chlorine and bromine levels may return to those prevalent before the onset of the ozone hole, but only if more stringent regulations are applied to halocarbon production than those currently proposed.

  15. Energetic particle induced inter-annual variability of ozone inside the Antarctic polar vortex observed in satellite data

    Directory of Open Access Journals (Sweden)

    T. Fytterer

    2014-12-01

    Full Text Available Measurements from 2002–2011 by three independent satellite instruments, namely MIPAS, SABER, and SMR on board the ENVISAT, TIMED, and Odin satellites are used to investigate the inter-annual variability of stratospheric and mesospheric O3 volume mixing ratio (vmr inside the Antarctic polar vortex due to solar and geomagnetic activity. In this study, we individually analysed the relative O3 vmr variations between maximum and minimum conditions of a number of solar and geomagnetic indices (F10.7 cm solar radio flux, Ap index, ≥ 2 MeV electron flux. The indices are 26 day averages centred at 1 April, 1 May, and 1 June while O3 is based on 26 day running means from 1 April–1 November at altitudes from 20–70 km. During solar quiet time from 2005–2010, the composite of all three instruments reveals an apparent negative O3 feedback associated to the geomagnetic activity (Ap index around 1 April, on average reaching amplitudes between −5 and −10% of the respective O3 background. The O3 response exceeds the significance level of 95% and propagates downwards throughout the polar winter from the stratopause down to ∼ 25 km. These observed results are in good qualitative agreement with the O3 vmr pattern simulated with a three-dimensional chemistry-transport model, which includes particle impact ionisation.

  16. Nobel Prize in Chemistry 1995 "for their work in atmospheric chemistry, particularly concerning the formation and decomposition of ozone" : Paul J Crutzen, Mario J Molina and F Sherwood Rowland

    CERN Multimedia

    1997-01-01

    Prof. Paul J Crutzen presents "The stratospheric ozone hole : a man-caused chemical instability".The discovery of the spring time stratospheric ozone hole by scientists of the British Antarctic Survey, led by Joe Farman, was one of the greatest surprises in the history of the atmospheric sciences and global change studies. After intensive research efforts by many international scientific teams it has clearly been demonstrated that the observed rapid ozone depletions are due to catalytic reactions involving CIO radicals, more than 80571130f which are produced by the photochemical breakdown of the industrial chlorofluorocarbon (CFC) gases. In this lecture I will present the course of events leading to the rapid ozone depletions. International agreements have been reached to forbid the production of the CFC gases. However, despite these measures, it will take almost 50 years before the ozone hole will have disappeared. I will also show that mankind has indeed been very lucky and that things could have been far w...

  17. Investigations of Stratosphere-Troposphere Exchange of Ozone Derived From MLS Observations

    Science.gov (United States)

    Olsen, Mark A.; Schoeberl, Mark R.; Ziemke, Jerry R.

    2006-01-01

    Daily high-resolution maps of stratospheric ozone have been constructed using observations by MLS combined with trajectory information. These fields are used to determine the extratropical stratosphere-troposphere exchange (STE) of ozone for the year 2005 using two diagnostic methods. The resulting two annual estimates compare well with past model- and observational-based estimates. Initial analyses of the seasonal characteristics indicate that significant STE of ozone in the polar regions occurs only during spring and early summer. We also examine evidence that the Antarctic ozone hole is responsible for a rapid decrease in the rate of ozone STE during the SH spring. Subtracting the high-resolution stratospheric ozone fiom OMI total column measurements creates a high-resolution tropospheric ozone residual (HTOR) product. The HTOR fields are compared to the spatial distribution of the ozone STE. We show that the mean tropospheric ozone maxima tend to occur near locations of significant ozone STE. This suggests that STE may be responsible for a significant fraction of many mean tropospheric ozone anomalies.

  18. Past changes, current state and future evolution of the ozone layer

    Science.gov (United States)

    Godin-Beekmann, S.

    2013-05-01

    The ozone layer has been under scrutiny since the discovery of the ozone hole over Antarctica in the mid-eighties (Farman et al., 1985). The rapid disclosure of the main processes involved in polar ozone destruction lead to the signature of the Montreal Protocol that regulates the emission of ozone depleting substances (ODS). The objective of this presentation is to review the current understanding of past changes and current state of the ozone layer, the evolution of ODS concentration in the atmosphere and assess the projections of ozone recovery. Satellite measurements revealed a peak of ODS concentration in the mid and end of the nineties and ODS concentrations have started to decrease, albeit at a slower pace than during the increase period due to the atmospheric lifetimes of these compounds. The total ozone content has stabilized at global scale since the beginning of the 21st century. In 2009, integrated ozone content was about 3.5 % smaller in the 60°S-60°N region compared to values prior to 1980 (WMO, 2011). Climate change will influence the recovery of stratospheric. Both ozone depletion and increase of carbon dioxide induce a cooling of the stratosphere. In the winter polar stratosphere, this cooling enhances the formation of polar stratospheric clouds involved in the formation of the ozone hole. In the high stratosphere, it slows the chemical reactions destroying ozone and accelerates its reformation (WMO, 2011). Besides, most chemistry-climate models predict an acceleration of the stratospheric meridional circulation, which would speed up the ozone recovery (Eyring et al., 2010). This recovery is forecasted in periods ranging between 2015 and 2030 and between 2030 and 2040 in the northern and southern hemispheres, respectively. The Antarctic ozone hole will not disappear before 2050. Because of the acceleration of the meridional circulation, models simulate a super-recovery of ozone in the high latitude regions and an under recovery in the tropics. At

  19. Climatology and trends in the forcing of the stratospheric ozone transport

    Directory of Open Access Journals (Sweden)

    E. Monier

    2011-02-01

    Full Text Available A thorough analysis of the ozone transport was carried out using the Transformed-Mean Eulerian (TEM tracer transport equation and the European Centre for Medium-Range Weather Forecasts (ECMWF Re-Analysis (ERA-40. In this budget analysis, the chemical net production term, which is calculated as the residual of the other terms, displays the correct features of a chemical sink and source term, including location and seasonality, and shows a good agreement in magnitude compared to other methods of calculating ozone loss rates. This study provides further insight into the role of the eddy ozone transport and underlines its fundamental role in the recovery of the ozone hole during spring. The trend analysis reveals that the ozone hole intensification over the 1980–2001 period is not directly related to the trend in chemical losses, but more specifically to the balance in the trends in chemical losses and transport. That is because, in the SH from October to December, the large increase in the chemical destruction of ozone is balanced by an equally large trend in the eddy transport, associated with a small increase in the mean transport. This study shows that the increase in the eddy transport is characterized by more poleward ozone eddy flux by transient waves in the midlatitudes and by stationary waves in the polar region. This is primarily due to the presence of storm tracks in the midlatitudes and of the asymmetric Antarctic topography and ice-sea heating contrasts near the pole. Overall, this study makes clear of the fact that without an increase in the eddy ozone transport over the 1980–2001 period, the ozone hole over Antarctica would be drastically more severe. This underlines the need for careful diagnostics of the eddy ozone transport in modeling studies of long-term changes in stratospheric ozone.

  20. CFCs, their replacements, and the ozone layer.

    Science.gov (United States)

    Noakes, T J

    1995-01-01

    Chlorofluorocarbons (CFCs) have become widely used in a variety of applications, ranging from aerosols to refrigeration, through their unique combination of the properties of nonflammability and general inertness. However, their chemical stability, which makes CFCs relatively safe and non-toxic, is also responsible for their potential to damage the environment. From 1974 opinion developed that CFCs might indirectly affect the stratospheric 'ozone layer' through their ability to transport halogens, particularly chlorine, to this level. By the mid 1980s a consensus emerged that atmospheric CFCs could contribute significantly to ozone depletion and an annual thinning (a 'hole') in the ozone layer over the Antarctic was reported. Some of the atmospheric chemistry which is believed to occur, and some of the measurements made on the ozone 'layer' are reviewed together with the environmental regulatory actions that have been taken. These are leading to a controlled rapid phase out of a number of industrial chemicals, including CFCs. The pharmaceutical industry uses significant quantities of CFCs as propellants in metered dose inhalers (MDIs). Two suitable alternative molecules, the hydrofluoroalkanes (HFAs) HFA134a and HFA227, which have the required properties but are not ozone depleting, are introduced. PMID:10150493

  1. Ozone threat

    International Nuclear Information System (INIS)

    Ozone hole was first discovered in 1980. Thus 15 years even after the first warming, the world is no where near to the elimination of man made gases that threaten to destroy the ozone layer. Ozone depletion has become a matter of enormous threat which remains to be solved by the Scientists and intelligentia of the world. Ozone (O3) is a pungent poisonous gas. It forms a layer at a distance of about 15 miles above the earth's surface which helps shield living things from the sun shearing ultra violet light. If ozone is lost, more ultra violet light reaches the earth, which can lead to increasing rate of skin cancer, the death of micro organisms and the failure of crops and plants. It was in 1974 when it was discovered that Chlorofluorocarbons (CFCs) cold rise slowly to the upper atmosphere and destroy the earth's fragile ozone shield. Chlorofluorocarbons are commonly used as coolants (such as Freon) for home and automobile air conditioners and in the making of fast food containers. CFCs take about 100 years or more to reach he stratosphere to damage the ozone layers. In 1988, Scientists confirmed that upto 3% of the ozone layer over the more populated Northern Hemisphere has been destroyed. it is believed that for every 1% decrease in ozone, skin cancers are expected to rise 5 to 6 per cent due to the increase of ultraviolet light. Cases of cataracts and certain human immune system diseases are also expected to rise. (author)

  2. The effects of entombment on water chemistry and bacterial assemblages in closed cryoconite holes on Antarctic glaciers.

    Science.gov (United States)

    Webster-Brown, Jenny G; Hawes, Ian; Jungblut, Anne D; Wood, Susanna A; Christenson, Hannah K

    2015-12-01

    Closed cryoconite holes (CCHs) are small aquatic ecosystems enclosed in glacier surface ice, and they collectively contribute substantial aquatic habitat to inland Antarctica. We examined the morphology, geochemistry and bacterial diversity of 57 CCHs, spread over seven sites, located on five glaciers, covering a range of latitudes, elevations and distance from open seawater. Isotopes confirmed glacial ice as the initial water source, with water chemistry evolving through freeze concentration and photosynthetic processes to have conductivities ranging from 4 mS cm(-1) and pH from 11. Nitrate concentrations were more elevated in inland, higher altitude sites. Bacterial communities were characterized by Automated Ribosomal Intergenic Spacer Analysis and high-throughput sequencing. The dominant phyla were Cyanobacteria, Bacteroides, Proteobacteria and Actinobacteria. CCH bacterial communities predominantly grouped by geographic location, suggesting initial wind-borne inocula from local and regional sources play a role in structuring assemblages. However, multivariate multiple regression analysis indicated that internal CCH conditions also influenced community structure, particularly the ion content and pH of the liquid water. This highlights the importance of founder bacterial populations, isolation and water chemistry in the evolution of CCH bacterial communities. PMID:26572547

  3. A meridional structure of static stability and ozone vertical gradient around the tropopause in the Southern Hemisphere extratropics

    Directory of Open Access Journals (Sweden)

    Y. Tomikawa

    2010-08-01

    Full Text Available An analysis of the static stability and ozone vertical gradient in the ozone tropopause based (OTB coordinate is applied to the ozonesonde data at 10 stations in the Southern Hemisphere (SH extratropics. The tropopause inversion layer (TIL with a static stability maximum just above the tropopause shows similar seasonal variations at two Antarctic stations, which are latitudinally far from each other. Since the sunshine hour varies with time in a quite different way between these two stations, it implies that the radiative heating due to solar ultraviolet absorption of ozone does not contribute to the seasonal variation of the TIL. A meridional section of the static stability in the OTB coordinate shows that the static stability just above the tropopause has a large latitudinal gradient between 60° S and 70° S in austral winter because of the absence of the TIL over the Antarctic. It is accompanied by an increase of westerly shear with height above the tropopause, so that the polar-night jet is formed above this latitude region. This result suggests a close relationship between the absence of the TIL and the stratospheric polar vortex in the Antarctic winter. A vertical gradient of ozone mixing ratio, referred to as ozone vertical gradient, around the tropopause shows similar latitudinal and seasonal variations with the static stability in the SH extratropics. In a height region above the TIL, a small ozone vertical gradient in the midlatitudes associated with the Antarctic ozone hole is observed in a height region of the subvortex but not around the polar vortex. This is a clear evidence of active latitudinal mixing between the midlatitudes and subvortex.

  4. Continuous Ozone Depletion over Antarctica After 2000 and Its Relationship with the Polar Vortex

    Institute of Scientific and Technical Information of China (English)

    ZHOU Libo; ZHANG Yu; MA Shupo

    2014-01-01

    Observations have shown highly variable ozone depletion over the Antarctic in the 2000s, which could aff ect the long-term ozone trend in this region as well as the global ozone recovery. By using the total column ozone data (1979-2011), interannual variation of the springtime Antarctic ozone low is investigated, together with its relationship with the polar vortex evolution in the lower stratosphere. The results show that springtime Antarctic ozone depletion has continued in the 2000s, seemingly contradicting the consensus view of a global ozone recovery expected at the beginning of the 21st century. The spring Antarctic polar vortex in the lower stratosphere is much stronger in the 2000s than before, with a larger area, delayed breakup time, and greater longevity during 2000-2011. Further analyses show that the recent continuation of springtime Antarctic ozone depletion could be largely attributed to the abnormal variation of the Antarctic polar vortex.

  5. Impact of greenhouse gases on the Earth's ozone layer

    Science.gov (United States)

    Zadorozhny, Alexander

    ozone layer here. The mechanism of the impact of the greenhouse gases on the polar ozone by means of modification of sulphate aerosol distribution in the atmosphere has been revealed and investigated, too. Numerical experiments show that enhancement of the surface area density of sulphate aerosol in the stratosphere caused by the growth of the greenhouse gases will reduce significantly the ozone depletion during the Antarctic ozone hole.

  6. How sensitive is the recovery of stratospheric ozone to changes in concentrations of very short-lived bromocarbons?

    Science.gov (United States)

    Yang, X.; Abraham, N. L.; Archibald, A. T.; Braesicke, P.; Keeble, J.; Telford, P. J.; Warwick, N. J.; Pyle, J. A.

    2014-10-01

    Naturally produced very short-lived substances (VSLS) account for almost a quarter of the current stratospheric inorganic bromine, Bry. Following VSLS oxidation, bromine radicals (Br and BrO) can catalytically destroy ozone. The extent to which possible increases in surface emissions or transport of these VSLS bromocarbons to the stratosphere could counteract the effect of halogen reductions under the Montreal Protocol is an important policy question. Here, by using a chemistry-climate model, UM-UKCA, we investigate the impact of a hypothetical doubling (an increase of 5 ppt Bry) of VSLS bromocarbons on ozone and how the resulting ozone changes depend on the background concentrations of chlorine and bromine. Our model experiments indicate that for the 5 ppt increase in Bry from VSLS, the ozone decrease in the lowermost stratosphere of the Southern Hemisphere (SH) may reach up to 10% in the annual mean; the ozone decrease in the Northern Hemisphere (NH) is smaller (4-6%). The largest impact on the ozone column is found in the Antarctic spring. There is a significantly larger ozone decrease following the doubling of the VSLS burden under a high stratospheric chlorine background than under a low chlorine background, indicating the importance of the inter-halogen reactions. For example, the decline in the high-latitude, lower-stratospheric ozone concentration as a function of Bry is higher by about 30-40% when stratospheric Cly is ~ 3 ppb (present day), compared with Cly of ~ 0.8 ppb (a pre-industrial or projected future situation). Bromine will play an important role in the future ozone layer. However, even if bromine levels from natural VSLS were to increase significantly later this century, changes in the concentration of ozone will likely be dominated by the decrease in anthropogenic chlorine. Our calculation suggests that for a 5 ppt increase in Bry from VSLS, the Antarctic ozone hole recovery date could be delayed by approximately 6-8 years, depending on Cly

  7. Antarctic clouds

    OpenAIRE

    Lachlan-Cope, Tom

    2010-01-01

    Sensitivity studies with global climate models show that, by their influence on the radiation balance, Antarctic clouds play a major role in the climate system, both directly at high southern latitudes and indirectly globally, as the local circulation changes lead to global teleconnections. Unfortunately, observations of cloud distribution in the Antarctic are limited and often of low quality because of the practical difficulty in observing clouds in the harsh Antarctic environment. The best ...

  8. Observations of Ozone-aerosol Correlated Behaviour in the Lower Stratosphere During the EASOE Campaign

    Science.gov (United States)

    Digirolamo, P.; Cacciani, M.; Disarra, A.; Fiocco, G.; Fua, D.; Joergensen, T. S.; Knudsen, B.; Larsen, N.

    1992-01-01

    The question of possible interactions between ozone and stratospheric aerosol has been open for a long time. Measurements carried out after the Mt. Agung and El Chicon eruptions showed evidence of negative correlations between the presence of volcanic stratospheric aerosols and ozone concentration. Evidence for negative correlations in the polar winter has been also found. It is only after the discovery of the Antarctic ozone hole that catalytic effects related to low temperature heterogeneous chemistry have become the object of much investigation, now extended to the role of volcanic aerosol in the ozone reduction. These phenomena can be the object of various interpretations, not mutually exclusive, including the effect of transport, diffuse radiation as well as heterogeneous chemistry. The present paper provides preliminary results of simultaneous measurements of ozone and aerosol, carried out at Thule, Greenland, during the winter 1991-92. The European Stratospheric Ozone Experiment (EASOE) was aimed at monitoring the winter Arctic stratosphere in order to obtain a deeper insight of the ozone destruction processes taking place in the polar regions. A large amount of aerosol was injected into the lower stratosphere by the recent eruption of Volcano Pinatubo. A lidar system, already operational in Thule since November 1990, has provided detailed measurements of the stratospheric aerosol concentration during EASOE. In the same period, a large number of ozonesondes were launched. Although no PSC formation was detected over Thule, the simultaneous measurement of the stratospheric aerosol and ozone profiles give the possibility to study interactions occurring in the stratosphere between these two constituents.

  9. Chemical ozone loss and ozone mini-hole event during the Arctic winter 2010/2011 as observed by SCIAMACHY and GOME-2

    OpenAIRE

    Hommel, R.; Eichmann, K.-U.; J. Aschmann; Bramstedt, K.; Weber, M.; Savigny, C.; A. Richter; Rozanov, A.; Wittrock, F.; F. Khosrawi; Bauer, R.; J. P. Burrows

    2014-01-01

    Record breaking loss of ozone (O3) in the Arctic stratosphere has been reported in winter–spring 2010/2011. We examine in detail the composition and transformations occurring in the Arctic polar vortex using total column and vertical profile data products for O3, bromine oxide (BrO), nitrogen dioxide (NO2), chlorine dioxide (OClO), and polar stratospheric clouds (PSC) retrieved from measurements made by SCIAMACHY (Scanning Imaging Absorption SpectroMeter for Atmospheric CHar...

  10. Ozone ProfilE Retrieval Algorithm for nadir-looking satellite instruments in the UV-VIS

    Directory of Open Access Journals (Sweden)

    J. C. A. van Peet

    2013-10-01

    Full Text Available For the retrieval of the vertical distribution of ozone in the atmosphere the Ozone ProfilE Retrieval Algorithm (OPERA has been further developed. The new version (1.26 of OPERA is capable of retrieving ozone profiles from UV-VIS observations of most nadir looking satellite instruments like GOME, SCIAMACHY, OMI and GOME-2. The set-up of OPERA is described and results are presented for GOME and GOME-2 observations. The retrieved ozone profiles are globally compared to ozone sondes for the year 1997 and 2008. Relative differences between GOME/GOME-2 and ozone sondes are within the limits as specified by the user requirements from the Climate Change Initiative (CCI program of ESA. To demonstrate the performance of the algorithm under extreme circumstances the 2009 Antarctic ozone hole season was investigated in more detail using GOME-2 ozone profiles and lidar data, which showed an unusual persistence of the vortex over the Río Gallegos observing station (51° S, 69.3° W. By applying OPERA to multiple instruments a timeseries of ozone profiles from 1996 to 2013 from a single robust algorithm can be created.

  11. Ozone ProfilE Retrieval Algorithm (OPERA for nadir-looking satellite instruments in the UV–VIS

    Directory of Open Access Journals (Sweden)

    J. C. A. van Peet

    2014-03-01

    Full Text Available For the retrieval of the vertical distribution of ozone in the atmosphere the Ozone ProfilE Retrieval Algorithm (OPERA has been further developed. The new version (1.26 of OPERA is capable of retrieving ozone profiles from UV–VIS observations of most nadir-looking satellite instruments like GOME, SCIAMACHY, OMI and GOME-2. The setup of OPERA is described and results are presented for GOME and GOME-2 observations. The retrieved ozone profiles are globally compared to ozone sondes for the years 1997 and 2008. Relative differences between GOME/GOME-2 and ozone sondes are within the limits as specified by the user requirements from the Climate Change Initiative (CCI programme of ESA (20% in the troposphere, 15% in the stratosphere. To demonstrate the performance of the algorithm under extreme circumstances, the 2009 Antarctic ozone hole season was investigated in more detail using GOME-2 ozone profiles and lidar data, which showed an unusual persistence of the vortex over the Río Gallegos observing station (51° S, 69.3° W. By applying OPERA to multiple instruments, a time series of ozone profiles from 1996 to 2013 from a single robust algorithm can be created.

  12. Modelling of long-term anthropogenic changes in stratospheric temperature and the ozone layer

    International Nuclear Information System (INIS)

    Complete text of publication follows. A numerical two-dimensional interactive dynamical-radiative-photochemical model including aerosol physics is used to examine the expected long-term changes in stratospheric temperature and the Earth's ozone layer due to anthropogenic pollution of the atmosphere by the greenhouse gases CO2, CH4, N2O and by ozone-depleting chlorine and bromine compounds. The model time-dependent runs were made for the period from 1975 to 2050. The mechanisms of the impact of each of the pollutants on stratospheric temperature have been analysed, their relative contributions to the predicted temperature change have been estimated. The processes, which determine the influence of anthropogenic growth of atmospheric abundance of the greenhouse gases on the dynamics of recovery of the Earth's ozone layer after reduction of anthropogenic discharges of ozone-depleting chlorine and bromine compounds into the atmosphere, have been studied in details. The contributions of different pollutions to the predicted ozone changes have been estimated. The results of the calculations show that the basic mechanism by which greenhouse gases influence the ozone layer is stratospheric cooling accompanied by a weakness in the efficiency of the catalytic cycles of ozone destruction due to temperature dependencies of the photochemical gas-phase reactions. Modification of polar stratospheric clouds (PSCs) caused by anthropogenic growth of the greenhouse gases is important only for the polar ozone. An essential influence of the greenhouse gases on the ozone by a modification of the stratospheric sulphate aerosol is revealed. The aerosol changes caused by the greenhouse gases modify the distribution of the ozone-active gaseous chlorine, bromine and nitrogen components by means of heterogeneous reactions on the aerosol surface, resulting in a significant decrease in springtime polar ozone depletion of the Antarctic ozone hole.

  13. Changes in Arctic and Antarctic Sea Ice as a Microcosm of Global Climate Change

    Science.gov (United States)

    Parkinson, Claire L.

    2014-01-01

    Polar sea ice is a key element of the climate system and has now been monitored through satellite observations for over three and a half decades. The satellite observations reveal considerable information about polar ice and its changes since the late 1970s, including a prominent downward trend in Arctic sea ice coverage and a much lesser upward trend in Antarctic sea ice coverage, illustrative of the important fact that climate change entails spatial contrasts. The decreasing ice coverage in the Arctic corresponds well with contemporaneous Arctic warming and exhibits particularly large decreases in the summers of 2007 and 2012, influenced by both preconditioning and atmospheric conditions. The increasing ice coverage in the Antarctic is not as readily explained, but spatial differences in the Antarctic trends suggest a possible connection with atmospheric circulation changes that have perhaps been influenced by the Antarctic ozone hole. The changes in the polar ice covers and the issues surrounding those changes have many commonalities with broader climate changes and their surrounding issues, allowing the sea ice changes to be viewed in some important ways as a microcosm of global climate change.

  14. Copernicus atmospheric service for stratospheric ozone: validation and intercomparison of four near real-time analyses, 2009-2012

    Science.gov (United States)

    Lefever, K.; van der A, R.; Baier, F.; Christophe, Y.; Errera, Q.; Eskes, H.; Flemming, J.; Inness, A.; Jones, L.; Lambert, J.-C.; Langerock, B.; Schultz, M. G.; Stein, O.; Wagner, A.; Chabrillat, S.

    2014-05-01

    This paper evaluates the performance of the stratospheric ozone analyses delivered in near real time by the MACC (Monitoring Atmospheric Composition and Climate) project during the 3 year period between September 2009 and September 2012. Ozone analyses produced by four different chemistry transport models and data assimilation techniques are examined: the ECMWF Integrated Forecast System (IFS) coupled to MOZART-3 (IFS-MOZART), the BIRA-IASB Belgian Assimilation System for Chemical ObsErvations (BASCOE), the DLR/RIU Synoptic Analysis of Chemical Constituents by Advanced Data Assimilation (SACADA), and the KNMI Data Assimilation Model based on Transport Model version 3 (TM3DAM). The assimilated satellite ozone retrievals differed for each system: SACADA and TM3DAM assimilated only total ozone observations, BASCOE assimilated profiles for ozone and some related species, while IFS-MOZART assimilated both types of ozone observations. The stratospheric ozone analyses are compared to independent ozone observations from ground-based instruments, ozone sondes and the ACE-FTS (Atmospheric Chemistry Experiment - Fourier Transform Spectrometer) satellite instrument. All analyses show total column values which are generally in good agreement with groundbased observations (biases good performance of the model in ozone hole conditions and the assimilation of offline MLS profiles going down to 215 hPa. TM3DAM provides very realistic total ozone columns, but is not designed to provide information on the vertical distribution of ozone. Compared to ozonesondes and ACE-FTS satellite data, SACADA performs best in the Arctic, but shows large biases (>50%) for ozone in the lower stratosphere in the Tropics and in the Antarctic, especially during ozone hole conditions. This study shows that ozone analyses with realistic total ozone column densities do not necessarily yield good agreement with the observed ozone profiles. It also shows the large benefit obtained from the assimilation of a

  15. Regional Changes in the Sea Ice Cover and Ice Production in the Antarctic

    Science.gov (United States)

    Comiso, Josefino C.

    2011-01-01

    Coastal polynyas around the Antarctic continent have been regarded as sea ice factories because of high ice production rates in these regions. The observation of a positive trend in the extent of Antarctic sea ice during the satellite era has been intriguing in light of the observed rapid decline of the ice extent in the Arctic. The results of analysis of the time series of passive microwave data indicate large regional variability with the trends being strongly positive in the Ross Sea, strongly negative in the Bellingshausen/Amundsen Seas and close to zero in the other regions. The atmospheric circulation in the Antarctic is controlled mainly by the Southern Annular Mode (SAM) and the marginal ice zone around the continent shows an alternating pattern of advance and retreat suggesting the presence of a propagating wave (called Antarctic Circumpolar Wave) around the circumpolar region. The results of analysis of the passive microwave data suggest that the positive trend in the Antarctic sea ice cover could be caused primarily by enhanced ice production in the Ross Sea that may be associated with more persistent and larger coastal polynyas in the region. Over the Ross Sea shelf, analysis of sea ice drift data from 1992 to 2008 yields a positive rate-of-increase in the net ice export of about 30,000 km2 per year. For a characteristic ice thickness of 0.6 m, this yields a volume transport of about 20 km3/year, which is almost identical, within error bars, to our estimate of the trend in ice production. In addition to the possibility of changes in SAM, modeling studies have also indicated that the ozone hole may have a role in that it causes the deepening of the lows in the western Antarctic region thereby causing strong winds to occur offthe Ross-ice shelf.

  16. Antarctic Entomology.

    Science.gov (United States)

    Chown, Steven L; Convey, Peter

    2016-01-01

    The Antarctic region comprises the continent, the Maritime Antarctic, the sub-Antarctic islands, and the southern cold temperate islands. Continental Antarctica is devoid of insects, but elsewhere diversity varies from 2 to more than 200 species, of which flies and beetles constitute the majority. Much is known about the drivers of this diversity at local and regional scales; current climate and glacial history play important roles. Investigations of responses to low temperatures, dry conditions, and varying salinity have spanned the ecological to the genomic, revealing new insights into how insects respond to stressful conditions. Biological invasions are common across much of the region and are expected to increase as climates become warmer. The drivers of invasion are reasonably well understood, although less is known about the impacts of invasion. Antarctic entomology has advanced considerably over the past 50 years, but key areas, such as interspecific interactions, remain underexplored.

  17. SPARC Data Initiative: A comparison of ozone climatologies from international satellite limb sounders

    Science.gov (United States)

    Tegtmeier, S.; Hegglin, M. I.; Anderson, J.; Bourassa, A.; Brohede, S.; Degenstein, D.; Froidevaux, L.; Fuller, R.; Funke, B.; Gille, J.; Jones, A.; Kasai, Y.; Krüger, K.; Kyrölä, E.; Lingenfelser, G.; Lumpe, J.; Nardi, B.; Neu, J.; Pendlebury, D.; Remsberg, E.; Rozanov, A.; Smith, L.; Toohey, M.; Urban, J.; Clarmann, T.; Walker, K. A.; Wang, R. H. J.

    2013-11-01

    comprehensive quality assessment of the ozone products from 18 limb-viewing satellite instruments is provided by means of a detailed intercomparison. The ozone climatologies in form of monthly zonal mean time series covering the upper troposphere to lower mesosphere are obtained from LIMS, SAGE I/II/III, UARS-MLS, HALOE, POAM II/III, SMR, OSIRIS, MIPAS, GOMOS, SCIAMACHY, ACE-FTS, ACE-MAESTRO, Aura-MLS, HIRDLS, and SMILES within 1978-2010. The intercomparisons focus on mean biases of annual zonal mean fields, interannual variability, and seasonal cycles. Additionally, the physical consistency of the data is tested through diagnostics of the quasi-biennial oscillation and Antarctic ozone hole. The comprehensive evaluations reveal that the uncertainty in our knowledge of the atmospheric ozone mean state is smallest in the tropical and midlatitude middle stratosphere with a 1σ multi-instrument spread of less than ±5%. While the overall agreement among the climatological data sets is very good for large parts of the stratosphere, individual discrepancies have been identified, including unrealistic month-to-month fluctuations, large biases in particular atmospheric regions, or inconsistencies in the seasonal cycle. Notable differences between the data sets exist in the tropical lower stratosphere (with a spread of ±30%) and at high latitudes (±15%). In particular, large relative differences are identified in the Antarctic during the time of the ozone hole, with a spread between the monthly zonal mean fields of ±50%. The evaluations provide guidance on what data sets are the most reliable for applications such as studies of ozone variability, model-measurement comparisons, detection of long-term trends, and data-merging activities.

  18. Mechanisms of impact of greenhouse gases on the Earth's ozone layer in the Polar Regions

    Science.gov (United States)

    Zadorozhny, Alexander; Dyominov, Igor

    the expected recovery of the ozone layer here. The difference in the impact of the greenhouse gases on the ozone layer at the southern and northern polar latitudes through PCS modification is determined by the difference in temperature regimes of the Polar Regions. The mechanism of the impact of the greenhouse gases on the polar ozone by means of modification of sulphate aerosol distribution in the atmosphere has been revealed and investigated, too. Numerical experiments show that enhancement of the surface area density of sulphate aerosol in the stratosphere caused by the growth of the greenhouse gases will reduce significantly the ozone depletion during the Antarctic ozone hole.

  19. Why unprecedented ozone loss in the Arctic in 2011? Is it related to climatic change?

    Directory of Open Access Journals (Sweden)

    J.-P. Pommereau

    2013-01-01

    Full Text Available An unprecedented ozone loss occurred in the Arctic in spring 2011. The details of the event are re-visited from the twice-daily total ozone and NO2 columns measurements of the eight SAOZ/NDACC (Système d'Analyse par Observation Zénitale/Network for Detection of Atmospheric Composition Changes stations in the Arctic. It is shown that the total ozone depletion in the polar vortex reached 38% (approx. 170 DU by the end of March that is larger than the 30% of the previous record in 1996. Asides from the long extension of the cold stratospheric NAT PSC period, the amplitude of the event is shown to be resulting from a record daily total ozone loss rate of 0.7% day���1 after mid-February, never seen before in the Arctic but similar to that observed in the Antarctic over the last 20 yr. This high loss rate is attributed to the absence of NOx in the vortex until the final warming, in contrast to all previous winters where, as shown by the early increase of NO2 diurnal increase, partial renoxification is occurring by import of NOx or HNO3 from the outside after minor warming episodes, leading to partial chlorine deactivation.

    The cause of the absence of renoxification and thus of high loss rate, is attributed to a vortex strength similar to that of the Antarctic but never seen before in the Arctic. The total ozone reduction on 20 March was identical to that of the 2002 Antarctic winter, which ended around 20 September, and a 15-day extension of the cold period would have been enough to reach the mean yearly amplitude of the Antarctic ozone hole. However there is no sign of trend since 1994, neither in PSC volume, early winter denitrification, late vortex renoxification, and vortex strength nor in total ozone loss. The unprecedented large Arctic ozone loss in 2011 appears to resulting from an extreme meteorological event and there is no indication of possible strengthening

  20. Why unprecedented ozone loss in the Arctic in 2011? Is it related to climate change?

    Directory of Open Access Journals (Sweden)

    J.-P. Pommereau

    2013-05-01

    Full Text Available An unprecedented ozone loss occurred in the Arctic in spring 2011. The details of the event are revisited from the twice-daily total ozone and NO2 column measurements of the eight SAOZ/NDACC (Système d'Analyse par Observation Zénithale/Network for Detection of Atmospheric Composition Changes stations in the Arctic. It is shown that the total ozone depletion in the polar vortex reached 38% (approx. 170 DU by the end of March, which is larger than the 30% of the previous record in 1996. Aside from the long extension of the cold stratospheric NAT PSC period, the amplitude of the event is shown to be resulting from a record daily total ozone loss rate of 0.7% d−1 after mid-February, never seen before in the Arctic but similar to that observed in the Antarctic over the last 20 yr. This high loss rate is attributed to the absence of NOx in the vortex until the final warming, in contrast to all previous winters where, as shown by the early increase of NO2 diurnal increase, partial renoxification occurs by import of NOx or HNO3 from the outside after minor warming episodes, leading to partial chlorine deactivation. The cause of the absence of renoxification and thus of high loss rate, is attributed to a vortex strength similar to that of the Antarctic but never seen before in the Arctic. The total ozone reduction on 20 March was identical to that of the 2002 Antarctic winter, which ended around 20 September, and a 15-day extension of the cold period would have been enough to reach the mean yearly amplitude of the Antarctic ozone hole. However there is no sign of trend since 1994, either in PSC (polar stratospheric cloud volume (volume of air cold enough to allow formation of PSCs, early winter denitrification, late vortex renoxification, and vortex strength or in total ozone loss. The unprecedented large Arctic ozone loss in 2011 appears to result from an extreme meteorological event and there is no indication of possible strengthening related to

  1. RESULTS OF OZONE OBSERVATION FROM THE EQUATORIAL REGION TO ANTARCTICA IN 1987

    OpenAIRE

    マツバラ, コウジ; ドイ, モトヒサ; ウエクボ, テツロウ; オカダ, ケンジ; アオキ, シュンジ; カワグチ, サダオ; Kouji, Matsubara; Motohisa, DOI; Tetsuro, UEKUBO; Kenji, Okada; Shuhji, AOKI; Sadao, KAWAGUCHI

    1991-01-01

    The first total ozone observation and vertical ozone sounding on board the research vessel 'SHIRASE' from the equatorial region to Antarctica was carried out in 1987 by meteorological members of the 29th JARE (Japanese Antarctic Research Expedition) team. Total ozone and vertical ozone profile were measured by Brewer ozone spectrophotometer and ozonesondes, respectively. The detailed latitudinal distribution of total ozone amount and height-latitude distributions of ozone concentration, tempe...

  2. Ozone depletion and UVB radiation: Impact on plant DNA damage in southern South America

    Science.gov (United States)

    Rousseaux, M. Cecilia; Ballaré, Carlos L.; Giordano, Carla V.; Scopel, Ana L.; Zima, Ana M.; Szwarcberg-Bracchitta, Mariela; Searles, Peter S.; Caldwell, Martyn M.; Díaz, Susana B.

    1999-01-01

    The primary motivation behind the considerable effort in studying stratospheric ozone depletion is the potential for biological consequences of increased solar UVB (280–315 nm) radiation. Yet, direct links between ozone depletion and biological impacts have been established only for organisms of Antarctic waters under the influence of the ozonehole;” no direct evidence exists that ozone-related variations in UVB affect ecosystems of temperate latitudes. Indeed, calculations based on laboratory studies with plants suggest that the biological impact of ozone depletion (measured by the formation of cyclobutane pyrimidine dimers in DNA) is likely to be less marked than previously thought, because UVA quanta (315–400 nm) may also cause significant damage, and UVA is unaffected by ozone depletion. Herein, we show that the temperate ecosystems of southern South America have been subjected to increasingly high levels of ozone depletion during the last decade. We found that in the spring of 1997, despite frequent cloud cover, the passages of the ozone hole over Tierra del Fuego (55° S) caused concomitant increases in solar UV and that the enhanced ground-level UV led to significant increases in DNA damage in the native plant Gunnera magellanica. The fluctuations in solar UV explained a large proportion of the variation in DNA damage (up to 68%), particularly when the solar UV was weighted for biological effectiveness according to action spectra that assume a sharp decline in quantum efficiency with increasing wavelength from the UVB into the UVA regions of the spectrum. PMID:10611381

  3. Interactive ozone and methane chemistry in GISS-E2 historical and future climate simulations

    Directory of Open Access Journals (Sweden)

    D. T. Shindell

    2012-09-01

    Full Text Available The new generation GISS climate model includes fully interactive chemistry related to ozone in historical and future simulations, and interactive methane in future simulations. Evaluation of ozone, its tropospheric precursors, and methane shows that the model captures much of the large-scale spatial structure seen in recent observations. While the model is much improved compared with the previous chemistry-climate model, especially for ozone seasonality in the stratosphere, there is still slightly too rapid stratospheric circulation too little stratosphere-to-troposphere ozone flux in the Southern Hemisphere and an Antarctic ozone hole that is too large and persists too long quantitative metrics of spatial and temporal correlations with satellite datasets as well as spatial autocorrelation to examine transport and mixing are presented to document improvements in model skill and provide a benchmark for future evaluations. The difference in radiative forcing (RF calculated using modeled tropospheric ozone versus tropospheric ozone observed by TES is only 0.016 W m−2. Historical 20th Century simulations show a steady increase in whole atmosphere ozone RF through 1970 after which there is a decrease through 2000 due to stratospheric ozone depletion. Ozone forcing increases in the future under RCP8.5 owing to a projected recovery of stratospheric ozone depletion and increases in methane, but decreases under other RCPs due to reductions in emissions of other ozone precursors. RF from methane is 0.05 to 0.18 W m−2 higher in our model calculations than in the RCP RF estimates. The surface temperature response to ozone through 1970 follows the increase in forcing due to tropospheric ozone. After that time, surface temperatures decrease as ozone RF declines due to stratospheric depletion. The stratospheric ozone depletion also induces substantial changes in surface winds and the Southern Ocean circulation, which may play a role

  4. Interactive ozone and methane chemistry in GISS-E2 historical and future climate simulations

    Directory of Open Access Journals (Sweden)

    D. T. Shindell

    2013-03-01

    Full Text Available The new generation GISS climate model includes fully interactive chemistry related to ozone in historical and future simulations, and interactive methane in future simulations. Evaluation of ozone, its tropospheric precursors, and methane shows that the model captures much of the large-scale spatial structure seen in recent observations. While the model is much improved compared with the previous chemistry-climate model, especially for ozone seasonality in the stratosphere, there is still slightly too rapid stratospheric circulation, too little stratosphere-to-troposphere ozone flux in the Southern Hemisphere and an Antarctic ozone hole that is too large and persists too long. Quantitative metrics of spatial and temporal correlations with satellite datasets as well as spatial autocorrelation to examine transport and mixing are presented to document improvements in model skill and provide a benchmark for future evaluations. The difference in radiative forcing (RF calculated using modeled tropospheric ozone versus tropospheric ozone observed by TES is only 0.016 W m−2. Historical 20th Century simulations show a steady increase in whole atmosphere ozone RF through 1970 after which there is a decrease through 2000 due to stratospheric ozone depletion. Ozone forcing increases throughout the 21st century under RCP8.5 owing to a projected recovery of stratospheric ozone depletion and increases in methane, but decreases under RCP4.5 and 2.6 due to reductions in emissions of other ozone precursors. RF from methane is 0.05 to 0.18 W m−2 higher in our model calculations than in the RCP RF estimates. The surface temperature response to ozone through 1970 follows the increase in forcing due to tropospheric ozone. After that time, surface temperatures decrease as ozone RF declines due to stratospheric depletion. The stratospheric ozone depletion also induces substantial changes in surface winds and the Southern Ocean circulation, which may play a role in

  5. Yearly variation and annual cycle of total column ozone over New Delhi (29°N, 77°E), India and Halley Bay (76°S, 27°W), British Antarctic Survey Station and its effect on night airglow intensity of OH(8, 3) for the period 1979–2005

    Indian Academy of Sciences (India)

    P K Jana; D K Saha; D Sarkar

    2012-12-01

    A critical analysis made on the long-term monthly, seasonal, yearly variation and annual cycle of total column ozone (TCO) concentration at New Delhi (29°N,77°E), India and Halley Bay (76°S, 27°W), a British Antarctic Service Station reveals more decline in yearly mean ozone concentration at Halley Bay than at New Delhi from 1979 to 2005. The nature of variations of monthly mean TCO during the months of August and September was the most identical with that of yearly mean ozone values at New Delhi and Halley Bay, respectively, for the same period. Annual cycles of TCO over these stations are completely different for the above period. The effect of O3 depletion on night airglow emission of OH(8, 3) line at New Delhi and Halley Bay has been studied. Calculations based on chemical kinetics show that the airglow intensity of OH(8, 3) has also been affected due to the depletion of O3 concentration. The yearly variations and annual cycle of intensities of OH(8, 3) line for the above two stations are depicted and compared. It has been shown that the rate of decrease of intensity of OH(8, 3) line was comparatively more at Halley Bay due to dramatic decrease of Antarctic O3 concentration.

  6. Yearly variation and annual cycle of total column ozone over New Delhi (29°N, 77°E), India and Halley Bay (76°S, 27°W), British Antarctic Survey Station and its effect on night airglow intensity of OH(8, 3) for the period 1979-2005

    Science.gov (United States)

    Jana, P. K.; Saha, D. K.; Sarkar, D.

    2012-12-01

    A critical analysis made on the long-term monthly, seasonal, yearly variation and annual cycle of total column ozone (TCO) concentration at New Delhi (29°N, 77°E), India and Halley Bay (76°S, 27°W), a British Antarctic Service Station reveals more decline in yearly mean ozone concentration at Halley Bay than at New Delhi from 1979 to 2005. The nature of variations of monthly mean TCO during the months of August and September was the most identical with that of yearly mean ozone values at New Delhi and Halley Bay, respectively, for the same period. Annual cycles of TCO over these stations are completely different for the above period. The effect of O3 depletion on night airglow emission of OH(8, 3) line at New Delhi and Halley Bay has been studied. Calculations based on chemical kinetics show that the airglow intensity of OH(8, 3) has also been affected due to the depletion of O3 concentration. The yearly variations and annual cycle of intensities of OH(8, 3) line for the above two stations are depicted and compared. It has been shown that the rate of decrease of intensity of OH(8, 3) line was comparatively more at Halley Bay due to dramatic decrease of Antarctic O3 concentration.

  7. Ozone and UV research at Finnish Meteorological Inst.: review of selected results

    Energy Technology Data Exchange (ETDEWEB)

    Taalas, P.; Koskela, T.; Damski, J.; Supperi, A. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research; Kyroe, E. [Finnish Meteorologican Inst., Sodankylae (Finland). Sodankylae Observatory; Ginzburg, M. [Servicio Meteorologico Nacional, Buenos Aires (Argentina); Dijkhuis, J.L. [Finnish Meteorological Inst., Helsinki (Finland). EUMETSAT

    1995-12-31

    Ozone and UV radiation research have become an important part of atmospheric research at Finnish Meteorological Institute after the discovery of chlorine based ozone loss in the Antarctic stratosphere

  8. Assessment and Consequences of the Delayed Breakup of the Antarctic Polar Vortex in Two Versions of the GEOS Chemistry-Climate Model

    Science.gov (United States)

    Hurwitz, M.M.; Newman, P.A.; Li, F.

    2008-01-01

    In mid-winter, winds circle the globe at speeds greater than 200 km/hr (approximately 130mph) in the middle atmosphere. This strong jet bounds the region known as the polar vortex. The presence of the Antarctic polar vortex is a key ingredient in the formation of the 'ozone hole', because the air inside the vortex is cold and isolated from lower latitudes, creating ideal conditions for large-scale chemical ozone depletion. Many atmospheric models are not able to reproduce observed winds in the middle atmosphere. Specifically, the polar vortices tend to break down too late and peak wind speeds are higher than observed. Hurwitz et al. find that the delayed break-up of the Antarctic polar vortex is due to weaker-than-observed wave driving from the lower atmosphere during the October-November period. The delayed break-up of the Antarctic polar vortex changes the temperature structure of the middle atmosphere, which biases the amount of chemical ozone depletion that can occur in late winter and spring. Also, the extended lifetime of the polar vortex strengthens the 'overturning' circulation cell in the middle atmosphere, changing the amount of ozone, methane and other chemical species that is transported from low to high latitudes. As greenhouse gas concentrations continue to rise, the atmospheric temperature structure and resulting wind structure are expected to change. Clearly, if models cannot duplicate the observed late 20th century high-latitude winds, their ability to simulate the polar vortices in future must be poor. Understanding model weaknesses and improving the modeled polar vortices will be necessary for accurate predictions of ozone recovery in the coming century.

  9. The stratospheric ozone and the ozone layer

    International Nuclear Information System (INIS)

    An overview is presented of the principal characteristics of the stratospheric ozone in the Earth's atmosphere, with particular emphasis on the tropics and the ozone hole over the poles. Some effects produced in the atmosphere as a consequence of the different human activities will be described, and some data on stratospheric ozone will be shown. We point out the existence of a nucleus of least ozone in the tropics, stretching from South America to central Africa, with annual mean values less than 240 DU, a value lower than in the middle latitudes and close to the mean values at the South Pole. The existence of such a minimum is confirmed by mean values from measurements made on satellites or with earthbound instruments, for different sectors in Colombia, like Medellin, Bogota and Leticia

  10. Intercomparison of ozone measurements over Antarctica

    International Nuclear Information System (INIS)

    Measurements of the abundances of ozone over Antarctic in August and September 1987 obtained during the Airborne Antarctic Ozone Experiment are intercompared. These measurements of ozone concentrations and total column abundance were obtained by three satellite instruments, two IR and one UV column-measuring instruments aboard the DC-8, one in situ DC-8, and two in situ ER-2 instruments, an upward looking lidar aboard the DC-8, and ozonesondes from four sites in Antarctica. Given the natural variability of ozone in the Antarctic and the fact that the data were not truly coincident spatially and temporally, this intercomparison is suitable only for identifying gross disparities among the techniques, rather than confirming the accuracies as rigorously as is normally done in an intercomparison. This paper presents a summary of the ozone data, using the data and accuracies given by the individual investigators in the individual papers in this issue, without any attempt to critically review or evaluate the data. In general, very good agreement (within about 10-20%, limited by natural variability) among the various techniques was found, with no systematic biases detected. These observations confirm the low ozone amounts reported in the Antarctic stratosphere

  11. The evolution of atmospheric ozone: 2015 update

    International Nuclear Information System (INIS)

    This report gives an update of the observations and researches concerning the evolution of the ozone concentration in the earth atmosphere: too much ozone in the troposphere (notably in the vicinity of large cities) which is harmful for health and vegetation, and a lack of ozone in certain parts of the stratosphere (notably above Antarctic). The report highlights these two distinct phenomena, which should not be confused as their remedies are not of the same nature. While the issue of ozone equilibrium in the atmosphere and the climate issue are a priori different, interactions between these both problems are inevitable

  12. Effect of column ozone on the variability of biologically effective UV radiation at high southern latitudes.

    Science.gov (United States)

    Sobolev, I

    2000-12-01

    Solar irradiance measurements from Ushuaia (Argentina) and Palmer and McMurdo Stations in Antarctica covering four seasons from mid-1993 through early 1997 have been analyzed and their variations compared with column ozone changes. UV irradiances were weighted for biological effectiveness using a published biological weighting function for dose-dependent inhibition of photosynthesis by phytoplankton from the Weddell Sea. All calculations involved integrated daily UV doses and visible exposures (weighted UV and unweighted visible irradiances, respectively). The results show that daily biologically effective total UV doses underwent large short-term variations at all three sites, with day-to-day increases up to 236% at Ushuaia, 285% at Palmer and 99% at McMurdo. Parallel changes in visible exposure indicated that the total UV changes were preponderantly due to variations in cloudiness. On a 12-month basis, daily biologically effective UV doses correlated strongly with visible exposures (R > or = 0.99). Anticorrelations of total UV with ozone, on the other hand, were poor (R > -0.11). The largest daily biologically effective UV doses, and their day-to-day increases, occurred as part of the normal variability related to cloud cover and were seldom associated with significant ozone depletion. UV dose/visible exposure ratios tended to reflect ozone depletion events somewhat more consistently than UV doses alone. With the Weddell Sea phytoplankton weighting function used in this study, antarctic ozone hole events were seldom readily discernible in the biologically effective UV record. The results suggest that, where the UV sensitivity of organisms was similar to that of the Weddell Sea phytoplankton, seasonal ozone depletion had no appreciable effect on annual primary productivity during the 1993-1997 period. Additional data on the geographical and seasonal variation of biological weighting functions are desirable for more comprehensive assessments of ozone depletion

  13. Variability of ozone and aerosols in the polar atmosphere (scientific paper)

    OpenAIRE

    Gernandt,Hartwig/Herber,Andreas/Von der Gathen,Peter/Rex,Markus/Rinke,Anette /Wessel ,Silke/Kaneto,Susumu

    1996-01-01

    Since 1980 the appearance of spring ozone depletion directly caused by chemical removal has significantly changed the pattern of vertical ozone distribution in the antarctic stratosphere, and has become a principal feature of a changing atmosphere. In recent years chemical ozone loss has also been found in the arctic stratosphere. Transient events like the presence of volcanic aerosols can additionally remove ozone in the lower polar stratosphere. Balloon-borne ozone observations and sun phot...

  14. Heterogeneous processing of bromine compounds by atmospheric aerosols: Relation to the ozone budget

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, J.M.; Henson, B.F.; Dubey, M.K.; Casson, J.L.; Johal, M.S. [Los Alamos National Lab., NM (US); Wilson, K.R. [Univ. of California, Berkeley, CA (US)

    1998-11-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The depletion of ozone, particularly above Antarctica, has been investigated extensively to formulate public policy on the use of halocarbons. While it has been shown that heterogeneous reactions of chlorine compounds on stratospheric particulates cause the ozone hole, little is known of the analogous bromine mechanisms, even though it has been recognized for two decades that catalytic destruction of ozone by bromine could be more efficient than chlorine. Furthermore, field measurements and modeling calculations suggest that these heterogeneous (gas/surface) reactions are not restricted to the Antarctic regions but occur globally. The authors have performed laboratory measurements of the uptake of bromine compounds and other halogens on simulated stratospheric aerosols to help elucidate their role in catalytic ozone destruction cycles. Their studies contribute to the data base required to make assessments of the effects of human activities on global change, including the Montreal Protocol.

  15. Impact of greenhouse gases on the ozone layer in the polar regions

    International Nuclear Information System (INIS)

    the expected recovery of the ozone layer here. The mechanism of the impact of the greenhouse gases on the polar ozone by means of modification of sulphate aerosol distribution in the atmosphere has been revealed and investigated, too. Numerical experiments show that enhancement of the surface area density of sulphate aerosol in the stratosphere caused by the growth of the greenhouse gases will reduce significantly the ozone depletion during the antarctic ozone hole. As for the global total ozone, continuous anthropogenic growth of the greenhouse gases will lead to significant acceleration of its recovery. In the case of the used scenario of expected long-term changes of the greenhouse gases, the global ozone will reach its undisturbed level of 1980 by about 2043. If the CO2 growth stops, the global total ozone will reach this level only by the end of the 21st century. (author)

  16. Effect of Antarctic solar radiation on sewage bacteria viability

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, K.A. [National Environment Research Council, Cambridge (United Kingdom). British Antarctic Survey

    2005-06-01

    The majority of coastal Antarctic research stations discard untreated sewage waste into the near-shore marine environment. However, Antarctic solar conditions are unique, with ozone depletion increasing the proportion of potentially damaging ultraviolet-B (UV-B) radiation reaching the marine environment. This study assessed the influence of Antarctic solar radiation on the viability of Escherichia coli and sewage microorganisms at Rothera Research Station, Adelaide Island, Antarctic Peninsula. Cell viability decreased with increased exposure time and with exposure to shorter wavelengths of solar radiation. Cell survival also declined with decreasing cloud cover, solar zenith angle and ozone column depth. However, particulates in sewage increased the persistence of viable bacteria. Ultraviolet radiation doses over Rothera Point were highest during the austral summer. During this time, solar radiation may act to partially reduce the number of viable sewage-derived microorganisms in the surface seawater around Antarctic outfalls. Nevertheless, this effect is not reliable and every effort should be made to fully treat sewage before release into the Antarctic marine environment. (author)

  17. Professor Paul Crutzen, the winner of the Nobel prize: The discovery of the ozone hole - knowledge and vision; Nobelpreistraeger Prof. Paul Crutzen: Entdeckung des Ozonlochs - Wissen und Vision

    Energy Technology Data Exchange (ETDEWEB)

    Crutzen, P.; Dellert-Ritter, M.

    1997-02-01

    On 10 December 1995, Professor Crutzen was awarded the Nobel prize for his epoch-making achievements in the field of atmospheric chemistry. This award underlines also Professor Crutzen`s commitment to the protection of the atmosphere. The atmospheric researcher discovered how sensitively the ozone layer reacts to air pollution. His work, together with that of others, led to the ban on ozone-depleting chlorofluorocarbons. As early as in 1970, Professor Crutzen demonstrated that nitrogen oxides react catalytically with ozone. His think tank provided numerous stimuli for further, intense research on atmospheric chemistry, which triggered a debate on the protection of the thinning ozone layer also among politicians. (orig.) [Deutsch] Am 10. Dezember 1995 wurde Prof. Crutzen fuer seine bahnbrechenden Leistungen auf dem Gebiet der Atmosphaerenchemie mit dem Nobelpreis geehrt. Diese Anerkennung unterstreicht auch das Engagement von Prof. Crutzen zum Schutz der Ozonschicht. Der Atmosphaerenforscher Prof. Crutzen entdeckte, wie empfindlich die Ozonschicht auf Luftverunreinigungen reagiert. Seine Arbeiten fuehrten mit zum Verbot der ozonvernichtenden Fluorchlorkohlenwasserstoffe. Bereits 1970 wies Prof. Crutzen nach, dass Stickstoffoxide katalytisch mit Ozon reagieren. Aus der Ideenfabrik von Prof. Crutzen kamen zahlreiche Anregungen fuer weitere intensive Forschungen zur Chemie der Atmosphaere, die auch unter Politikern eine Debatte ueber den Schutz der hauchduennen Ozonschicht ausloeste. (orig.)

  18. Researcher and Educator Long Term Collaboration with NOAA ESRL Regarding Atmospheric Ozone Changes at the South Pole Through the NSF PolarTREC Program

    Science.gov (United States)

    Bergholz, E. H.; Hofmann, D. J.; Johnson, B. J.

    2009-12-01

    The NOAA/ESRL team at South Pole has been monitoring the development of the annual ozone hole over two decades using balloon-borne and ground based instruments. Collaboration with educators has become an important aspect of NOAA/ESRL to educate the public about ozone loss and ozone hole formation. Researcher Bryan Johnson and educator Elke Bergholz worked together at South Pole in 1998/1999 as part of the NSF teacher outreach program called Teachers Experiencing Antarctica (TEA).It has been almost a decade when they collaborated again concerning the ozone changes at South Pole as part of the International Polar Year (IPY) and the PolarTREC ( http://wwpolartrec.com ) teacher outreach program sponsored by NSF. The TEA and PolarTREC programs selected teachers to travel to polar locations to work with research scientists collecting data and running experiments at various Arctic and Antarctic field sites, including Elke Bergholz working at the South Pole with the NOAA/ESRL team. While in the field, daily contact with classrooms and students around the globe was done through the internet journals, answering emails from students, and webinars. This has been followed up with presentations to schools and the public relating Ms. Bergholz’s experience and new “hands-on” understanding of ozone instruments and ozone depletion over Antarctica, and discussing what changes in the ozone we have seen at South Pole since the first outreach program nearly a decade ago. The lesson plans are available through the PolarTREC website or by contacting Elke Bergholz at ebergholz@unis.org.

  19. Ab Initio Studies of Stratospheric Ozone Depletion Chemistry

    Science.gov (United States)

    Lee, Timothy J.; Head-Gordon, Martin; Langhoff, Stephen R. (Technical Monitor)

    1995-01-01

    An overview of the current understanding of ozone depletion chemistry, particularly with regards the formation of the so-called Antarctic ozone hole, will be presented together with an outline as to how ab initio quantum chemistry can be used to further our understanding of stratospheric chemistry. The ability of modern state-of-the art ab initio quantum chemical techniques to characterize reliably the gas-phase molecular structure, vibrational spectrum, electronic spectrum, and thermal stability of fluorine, chlorine, bromine and nitrogen oxide species will be demonstrated by presentation of some example studies. The ab initio results will be shown to be in excellent agreement with the available experimental data, and where the experimental data are either not known or are inconclusive, the theoretical results are shown to fill in the gaps and to resolve experimental controversies. In addition, ab initio studies in which the electronic spectra and the characterization of excited electronic states of halogen oxide species will also be presented. Again where available, the ab initio results are compared to experimental observations, and are used to aid in the interpretation of experimental studies.

  20. Catastrophic loss of stratospheric ozone in dense volcanic clouds

    Science.gov (United States)

    Prather, Michael

    1992-01-01

    Rapid, localized loss of ozone is predicted to occur in the midlatitude and tropical stratosphere in the presence of very large concentrations of sulfate aerosols. Volcanic eruptions can increase the effective surface area of sulfuric acid so that heterogeneous reactions involving ClONO2, and secondarily N2O5, are able to suppress NO(x) abundances by more than a factor of 10 relative to gas phase chemistry. When NO(x) levels fall below a threshold, e.g., 0.6 ppb at 24 km in mid-latitudes, the chlorine-catalyzed loss of O3 proceeds at rates comparable to those during the formation of the Antarctic ozone hole, more than 50 ppb per day. If such losses occurred following the eruption of Mount Pinatubo in the most volcanically perturbed regions over the tropics and mid-latitudes, this model predicts that they are driven primarily by the suppression of NO(x) below these critical levels. The increase in stratospheric chlorine since El Chichon has made Mount Pinatubo more than twice as effective in causing rapid O3 loss.

  1. Calculations of Polar Ozone Loss Rates

    Science.gov (United States)

    Dessler, A. E.; Wu, J.

    1999-01-01

    We calculate vortex-averaged ozone loss rates at 465-K potential temperature during the Aug.-Sept. time period in the southern hemisphere and Feb.-Mar. time period in the northern hemisphere. Ozone loss rates are calculated two ways. First, from the time series of measurements of 03. Second, from measurements of ClO, from which ozone loss is inferred based on our theories of Cl-catalyzed ozone destruction. Both measurement sets are from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) instrument. We find good agreement between vortex-averaged ozone loss rates calculated from these methods. Our analysis provides no support for recent work suggesting that current theories of Cl-catalyzed ozone loss underestimate the observed decrease in polar ozone during the ozone "hole" period.

  2. Antarctic research today

    International Nuclear Information System (INIS)

    With the appetite for living and dead natural resources, the political and economical interest concerning the Antarctic increases throughout the world. There are three interrelated main subjects accounting for the international interest: The shelf tectonic puzzle of the original continent of Gondwana, where the Antarctic is situated in the centre, between Australia, South Africa and South America, and the hopes concerning the existence of mineral resources under the ice of the Antarctic are based thereon. The Antarctic forms the biggest unified living space of the world. (orig.)

  3. Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models

    Directory of Open Access Journals (Sweden)

    V. Eyring

    2010-05-01

    ozone to its 1980 level. The latest return of total column ozone is projected to occur over Antarctica (~2050–2060 whereas it is not likely that full ozone recovery is reached by the end of the 21st century in this region. Arctic total column ozone is projected to return to 1980 levels well before Cly does so (~2020–2030 and while it is likely that full recovery of ozone from the effects of ODSs has occurred by ~2035, at no time before 2100 is it very likely that full recovery has occurred. In contrast to the Antarctic, by 2100 Arctic total column ozone is projected to be above 1960 levels, but not in the fixed GHG simulation, indicating that climate change plays a significant role.

  4. Differences in Arctic and Antarctic PSC occurrence as observed by lidar in Ny-Ålesund (79° N, 12° E and McMurdo (78° S, 167° E

    Directory of Open Access Journals (Sweden)

    M. Maturilli

    2005-01-01

    Full Text Available The extent of springtime Arctic ozone loss does not reach Antarctic ``ozone hole'' dimensions because of the generally higher temperatures in the northern hemisphere vortex and consequent less polar stratospheric cloud (PSC particle surface for heterogeneous chlorine activation. Yet, with increasing greenhouse gases stratospheric temperatures are expected to further decrease. To infer if present Antarctic PSC occurrence can be applied to predict future Arctic PSC occurrence, lidar observations from McMurdo station (78° S, 167° E and NyÅlesund (79° N, 12° E have been analysed for the 9 winters between 1995 (1995/1996 and 2003 (2003/2004. Although the statistics may not completely cover the overall hemispheric PSC occurrence, the observations are considered to represent the main synoptic cloud features as both stations are mostly situated in the centre or at the inner edge of the vortex. Since the focus is set on the occurrence frequency of solid and liquid particles, the analysis has been restricted to volcanic aerosol free conditions. In McMurdo, by far the largest part of PSC observations is associated with NAT PSCs. The observed persistent background of NAT particles and their potential ability to cause denoxification and irreversible denitrification is presumably more important to Antarctic ozone chemistry than the scarcely observed ice PSCs. Meanwhile in Ny-Ålesund, ice PSCs have never been observed, while solid NAT and liquid STS clouds both occur in large fraction. Although they are also found solely, the majority of observations reveals solid and liquid particle layers in the same profile. For the Ny-Ålesund measurements, the frequent occurrence of liquid PSC particles yields major significance in terms of ozone chemistry, as their chlorine activation rates are more efficient. The relationship between temperature, PSC formation, and denitrification is nonlinear and the McMurdo and Ny-Ålesund PSC observations imply that for

  5. Spatial observation of the ozone layer

    Science.gov (United States)

    Godin-Beekmann, Sophie

    2010-04-01

    This article provides an overview of the various satellite instruments, which have been used to observe stratospheric ozone and other chemical compounds playing a key role in stratospheric chemistry. It describes the various instruments that have been launched since the late 1970s for the measurement of total ozone column and ozone vertical profile, as well as the major satellite missions designed for the study of stratospheric chemistry. Since the discovery of the ozone hole in the early 1980s, spatial ozone measurements have been widely used to evaluate and quantify the spatial extension of polar ozone depletion and global ozone decreasing trends as a function of latitude and height. Validation and evaluation of satellite ozone data have been the subject of intense scientific activity, which was reported in the various ozone assessments of the state of the ozone layer published after the signature of the Montreal protocol. Major results, based on satellite observations for the study of ozone depletion at the global scale and chemical polar ozone loss, are provided. The use of satellite observations for the validation of chemistry climate models that simulate the recovery of the ozone layer and in data assimilation is also described.

  6. Testing oils in antarctic soils

    International Nuclear Information System (INIS)

    The resident seals, whales and penguins in Antarctica's Ross Sea region have only environmentally friendly ways of getting around. In contrast, wherever humans go in the Antarctic and whatever they do, be it research, tourism or fishing, they need fuel for their planes, icebreaker ships, land vehicles and generators. Because of this, petroleum hydrocarbons are the most likely source of pollution in the Antarctic. Accidental oil spills often occur near scientific stations, where storage and refuelling of aircraft and vehicles can result in spills. Spills also occur as a consequence of drilling activities. Dr Jackie Aislabie, a microbiologist from the New Zealand government's research company Landcare Research, is leading a program aimed at understanding how oil spills impact on Antarctic soils. The properties of pristine soils were compared with oil-contaminated soil at three locations: Scott Base, Marble Point and in the Wright Valley at Bull Pass. Soils in the Scott Base area are impacted by the establishment and continuous habitation of the base over 40 years, and a hydrocarbon-contaminated site was sampled near a former storage area for drums of mixed oils. Soil sampled from Marble Point was taken from near the old Marble Point camp, which was inhabited from 1957 to about 1963. Oil stains were visible on the soil surface, and are assumed to have been there for more than 30 years. The samples selected for analysis from the Wright Valley came from a spill site near Bull Pass that occurred during seismic bore-hole drilling activities in 1985. The contamination levels ranged from below detection to just over 29,000 μg/g of soil. Descriptions and analyse results are included into a Geographic Information System and associated soils database

  7. Tropical pacing of Antarctic sea ice increase

    Science.gov (United States)

    Schneider, D. P.

    2015-12-01

    One reason why coupled climate model simulations generally do not reproduce the observed increase in Antarctic sea ice extent may be that their internally generated climate variability does not sync with the observed phases of phenomena like the Pacific Decadal Oscillation (PDO) and ENSO. For example, it is unlikely for a free-running coupled model simulation to capture the shift of the PDO from its positive to negative phase during 1998, and the subsequent ~15 year duration of the negative PDO phase. In previously presented work based on atmospheric models forced by observed tropical SSTs and stratospheric ozone, we demonstrated that tropical variability is key to explaining the wind trends over the Southern Ocean during the past ~35 years, particularly in the Ross, Amundsen and Bellingshausen Seas, the regions of the largest trends in sea ice extent and ice season duration. Here, we extend this idea to coupled model simulations with the Community Earth System Model (CESM) in which the evolution of SST anomalies in the central and eastern tropical Pacific is constrained to match the observations. This ensemble of 10 "tropical pacemaker" simulations shows a more realistic evolution of Antarctic sea ice anomalies than does its unconstrained counterpart, the CESM Large Ensemble (both sets of runs include stratospheric ozone depletion and other time-dependent radiative forcings). In particular, the pacemaker runs show that increased sea ice in the eastern Ross Sea is associated with a deeper Amundsen Sea Low (ASL) and stronger westerlies over the south Pacific. These circulation patterns in turn are linked with the negative phase of the PDO, characterized by negative SST anomalies in the central and eastern Pacific. The timing of tropical decadal variability with respect to ozone depletion further suggests a strong role for tropical variability in the recent acceleration of the Antarctic sea ice trend, as ozone depletion stabilized by late 1990s, prior to the most

  8. Eight years of stratospheric ozone observations at Marambio, Antarctica

    Energy Technology Data Exchange (ETDEWEB)

    Damski, J.; Taalas, P. [Finnish Meteorological Inst., Helsinki (Finland). Section of Ozone and UV Research

    1995-12-31

    In this work behaviour of the stratospheric ozone using the total ozone and ozone sounding measurements from Marambio (64 deg 14`S, 56 deg 37`W) at Antarctic Peninsula has been studied. The effects of depleted stratospheric ozone to the UV-B-radiation are investigated employing a radiative transfer model, and the Marambio total ozone measurements. The levels of UV-B radiation have been studied from the point of the erythemal UV-B-doses on the horizontal human epidermis. The low values of total ozone at Marambio are also reflected to the received UV-doses which have increased roughly 20-80% (compared to long term average) during austral spring and summer. In respective to the total amount of ozone, the model calculations show that during October the UV-B-doses can be at the same level they should be during normal summer

  9. Scientific information and public opinion. Daily press analysis about ozone hole in the years 1996-1997; Informazione scientifica e opinione pubblica. Analisi della stampa quotidiana italiana negli anni 1996-1997 sul tema del buco dell'ozono

    Energy Technology Data Exchange (ETDEWEB)

    Bertuzzi, D. [ENEA, Centro Ricerche E. Clementel, Bologna (Italy). Unita' Comunicazione e Informazione; Borrelli, G. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Sezione Ambiente Globale e Clima

    1999-07-01

    One of ENEA's many activities consists in dealing with the analysis of information strategies. In this case the analysis concerns an environmental issue, the ozone hole which, in spite of the consideration given by the media, is not sufficiently highlighted, as well as in the case of climate changes issue. A survey of the coverage of four daily newspapers was realized; the time period covered by the analysis spans form January 1996 to December 1997, 77 articles in total. The newspapers involved are: La Repubblica, Il Corriere della Sera, L'Unita' on a national scale, and Il Resto del Carlino on a regional scale. The number of articles analyzed is divided as follows: 26 for the Repubblica, 24 for the Corriere della Sera, 21 for the Unita', 6 for the Resto del Carlino. The purpose of the work was to detect quality and quantity indicators of the Italian press about the ozone hole issue and possible environmental risks conveyed to the public, using the classical methods of the Content analysis. The analysis, carried out through a questionnaire realized for another research on climate change and daily press and appropriately readapted, consisted of 35 questions pointing out the fundamental characteristics of each article: (i) morphological characteristics; (ii) modalities describing the ozone hole; (iii) communication connotations. [Italian] Tra le attivita' dell'ENEA rientra l'analisi delle strategie dell'informazione, rivolta in questo caso ad un tema ambientale, il buco dell'ozono, che pur avendo recentemente grande rilevanza sui media, viene trattato con scarsa evidenza, cosi' come avviene, ad esempio, per i cambiamenti climatici. L'analisi presentata copre quattro testate per un arco temporale di due anni, dal gennaio 1996 al dicembre 1997, per un totale di 77 rilevati. Sono state analizzate tre testate nazionali, La Repubblica, il Corriere della Sera, l'Unita', e un giornale a carattere regionale, il

  10. Underwater Optics in Sub-Antarctic and Antarctic Coastal Ecosystems.

    Science.gov (United States)

    Huovinen, Pirjo; Ramírez, Jaime; Gómez, Iván

    2016-01-01

    Understanding underwater optics in natural waters is essential in evaluating aquatic primary production and risk of UV exposure in aquatic habitats. Changing environmental conditions related with global climate change, which imply potential contrasting changes in underwater light climate further emphasize the need to gain insights into patterns related with underwater optics for more accurate future predictions. The present study evaluated penetration of solar radiation in six sub-Antarctic estuaries and fjords in Chilean North Patagonian region (39-44°S) and in an Antarctic bay (62°S). Based on vertical diffuse attenuation coefficients (Kd), derived from measurements with a submersible multichannel radiometer, average summer UV penetration depth (z1%) in these water bodies ranged 2-11 m for UV-B (313 nm), 4-27 m for UV-A (395 nm), and 7-30 m for PAR (euphotic zone). UV attenuation was strongest in the shallow Quempillén estuary, while Fildes Bay (Antarctica) exhibited the highest transparency. Optically non-homogeneous water layers and seasonal variation in transparency (lower in winter) characterized Comau Fjord and Puyuhuapi Channel. In general, multivariate analysis based on Kd values of UV and PAR wavelengths discriminated strongly Quempillén estuary and Puyuhuapi Channel from other study sites. Spatial (horizontal) variation within the estuary of Valdivia river reflected stronger attenuation in zones receiving river impact, while within Fildes Bay a lower spatial variation in water transparency could in general be related to closeness of glaciers, likely due to increased turbidity through ice-driven processes. Higher transparency and deeper UV-B penetration in proportion to UV-A/visible wavelengths observed in Fildes Bay suggests a higher risk for Antarctic ecosystems reflected by e.g. altered UV-B damage vs. photorepair under UV-A/PAR. Considering that damage repair processes often slow down under cool temperatures, adverse UV impact could be further

  11. Underwater Optics in Sub-Antarctic and Antarctic Coastal Ecosystems.

    Science.gov (United States)

    Huovinen, Pirjo; Ramírez, Jaime; Gómez, Iván

    2016-01-01

    Understanding underwater optics in natural waters is essential in evaluating aquatic primary production and risk of UV exposure in aquatic habitats. Changing environmental conditions related with global climate change, which imply potential contrasting changes in underwater light climate further emphasize the need to gain insights into patterns related with underwater optics for more accurate future predictions. The present study evaluated penetration of solar radiation in six sub-Antarctic estuaries and fjords in Chilean North Patagonian region (39-44°S) and in an Antarctic bay (62°S). Based on vertical diffuse attenuation coefficients (Kd), derived from measurements with a submersible multichannel radiometer, average summer UV penetration depth (z1%) in these water bodies ranged 2-11 m for UV-B (313 nm), 4-27 m for UV-A (395 nm), and 7-30 m for PAR (euphotic zone). UV attenuation was strongest in the shallow Quempillén estuary, while Fildes Bay (Antarctica) exhibited the highest transparency. Optically non-homogeneous water layers and seasonal variation in transparency (lower in winter) characterized Comau Fjord and Puyuhuapi Channel. In general, multivariate analysis based on Kd values of UV and PAR wavelengths discriminated strongly Quempillén estuary and Puyuhuapi Channel from other study sites. Spatial (horizontal) variation within the estuary of Valdivia river reflected stronger attenuation in zones receiving river impact, while within Fildes Bay a lower spatial variation in water transparency could in general be related to closeness of glaciers, likely due to increased turbidity through ice-driven processes. Higher transparency and deeper UV-B penetration in proportion to UV-A/visible wavelengths observed in Fildes Bay suggests a higher risk for Antarctic ecosystems reflected by e.g. altered UV-B damage vs. photorepair under UV-A/PAR. Considering that damage repair processes often slow down under cool temperatures, adverse UV impact could be further

  12. Climate action. What can be done to fight the ozone hole and greenhouse effect. Klima Aktionsbuch. Was tun gegen Ozonloch und Teibhauseffekt

    Energy Technology Data Exchange (ETDEWEB)

    Blanck, K.; Matzen, D.; Schott, P.; Wiegand, J. (Robin Wood, Bremen (Germany). Arbeitskreis Ozon)

    1990-10-01

    The greenhouse effect is caused by an increase in gases that bear on climate - carbon dioxide, methane, and nitrous oxide. They stem mainly from combustion processes, for instance in automobile engines, power plants and heatings, the burning down of tropical forests, and intensive farming. Chapter 1 explains these relationships in detail, while chapters 2 and 3 are concerned with who causes these increases in trace gases as well as with possible countermeasures in the sectors of energy and transport. The contribution of tropical deforestation to the climate catastrophe is explained in chapter 4. Responsible for the thinning of the ozone layer at the altitude of 15 to 30 kilometres, which protects us from excessive UV radiation, is a group of gases containing chlorine and which are known as chlorofluorocarbons. What is less widely known are their many every-day uses, which are more closely dealt with in chapter 5. (orig./KW).

  13. 利用被动差分吸收光谱技术反演南极中山站地区夏季臭氧柱浓度%The Retrieval of Ozone Column Densities by Passive Differential Optical Absorption Spectroscopy during Summer at Zhongshan Station, Antarctic

    Institute of Scientific and Technical Information of China (English)

    罗宇涵; 刘文清; 卞林根; 逯昌贵; 谢品华; 司福祺; 孙立广

    2011-01-01

    Daily ozone column densities were monitored by Passive DOAS (differential optical absorption spectroscopy) from December 10th, 2008 to Feb 19th, 2009 at Zhongshan Station, Antarctic (69°22′24" S, 76°22′14″ E). Considering the absorption of O3, OClO, NC2, O4, BrO and the Ring effect, ozone slant column densities were retrieved using the zenith scattered sunlight as the light source. The results showed that there was no obvious “ozone hole” during the monitoring period, but ozone VCD (vertical column density) had greatly changed within short time scale, especially in middle December and early February.The analysis of passive DOAS and Brewer measurements of ozone VCD showed good agreement with the correlative coefficient of 0. 863, while satellite board OMI measurements with the correlative coefficient of 0. 840, which confirmed the validity of the monitoring of Passive DOAS.%采用被动差分吸收光谱技术(differential optical absorption spectroscopy,DOAS)对南极中山站地区(69°22′24′′S,76°22′14′′E)的臭氧柱含量进行了72天(2008年12月10日-2009年2月19日)观测,通过被动差分吸收光谱处理方法对系统采集的天顶太阳散射光谱进行处理.在反演过程中,考虑了O3,OCIO,NO2,O4和BrO的吸收以及大气Ring效应对测量光谱的贡献,获得该区域臭氧柱含量逐日变化趋势.结果表明,观测期间中山站地区没有出现明显的臭氧空洞,但在短时间尺度臭氧含量有较大幅度变化,尤其在12月中旬和2月上旬.与中山站地区Brewer臭氧光谱仪和星载OMI观测资料进行比较分析得出,被动DOAS与Brewer臭氧光谱仪观测数据的相关系数为0.863与星载OMI观测数据的相关系数为0.840,均表现了很好的相关性,说明在南极地区采用被动DOAS在线观测O3柱含量的方法是可靠的.

  14. The spatial scale of ozone depletion events derived from an autonomous surface ozone network in coastal Antarctica

    OpenAIRE

    Jones, A. E.; Wolff, E. W.; Brough, N.; Bauguitte, S. J.-B.; Weller, R; Yela, M; M. Navarro-Comas; H. A. Ochoa; Theys, N.

    2013-01-01

    To probe the spatial extent of tropospheric ozone depletion events during Antarctic spring, a network of 10 autonomous ozone monitors was established around the Dronning Maud Land sector of Antarctica for a full calendar year. Together with manned stations in the area, the network covered a ~1200 km stretch of coast, as well as a transect ~300 km inland and to ~2000 m above sea level (a.s.l.). Here we present results from the spring period (August to October 2008). While ...

  15. A network of autonomous surface ozone monitors in Antarctica: technical description and first results

    OpenAIRE

    S. J.-B. Bauguitte; Brough, N; M. M. Frey; Jones, A E; Maxfield, D.J.; Roscoe, H. K.; Rose, M.C.; Wolff, E. W.

    2010-01-01

    A suite of 10 autonomous ozone monitors, each powered using renewable energy, was developed and built to study surface ozone in Antarctica during the International Polar Year (2007–2009). The monitoring systems were deployed in a network around the Weddell Sea sector of coastal Antarctica with a transect up onto the Antarctic Plateau. The aim was to measure for a full year, thus gaining a much-improved broader view of boundary layer ozone seasonality at different locations as well as o...

  16. A network of autonomous surface ozone monitors in Antarctica: technical description and first results

    OpenAIRE

    Bauguitte, S. J.-B.; Brough, N; M. M. Frey; Jones, A E; Maxfield, D.J.; Roscoe, H. K.; Rose, M.C.; Wolff, E. W.

    2011-01-01

    A suite of 10 autonomous ozone monitoring units, each powered using renewable energy, was developed and built to study surface ozone in Antarctica during the International Polar Year (2007–2009). The monitoring systems were deployed in a network around the Weddell Sea sector of coastal Antarctica with a transect up onto the Antarctic Plateau. The aim was to measure for a full year, thus gaining a much-improved broader view of boundary layer ozone seasonality at different loc...

  17. Sugars in Antarctic aerosol

    Science.gov (United States)

    Barbaro, Elena; Kirchgeorg, Torben; Zangrando, Roberta; Vecchiato, Marco; Piazza, Rossano; Barbante, Carlo; Gambaro, Andrea

    2015-10-01

    The processes and transformations occurring in the Antarctic aerosol during atmospheric transport were described using selected sugars as source tracers. Monosaccharides (arabinose, fructose, galactose, glucose, mannose, ribose, xylose), disaccharides (sucrose, lactose, maltose, lactulose), alcohol-sugars (erythritol, mannitol, ribitol, sorbitol, xylitol, maltitol, galactitol) and anhydrosugars (levoglucosan, mannosan and galactosan) were measured in the Antarctic aerosol collected during four different sampling campaigns. For quantification, a sensitive high-pressure anion exchange chromatography was coupled with a single quadrupole mass spectrometer. The method was validated, showing good accuracy and low method quantification limits. This study describes the first determination of sugars in the Antarctic aerosol. The total mean concentration of sugars in the aerosol collected at the "Mario Zucchelli" coastal station was 140 pg m-3; as for the aerosol collected over the Antarctic plateau during two consecutive sampling campaigns, the concentration amounted to 440 and 438 pg m-3. The study of particle-size distribution allowed us to identify the natural emission from spores or from sea-spray as the main sources of sugars in the coastal area. The enrichment of sugars in the fine fraction of the aerosol collected on the Antarctic plateau is due to the degradation of particles during long-range atmospheric transport. The composition of sugars in the coarse fraction was also investigated in the aerosol collected during the oceanographic cruise.

  18. Geoethical Approach to Antarctic Subglacial Lakes Exploration

    Science.gov (United States)

    Talalay, Pavel; Markov, Alexey; Sysoev, Mikhail

    2014-05-01

    Antarctic subglacial aquatic environment have become of great interest to the science community because they may provide unique information about microbial evolution, the past climate of the Earth, and the formation of the Antarctic ice sheet. Nowadays it is generally recognized that a vast network of lakes, rivers, and streams exists thousands of meters beneath Antarctic Ice Sheets. Up to date only four boreholes accessed subglacial aquatic system but three of them were filled with high-toxic drilling fluid, and the subglacial water was contaminated. Two recent exploration programs proposed by UK and USA science communities anticipated direct access down to the lakes Ellsworth and Whillans, respectively, in the 2012/2013 Antarctic season. A team of British scientists and engineers engaged in the first attempt to drill into Lake Ellsworth but failed. US research team has successfully drilled through 800 m of Antarctic ice to reach a subglacial lake Whillans and retrieve water and sediment samples. Both activities used hot-water drilling technology to access lakes. Hot water is considered by the world science community as the most clean drilling fluid medium from the present point of view but it cannot solve environmental problems in total because hot-water even when heated to 90 °C, filtered to 0.2 μm, and UV treated at the surface could pick up microorganisms from near-surface snow and circulate them in great volume through the borehole. Another negative impact of hot-water circulation medium is thermal pollution of subglacial water. The new approach to Antarctic subglacial lakes exploration is presented by sampling technology with recoverable autonomous sonde which is equipped by two hot-points with heating elements located on the bottom and top sides of the sonde. All down-hole sonde components will be sterilized by combination of chemical wash, HPV and UV sterilization prior using. At the beginning of the summer season sonde is installed on the surface of the

  19. Ozone decomposition

    Science.gov (United States)

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho

    2014-01-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  20. Experimental study on ozone generation using DC driven micro- plasma

    International Nuclear Information System (INIS)

    A new type of ozone generator using a micro hollow cathode discharge has been developed. The electrode system consists of two thin metal cathodes and a ceramic spacer with center holes of a few 100 mm diameter. The ozone generation efficiency increases up to 45 g/kWh at the ozone concentration of 7.6 g/Nm3 without any cooling systems by feeding high-pressure oxygen. In this ozone generating system, the ozone decomposition mechanisms such as electron impacts and the heat rise of oxygen gas are effectively removed by decreasing the gas-residence time in the discharge space. (author)

  1. Alert with destruction of stratospheric ozone: 95 Nobel Prize Winners

    International Nuclear Information System (INIS)

    After briefly summarizing the discoveries of the 95 Nobel Prize Winners in Chemistry related to the threats to the ozone layer by chemical pollutants, we make a soft presentation of the overall problem of stratospheric ozone, starting with the destructive catalytic cycles of the pollutant-based free radicals, following with the diffusion mathematical models in Atmospheric Chemistry, and ending with the increasing annual drama of the ozone hole in the Antarctica. (Author)

  2. Regional genetic diversity patterns in Antarctic hairgrass (Deschampsia antartica Desv.)

    NARCIS (Netherlands)

    van de Wouw, M.J.; Van Dijk, P.J.; Huiskes, A.H.L.

    2008-01-01

    Aim To determine patterns in diversity of a major Antarctic plant species, including relationships of Antarctic populations with those outside the Antarctic zone. Location Antarctic Peninsula, Maritime Antarctica, sub-Antarctic islands, Falkland Islands and South America. Methods Amplified fragment

  3. Children's and Adults' Knowledge and Models of Reasoning about the Ozone Layer and Its Depletion.

    Science.gov (United States)

    Leighton, Jacqueline P.; Bisanz, Gay L.

    2003-01-01

    Examines children's and adults' knowledge of the ozone layer and its depletion, whether this knowledge increases with age, and how the ozone layer and ozone hole might be structured as scientific concepts. Uses a standardized set of questions to interview children and adults in Canada. Discusses implications of the results for health…

  4. Children's Models of Understanding of Two Major Global Environmental Issues (Ozone Layer and Greenhouse Effect).

    Science.gov (United States)

    Boyes, Edward; Stanisstreet, Martin

    1997-01-01

    Aims to quantify the models that 13- and 14 year-old students hold about the causes of the greenhouse effect and ozone layer depletion. Assesses the prevalence of those ideas that link the two phenomena. Twice as many students think that holes in the ozone layer cause the greenhouse effect than think the greenhouse effect causes ozone depletion.…

  5. Modelling the Antarctic Ice Sheet

    DEFF Research Database (Denmark)

    Pedersen, Jens Olaf Pepke; Holm, A.

    2015-01-01

    The Antarctic ice sheet is a major player in the Earth’s climate system and is by far the largest depository of fresh water on the planet. Ice stored in the Antarctic ice sheet (AIS) contains enough water to raise sea level by about 58 m, and ice loss from Antarctica contributed significantly...... Science) Antarctic Ice Sheet (DAIS) model (Shaffer 2014) is forced by reconstructed time series of Antarctic temperature, global sea level and ocean subsurface temperature over the last two glacial cycles. In this talk a modelling work of the Antarctic ice sheet over most of the Cenozoic era using...... the DAIS model will be presented. G. Shaffer (2014) Formulation, calibration and validation of the DAIS model (version 1), a simple Antarctic ice sheet model sensitive to variations of sea level and ocean subsurface temperature, Geosci. Model Dev., 7, 1803‐1818...

  6. Multi-model assessment of stratospheric ozone return dates and ozone recovery in CCMVal-2 models

    Directory of Open Access Journals (Sweden)

    V. Eyring

    2010-10-01

    return of total column ozone to its 1980 level. The latest return of total column ozone is projected to occur over Antarctica (~2045–2060 whereas it is not likely that full ozone recovery is reached by the end of the 21st century in this region. Arctic total column ozone is projected to return to 1980 levels well before polar stratospheric halogen loading does so (~2025–2030 for total column ozone, cf. 2050–2070 for Cly+60×Bry and it is likely that full recovery of total column ozone from the effects of ODSs has occurred by ~2035. In contrast to the Antarctic, by 2100 Arctic total column ozone is projected to be above 1960 levels, but not in the fixed GHG simulation, indicating that climate change plays a significant role.

  7. Antarctic Tourism and Maritime Heritage

    OpenAIRE

    Basberg, Bjørn L.

    2010-01-01

    Maritime activities in the Antarctic region date back to the eighteenth century. They evolved from exploration and discoveries to commercial enterprises, especially sealing, whaling and fishing. Antarctic tourism is a much more recent phenomenon, developing mainly from the 1950s and 1960s. Today over 40,000 tourists visit the Antarctic annually, most of them on cruise ships. This essay reviews the historical development of this tourism. The focus is on how maritime heritage has been treated a...

  8. Antarctic science preserve polluted

    Science.gov (United States)

    Simarski, Lynn Teo

    Geophysicists are alarmed at the electromagnetic pollution of a research site in the Antarctic specifically set aside to study the ionosphere and magnetosphere. A private New Zealand communications company called Telecom recently constructed a satellite ground station within the boundaries of this Site of Special Scientific Interest (SSSI), protected since the mid-1970s. The placement of a commercial facility within this site sets an ominous precedent not only for the sanctity of other SSSIs, but also for Specially Protected Areas—preserves not even open to scientific research, such as certain penguin rookeries.The roughly rectangular, one-by-one-half mile site, located at Arrival Heights not far from McMurdo Station, is one of a number of areas protected under the Antarctic treaty for designated scientific activities. Many sites are set aside for geological or biological research, but this is the only one specifically for physical science.

  9. Estimation of surface UV levels based on Meteor-3/TOMS ozone data

    Energy Technology Data Exchange (ETDEWEB)

    Borisov, Y.A. [Central Aerological Observatory, Moscow (Russian Federation); Geogdzhaev, I.V. [Moscow Inst. of Physics and Technology, Moscow (Russian Federation); Khattatov, V.U. [Central Aerological Observatory, Moscow (Russian Federation)

    1995-12-31

    The major consequence of ozone layer depletion for the environment is an increase of harmful ultraviolet (UV) radiation on the Earth surface and in the upper ocean. This implies the importance of environmental UV monitoring. Since the direct global monitoring is not currently possible, indirect estimations of surface UV levels may be used based on satellite ozone data (Madronich, S. 1992). Total Ozone Mapping Spectrometer (TOMS) on board the METEOR-3 satellite provided regular set of data for such estimates. During the time of its operation (August, 1991 - December, 1994) the instrument registered several ozone hole events over Antarctica, when ozone levels dropped by as much as 60 % from their unperturbed values. Probably even more alarming ozone depletions were observed over highly populated regions of middle latitudes of northern hemisphere. Radiative transfer modeling was used to convert METEOR-3/TOMS daily ozone values into regional and global maps of biologically active UV. Calculations demonstrate the effect on surface UV levels produced by ozone hole over Antarctica and ozone depletions over the territory of Russia (March, 1994). UV contour lines deviate from the normal appearance which is determined by growing southward solar elevation. UV contour lines are almost perpendicular to the ozone ones in the ozone depletions areas. The 30 % ozone depletion, over Siberia caused more than 30 % increase in noontime erythemal UV levels, which is equivalent to 10-15 degrees southward latitude displacement. Higher UV radiation increases were found in ozone hole over South America (October 1992) equivalent to about 20 degrees southward displacement

  10. Responses of Antarctic Oscillation to global warming

    Science.gov (United States)

    Feng, S.

    2015-12-01

    The Antarctic Oscillation (AAO) is the major annular mode dominates the spatiotemporal variability of the atmospheric circulation in the Southern Hemisphere. This study examined the sensitivity of AAO to future warming by analyzing the outputs of 34 state-of-the-art climate models participating in phase 5 of the Coupled Model Intercomparion Project (CMIP5). The model simulations include the stabilized (RCP4.5) and business as usual (RCP8.5) scenarios as well as the idealized 1% per year increase in atmospheric CO2 to quadrupling (1pctCO2) and an instantaneous quadrupling of CO2 (abrupt4xCO2). We show that the CMIP5 models on average simulate increases in the AAO in every season by 2100 under the RCP4.5 and RCP8.5 scenarios. However, due to the impacts of ozone, aerosol and land use changes, the amplitudes of the projected changes in AAO to future climate scenarios are quit different on different seasons. After the impact of ozone, aerosol and land use changes were removed; it was found that the impact of greenhouse gases (GHGs) on AAO is similar on all seasons. The increases of AAO are accelerating following the increase of GHGs. Our results are also consistent with the simulations of 1pctCO2 and abrupt4xCO2.

  11. Changes in tropospheric composition and air quality due to stratospheric ozone depletion and climate change.

    Science.gov (United States)

    Wilson, S R; Solomon, K R; Tang, X

    2007-03-01

    It is well-understood that reductions in air quality play a significant role in both environmental and human health. Interactions between ozone depletion and global climate change will significantly alter atmospheric chemistry which, in turn, will cause changes in concentrations of natural and human-made gases and aerosols. Models predict that tropospheric ozone near the surface will increase globally by up to 10 to 30 ppbv (33 to 100% increase) during the period 2000 to 2100. With the increase in the amount of the stratospheric ozone, increased transport from the stratosphere to the troposphere will result in different responses in polluted and unpolluted areas. In contrast, global changes in tropospheric hydroxyl radical (OH) are not predicted to be large, except where influenced by the presence of oxidizable organic matter, such as from large-scale forest fires. Recent measurements in a relatively clean location over 5 years showed that OH concentrations can be predicted by the intensity of solar ultraviolet radiation. If this relationship is confirmed by further observations, this approach could be used to simplify assessments of air quality. Analysis of surface-level ozone observations in Antarctica suggests that there has been a significant change in the chemistry of the boundary layer of the atmosphere in this region as a result of stratospheric ozone depletion. The oxidation potential of the Antarctic boundary layer is estimated to be greater now than before the development of the ozone hole. Recent modeling studies have suggested that iodine and iodine-containing substances from natural sources, such as the ocean, may increase stratospheric ozone depletion significantly in polar regions during spring. Given the uncertainty of the fate of iodine in the stratosphere, the results may also be relevant for stratospheric ozone depletion and measurements of the influence of these substances on ozone depletion should be considered in the future. In agreement with

  12. The 2002 Antarctic Vortex Splitting as Observed from Visible Spectroscopy and Ozonesoundings

    Science.gov (United States)

    Yela, M.; Parrondo, C.; Rodríguez, S.; Gil, M.; Araujo, J.; Ochoa, H.; Diaz, S.; Deferrari, G.; Reimer, E.

    2003-04-01

    The records of NO2 total column and ozone obtained by visible spectroscopy at Ushuaia (55S, 68W), Marambio (64S, 55W) and Belgrano (78S, 35W) and electrochemical ozonesoundings from the later station provide insight on the unusual major warming and vortex splitting phenomenon observed above Antarctica in the last week of September. The signature of poleward transported air is clearly visible in the data in all three stations. At Belgrano, a sudden increase of the NO2 column 4-5 times larger than normal values for the season is observed, peaking to 5x1015 molec.cm-2 on September 25 to 29. The diurnal variation, which is almost lacking at southern hemisphere high latitudes in spring, resembles that of fall, providing further evidence of no-denitrified extra vortex air. Back-trajectories from Free University of Berlin calculations show poleward transport of airmasses from latitudes of 50º S at 675 K. At the same time O3 rose from 155 DU to 350 DU in less than ten days with its maximum delayed by 4-5 days to that of NO2. The temperature increased from below NAT (190K) to 230K at the isentropic level of 550 K from September 18 to 25 and was maximum at 700-750 K with 54K of increase. The anomaly in temperature was observed down to 310 K (200 hPa) in which a well defined tropopause was established. From comparison of the ozone profiles before and during the phenomenon it can be seen that the increase in O3 takes place basically above 500 K, rising dramatically from 4 to 20 mPa at 700 K, but the layer where the ozone hole occurs is barely affected. Although the vortex was weaker than previous years, the PV values from 400 K to 500 K do not show any evidence of anomaly at Belgrano, and are representative of in-vortex air. Above 550 K, on the contrary, a very strong reduction in PV was observed, confirming that the vortex split was "confined" to heights above the layer of the Antarctic spring depletion.

  13. Antarctic, Sub-Antarctic and cold temperate echinoid database

    Directory of Open Access Journals (Sweden)

    Benjamin Pierrat

    2012-06-01

    Full Text Available This database includes spatial data of Antarctic, Sub-Antarctic and cold temperate echinoid distribution (Echinodermata: Echinoidea collected during many oceanographic campaigns led in the Southern Hemisphere from 1872 to 2010. The dataset lists occurrence data of echinoid distribution south of 35°S latitude, together with information on taxonomy (from species to genus level, sampling sources (cruise ID, sampling dates, ship names and sampling sites (geographic coordinates and depth. Echinoid occurrence data were compiled from the Antarctic Echinoid Database (David et al., 2005a, which integrates records from oceanographic cruises led in the Southern Ocean until 2003. This database has been upgraded to take into account data from oceanographic cruises led after 2003. The dataset now reaches a total of 6160 occurrence data that have been checked for systematics reliability and consistency. It constitutes today the most complete database on Antarctic and Sub-Antarctic echinoids.

  14. "Holes" in Student Understanding: Addressing Prevalent Misconceptions regarding Atmospheric Environmental Chemistry

    Science.gov (United States)

    Kerr, Sara C.; Walz, Kenneth A.

    2007-01-01

    There is a misconception among undergraduate students that global warming is caused by holes in the ozone layer. In this study, we evaluated the presence of this and other misconceptions surrounding atmospheric chemistry that are responsible for the entanglement of the greenhouse effect and the ozone hole in students' conceptual frameworks. We…

  15. Annual cycle of Antarctic baseline aerosol: controlled by photooxidation-limited aerosol formation

    Directory of Open Access Journals (Sweden)

    M. Fiebig

    2013-09-01

    Full Text Available This article investigates the annual cycle observed in the Antarctic baseline aerosol scattering coefficient, total particle number concentration, and particle number size distribution (PNSD as measured at Troll Atmospheric Observatory. Mie-theory shows that the annual cycles in microphysical and optical aerosol properties have a common cause. By comparison with observations at other Antarctic stations, it is shown that the annual cycle is not a local phenomenon, but common to Central Antarctic baseline air masses. Observations of ground-level ozone at Troll as well as backward plume calculations for the air masses arriving at Troll demonstrate that the baseline air masses originate from the free troposphere and lower stratosphere region, and descend over the Central Antarctic continent. The Antarctic summer PNSD is dominated by particles with diameters 3/(MJ m. Further research is proposed to investigate the applicability of this number to other atmospheric reservoirs, and to use the observed annual cycle in Antarctic baseline aerosol properties as a benchmark for the representation of natural atmospheric aerosol processes in climate models.

  16. Stardust in Antarctic Micrometeorites

    Energy Technology Data Exchange (ETDEWEB)

    Yada, Toru; Floss, Christine; Stadermann, Frank J.; Zinner, E.; Nakamura, T.; Noguchi, T.; Lea, Alan S.

    2008-03-07

    We report the discovery of presolar silicate, oxide (hibonite) and (possibly) SiC grains from four Antarctic micrometeorites. The oxygen isotopic compositions of the eighteen presolar silicate (and one oxide) grains found are consistent with those observed previously in primitive meteorites and interplanetary dust particles, and indicate origins in oxygen-rich red giant or asymptotic giant branch stars. Four grains with anomalous C isotopic compositions were also detected. 12C/13C as well as Si ratios are similar to those of mainstream SiC grains; the N isotopic composition of one grain is also consistent with a mainstream SiC classification. Presolar silicate grains were found in three of the seven AMMs studied, and are heterogeneously distributed within these micrometeorites. Fourteen of the 18 presolar silicate grains and 3 of the 4 C-anomalous grains were found within one AMM, T98G8. The presence of magnesiowüstite, which forms mainly through the decomposition of carbonates, in AMMs without presolar silicates, and its absence in the presolar silicate-bearing micrometeorites, suggests that parent body processes (specifically aqueous alteration) may determine the presence or absence of presolar silicates in Antarctic micrometeorites.

  17. Earth's Endangered Ozone

    Science.gov (United States)

    Panofsky, Hans A.

    1978-01-01

    Included are (1) a discussion of ozone chemistry; (2) the effects of nitrogen fertilizers, fluorocarbons, and high level aircraft on the ozone layer; and (3) the possible results of a decreasing ozone layer. (MR)

  18. Metazoan Parasites of Antarctic Fishes.

    Science.gov (United States)

    Oğuz, Mehmet Cemal; Tepe, Yahya; Belk, Mark C; Heckmann, Richard A; Aslan, Burçak; Gürgen, Meryem; Bray, Rodney A; Akgül, Ülker

    2015-06-01

    To date, there have been nearly 100 papers published on metazoan parasites of Antarctic fishes, but there has not yet been any compilation of a species list of fish parasites for this large geographic area. Herein, we provide a list of all documented occurrences of monogenean, cestode, digenean, acanthocephalan, nematode, and hirudinean parasites of Antarctic fishes. The list includes nearly 250 parasite species found in 142 species of host fishes. It is likely that there are more species of fish parasites, which are yet to be documented from Antarctic waters.

  19. Polar vortex evolution during the 2002 Antarctic major warming as observed by the Odin satellite

    OpenAIRE

    RICAUD, Philippe; Lefèvre, Franck; Berthet, Gwenaël; Murtagh, D.; Llewellyn, E.-J.; Mégie, Gérard; E. Kyrölä; Leppelmeier, G.-W.; Auvinen, H.; Boonne, C.; Brohede, S.; Degenstein, D.-A.; De La Noe, J.; E. Dupuy; El Amraoui, L.

    2005-01-01

    In September 2002 the Antarctic polar vortex split in two under the influence of a sudden warming. During this event, the Odin satellite was able to measure both ozone (O3) and chlorine monoxide (ClO), a key constituent responsible for the so-called “ozone hole”, together with nitrous oxide (N2O), a dynamical tracer, and nitric acid (HNO3) and nitrogen dioxide (NO2), tracers of denitrification. The submillimeter radiometer (SMR) microwave instrument and the Optical Spectrograph and Infrared I...

  20. Filter measurement results from the Airborne Antarctic Ozone Experiment

    Science.gov (United States)

    Gandrud, B. W.; Sperry, P. D.; Sanford, L.; Kelly, K. K.; Ferry, G. V.; Chan, K. R.

    1989-08-01

    Filter samples obtained as part of the AAOE to determine the total nitrate, sulfate, acidic chloride, and acidic fluoride content along the flight path of the NASA ER-2 are studied. These compounds were obtained in the aerosol and vapor phase. The ratio of particulate sulfate observed outside the chemically perturbed region (CPR) of the vortex to that inside the CPR was 2.6. The ratio of total acidic chloride to total acidic flouride within the CPR is near 1, indicating the removal of chloride from the air mass or the partitioning of chloride into an unmeasured species.

  1. Black Holes

    Science.gov (United States)

    Luminet, Jean-Pierre

    1992-09-01

    Foreword to the French edition; Foreword to the English edition; Acknowledgements; Part I. Gravitation and Light: 1. First fruits; 2. Relativity; 3. Curved space-time; Part II. Exquisite Corpses: 4. Chronicle of the twilight years; 5. Ashes and diamonds; 6. Supernovae; 7. Pulsars; 8. Gravitation triumphant; Part III. Light Assassinated: 9. The far horizon; 10. Illuminations; 11. A descent into the maelstrom; 12. Map games; 13. The black hole machine; 14. The quantum black hole; Part IV. Light Regained: 15. Primordial black holes; 16. The zoo of X-ray stars; 17. Giant black holes; 18. Gravitational light; 19. The black hole Universe; Appendices; Bibliography; Name index; Subject index.

  2. Altitude troposphere ozone profiles over Kyiv-Goloseyev station by simultaneous Umkehr and FTIR observations

    Science.gov (United States)

    Milinevsky, Gennadi; Shavrina, Angelina; Udodov, Evgeny; Liptuga, Anatoly; Kyslyi, Volodymyr; Danylevsky, Vassyl; Kravchenko, Volodymyr; Ivanov, Yuri; Synyavski, Ivan; Romanyuk, Yaroslav; Pavlenko, Yakov; Veles, Oleksandr

    2016-04-01

    Total ozone column and ozone profile data have been obtained from both: (1) standard Dobson measurements and Umkehr method, and (2) using modeling of the ozone absorption spectral band profile near 9.6 microns with the MODTRAN4.3 Atmospheric Radiation Transfer Model based on the HITRAN molecular absorption database from Fourier transform infrared spectroscopy (FTIR) observations. The simultaneous ground-based Dobson/Umkehr and FTIR ozone observations have been performed in 2014-2015 at the mid-latitude Kyiv-Goloseyev KGV GAW station for joint altitude troposphere ozone profiles analysis. To retrieve ozone column estimates and ozone profiles from FTIR observations, we used the satellite Aqua-AIRS water vapor, temperature and ozone profiles, and the simultaneous with FTIR observations the Umkehr ozone profiles and surface ozone measurements as input a priori information for the MODTRAN4.3 model. The altitude ozone profiles retrieved from Umkehr method and satellite measurements are in good correspondence in stratosphere layer. However the troposphere part of ozone profiles is uncertain and reproduced with large errors. Therefore we use the MODTRAN4.3 model for interpretation of observed FTIR absorption spectrum to retrieve and improve the troposphere part of ozone altitude distribution. The synergy of Umkehr, satellite and FTIR simultaneous observations including surface ozone measurements allows rendering the ozone profile features in troposphere that indicate the stratosphere-troposphere exchange processes. Season ozone profile variations observed from Umkehr measurements are discussed as well. This work was partly supported by the Polar FORCeS project no. 4012 of the Australian Antarctic Science Program.

  3. Antarctic crabs: invasion or endurance?

    Science.gov (United States)

    Griffiths, Huw J; Whittle, Rowan J; Roberts, Stephen J; Belchier, Mark; Linse, Katrin

    2013-01-01

    Recent scientific interest following the "discovery" of lithodid crabs around Antarctica has centred on a hypothesis that these crabs might be poised to invade the Antarctic shelf if the recent warming trend continues, potentially decimating its native fauna. This "invasion hypothesis" suggests that decapod crabs were driven out of Antarctica 40-15 million years ago and are only now returning as "warm" enough habitats become available. The hypothesis is based on a geographically and spatially poor fossil record of a different group of crabs (Brachyura), and examination of relatively few Recent lithodid samples from the Antarctic slope. In this paper, we examine the existing lithodid fossil record and present the distribution and biogeographic patterns derived from over 16,000 records of Recent Southern Hemisphere crabs and lobsters. Globally, the lithodid fossil record consists of only two known specimens, neither of which comes from the Antarctic. Recent records show that 22 species of crabs and lobsters have been reported from the Southern Ocean, with 12 species found south of 60 °S. All are restricted to waters warmer than 0 °C, with their Antarctic distribution limited to the areas of seafloor dominated by Circumpolar Deep Water (CDW). Currently, CDW extends further and shallower onto the West Antarctic shelf than the known distribution ranges of most lithodid species examined. Geological evidence suggests that West Antarctic shelf could have been available for colonisation during the last 9,000 years. Distribution patterns, species richness, and levels of endemism all suggest that, rather than becoming extinct and recently re-invading from outside Antarctica, the lithodid crabs have likely persisted, and even radiated, on or near to Antarctic slope. We conclude there is no evidence for a modern-day "crab invasion". We recommend a repeated targeted lithodid sampling program along the West Antarctic shelf to fully test the validity of the "invasion hypothesis".

  4. Secondary maxima in ozone profiles

    OpenAIRE

    R. Lemoine

    2004-01-01

    International audience Ozone profiles from balloon soundings as well as SAGE II ozone profiles were used to detect anomalous large ozone concentrations of ozone in the lower stratosphere. These secondary ozone maxima are found to be the result of differential advection of ozone-poor and ozone-rich air associated with Rossby wave breaking events. The frequency and intensity of secondary ozone maxima and their geographical distribution is presented. The occurrence and amplitude of ozone seco...

  5. Contributions of a Tunable Diode Laser Instrument (ATLAS) to the Stratospheric Ozone Depletion Question

    Science.gov (United States)

    Loewenstein, Max; Russell, Philip B. (Technical Monitor)

    1994-01-01

    The Airborne Tunable Laser Absorption Spectrometer - ATLAS - was designed and built at the NASA Ames Research Center and operates on the NASA ER-2 high altitude research aircraft. ATLAS has taken part in a number of important polar and mid-latitude research campaigns, since 1987, focused on various aspects of stratospheric ozone chemistry and dynamics. The chief measurement carried out by the ATLAS second harmonic diode laser spectrometer is of the important atmospheric tracer N2O. Using N2O as an inert tracer we have been able to gain significant new information on polar vortex dynamics and on the correlations of several important long-lived tracers in the stratosphere. The correlation of N2O with NOy (total reactive nitrogen) has been shown to be linear for a great variety of unperturbed stratospheric conditions, and the breakdown of this correlation has been used to detect denitrification by PSCs in the polar vortex, especially in the Antarctic spring. Denitrification is an important step in the process of ozone hole formation in the austral spring. Correlations of N2O with CFCs and CH4 have led to improved estimates of atmospheric lifetimes of these important molecules. Finally the correlation of N2O with CO2, the latter now being measured with great precision by a new instrument on the ER-2, has led to a significant new tool for studying horizontal and vertical mixing in the lower stratosphere, a tool which is very useful in assessing the potential effects of high speed civil transport aircraft in the lower stratosphere. A new, light-weight version of ATLAS is currently being built for unmanned high altitude aircraft, specifically the new Perseus vehicle. We will give a brief description of this effort.

  6. Arctic and Antarctic Sea Ice Changes and Impacts (Invited)

    Science.gov (United States)

    Nghiem, S. V.

    2013-12-01

    The extent of springtime Arctic perennial sea ice, important to preconditioning summer melt and to polar sunrise photochemistry, continues its precipitous reduction in the last decade marked by a record low in 2012, as the Bromine, Ozone, and Mercury Experiment (BROMEX) was conducted around Barrow, Alaska, to investigate impacts of sea ice reduction on photochemical processes, transport, and distribution in the polar environment. In spring 2013, there was further loss of perennial sea ice, as it was not observed in the ocean region adjacent to the Alaskan north coast, where there was a stretch of perennial sea ice in 2012 in the Beaufort Sea and Chukchi Sea. In contrast to the rapid and extensive loss of sea ice in the Arctic, Antarctic sea ice has a trend of a slight increase in the past three decades. Given the significant variability in time and in space together with uncertainties in satellite observations, the increasing trend of Antarctic sea ice may arguably be considered as having a low confidence level; however, there was no overall reduction of Antarctic sea ice extent anywhere close to the decreasing rate of Arctic sea ice. There exist publications presenting various factors driving changes in Arctic and Antarctic sea ice. After a short review of these published factors, new observations and atmospheric, oceanic, hydrological, and geological mechanisms contributed to different behaviors of sea ice changes in the Arctic and Antarctic are presented. The contribution from of hydrologic factors may provide a linkage to and enhance thermal impacts from lower latitudes. While geological factors may affect the sensitivity of sea ice response to climate change, these factors can serve as the long-term memory in the system that should be exploited to improve future projections or predictions of sea ice changes. Furthermore, similarities and differences in chemical impacts of Arctic and Antarctic sea ice changes are discussed. Understanding sea ice changes and

  7. Environmental contamination in Antarctic ecosystems.

    Science.gov (United States)

    Bargagli, R

    2008-08-01

    Although the remote continent of Antarctica is perceived as the symbol of the last great wilderness, the human presence in the Southern Ocean and the continent began in the early 1900s for hunting, fishing and exploration, and many invasive plant and animal species have been deliberately introduced in several sub-Antarctic islands. Over the last 50 years, the development of research and tourism have locally affected terrestrial and marine coastal ecosystems through fuel combustion (for transportation and energy production), accidental oil spills, waste incineration and sewage. Although natural "barriers" such as oceanic and atmospheric circulation protect Antarctica from lower latitude water and air masses, available data on concentrations of metals, pesticides and other persistent pollutants in air, snow, mosses, lichens and marine organisms show that most persistent contaminants in the Antarctic environment are transported from other continents in the Southern Hemisphere. At present, levels of most contaminants in Antarctic organisms are lower than those in related species from other remote regions, except for the natural accumulation of Cd and Hg in several marine organisms and especially in albatrosses and petrels. The concentrations of organic pollutants in the eggs of an opportunistic top predator such as the south polar skua are close to those that may cause adverse health effects. Population growth and industrial development in several countries of the Southern Hemisphere are changing the global pattern of persistent anthropogenic contaminants and new classes of chemicals have already been detected in the Antarctic environment. Although the Protocol on Environmental Protection to the Antarctic Treaty provides strict guidelines for the protection of the Antarctic environment and establishes obligations for all human activity in the continent and the Southern Ocean, global warming, population growth and industrial development in countries of the Southern

  8. Environmental contamination in Antarctic ecosystems.

    Science.gov (United States)

    Bargagli, R

    2008-08-01

    Although the remote continent of Antarctica is perceived as the symbol of the last great wilderness, the human presence in the Southern Ocean and the continent began in the early 1900s for hunting, fishing and exploration, and many invasive plant and animal species have been deliberately introduced in several sub-Antarctic islands. Over the last 50 years, the development of research and tourism have locally affected terrestrial and marine coastal ecosystems through fuel combustion (for transportation and energy production), accidental oil spills, waste incineration and sewage. Although natural "barriers" such as oceanic and atmospheric circulation protect Antarctica from lower latitude water and air masses, available data on concentrations of metals, pesticides and other persistent pollutants in air, snow, mosses, lichens and marine organisms show that most persistent contaminants in the Antarctic environment are transported from other continents in the Southern Hemisphere. At present, levels of most contaminants in Antarctic organisms are lower than those in related species from other remote regions, except for the natural accumulation of Cd and Hg in several marine organisms and especially in albatrosses and petrels. The concentrations of organic pollutants in the eggs of an opportunistic top predator such as the south polar skua are close to those that may cause adverse health effects. Population growth and industrial development in several countries of the Southern Hemisphere are changing the global pattern of persistent anthropogenic contaminants and new classes of chemicals have already been detected in the Antarctic environment. Although the Protocol on Environmental Protection to the Antarctic Treaty provides strict guidelines for the protection of the Antarctic environment and establishes obligations for all human activity in the continent and the Southern Ocean, global warming, population growth and industrial development in countries of the Southern

  9. Iodine monoxide in the Antarctic snowpack

    Directory of Open Access Journals (Sweden)

    U. Platt

    2009-11-01

    Full Text Available Recent ground-based and space borne observations suggest the presence of significant amounts of iodine monoxide in the boundary layer of Antarctica, which are expected to have an impact on the ozone budget and might contribute to the formation of new airborne particles. So far, the source of these iodine radicals has been unknown. This paper presents long-term measurements of iodine monoxide at the German Antarctic research station Neumayer, which indicate that the snowpack is the main source for iodine radicals. The measurements have been performed using multi-axis differential optical absorption spectroscopy (MAX-DOAS. Using a coupled atmosphere-snowpack radiative transfer model, the comparison of the signals observed from scattered skylight and from light reflected by the snowpack yields several ppb of iodine monoxide in the upper layers of the sunlit snowpack throughout the year. Snow pit samples from Neumayer Station contain up to 700 ng/l of total iodine, representing a sufficient reservoir for these extraordinarily high IO concentrations.

  10. Iodine monoxide in the Antarctic snowpack

    Directory of Open Access Journals (Sweden)

    U. Frieß

    2010-03-01

    Full Text Available Recent ground-based and space borne observations suggest the presence of significant amounts of iodine monoxide in the boundary layer of Antarctica, which are expected to have an impact on the ozone budget and might contribute to the formation of new airborne particles. So far, the source of these iodine radicals has been unknown. This paper presents long-term measurements of iodine monoxide at the German Antarctic research station Neumayer, which indicate that high IO concentrations in the order of 50 ppb are present in the snow interstitial air. The measurements have been performed using multi-axis differential optical absorption spectroscopy (MAX-DOAS. Using a coupled atmosphere – snowpack radiative transfer model, the comparison of the signals observed from scattered skylight and from light reflected by the snowpack yields several ppb of iodine monoxide in the upper layers of the sunlit snowpack throughout the year. Snow pit samples from Neumayer Station contain up to 700 ng/l of total iodine, representing a sufficient reservoir for these extraordinarily high IO concentrations.

  11. Evolution and ecology of antarctic sponges

    OpenAIRE

    Vargas Ramirez, Sergio

    2012-01-01

    Sponges are abundant and species-rich in Antarctic waters, and play important roles in the benthic ecosystems of the continent. The taxonomy of Antarctic sponges is, to some extent, well established, yet the phylogenetic relationships of this fauna remain unknown. Here, the first contributions to the knowledge of the evolution of Antarctic sponges are presented. A molecular phylogeny for the common Antarctic shelf glass sponge genus Rossella is provided. Based on nuclear and mitochondrial mar...

  12. Observed Low Ozone Events in Coastal Antarctica - The Critical Role of Meteorology

    Science.gov (United States)

    Jones, A. E.; Wolff, E. W.; Anderson, P. S.; Turner, J.; Rankin, A. M.

    2004-12-01

    Episodic loss of tropospheric ozone has been observed in both polar regions. The destruction of ozone appears to be associated with halogen chemistry, generally accepted as being driven by bromine released from sea ice surfaces. Since March 2003, measurements of surface ozone have been made at the British Antarctic Survey Clean Air Sector Laboratory (CASLab) at Halley station in coastal Antarctica. Detailed measurements of boundary layer meteorology as well as standard meteorology are also measured at the CASLab. Combining the data allows us to probe the role of meteorology in these "low ozone events". Low ozone events are observed at Halley on numerous occasions during Antarctic spring; on occasions the development of the event and its recovery are strongly associated with the build-up and decline of a stable boundary layer; on occasions, extremely rapid loss of ozone is observed (loss of 20ppbv in 3 minutes on one occasion) which are associated with larger scale transport. We report here on the events recorded during spring 2003, and show the critical influence of meteorology. The association suggests that the role of meteorology must be considered when striving to understand the mechanisms controlling observed low ozone events, and hence extremely good meteorology will need to be included in any modeling calculations trying to reproduce observed events.

  13. Regulating Antarctic Tourism and the Precautionary Principle

    NARCIS (Netherlands)

    Bastmeijer, C.J.; Roura, R.

    2004-01-01

    On the basis of an overview of the developments in Antarctic tourism since 1956, this current development note examines the issue of international regulation of Antarctic tourism. After discussing one of the main management issues in respect of Antarctic tourism ¿ the assessment and prevention of cu

  14. Stratospheric ozone depletion

    International Nuclear Information System (INIS)

    The amount of stratospheric ozone and the reduction of the ozone layer vary according to seasons and latitudes. At present total and vertical ozone is monitored over all Austria. The mean monthly ozone levels between 1994 and 2000 are presented. Data on stratospheric ozone and UV-B radiation are published daily on the home page http: www.lebesministerium.at. The use of ozone depleting substances such as chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) is provided. Besides, the national measures taken to reduce their use. Figs. 2, Tables 2. (nevyjel)

  15. Polar tropospheric ozone depletion events observed in IGY

    Directory of Open Access Journals (Sweden)

    H. K. Roscoe

    2006-05-01

    Full Text Available The Royal Society expedition to Antarctica established a base at Halley Bay, in support of the International Geophysical Year of 1957–1958. Surface ozone was measured during 1958 only, using a prototype Brewer-Mast sonde. The envelope of maximum ozone was an annual cycle from 10 ppbv in January to 22 ppbv in August. These values are 35% less at the start of the year and 15% less at the end than modern values from Neumayer, also a coastal site. This may reflect a general increase in surface ozone since 1958 and differences in summer at the less windy site of Halley, or it may reflect ozone loss on the inlet together with long-term conditioning. There were short periods in September when ozone values decreased rapidly to near-zero, and some in August when ozone values were rapidly halved. Such ozone-loss episodes, catalysed by bromine compounds, became well-known in the Artic in the 1980s, and were observed more recently in the Antarctic. In 1958, very small ozone values were recorded for a week in midwinter during clear weather with light winds. The absence of similar midwinter reductions at Neumayer, or at Halley in the few measurements during 1987, means we must remain suspicious of these small values, but we can find no obvious reason to discount them. The dark reaction of ozone and seawater ice observed in the laboratory may be fast enough to explain them if the salinity and surface area of the ice is sufficiently amplified by frost flowers.

  16. Impact of climate variability on tropospheric ozone

    International Nuclear Information System (INIS)

    A simulation with the climate-chemistry model (CCM) E39/C is presented, which covers both the troposphere and stratosphere dynamics and chemistry during the period 1960 to 1999. Although the CCM, by its nature, is not exactly representing observed day-by-day meteorology, there is an overall model's tendency to correctly reproduce the variability pattern due to an inclusion of realistic external forcings, like observed sea surface temperatures (e.g. El Nino), major volcanic eruption, solar cycle, concentrations of greenhouse gases, and Quasi-Biennial Oscillation. Additionally, climate-chemistry interactions are included, like the impact of ozone, methane, and other species on radiation and dynamics, and the impact of dynamics on emissions (lightning). However, a number of important feedbacks are not yet included (e.g. feedbacks related to biogenic emissions and emissions due to biomass burning). The results show a good representation of the evolution of the stratospheric ozone layer, including the ozone hole, which plays an important role for the simulation of natural variability of tropospheric ozone. Anthropogenic NOx emissions are included with a step-wise linear trend for each sector, but no interannual variability is included. The application of a number of diagnostics (e.g. marked ozone tracers) allows the separation of the impact of various processes/emissions on tropospheric ozone and shows that the simulated Northern Hemisphere tropospheric ozone budget is not only dominated by nitrogen oxide emissions and other ozone pre-cursors, but also by changes of the stratospheric ozone budget and its flux into the troposphere, which tends to reduce the simulated positive trend in tropospheric ozone due to emissions from industry and traffic during the late 80s and early 90s. For tropical regions the variability in ozone is dominated by variability in lightning (related to ENSO) and stratosphere-troposphere exchange (related to Northern Hemisphere Stratospheric

  17. Impact of climate variability on tropospheric ozone

    International Nuclear Information System (INIS)

    A simulation with the climate-chemistry model (CCM) E39/C is presented, which covers both the troposphere and stratosphere dynamics and chemistry during the period 1960 to 1999. Although the CCM, by its nature, is not exactly representing observed day-by-day meteorology, there is an overall model's tendency to correctly reproduce the variability pattern due to an inclusion of realistic external forcings, like observed sea surface temperatures (e.g. El Nino), major volcanic eruption, solar cycle, concentrations of greenhouse gases, and Quasi-Biennial Oscillation. Additionally, climate-chemistry interactions are included, like the impact of ozone, methane, and other species on radiation and dynamics, and the impact of dynamics on emissions (lightning). However, a number of important feedbacks are not yet included (e.g. feedbacks related to biogenic emissions and emissions due to biomass burning). The results show a good representation of the evolution of the stratospheric ozone layer, including the ozone hole, which plays an important role for the simulation of natural variability of tropospheric ozone. Anthropogenic NO x emissions are included with a step-wise linear trend for each sector, but no interannual variability is included. The application of a number of diagnostics (e.g. marked ozone tracers) allows the separation of the impact of various processes/emissions on tropospheric ozone and shows that the simulated Northern Hemisphere tropospheric ozone budget is not only dominated by nitrogen oxide emissions and other ozone pre-cursors, but also by changes of the stratospheric ozone budget and its flux into the troposphere, which tends to reduce the simulated positive trend in tropospheric ozone due to emissions from industry and traffic during the late 80s and early 90s. For tropical regions the variability in ozone is dominated by variability in lightning (related to ENSO) and stratosphere-troposphere exchange (related to Northern Hemisphere Stratospheric

  18. Climatology and trends in the forcing of the stratospheric ozone transport

    Science.gov (United States)

    Monier, E.; Weare, B. C.

    2011-07-01

    A thorough analysis of the ozone transport was carried out using the Transformed-Mean Eulerian (TEM) tracer continuity equation and the European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40). In this budget analysis, the chemical net production term, which is calculated as the residual of the other terms, displays the correct features of a chemical sink and source term, including location and seasonality, and shows good agreement in magnitude compared to other methods of calculating ozone loss rates. This study provides further insight into the role of the eddy ozone transport and underlines its fundamental role in the recovery of the ozone hole during spring. The trend analysis reveals that the ozone hole intensification over the 1980-2001 period is not solely related to the trend in chemical losses, but more specifically to the balance between the trends in chemical losses and ozone transport. That is because, in the Southern Hemisphere from October to December, the large increase in the chemical destruction of ozone is balanced by an equally large trend in the eddy transport, associated with a small increase in the mean transport. This study shows that the increase in the eddy transport is characterized by more poleward ozone eddy flux by transient waves in the midlatitudes and by stationary waves in the polar region. Overall, this study makes clearer the close interaction between the trends in ozone chemistry and ozone transport. It reveals that the eddy ozone transport and its long-term changes are an important natural mitigation mechanism for the ozone hole. This work also underlines the need for diagnostics of the eddy transport in chemical transport models used to investigate future ozone recovery.

  19. Climatology and trends in the forcing of the stratospheric ozone transport

    Directory of Open Access Journals (Sweden)

    E. Monier

    2011-07-01

    Full Text Available A thorough analysis of the ozone transport was carried out using the Transformed-Mean Eulerian (TEM tracer continuity equation and the European Centre for Medium-Range Weather Forecasts (ECMWF Re-Analysis (ERA-40. In this budget analysis, the chemical net production term, which is calculated as the residual of the other terms, displays the correct features of a chemical sink and source term, including location and seasonality, and shows good agreement in magnitude compared to other methods of calculating ozone loss rates. This study provides further insight into the role of the eddy ozone transport and underlines its fundamental role in the recovery of the ozone hole during spring. The trend analysis reveals that the ozone hole intensification over the 1980–2001 period is not solely related to the trend in chemical losses, but more specifically to the balance between the trends in chemical losses and ozone transport. That is because, in the Southern Hemisphere from October to December, the large increase in the chemical destruction of ozone is balanced by an equally large trend in the eddy transport, associated with a small increase in the mean transport. This study shows that the increase in the eddy transport is characterized by more poleward ozone eddy flux by transient waves in the midlatitudes and by stationary waves in the polar region. Overall, this study makes clearer the close interaction between the trends in ozone chemistry and ozone transport. It reveals that the eddy ozone transport and its long-term changes are an important natural mitigation mechanism for the ozone hole. This work also underlines the need for diagnostics of the eddy transport in chemical transport models used to investigate future ozone recovery.

  20. Principles of the Antarctic Treaty

    Science.gov (United States)

    Candidi, M.

    The operation of any base or expedition to Antarctica is regulated by the mutual agreement among nations in the “Antarctic Treaty”. This treaty deals with the major aspects of life in Antarctica and its main principles and provisions are described in what follows.

  1. Special Stamps:Antarctic Scenery

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In July 2002, the State Postal Bureau issued a set of three stamps, whose theme is Antarctic scenery.The first stamp depicts an iceberg. Antarctica is where 90 percent of the world’s ice exists. Each year countless icebergs float majestically through the sea, and are a magnificent scenic feature of Antarctica.

  2. Stratospheric ozone reduction and its relation to natural and man made sources

    Energy Technology Data Exchange (ETDEWEB)

    Isaksen, I.S. [Oslo Univ. (Norway). Dept. of Geophysics

    1995-12-31

    Approximately 90 % of the total ozone mass is in the stratosphere (between approximately 12 and 50 km), the rest is in the troposphere (below 12 km). The global distribution of ozone in the stratosphere and its variation over time have been studied extensively over several decades. These studies include observations by ground based instruments (e.g. Dobson instruments), instruments on airborne platforms (e.g. ozone sondes) and on satellites, and model studies which simulate the chemical and dynamical behaviour of the stratosphere. These studies have given good information about the processes which determine the ozone distribution, and how man made emissions affect the distribution. Observations have revealed that there are large year to year variations in stratospheric ozone above a particular location. These variations are difficult to predict as they are connected to irregular weather patterns. However, the observations have shown that there has been a long term decrease in stratospheric ozone on a global scale during the last two decades. The decrease has been most pronounced during the last five to six years and is seen both in the Northern and the Southern Hemispheres. The strong decrease in stratospheric ozone over the Antarctic continent, which has been observed since the mid 80s, and which has reduced the total ozone column with more than 50 % compared with earlier observations, is proven to be a result of increased man made emissions of CFCs. There are also mounting evidences that Northern Hemispheric ozone reductions observed since 1980 are connected to man made emissions of CFCs

  3. A network of autonomous surface ozone monitors in Antarctica: technical description and first results

    Science.gov (United States)

    Bauguitte, S. J.-B.; Brough, N.; Frey, M. M.; Jones, A. E.; Maxfield, D. J.; Roscoe, H. K.; Rose, M. C.; Wolff, E. W.

    2011-04-01

    A suite of 10 autonomous ozone monitoring units, each powered using renewable energy, was developed and built to study surface ozone in Antarctica during the International Polar Year (2007-2009). The monitoring systems were deployed in a network around the Weddell Sea sector of coastal Antarctica with a transect up onto the Antarctic Plateau. The aim was to measure for a full year, thus gaining a much-improved broader view of boundary layer ozone seasonality at different locations as well as of factors affecting the budget of surface ozone in Antarctica. Ozone mixing ratios were measured based on UV photometry using a modified version of the commercial 2B Technologies Inc. Model 202 instrument. All but one of the autonomous units measured successfully within its predefined duty cycle throughout the year, with some differences in performance dependent on power availability and ambient temperature. Mean data recovery after removal of outliers was on average 70% (range 44-83%) and precision varied between 1.5 and 8 ppbv, thus was sufficiently good to resolve year-round the main ozone features of scientific interest. We conclude that, with adequate power, and noting a minor communication problem, our units would be able to operate successfully at ambient temperatures down to -60 °C. Systems such as the one described in this paper, or derivatives of it, could therefore be deployed either as local or regional networks elsewhere in the Arctic or Antarctic. Here we present technical information and first results from the experiment.

  4. Quality Assurance of A Solar Uv Network In The Antarctic

    Science.gov (United States)

    Lakkala, K.; Redondas, A.; Koskela, T.; Taalas, P.; Torres, C.; Cuevas, E.; Deferrari, G.

    This work will present the quality assurance of the solar UV network of the Mea- surement of Antarctic Radiance for monitoring the ozone layer (MAR) -project. The network consists on three NILU-UV multichannel filter radiometers, which have been installed at the Argentinean Antarctic bases of Vicecomodoro Marambio and Bel- grano II and at the Centro Austral De Investigationes Cientificas (CADIC) in Ushuaia in December 1999­January 2000. The location of the three sites gives a possibility to study the impact of the daily changes of the polar vortex on ozone and UV radiation reaching the ground: Belgrano being located mostly inside the vortex, Marambio at the edge and Ushuaia mostly outside the vortex. The network has been established as co-operation between the Instituto Nacional de Meteorologia (INM), Spain, the Insti- tuto Antártico Argentino (IAA) from Dirrección Nacional del Antártico (DNA), the Finnish Meteorological Institute (FMI) and the CADIC. The quality assurance procedure, which includes a travelling reference and relative lamp tests, will be described. The travelling reference has been provided to trans- fer calibration factors from the absolute reference spectroradiometer to the NILU-UV radiometers of the network. Results of solar comparisons between the travelling ref- erence and the site instruments of Marambio and Ushuaia will be presented. Relative lamp tests are performed every second week in order to monitor the stability of the instruments. Time series of these lamp tests are analysed to perform corrections to each channel during the measurement period.

  5. Black holes

    CERN Document Server

    Chrúsciel, P T

    2002-01-01

    This paper is concerned with several not-quantum aspects of black holes, with emphasis on theoretical and mathematical issues related to numerical modeling of black hole space-times. Part of the material has a review character, but some new results or proposals are also presented. We review the experimental evidence for existence of black holes. We propose a definition of black hole region for any theory governed by a symmetric hyperbolic system of equations. Our definition reproduces the usual one for gravity, and leads to the one associated with the Unruh metric in the case of Euler equations. We review the global conditions which have been used in the Scri-based definition of a black hole and point out the deficiencies of the Scri approach. Various results on the structure of horizons and apparent horizons are presented, and a new proof of semi-convexity of horizons based on a variational principle is given. Recent results on the classification of stationary singularity-free vacuum solutions are reviewed. ...

  6. Inter-annual variability of surface ozone at coastal (Dumont d'Urville, 2004-2014) and inland (Concordia, 2007-2014) sites in East Antarctica

    Science.gov (United States)

    Legrand, Michel; Preunkert, Susanne; Savarino, Joël; Frey, Markus M.; Kukui, Alexandre; Helmig, Detlev; Jourdain, Bruno; Jones, Anna E.; Weller, Rolf; Brough, Neil; Gallée, Hubert

    2016-07-01

    Surface ozone has been measured since 2004 at the coastal East Antarctic site of Dumont d'Urville (DDU), and since 2007 at the Concordia station located on the high East Antarctic plateau. This paper discusses long-term changes, seasonal and diurnal cycles, as well as inter-annual summer variability observed at these two East Antarctic sites. At Concordia, near-surface ozone data were complemented by balloon soundings and compared to similar measurements done at the South Pole. The DDU record is compared to those obtained at the coastal site of Syowa, also located in East Antarctica, as well as the coastal sites of Neumayer and Halley, both located on the coast of the Weddell Sea in West Antarctica. Surface ozone mixing ratios exhibit very similar seasonal cycles at Concordia and the South Pole. However, in summer the diurnal cycle of ozone is different at the two sites with a drop of ozone in the afternoon at Concordia but not at the South Pole. The vertical distribution of ozone above the snow surface also differs. When present, the ozone-rich layer located near the ground is better mixed and deeper at Concordia (up to 400 m) than at the South Pole during sunlight hours. These differences are related to different solar radiation and wind regimes encountered at these two inland sites. DDU appears to be the coastal site where the impact of the late winter/spring bromine chemistry is the weakest, but where the impact of elevated ozone levels caused by NOx snow emissions from the high Antarctic plateau is the highest. The highest impact of the bromine chemistry is seen at Halley and Neumayer, and to a lesser extent at Syowa. These three sites are only weakly impacted by the NOx chemistry and the net ozone production occurring on the high Antarctic plateau. The differences in late winter/spring are attributed to the abundance of sea ice offshore from the sites, whereas those in summer are related to the topography of East Antarctica that promotes the katabatic flow

  7. Multibranch Antarctic Seismic Data Library facilitates research

    Science.gov (United States)

    Cooper, Alan K.

    In 1991, investigators from 11 nations involved in Antarctic multichannel seismic (MCS) reflection research sought a way to keep the Antarctic Treaty's promise of open access to data, and in the process to encourage Earth-science research using seismic data. The Antarctic Seismic Data Library System for Cooperative Research (SDLS) was the solution, and is now a recommendation of the Antarctic Treaty Consultative Parties (ATCP). Today—at 12 branches spanning the world—researchers can access over 68,000 km of marine MCS data to use for cooperative research.More than 150,000 km of MCS data have been accumulated since 1976 by 13 countries on nearly 70 cruises. The majority of data now in the library cover the Ross Sea, Wilkes Land, and Prydz Bay sectors of the Antarctic margin, with smaller amounts from the Weddell Sea and the Antarctic Peninsula.

  8. Antarctic tourism and the maritime heritage

    OpenAIRE

    Basberg, Bjørn L.

    2008-01-01

    Maritime activity in the Antarctic region goes back to the 18th Century. It evolved from exploration and discoveries to commercial activities, especially sealing and whaling. Antarctic tourism is a more recent phenomenon, developing gradually from the 1960s. Today, more than 20.000 tourists visit the Antarctic annually – mostly on cruise ships. The paper reviews the historical development of these activities. The main focus is on how the maritime heritage has been dealt with an...

  9. Tropospheric ozone variations in polar regions; Troposphaerische Ozonvariationen in Polarregionen

    Energy Technology Data Exchange (ETDEWEB)

    Wessel, S.

    1997-08-01

    An extensive analysis for the description of chemical and dynamical processes during tropospheric ozone minima in the Arctic and Antarctic was carried out in this work. One main task was the analysis of the source regions of tropospheric ozone destruction and the following transport of ozone depleted air masses to the measuring site. Furtheron the ozone destruction mechanism itself should be examined as well as the efficiency of heterogeneous reactions for the regeneration of non-reative bromine compounds, which seems to be necessary because bromine may be the key component in the destruction of tropospheric ozone in polar regions. (orig./KW) [Deutsch] In der vorliegenden Arbeit wurde eine umfangreiche Analyse zur Beschreibung der chemischen und dynamischen Prozesse waehrend troposphaerischer Ozonminima in der Arktis und Antarktis durchgefuehrt. Ziel war es, die Quellregion des Ozonabbaus sowie den ausloesenden ozonabbauenden Mechanismus zu benennen, die Effizienz heterogener Reaktionen zur Regenerierung nichtreaktiver Bromverbindungen waehrend des Ozonabbaus zu ermitteln und den Transport der ozonarmen Luftmassen zum Messort zu untersuchen. (orig./KW)

  10. Antarctic skuas recognize individual humans.

    Science.gov (United States)

    Lee, Won Young; Han, Yeong-Deok; Lee, Sang-Im; Jablonski, Piotr G; Jung, Jin-Woo; Kim, Jeong-Hoon

    2016-07-01

    Recent findings report that wild animals can recognize individual humans. To explain how the animals distinguish humans, two hypotheses are proposed. The high cognitive abilities hypothesis implies that pre-existing high intelligence enabled animals to acquire such abilities. The pre-exposure to stimuli hypothesis suggests that frequent encounters with humans promote the acquisition of discriminatory abilities in these species. Here, we examine individual human recognition abilities in a wild Antarctic species, the brown skua (Stercorarius antarcticus), which lives away from typical human settlements and was only recently exposed to humans due to activities at Antarctic stations. We found that, as nest visits were repeated, the skua parents responded at further distances and were more likely to attack the nest intruder. Also, we demonstrated that seven out of seven breeding pairs of skuas selectively responded to a human nest intruder with aggression and ignored a neutral human who had not previously approached the nest. The results indicate that Antarctic skuas, a species that typically inhabited in human-free areas, are able to recognize individual humans who disturbed their nests. Our findings generally support the high cognitive abilities hypothesis, but this ability can be acquired during a relatively short period in the life of an individual as a result of interactions between individual birds and humans.

  11. Ozone chemistry in aqueous solution : ozone decomposition and stabilisation

    OpenAIRE

    Eriksson, Margareta

    2005-01-01

    Ozone is used in many applications in the industry as an oxidising agent for example for bleaching and sterilisation. The decomposition of ozone in aqueous solutions is complex, and is affected by many properties such as, pH, temperature and substances present in the water. Additives can either accelerate the decomposition rate of ozone or have a stabilising effect of the ozone decay. By controlling the decomposition of ozone it is possible to increase the oxidative capacity of ozone. In this...

  12. Organic pollutants removal in wastewater by heterogeneous photocatalytic ozonation.

    Science.gov (United States)

    Xiao, Jiadong; Xie, Yongbing; Cao, Hongbin

    2015-02-01

    Heterogeneous photocatalysis and ozonation are robust advanced oxidation processes for eliminating organic contaminants in wastewater. The combination of these two methods is carried out in order to enhance the overall mineralization of refractory organics. An apparent synergism between heterogeneous photocatalysis and ozonation has been demonstrated in many literatures, which gives rise to an improvement of total organic carbon removal. The present overview dissects the heterogeneous catalysts and the influences of different operational parameters, followed by the discussion on the kinetics, mechanism, economic feasibility and future trends of this integrated technology. The enhanced oxidation rate mainly results from a large amount of hydroxyl radicals generated from a synergistically induced decomposition of dissolved ozone, besides superoxide ion radicals and the photo-induced holes. Six reaction pathways possibly exist for the generation of hydroxyl radicals in the reaction mechanism of heterogeneous photocatalytic ozonation.

  13. Coronal Holes

    Directory of Open Access Journals (Sweden)

    Steven R. Cranmer

    2009-09-01

    Full Text Available Coronal holes are the darkest and least active regions of the Sun, as observed both on the solar disk and above the solar limb. Coronal holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar wind. This paper reviews measurements of the plasma properties in coronal holes and how these measurements are used to reveal details about the physical processes that heat the solar corona and accelerate the solar wind. It is still unknown to what extent the solar wind is fed by flux tubes that remain open (and are energized by footpoint-driven wave-like fluctuations, and to what extent much of the mass and energy is input intermittently from closed loops into the open-field regions. Evidence for both paradigms is summarized in this paper. Special emphasis is also given to spectroscopic and coronagraphic measurements that allow the highly dynamic non-equilibrium evolution of the plasma to be followed as the asymptotic conditions in interplanetary space are established in the extended corona. For example, the importance of kinetic plasma physics and turbulence in coronal holes has been affirmed by surprising measurements from the UVCS instrument on SOHO that heavy ions are heated to hundreds of times the temperatures of protons and electrons. These observations point to specific kinds of collisionless Alfvén wave damping (i.e., ion cyclotron resonance, but complete theoretical models do not yet exist. Despite our incomplete knowledge of the complex multi-scale plasma physics, however, much progress has been made toward the goal of understanding the mechanisms ultimately responsible for producing the observed properties of coronal holes.

  14. Ozone flow visualization techniques

    Science.gov (United States)

    Dickerson, R. R.; Stedman, D. H.

    1981-01-01

    Flow visualization techniques using ozone for tracing gas flows are proposed whereby ozone is detected through its strong absorption of ultraviolet light, which is easily made visible with fluorescent materials, or through its reaction with nitric oxide to form excited nitrogen dioxide, which in relaxing emits detectable light. It is shown that response speeds in the kHz range are possible with an ultraviolet detection system for initial ozone concentrations of about 1%.

  15. ER-2 #809 on the SAGE III Ozone Loss and Validation Experiment (SOLVE) with pilot Dee Porter prepari

    Science.gov (United States)

    2000-01-01

    Lockheed Martin pilot Dee Porter climbs up the ladder wearing a heavy tan pressure suit, preparing to board NASA ER-2 #809 at Kiruna, Sweden, for the third flight in the SAGE III Ozone Loss and Validation Experiment. Assisting him is Jim Sokolik, a Lockheed Martin life support technician. Number 809, one of Dryden's two high-flying ER-2 Airborne Science aircraft, a civilian variant of Lockheed's U-2, and another NASA flying laboratory, Dryden's DC-8, were based north of the Arctic Circle in Kiruna, Sweden during the winter of 2000 to study ozone depletion as part of the SAGE III Ozone Loss and Validation Experiment (SOLVE). A large hangar built especially for research, 'Arena Arctica' housed the instrumented aircraft and the scientists. Scientists have observed unusually low levels of ozone over the Arctic during recent winters, raising concerns that ozone depletion there could become more widespread as in the Antarctic ozone hole. The NASA-sponsored international mission took place between November 1999 and March 2000 and was divided into three phases. The DC-8 was involved in all three phases returning to Dryden between each phase. The ER-2 flew sample collection flights between January and March, remaining in Sweden from Jan. 9 through March 16. 'The collaborative campaign will provide an immense new body of information about the Arctic stratosphere,' said program scientist Dr. Michael Kurylo, NASA Headquarters. 'Our understanding of the Earth's ozone will be greatly enhanced by this research.' ER-2s bearing tail numbers 806 and 809 are used as airborne science platforms by NASA's Dryden Flight Research Center. The aircraft are platforms for a variety of high-altitude science missions flown over various parts of the world. They are also used for earth science and atmospheric sensor research and development, satellite calibration and data validation. The ER-2s are capable of carrying a maximum payload of 2,600 pounds of experiments in a nose bay, the main

  16. Variability in solar irradiance observed at two contrasting Antarctic sites

    Science.gov (United States)

    Petkov, Boyan H.; Láska, Kamil; Vitale, Vito; Lanconelli, Christian; Lupi, Angelo; Mazzola, Mauro; Budíková, Marie

    2016-05-01

    The features of erythemally weighted (EW) and short-wave downwelling (SWD) solar irradiances, observed during the spring-summer months of 2007-2011 at Johann Gregor Mendel (63°48‧S, 57°53‧W, 7 m a.s.l.) and Dome Concordia (75°06‧S, 123°21‧E, 3233 m a.s.l.) stations, placed at the Antarctic coastal region and on the interior plateau respectively, have been analysed and compared to each other. The EW and SWD spectral components have been presented by the corresponding daily integrated values and were examined taking into account the different geographic positions and different environmental conditions at both sites. The results indicate that at Mendel station the surface solar irradiance is strongly affected by the changes in the cloud cover, aerosols and albedo that cause a decrease in EW between 20% and 35%, and from 0% to 50% in SWD component, which contributions are slightly lower than the seasonal SWD variations evaluated to be about 71%. On the contrary, the changes in the cloud cover features at Concordia station produce only a 5% reduction of the solar irradiance, whilst the seasonal oscillations of 94% turn out to be the predominant mode. The present analysis leads to the conclusion that the variations in the ozone column cause an average decrease of about 46% in EW irradiance with respect to the value found in the case of minimum ozone content at each of the stations. In addition, the ratio between EW and SWD spectral components can be used to achieve a realistic assessment of the radiation amplification factor that quantifies the relationship between the atmospheric ozone and the surface UV irradiance.

  17. EVIDENCE OF ARCTIC AND ANTARCTIC CHANGES AND THEIR REGULATION OF GLOBAL CLIMATE CHANGE (FURTHER FINDINGS SINCE THE FOURTH IPCC ASSESSMENT REPORT RELEASED)%南极和北极地区变化对全球气候变化的指示和调控作用——第四次IPCC评估报告以来一些新认知

    Institute of Scientific and Technical Information of China (English)

    陈立奇

    2013-01-01

    Changes in the climate of the Arctic and the Antarctic have been of great concern to international scientific and social communities since the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) was released in 2007. Since then, many new findings have been reported from observations and research carried out in the Arctic and Antarctic during the 4th International Polar Year (IPY). There is evidence that rapid changes in the Arctic and Antarctic induced by global warming are occurring in a quantitative and qualitative sense, and Arctic and Antarctic regional changes could be used indicators of global climate change. Declining Arctic sea ice could impact on winter snowfall in much of the Northern Hemisphere, with colder winters and more snow. Projections suggest that summertime Arctic sea ice will disappear by 2040. By 2050, the Antarctic ozone hole will have recovered to the level of the early 1980s, when the production of freon was completely prohibited. With weakening the shielding effect of the ozone hole to the global warming, it will become warmer in Antarctica and East Antarctica, leading to melting of ice sheets and retreating sea ice. Sea level rise will be a serious issue. As sea surface temperature rises the air-sea exchange of CO2 will be enhanced and surface water will take up more C02. This will lead to ocean acidification with important effects on ecological systems and food chains.%政府间气候变化专门委员会(IPCC) 2007年发布了第四次评估报告,全球气候变化问题再次成为一个重要的国际科学和政治议题.2007年以来,通过实施第四次国际极地年行动所获得的成果进一步证明,全球变暖所诱发极区出现的快速变化正在经历由量到质的转变,表明两极变化对全球气候变化起着一种指示和调控作用.一些研究指出:北冰洋会在2040年前后出现夏季无海冰并将引起北半球大范围的持续暴雪的寒冷冬季发生;2050

  18. Toward Describing the Effects of Ozone Depletion on Marine Primary Productivity and Carbon Cycling

    Science.gov (United States)

    Cullen, John J.

    1995-01-01

    This project was aimed at improved predictions of the effects of UVB and ozone depletion on marine primary productivity and carbon flux. A principal objective was to incorporate a new analytical description of photosynthesis as a function of UV and photosynthetically available radiation (Cullen et. al., Science 258:646) into a general oceanographic model. We made significant progress: new insights into the kinetics of photoinhibition were used in the analysis of experiments on Antarctic phytoplankton to generate a general model of UV-induced photoinhibition under the influence of ozone depletion and vertical mixing. The way has been paved for general models on a global scale.

  19. JCADM, new directions in Antarctic data management

    Science.gov (United States)

    Campbell, H.; de Bruin, T. F.

    2008-12-01

    The Joint Committee on Antarctic Data Management (JCADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), to assist in the fulfilment of the data management obligations imposed by the Antarctic Treaty (section III.1.c): "Scientific observations and results from Antarctica shall be exchanged and made freely available." JCADM comprises representatives of the National Antarctic Data Centres or national points of contact. Currently 31 nations around the world are represented in JCADM. So far, JCADM has been focussing on the coordination of the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. Currently, JCADM is in a transition phase, moving forward to provide data access. Existing systems and web services technology will be used as much as possible, to increase efficiency and prevent 're-inventing the wheel' This poster will give an overview of this process, the current status and the expected results.

  20. Impact of climate change on Antarctic krill

    NARCIS (Netherlands)

    Florentino De Souza Silva, A.P.; Atkinson, A.; Kawaguchi, S.; Bravo Rebolledo, E.; Franeker, van J.A.

    2012-01-01

    Antarctic krill Euphausia superba (hereafter ‘krill’) occur in regions undergoing rapid environmental change, particularly loss of winter sea ice. During recent years, harvesting of krill has increased, possibly enhancing stress on krill and Antarctic ecosystems. Here we review the overall impact of

  1. Seven years of total ozone from the TOMS instrument - A report on data quality

    Science.gov (United States)

    Fleig, Albert J.; Bhartia, Pawan K.; Wellemeyer, Charles G.; Silberstein, David S.

    1986-01-01

    Seven years of TOMS total ozone data are currently available. Recently a new ozone retrieval algorithm based on improved ozone absorption cross section was implemented that has introduced 6-7 percent discontinuity in the archived data sets at the end of the fifth year of instrument operation. Until all data are reprocessed with the new algorithm users can use a table of correction factors given in this paper to make the data set internally consistent. This paper also presents a comparison of TOMS results with Amundsen Scott Dobson station. Though the agrement in most years is good, in 1983-84 the Dobson station reported unusually high values of ozone while TOMS saw the very low ozone values associated with the Antarctica ozone hole.

  2. Ozone depletion in the high latitude lower stratosphere - 1979-1990

    Science.gov (United States)

    Callis, Linwood B.; Boughner, Robert E.; Natarajan, Murali; Lambeth, James D.; Baker, Daniel N.

    1991-01-01

    Archived Stratospheric Aerosol and Gas Experiment (SAGE, SAGE II) and Solar and Backscattered Ultraviolet (SBUV) data are used to examine lower stratospheric O3 variations at 50 deg latitude in both hemispheres. These data indicate that from 1979 to 1985, 73-90 percent of the total O3 changes have occurred below approximately 25 km in altitude. Significant O3 depletions (up to 15 percent) have occurred in the partial column (127-15.8 mbar) in both hemispheres with indications of a recovery after 1985. Two-dimensional model simulations of O3 changes from 1979 to 1990 have been carried out. Comparisons with O3 data are presented. Model results suggest that by 1985, significant declines in global O3 were caused by destruction by odd nitrogen associated with long-term variations in the flux of precipitating relativistic electrons (2.6 percent); solar UV flux changes (1.8 percent); the dilution effect associated with the Antarctic O3 hole (1.2 percent); and atmospheric increases in CH4, N2O, and chlorofluorocarbons (0.4 percent). Analyses of drift-corrected SBUV and Total Ozone Mapping Spectrometer data and model calculations indicate that between 1979 and 1985, reductions of 4.3 to 4.8 percent in total column O3 averaged between 65 deg S and 65 deg N have occurred. Calculations indicate a full global O3 decline of 5.2 percent (peak-to-peak) or 6 percent (annual average) between 1979 and 1985 with a partial recovery between 1985 and 1989.

  3. A study of polar ozone depletion based on sequential assimilation of satellite data from the ENVISAT/MIPAS and Odin/SMR instruments

    Directory of Open Access Journals (Sweden)

    J. D. Rösevall

    2007-01-01

    Full Text Available The objective of this study is to demonstrate how polar ozone depletion can be mapped and quantified by assimilating ozone data from satellites into the wind driven transport model DIAMOND, (Dynamical Isentropic Assimilation Model for OdiN Data. By assimilating a large set of satellite data into a transport model, ozone fields can be built up that are less noisy than the individual satellite ozone profiles. The transported fields can subsequently be compared to later sets of incoming satellite data so that the rates and geographical distribution of ozone depletion can be determined. By tracing the amounts of solar irradiation received by different air parcels in a transport model it is furthermore possible to study the photolytic reactions that destroy ozone. In this study, destruction of ozone that took place in the Antarctic winter of 2003 and in the Arctic winter of 2002/2003 have been examined by assimilating ozone data from the ENVISAT/MIPAS and Odin/SMR satellite-instruments. Large scale depletion of ozone was observed in the Antarctic polar vortex of 2003 when sunlight returned after the polar night. By mid October ENVISAT/MIPAS data indicate vortex ozone depletion in the ranges 80–100% and 70–90% on the 425 and 475 K potential temperature levels respectively while the Odin/SMR data indicates depletion in the ranges 70–90% and 50–70%. The discrepancy between the two instruments has been attributed to systematic errors in the Odin/SMR data. Assimilated fields of ENVISAT/MIPAS data indicate ozone depletion in the range 10–20% on the 475 K potential temperature level, (~19 km altitude, in the central regions of the 2002/2003 Arctic polar vortex. Assimilated fields of Odin/SMR data on the other hand indicate ozone depletion in the range 20–30%.

  4. Estonian total ozone climatology

    Directory of Open Access Journals (Sweden)

    K. Eerme

    Full Text Available The climatological characteristics of total ozone over Estonia based on the Total Ozone Mapping Spectrometer (TOMS data are discussed. The mean annual cycle during 1979–2000 for the site at 58.3° N and 26.5° E is compiled. The available ground-level data interpolated before TOMS, have been used for trend detection. During the last two decades, the quasi-biennial oscillation (QBO corrected systematic decrease of total ozone from February–April was 3 ± 2.6% per decade. Before 1980, a spring decrease was not detectable. No decreasing trend was found in either the late autumn ozone minimum or in the summer total ozone. The QBO related signal in the spring total ozone has an amplitude of ± 20 DU and phase lag of 20 months. Between 1987–1992, the lagged covariance between the Singapore wind and the studied total ozone was weak. The spring (April–May and summer (June–August total ozone have the best correlation (coefficient 0.7 in the yearly cycle. The correlation between the May and August total ozone is higher than the one between the other summer months. Seasonal power spectra of the total ozone variance show preferred periods with an over 95% significance level. Since 1986, during the winter/spring, the contribution period of 32 days prevails instead of the earlier dominating 26 days. The spectral densities of the periods from 4 days to 2 weeks exhibit high interannual variability.

    Key words. Atmospheric composition and structure (middle atmosphere – composition and chemistry; volcanic effects – Meteorology and atmospheric dynamics (climatology

  5. Ozone as an air pollutant

    DEFF Research Database (Denmark)

    Berg, Rolf W.

    1996-01-01

    A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995.......A Danish new book on ozone as an air pollutant has been reviewed. The Book is "Ozon som luftforurening" by Jes Fenger, Published by "Danmarks Miljøundersøgelser, 1995....

  6. Assimilation of stratospheric ozone in the chemical transport model STRATAQ

    Directory of Open Access Journals (Sweden)

    B. Grassi

    2004-09-01

    Full Text Available We describe a sequential assimilation approach useful for assimilating tracer measurements into a three-dimensional chemical transport model (CTM of the stratosphere. The numerical code, developed largely according to Kha00, uses parameterizations and simplifications allowing assimilation of sparse observations and the simultaneous evaluation of analysis errors, with reasonable computational requirements. Assimilation parameters are set by using χ2 and OmF (Observation minus Forecast statistics. The CTM used here is a high resolution three-dimensional model. It includes a detailed chemical package and is driven by UKMO (United Kingdom Meteorological Office analyses. We illustrate the method using assimilation of Upper Atmosphere Research Satellite/Microwave Limb Sounder (UARS/MLS ozone observations for three weeks during the 1996 antarctic spring. The comparison of results from the simulations with TOMS (Total Ozone Mapping Spectrometer measurements shows improved total ozone fields due to assimilation of MLS observations. Moreover, the assimilation gives indications on a possible model weakness in reproducing polar ozone values during springtime.

  7. Sensitivity of polar stratospheric ozone loss to uncertainties in chemical reaction kinetics

    Directory of Open Access Journals (Sweden)

    S. R. Kawa

    2009-06-01

    Full Text Available The impact and significance of uncertainties in model calculations of stratospheric ozone loss resulting from known uncertainty in chemical kinetics parameters is evaluated in trajectory chemistry simulations for the Antarctic and Arctic polar vortices. The uncertainty in modeled ozone loss is derived from Monte Carlo scenario simulations varying the kinetic (reaction and photolysis rate parameters within their estimated uncertainty bounds. Simulations of a typical winter/spring Antarctic vortex scenario and Match scenarios in the Arctic produce large uncertainty in ozone loss rates and integrated seasonal loss. The simulations clearly indicate that the dominant source of model uncertainty in polar ozone loss is uncertainty in the Cl2O2 photolysis reaction, which arises from uncertainty in laboratory-measured molecular cross sections at atmospherically important wavelengths. This estimated uncertainty in JCl2O2 from laboratory measurements seriously hinders our ability to model polar ozone loss within useful quantitative error limits. Atmospheric observations, however, suggest that the Cl2O2 photolysis uncertainty may be less than that derived from the lab data. Comparisons to Match, South Pole ozonesonde, and Aura Microwave Limb Sounder (MLS data all show that the nominal recommended rate simulations agree with data within uncertainties when the Cl2O2 photolysis error is reduced by a factor of two, in line with previous in situ ClOx measurements. Comparisons to simulations using recent cross sections from Pope et al. (2007 are outside the constrained error bounds in each case. Other reactions producing significant sensitivity in polar ozone loss include BrO+ClO and its branching ratios. These uncertainties challenge our confidence in modeling polar ozone depletion and projecting future changes in response to changing halogen

  8. Microbial ecology of Antarctic aquatic systems.

    Science.gov (United States)

    Cavicchioli, Ricardo

    2015-11-01

    The Earth's biosphere is dominated by cold environments, and the cold biosphere is dominated by microorganisms. Microorganisms in cold Southern Ocean waters are recognized for having crucial roles in global biogeochemical cycles, including carbon sequestration, whereas microorganisms in other Antarctic aquatic biomes are not as well understood. In this Review, I consider what has been learned about Antarctic aquatic microbial ecology from 'omic' studies. I assess the factors that shape the biogeography of Antarctic microorganisms, reflect on some of the unusual biogeochemical cycles that they are associated with and discuss the important roles that viruses have in controlling ecosystem function.

  9. OZONE ABSORPTION IN RAW WATERS

    Directory of Open Access Journals (Sweden)

    LJILJANA TAKIĆ

    2008-03-01

    Full Text Available The ozone absorption in raw water entering the main ozonization step at the Belgrade drinking water supply plant was investigated in a continuous stirred tank reactor (CSTR. A slow chemical reaction rate of dissolved ozone and pollutants present in raw water have been experimentally determined. The modified Hatta number was defined and calculated as a criterion which determines whether and to which extent the reactions of ozone and pollutants influence the rate of the pure physical ozone absorption.

  10. DEVELOPMENTS IN OZONATION OF WATERS

    OpenAIRE

    OĞUZ, Ensar; ÇELİK, Zeynep

    2001-01-01

    Ozone, has been used in both industrial and synthetic chemistry. From this point of view, ozone-organic chemistry related papaers have been published by many researcher. Forthermore; its role in air and water pollution problems is more important today. As a result of ozone researches, it is clear that ozone is to be the brightest expection for future in industrial, domestic, and driking water treatment. Ozone, a high grade oxidation matter, has been used for removing the pollutants and toxic ...

  11. Ozone, greenhouse effect. Ozone, effet de serre

    Energy Technology Data Exchange (ETDEWEB)

    Aviam, A.M.; Arthaut, R.

    1992-12-01

    This file is made of eight general papers on environment (climates under observation, research on photo-oxidizing pollution, scientific aspects of stratospheric ozone layer, urban engineering and environment, glory of public gardens, earths not very natural, darwinism and society, economical data on environment). (A.B.). refs., 3 tabs.

  12. Ozone - plant surface reactions an important ozone loss term?

    Science.gov (United States)

    Hansel, Armin; Jud, Werner; Fischer, Lukas; Canaval, Eva; Wohlfahrt, Georg; Tissier, Alain

    2015-04-01

    Elevated tropospheric ozone concentrations are considered a toxic threat to plants responsible for global crop losses with associated economic costs of several billions dollar per year. Plant injuries have been related to the uptake of ozone through stomatal pores and oxidative effects damaging the internal leaf tissue. But a striking question remains: How much ozone enters the plant through open stomata and how much ozone is lost by chemical reactions at the plant surface? Until now surface losses are estimated from measured total ozone deposition fluxes and calculated stomatal conductance values. While stomatal conductance of CO2 and H2O is well understood and extensively used in describing plant atmosphere gas exchange, stomatal conductance of ozone is not well known. Here we use different Nicotiana tabacum varieties and find that surface reactions of ozone with diterpenoids synthesized by glandular trichomes reduce ozone flux through open stomata. Our measurements reveal that fast ozone loss at the plant surface is accompanied with prompt release of oxygenated volatile compounds. In the ozone fumigation experiments of different Nicotiana tabacum varieties the release of specific volatile oxy-VOCs allowed to identify the semi volatile precursor compounds at the plant surface. Ozone fumigation experiments with Norway spruce (Picea abies) and Scots Pine (Pinus sylvestris), two common species in the Northern Hemisphere, show also a significant ozone loss at the plant surface for Picea abies. Fluid dynamic calculations of ozone transport in the diffusive leaf boundary layer reveal a vertical but no horizontal ozone gradient thus reducing ozone fluxes through the pores in case of efficient ozone scavenging plant surfaces. We explain this efficient ozone protection mechanism by the porous surface architecture of plants in combination with unsaturated semi-volatile compounds deposited at the plant surface. These results show that unsaturated semi-volatile compounds at

  13. Measurements of nitric oxide and total reactive nitrogen in the Antarctic stratosphere: Observations and chemical implications

    International Nuclear Information System (INIS)

    Measurements of NO and the sum of reactive nitrogen species, NOy, were made as part of the Airborne Antarctic Ozone Experiment (AAOE) on flights of the NASA ER-2 aircraft over the Antarctic continent. Reactive nitrogen species include NO,NO2, NO3, N2O5, HNO3, and ClONO2. The technique utilized the conversion of NOy components to NO on a gold catalyst and the subsequent detection of NO by the chemiluminescent reaction of NO with O3. NO was measured on two of the flights by removing the catalyst from the sample line. The boundary of a chemically perturbed region (CPR) above the continent occurred on average near 66 degree S as indicated by a sharp increase in the level of ClO. Outside or equatorward of the CPR, NOy mixing ratios ranged between 6 and 12 parts per billion by volume (ppbv), with values increasing with latitude. At the edge of the CPR, large latitude gradients of NOyand NO were found with values decreasing poleward. Total NOy levels dropped to 4 ppbv or less within 5 degree poleward of the boundary. NO values were 0.1-0.2 ppbv outside and below the detection limit of 0.03 ppbv inside the CPR. The levels of NO and NOy observed preclude a chemical loss of ozone due to reaction with NO

  14. Dynamic recycling of gaseous elemental mercury in the boundary layer of the Antarctic Plateau

    Directory of Open Access Journals (Sweden)

    A. Dommergue

    2012-11-01

    Full Text Available Gaseous elemental mercury (Hg0 was investigated in the troposphere and in the interstitial air extracted from the snow at Dome Concordia station (alt. 3320 m on the Antarctic Plateau during January 2009. Measurements and modeling studies showed evidence of a very dynamic and daily cycling of Hg0 inside the mixing layer with a range of values from 0.2 ng m−3 up to 2.3 ng m−3. During low solar irradiation periods, fast Hg0 oxidation processes in a confined layer were suspected. Unexpectedly high Hg0 concentrations for such a remote place were measured under higher solar irradiation due to snow photochemistry. We suggest that a daily cycling of reemission/oxidation occurs during summer within the mixing layer at Dome Concordia. Hg0 concentrations showed a negative correlation with ozone mixing ratios, which contrasts with atmospheric mercury depletion events observed during the Arctic spring. Unlike previous Antarctic studies, we think that atmospheric Hg0 removal may not be the result of advection processes. The daily and dramatic Hg0 losses could be a consequence of surface or snow induced oxidation pathways. It remains however unclear whether halogens are involved. The cycling of other oxidants should be investigated together with Hg species in order to clarify the complex reactivity on the Antarctic plateau.

  15. Ozone and carbon monoxide at the Ushuaia GAW-WMO global station

    Science.gov (United States)

    Adame, Jose; Cupeiro, Manuel; Yela, Margarita; Cuevas, Emilio; Carbajal, Gerardo

    2016-04-01

    Ozone and carbon monoxide have been investigated in the GAW-WMO station of Ushuaia (Argentina), using hourly values during five years (2010-2014). This work has been developed in the framework of HELADO (Halogens in the Antarctic atmosphere and its role in the Ozone distribution) project and under the collaboration between INTA (National Institute for Aerospace Technology - Spain), SMN (National Meteorological Service - Argentina) and AEMET (State Meteorological Agency - Spain). Meteorological features have been analyzed with in-situ observations and meteorological fields from ECMWF 0.5° as spatial resolution model. These fields have been applied to compute back trajectories with HYSPLIT model. Independently of season, mostly atmospheric flows coming from W-SW (South Pacific Ocean), theses westerlies winds are associated with low pressure systems; in addition with lower frequencies are collected winds from South (Antarctic Peninsula and Weddell Sea), polar easterlies. Hourly averages of surface (in-situ) ozone and CO levels were 20±7 and 71±45 ppb respectively, typical values of remote environments. A clear seasonal pattern has been obtained for surface ozone with monthly peaks in winter of 25 ppb and minimum in summer with 12 ppb; a similar behaviour is found for CO, 93 and 48 ppb for maximum and minimum values, respectively. A weak daily cycle has been obtained in both species, amplitude for ozone of 2-4 ppb and 13-20 ppb for CO. The seasonal levels behaviour for surface ozone is also observed in upper levels, approximately from surface up to 5 km. This result has been obtained from 139 ozone profiles launched in the studied period. Since the ozone precursors and carbon monoxide emissions are low in this area, the origin of the values observed could be in the atmospheric transport processes. As hypothesis to explain the behaviour observed, we suggest that in the warm season with solar radiation, the photochemical mechanisms are active, and the elimination

  16. Abundance, viability and culturability of Antarctic bacteria

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; DeSouza, M.J.B.D.; Nair, S.; Chandramohan, D.

    The viability of total number of bacteria decide the mineralisation rate in any ecosystem and ultimately the fertility of the region. This study aims at establishing the extent of viability in the standing stock of the Antarctic bacterial population...

  17. Ozone health effects

    International Nuclear Information System (INIS)

    Ozone is a principal component of photochemical air pollution endogenous to numerous metropolitan areas. It is primarily formed by the oxidation of NOx in the presence of sunlight and reactive organic compounds. Ozone is a highly active oxidizing agent capable of causing injury to the lung. Lung injury may take the form of irritant effects on the respiratory tract that impair pulmonary function and result in subjective symptoms of respiratory discomfort. These symptoms include, but are not limited to, cough and shortness of breath, and they can limit exercise performance. The effects of ozone observed in humans have been primarily limited to alterations in respiratory function, and a range of respiratory physiological parameters have been measured as a function of ozone exposure in adults and children. These affects have been observed under widely varying (clinical experimental and environmental settings) conditions

  18. 2001 Ozone Design Value

    Data.gov (United States)

    U.S. Environmental Protection Agency — Ozone is generated by a complex atmoshperic chemical process. Industrial and automobile pollutants in the form of oxides of nitrogen and hydrocarbons react in the...

  19. Breakup of Pack Ice, Antarctic Ice Shelf

    Science.gov (United States)

    1991-01-01

    Breakup of Pack Ice along the periphery of the Antarctic Ice Shelf (53.5S, 3.0E) produced this mosaic of ice floes off the Antarctic Ice Shelf. Strong offshore winds, probably associated with strong katabatic downdrafts from the interior of the continent, are seen peeling off the edges of the ice shelf into long filamets of sea ice, icebergs, bergy bits and growlers to flow northward into the South Atlantic Ocean. 53.5S, 3.0E

  20. Role of the meiobenthos in Antarctic ecosystems

    OpenAIRE

    Vanhove, S.; Wittoeck, J; Beghyn, M.; Van Gansbeke, D.; Van Kenhove, A.; Coomans, A.; Vincx, M.

    1997-01-01

    To date meiobenthic research remained a big white spot in the systematic-ecological work on Antarctic zoobenthos. Therefore the relative importance of the meiofauna (organisms within the size range of 38-1000µm) in the Antarctic benthic community has been assessed by a combined field ecology and experimental approach. This was done in two contrasting conditions, e.g. the deep sea and low subtidal, where as to the depth of the water column the benthic characteristics were, respectively, indire...

  1. Ozone therapy in periodontics

    OpenAIRE

    Gupta, G; Mansi, B

    2012-01-01

    Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of oz...

  2. Stratospheric ozone depletion

    OpenAIRE

    Rowland, F. Sherwood

    2006-01-01

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the c...

  3. COMPRESSOR TYPE OZONATOR

    Directory of Open Access Journals (Sweden)

    Gulyaev P. V.

    2016-05-01

    Full Text Available The article is devoted to the development of a compressor type ozonator. It describes the design of a high-productivity compressor ozone generator, which can be used for industrial decontamination of mixed feeds, water, milk, and in the system of presowing treatment of seeds. This construction allows generating ozone with high concentration to 5 g/m3 at high feed air or oxygen from the compressor station (up to 2000 l/min. The article describes the design of the basic elements of tubular ozone generator, examines the factors influencing the productivity of the ozonator. The proposed mathematical model allows calculating the productivity of the ozonator when considering multiple influencing factors. These factors take into account: the parameters of supply voltage, such as the magnitude and frequency of the supply voltage; the configuration and geometrical parameters of electrodes such as, the area of the electrodes, the configuration of the surface of the electrodes and distance between electrodes; parameters dielectric barrier; and the transported gas parameters such as volume, temperature, pressure and composition. Special attention is paid to the design of the electrodes made of woven wire mesh with mesh sizes from 1.5×1.5 to 2.0×2.0 mm. It is noted, that such electrodes allow obtaining the maximum productivity of an ozonator, and they do not lead to overheating of the dielectric barrier, and do not output down the generator. In the same way, the article presents the results of the mathematical modeling of ozone generator productivity while changing various factors

  4. Ozone Therapy in Dentistry

    OpenAIRE

    Sudarshan, Ramachandran; Vijayabala, G. Sree

    2013-01-01

    With the advancements in the field of dentistry, new treatment protocols are budding day by day to combat human ailments in a much natural better and simpler way. One such advancement is the application of ozone in dentistry. Ozone is a natural element protects us from ultraviolet rays. It has several properties including analgesics, immunostimulant and antimicrobial properties. In Dentistry its uses are abundance from gingival diseases, infection control, temporomandibular disorders, radiati...

  5. Plant ozone injury symptoms

    Energy Technology Data Exchange (ETDEWEB)

    Nouchi, I.; Odaira, T.; Sawada, T.; Oguchi, K.; Komeiji, T.

    1973-01-01

    A study of the phytotoxicity of ozone to plants was conducted in controlled-atmosphere greenhouses to determine if the symptoms of such exposure would be similar to symptoms exhibited by plants exposed to photochemical smog (which contains ozone) in the Tokyo area. Test plants used were herbaceous plants and woody plants, which were fumigated to 20 pphm ozone. Plants used as controls for the oxone exposure experiments were placed in a carbon filtered greenhouse. Herbaceous plants were generally sensitive to injury, especially Brassica rapa, Brassica pekinensis and others were extremely responsive species. In comparison with herbaceous plants, woody plants were rather resistant except for poplar. Depending on plant species and severity of injury, ozone-injury symptoms of herbaceous plants were bleaching, chlorosis, necrosis, and red-dish-brown flecks. Leaves of woody plants developed discrete, punctate spots, reddish-brown pigment on the upper surfaces and lastly defoliation. Ozone injury was typically confined to the upper leaf surfaces and notably greater mature leaves. Microscopic examination showed that pallisade cells were much more prone to ozone injury than other tissues.

  6. The use of visible-channel data from NOAA satellites to measure total ozone amount over Antarctica

    Science.gov (United States)

    Boime, Robert D.; Warren, Steven G.; Gruber, Arnold

    1994-01-01

    Accurate, detailed maps of total ozone were not available until the launch of the Total Ozone Mapping Spectrometer (TOMS) in late 1978. However, the Scanning Radiometer (SR), an instrument on board the NOAA series satellites during the 1970s, had a visible channel that overlapped closely with the Chappuis absorption band of ozone. We are investigating whether data from the SR can be used to map Antarctic ozone prior to 1978. The method is being developed with 1980s data from the Advanced Very High Resolution Radiometer (AVHRR), which succeeded the SR on the NOAA polar-orbiting satellites. Visible-derived total ozone maps can then be compared able on the NOAA satellites, which precludes the use of a differential absorption technique to measure ozone. Consequently, our method works exclusively over scenes whose albedos are large and unvarying, i.e. scenes that contain ice sheets and/or uniform cloud-cover. Initial comparisons of time series for October-December 1987 at locations in East Antarctica show that the visible absorption by ozone in measurable and that the technique may be usable for the 1970s, but with much less accuracy than TOMS. This initial test assumes that clouds, snow, and ice all reflect the same percentage of visible light towards the satellite, regardless of satellite position or environmental conditions. This assumption is our greatest source of error. To improve the accuracy of ozone retrievals, realistic anisotropic reflectance factors are needed, which are strongly influenced by cloud and snow surface features.

  7. An evaluation of the simulation of the edge of the Antarctic vortex by chemistry-climate models

    Directory of Open Access Journals (Sweden)

    H. Struthers

    2008-12-01

    Full Text Available The dynamical barrier to meridional mixing at the edge of the Antarctic spring stratospheric vortex is examined. Diagnostics are presented which demonstrate the link between the shape of the meridional mixing barrier at the edge of the vortex and the meridional gradients in total column ozone across the vortex edge. Results derived from reanalysis and measurement data sets are compared with equivalent diagnostics from five coupled chemistry-climate models to test how well the models capture the interaction between the dynamical structure of the stratospheric vortex and the chemical processes occurring within the vortex. Results show that the accuracy of the simulation of the dynamical vortex edge varies widely amongst the models studied here. This affects the ability of the models to simulate the large observed meridional gradients in total column ozone. Three of the models in this study simulated the inner edge of the vortex to be more than 7° closer to the pole than observed. This is expected to have important implications for how well these models simulate the extent of severe springtime ozone loss that occurs within the Antarctic vortex.

  8. 21st Century Trends in Antarctic Temperature and Polar Stratospheric Cloud (PSC) Area in the GEOS Chemistry-Climate Model

    Science.gov (United States)

    Hurwitz, M. M.; Newman, P. A.

    2010-01-01

    This study examines trends in Antarctic temperature and APSC, a temperature proxy for the area of polar stratospheric clouds, in an ensemble of Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) simulations of the 21st century. A selection of greenhouse gas, ozone-depleting substance, and sea surface temperature scenarios is used to test the trend sensitivity to these parameters. One scenario is used to compare temperature trends in two versions of the GEOS CCM. An extended austral winter season is examined in detail. In May, June, and July, the expected future increase in CO2-related radiative cooling drives temperature trends in the Antarctic lower stratosphere. At 50 hPa, a 1.3 K cooling is expected between 2000 and 2100. Ozone levels increase, despite this robust cooling signal and the consequent increase in APSC, suggesting the enhancement of stratospheric transport in future. In the lower stratosphere, the choice of climate change scenarios does not affect the magnitude of the early winter cooling. Midwinter temperature trends are generally small. In October, APSC trends have the same sign as the prescribed halogen trends. That is, there are negative APSC trends in "grealistic future" simulations, where halogen loading decreases in accordance with the Montreal Protocol and CO2 continues to increase. In these simulations, the speed of ozone recovery is not influenced by either the choice of sea surface temperature and greenhouse gas scenarios or by the model version.

  9. The SCAR Standing Committee on Antarctic Data Management - new directions in access to Antarctic research data

    Science.gov (United States)

    de Bruin, T.

    2009-04-01

    The SCAR Standing Committee on Antarctic Data Management (SC-ADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP), to assist in the fulfillment of the data management obligations imposed by the Antarctic Treaty (section III.1.c): "Scientific observations and results from Antarctica shall be exchanged and made freely available." SC-ADM comprises representatives of the National Antarctic Data Centres or national points of contact. Currently 31 nations around the world are represented in SC-ADM. So far, SC-ADM has been focussing on the coordination of the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. Currently, SC-ADM is in a transition phase, moving forward to provide data access. Existing systems and web services technology will be used as much as possible, to increase efficiency and prevent 're-inventing the wheel' This poster will give an overview of this process, the current status and the expected results.

  10. Ozone: The secret greenhouse gas

    International Nuclear Information System (INIS)

    The atmospheric ozone not only protects against harmful ultraviolet radiation; it also contributes to the greenhouse effect. Ozone is one of the jokers to make it difficult to calculate the climatic effect of anthropogenic emissions. The greenhouse effect and the ozone layer should not be confused. The greenhouse effect creates problems when it becomes enhanced, so that the earth becomes warmer. The problem with the ozone layer, on the contrary, is that it becomes thinner and so more of the harmful ultraviolet radiation gets through to the earth. However, ozone is also a greenhouse gas and so the greenhouse effect and the ozone layer are connected

  11. Ultraviolet-ozone-treated PEDOT:PSS as anode buffer layer for organic solar cells.

    Science.gov (United States)

    Su, Zisheng; Wang, Lidan; Li, Yantao; Zhao, Haifeng; Chu, Bei; Li, Wenlian

    2012-08-17

    Ultraviolet-ozone-treated poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)was used as the anode buffer layer in copper phthalocyanine (CuPc)/fullerene-based solar cells. The power conversion efficiency of the cells with appropriated UV-ozone treatment was found to increase about 20% compared to the reference cell. The improved performance is attributed to the increased work function of the PEDOT:PSS layer, which improves the contact condition between PEDOT:PSS and CuPc, hence increasing the extraction efficiency of the photogenerated holes and decreasing the recombination probability of holes and electrons in the active organic layers.

  12. Feasibility of gas-discharge and optical methods of creating artificial ozone layers of the earth

    International Nuclear Information System (INIS)

    Gas-discharge (microwave) and optical (laser) methods of generating large-scale artificial ozone layers in the stratosphere are analyzed. A kinetic model is developed to calculate the plasma-chemical consequences of discharges localized in the stratosphere. Computations and simple estimates indicate that, in order to implement gas-discharge and optical methods, the operating power of ozone-producing sources should be comparable to or even much higher than the present-day power production throughout the world. Consequently, from the engineering and economic standpoints, microwave and laser methods cannot be used to repair large-scale ozone 'holes'

  13. Simulations of Arctic ozone depletion with current and doubled levels of CO2

    Science.gov (United States)

    Butchart, Neal; Austin, John; Shine, Keith P.

    1994-01-01

    Results from idealized 3-D simulations of a dynamical-radiative-photochemical model of the stratosphere are presented for the Northern Hemisphere winter and spring. For a simulation of a quiescent winter, it is found that with current levels of CO2 only modest polar ozone depletion occurs, consistent with observations. For a second simulation with the same planetary wave amplitudes in the upper troposphere but with doubled CO2, the model predicts a northern hemisphere ozone hole comparable to that observed in Antarctica with almost complete ozone destruction at 20 km. Reasons for the marked difference between the simulations are identified.

  14. Polar tropospheric ozone depletion events observed in the International Geophysical Year of 1958

    Directory of Open Access Journals (Sweden)

    H. K. Roscoe

    2006-01-01

    Full Text Available The Royal Society expedition to Antarctica established a base at Halley Bay, in support of the International Geophysical Year of 1957–1958. Surface ozone was measured during 1958 only, using a prototype Brewer-Mast sonde. The envelope of maximum ozone was an annual cycle from 10 ppbv in January to 22 ppbv in August. These values are 35% less at the start of the year and 15% less at the end than modern values from Neumayer, also a coastal site. This may reflect a general increase in surface ozone since 1958 and differences in summer at the less windy site of Halley, or it may reflect ozone loss on the inlet together with long-term conditioning. There were short periods in September when ozone values decreased rapidly to near-zero, and some in August when ozone values were rapidly halved. Such ozone-loss episodes, catalysed by bromine compounds, became well-known in the Artic in the 1980s, and were observed more recently in the Antarctic. In 1958, very small ozone values were recorded for a week in midwinter during clear weather with light winds. The absence of similar midwinter reductions at Neumayer, or at Halley in the few measurements during 1987, means we must remain suspicious of these small values, but we can find no obvious reason to discount them. The dark reaction of ozone and seawater ice observed in the laboratory may be fast enough to explain them if the salinity and surface area of the ice is sufficiently amplified by frost flowers.

  15. What Do We Need To Do To Improve Our Understanding of How Volcanoes Affect Stratospheric Ozone?

    Science.gov (United States)

    Solomon, S.

    2015-12-01

    This talk will briefly survey what is known and what is not known about stratospheric ozone depletion and volcanic events, and will describe some ways to improve our understanding. Observations of total ozone following the eruption of El Chichon in the 1980s provided some of the earliest and clearest indications of the importance of volcanic aerosol on ozone depletion. In subsequent decades, improved laboratory information, modeling studies, and observations showed how heterogeneous chemical processing on and in volcanic aerosols could enhance chlorine-catalyzed ozone loss in the lower stratosphere, while decreasing nitrogen-catalyzed ozone loss in the upper stratosphere. Recent satellite observations shed important light on this chemistry but major gaps in understanding remain, including for example a lack of knowledge of whether hydrochloric acid can be efficiently taken up in stratospheric particles under cold conditions, interactions and competition between volcanic aerosols and ice clouds, and the effects of volcanic aerosols on chemistry in the tropopause region. Effects of volcanic aerosols on Arctic and Antarctic ozone depletion are also subject to many certainties, owing in large part to observational deficiencies. Implications for gaining an improved understanding through both laboratory studies and new observations will be briefly described.

  16. Coupling of HOx, NOx and halogen chemistry in the antarctic boundary layer

    Directory of Open Access Journals (Sweden)

    R. A. Salmon

    2010-11-01

    Full Text Available A modelling study of radical chemistry in the coastal Antarctic boundary layer, based upon observations performed in the course of the CHABLIS (Chemistry of the Antarctic Boundary Layer and the Interface with Snow campaign at Halley Research Station in coastal Antarctica during the austral summer 2004/2005, is described: a detailed zero-dimensional photochemical box model was used, employing inorganic and organic reaction schemes drawn from the Master Chemical Mechanism, with additional halogen (iodine and bromine reactions added. The model was constrained to observations of long-lived chemical species, measured photolysis frequencies and meteorological parameters, and the simulated levels of HOx, NOx and XO compared with those observed. The model was able to replicate the mean levels and diurnal variation in the halogen oxides IO and BrO, and to reproduce NOx levels and speciation very well. The NOx source term implemented compared well with that directly measured in the course of the CHABLIS experiments. The model systematically overestimated OH and HO2 levels, likely a consequence of the combined effects of (a estimated physical parameters and (b uncertainties within the halogen, particularly iodine, chemical scheme. The principal sources of HOx radicals were the photolysis and bromine-initiated oxidation of HCHO, together with O(1D + H2O. The main sinks for HOx were peroxy radical self- and cross-reactions, with the sum of all halogen-mediated HOx loss processes accounting for 40% of the total sink. Reactions with the halogen monoxides dominated CH3O2-HO2-OH interconversion, with associated local chemical ozone destruction in place of the ozone production which is associated with radical cycling driven by the analogous NO reactions. The analysis highlights the need for observations of physical parameters such as aerosol surface area and boundary layer structure to constrain such calculations, and the dependence of simulated radical levels

  17. A network of autonomous surface ozone monitors in Antarctica: technical description and first results

    Directory of Open Access Journals (Sweden)

    S. J.-B. Bauguitte

    2010-12-01

    Full Text Available A suite of 10 autonomous ozone monitors, each powered using renewable energy, was developed and built to study surface ozone in Antarctica during the International Polar Year (2007–2009. The monitoring systems were deployed in a network around the Weddell Sea sector of coastal Antarctica with a transect up onto the Antarctic Plateau. The aim was to measure for a full year, thus gaining a much-improved broader view of boundary layer ozone seasonality at different locations as well as of factors affecting the budget of surface ozone in Antarctica. Ozone mixing ratios were measured based on UV photometry using a modified version of the commercial 2B Technologies Inc. Model 202 instrument. All but one of the autonomous units measured successfully within its predefined duty cycle throughout the year, with some differences in performance dependent on power availability and ambient temperature. Mean data recovery after removal of outliers was on average 70% (range 44–83% and precision varied between 1.5 and 8 ppbv, thus was sufficiently good to resolve year-round the main ozone features of scientific interest. We conclude that, with adequate power, and noting a minor communication problem, our units would be able to operate successfully at ambient temperatures down to −60 °C. Systems such as the one described in this paper, or derivatives of it, could therefore be deployed either as local or regional networks elsewhere in the Arctic or Antarctic. Here we present technical information and first results from the experiment.

  18. A network of autonomous surface ozone monitors in Antarctica: technical description and first results

    Directory of Open Access Journals (Sweden)

    S. J.-B. Bauguitte

    2011-04-01

    Full Text Available A suite of 10 autonomous ozone monitoring units, each powered using renewable energy, was developed and built to study surface ozone in Antarctica during the International Polar Year (2007–2009. The monitoring systems were deployed in a network around the Weddell Sea sector of coastal Antarctica with a transect up onto the Antarctic Plateau. The aim was to measure for a full year, thus gaining a much-improved broader view of boundary layer ozone seasonality at different locations as well as of factors affecting the budget of surface ozone in Antarctica. Ozone mixing ratios were measured based on UV photometry using a modified version of the commercial 2B Technologies Inc. Model 202 instrument. All but one of the autonomous units measured successfully within its predefined duty cycle throughout the year, with some differences in performance dependent on power availability and ambient temperature. Mean data recovery after removal of outliers was on average 70% (range 44–83% and precision varied between 1.5 and 8 ppbv, thus was sufficiently good to resolve year-round the main ozone features of scientific interest. We conclude that, with adequate power, and noting a minor communication problem, our units would be able to operate successfully at ambient temperatures down to −60 °C. Systems such as the one described in this paper, or derivatives of it, could therefore be deployed either as local or regional networks elsewhere in the Arctic or Antarctic. Here we present technical information and first results from the experiment.

  19. Ozone modeling within plasmas for ozone sensor applications

    OpenAIRE

    Arshak, Khalil; Forde, Edward; Guiney, Ivor

    2007-01-01

    peer-reviewed Ozone (03) is potentially hazardous to human health and accurate prediction and measurement of this gas is essential in addressing its associated health risks. This paper presents theory to predict the levels of ozone concentration emittedfrom a dielectric barrier discharge (DBD) plasma for ozone sensing applications. This is done by postulating the kinetic model for ozone generation, with a DBD plasma at atmospheric pressure in air, in the form of a set of rate equations....

  20. Health aspects of Antarctic tourism.

    Science.gov (United States)

    Prociv, P

    1998-12-01

    Increasing numbers of seaborne tourists are visiting Antarctica, with most coming from the United States (3503 in 1996-97), Germany (777), and Australia (680; cf. 356 in 1994-95 and 410 in 1995-96). The impression among travel medicine clinicians is that, each year, more prospective travelers seek advice about the health demands of this type of adventure, mostly relating to fitness for travel, exposure to extreme cold, hazards in ice and snow, and other potential health risks. This is a recent phenomenon. While a regular shipping service had been established between the Falklands and the subantarctic islands of South Georgia and the South Shetlands by 1924, the first documented tourists accompanied an Argentine expedition to the South Orkneys in 1933.1 Commercial airline flights over these islands and the Antarctic Peninsula began in 1956, from Chile, and recreational cruises to the Peninsula began in 1958. Tourist numbers subsequently grew slowly, for what was clearly an exclusive and very expensive undertaking, with few ships available for these hazardous voyages. From 1957 to 1993, 37,000 tourists visited by sea, most seeing only the Peninsula.2 The dramatic recent growth in numbers is a consequence of the collapse of the Soviet Union. The small fleet of ice-strengthened research vessels and working icebreakers, which was made redundant by withdrawal of central government support from isolated communities and military activities along the northern coast of Siberia (and from Antarctic research bases), now accounts for the bulk of charter-cruise tourism to Antarctica, at competitive prices. According to the International Association of Antarctica Tour Operators,3 7322 people traveled to Antarctica on commercially organized voyages in the 1996-97 season, and a record 10,000 shipborne visitors were expected for the 1997-98 season (November-March), traveling mainly from South America to the Peninsula on 15 ice-reinforced vessels, each carrying between 36 and 180

  1. Children's Models of the Ozone Layer and Ozone Depletion.

    Science.gov (United States)

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  2. Controls and variability of solute and sedimentary fluxes in Antarctic and sub-Antarctic Environments

    Science.gov (United States)

    Zwolinski, Zbigniew

    2015-04-01

    The currently prepared SEDIBUD Book on "Source-to-Sink Fluxes in Undisturbed Cold Environments" (edited by Achim A. Beylich, John C. Dixon and Zbigniew Zwolinski and published by Cambridge University Press) is summarizing and synthesizing the achievements of the International Association of Geomorphologists` (I.A.G./A.I.G.) Working Group SEDIBUD (Sediment Budgets in Cold Environments), which has been active since 2005 (http://www.geomorph.org/wg/wgsb.html). The book comprises five parts. One of them is part about sub-Antarctic and Antarctic Environments. This part "Sub-Antarctic and Antarctic Environments" describes two different environments, namely oceanic and continental ones. Each part contains results of research on environmental drivers and rates of contemporary solute and sedimentary fluxes in selected sites. Apart from describing the environmental conditions of the whole continent of Antarctica and sub-Antarctic islands (Zb.Zwolinski, M.Kejna, A.N.Lastochkin, A.Zhirov, S.Boltramovich) this part of the book characterizes terrestrial polar oases free from multi-year ice and snow covers (Zb.Zwolinski). The detailed results of geoecological and sedimentological research come from different parts of Antarctica. Antarctic continental shelf (E.Isla) is an example of sub-Antarctic oceanic environment. South Shetlands, especially King George Island (Zb.Zwolinski, M.Kejna, G.Rachlewicz, I.Sobota, J.Szpikowski), is an example of sub-Antarctic terrestrial environment. Antarctic Peninsula (G.Vieira, M.Francelino, J.C.Fernandes) and surroundings of McMurdo Dry Valleys (W.B.Lyons, K.A.Welch, J.Levy, A.Fountain, D.McKnight) are examples of Antarctic continental environments. The key goals of the Antarctic and sub-Antarctic book chapters are following: (i) identify the main environmental drivers and rates of contemporary solute and sedimentary fluxes, and (ii) model possible effects of projected climate change on solute and sedimentary fluxes in cold climate environments

  3. Noncommutative black holes

    International Nuclear Information System (INIS)

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole

  4. Deburring small intersecting holes

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, L.K.

    1980-08-01

    Deburring intersecting holes is one of the most difficult deburring tasks faced by many industries. Only 14 of the 37 major deburring processes are applicable to most intersecting hole applications. Only five of these are normally applicable to small or miniature holes. Basic process capabilities and techniques used as a function of hole sizes and intersection depths are summarized.

  5. Ozone - Current Air Quality Index

    Science.gov (United States)

    ... more announcements Air Quality Basics Air Quality Index | Ozone | Particle Pollution | Smoke from fires | What You Can ... Partners Kids Movies NAQ Conferences NOAA Older Adults Ozone Particle Pollution (PM2.5, PM10) Publications Publicaciones (En ...

  6. Ozone-depleting Substances (ODS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — This site includes all of the ozone-depleting substances (ODS) recognized by the Montreal Protocol. The data include ozone depletion potentials (ODP), global...

  7. Air Quality Guide for Ozone

    Science.gov (United States)

    Local Air Quality Conditions Zip Code: State : My Current Location Air Quality Guide for Ozone Ground-level ozone is one of our nation’s most common air pollutants. Use the chart below to help reduce ...

  8. Ozonated Olive Oils and Troubles

    Directory of Open Access Journals (Sweden)

    Bulent Uysal

    2014-04-01

    Full Text Available One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. [J Intercult Ethnopharmacol 2014; 3(2.000: 49-50

  9. Ozone Therapy in Dentistry

    Directory of Open Access Journals (Sweden)

    Ramachandran Sudarshan

    2013-02-01

    Full Text Available With the advancements in the field of dentistry, new treatment protocols are budding day by day to combat human ailments in a much natural better and simpler way. One such advancement is the application of ozone in dentistry. Ozone is a natural element protects us from ultraviolet rays. It has several properties including analgesics, immunostimulant and antimicrobial properties. In Dentistry its uses are abundance from gingival diseases, infection control, temporomandibular disorders, radiation and chemotherapy induced mucositis, lichen planus etc. Researchers believe that this therapy is in state of equilibrium with benefit and drawback. This review throws light on the history, properties, methods of administration, uses in the field of medicine and dentistry, toxicity, contraindications of ozone. [Archives Medical Review Journal 2013; 22(1.000: 45-54

  10. 76 FR 9849 - Comprehensive Environmental Evaluations for Antarctic Activities

    Science.gov (United States)

    2011-02-22

    .... SUPPLEMENTARY INFORMATION: Article 3 of Annex I to the Protocol on Environmental Protection to the Antarctic Treaty requires the preparation of a CEE for any proposed Antarctic activity likely to have more than a... Comprehensive Environmental Evaluations for Antarctic Activities SUMMARY: The Department of State gives...

  11. NSF's role in Antarctic environment scrutinized

    Science.gov (United States)

    Bush, Susan

    In the last few years, the National Science Foundation has come under criticism by environmental groups for inadequate stewardship in the U.S. Antarctic Program's environmental issues. Since 1978, NSF was given full responsibility, by Executive Order, for budgeting and managing the entire U.S. national program in Antarctica, including logistics support. NSF has also been responsible for the compliance of the U.S. Antarctic Program with environmental protection measures agreed to by the Antarctic Treaty nations. Specifically under fire by environmentalists have been NSF's maintenance of a land-fill, open-air burning of solid waste, and the removal of toxic substances. According to Peter E. Wilkniss, director of the Division of Polar Programs at NSF, open burning is no longer taking place and will not be allowed in the future.

  12. Antarctic “quiet” site stirs debate

    Science.gov (United States)

    Simarski, Lynn Teo

    Geophysicists from the United States and New Zealand plan to meet in the coming months to assess the electromagnetic pollution of an Antarctic site especially designated for research. U.S. scientists charge that a satellite Earth station erected apparently inside the preserve by New Zealand's Telecom company could interfere with experiments on the ionosphere and magnetosphere (Eos, April 28, 1992). The Site of Special Scientific Interest at Arrival Heights, the only Antarctic preserve specifically for physical science, is located near the U.S. McMurdo and New Zealand Scott bases.Debate over the Telecom facility inter-twines diplomatic and scientific issues. One question is whether the station violates the Antarctic treaty. Secondly, does it actually impair research at the site—or could it harm future experiments? To deepen the imbroglio, those involved from both nations say that transmissions from sources off-site also interfere with research—raising doubts about how pristine the site really is.

  13. The Antarctic cryptoendolithic ecosystem - Relevance to exobiology

    Science.gov (United States)

    Friedmann, E. I.; Ocampo-Friedmann, R.

    1984-01-01

    Cryptoendolithic microorganisms in the Antarctic desert live inside porous sandstone rocks, protected by a thin rock crust. While the rock surface is abiotic, the microclimate inside the rock is comparatively mild. These organisms may have descended from early, pre-glaciation Antarctic life forms and thus may represent the last outpost of life in a gradually deteriorating environment. Assuming that life once arose on Mars, it is conceivable that, following the loss of water, the last of surviving organisms withdrew to similar insulated microenvironments. Because such microscopic pockets have little connection with the outside environment, their detection may be difficult. The chances that the Viking lander could sample cryptoendolithic microorganisms in the Antarctic desert would be infinitesimal.

  14. Solar flare irradiation records in Antarctic meteorites

    Science.gov (United States)

    Goswami, J. N.

    1981-01-01

    The observation of tracks from solar flare heavy nuclei in Antarctic meteorite samples is reported. In an analysis of nuclear track densities in eight L and H chondrites of low metamorphic grade, it was found that two interior specimens of sample 77216, an L-3 chondrite, contain olivine grains with track densities much higher than the average track densities, indicating precompaction irradiation by solar flares in different shielding conditions. Preliminary data from mass spectroscopic analyses show a large excess of noble gases, with a Ne-20/Ne-22 ratio of greater than or equal to 10, indicating the presence of solar-type noble gas. Results of track density measurements in the other Antarctic meteorites range from 10,000 to 4,000,000/sq cm, which is within the range observed in non-Antarctic L-group meteorites

  15. Meteorological observatory for Antarctic data collection

    International Nuclear Information System (INIS)

    In the last years, a great number of automatic weather stations was installed in Antarctica, with the aim to examine closely the weather and climate of this region and to improve the coverage of measuring points on the Antarctic surface. In 1987 the Italian Antarctic Project started to set up a meteorological network, in an area not completely covered by other countries. Some of the activities performed by the meteorological observatory, concerning technical functions such as maintenance of the AWS's and the execution of radio soundings, or relating to scientific purposes such as validation and elaboration of collected data, are exposed. Finally, some climatological considerations on the thermal behaviour of the Antarctic troposphere such as 'coreless winter', and on the wind field, including katabatic flows in North Victoria Land are described

  16. Precision ozone vapor pressure measurements

    Science.gov (United States)

    Hanson, D.; Mauersberger, K.

    1985-01-01

    The vapor pressure above liquid ozone has been measured with a high accuracy over a temperature range of 85 to 95 K. At the boiling point of liquid argon (87.3 K) an ozone vapor pressure of 0.0403 Torr was obtained with an accuracy of + or - 0.7 percent. A least square fit of the data provided the Clausius-Clapeyron equation for liquid ozone; a latent heat of 82.7 cal/g was calculated. High-precision vapor pressure data are expected to aid research in atmospheric ozone measurements and in many laboratory ozone studies such as measurements of cross sections and reaction rates.

  17. DEVELOPMENTS IN OZONATION OF WATERS

    Directory of Open Access Journals (Sweden)

    Ensar OĞUZ

    2001-03-01

    Full Text Available Ozone, has been used in both industrial and synthetic chemistry. From this point of view, ozone-organic chemistry related papaers have been published by many researcher. Forthermore; its role in air and water pollution problems is more important today. As a result of ozone researches, it is clear that ozone is to be the brightest expection for future in industrial, domestic, and driking water treatment. Ozone, a high grade oxidation matter, has been used for removing the pollutants and toxic materials from waste waters.

  18. Infrared measurements in the spring 1987 ozone hole

    Science.gov (United States)

    Murcray, F. J.; Murcray, D. G.; Goldman, Aaron; Keys, J. G.; Matthews, W. A.

    1988-01-01

    Solar spectra were recorded from Arrival Heights (McMurdo), Antartica, with a FTIR system during the austral spring of 1987. Spectra were recorded on 22 days from September 13 through October 28. The instrument was setup with 2 detectors for simultaneous operation in 2 wavelength regions. Several stratospheric gases have measurable absorptions in these regions including HCl, HNO3, O3, ClONO2, and NO2. The system is equipped with an automatic solar tracking system and records data on tape cartridges. A portable personal computer allows Fourier transforming and initial processing of some of the data. The HNO3 gas column amount shows large variations, but no apparent correlation with stratospheric temperature. The HCl column shows a steady increase from 0.9 x 10 to the 15th power molecules/sq.cm. on September 13 to 1.5 x 10 to the 15th power on October 6. McMurdo moved out of the polar vortex for a few days, and the HCl column jumped to 2.9 x 10 to the 15th power by October 11. Although McMurdo moved back under the vortex, the HCl continued to increase, reaching 3.4 x 10 to the 15th power at the end of the period.

  19. First geomagnetic measurements in the Antarctic region

    Science.gov (United States)

    Raspopov, O. M.; Demina, I. M.; Meshcheryakov, V. V.

    2014-05-01

    Based on data from literature and archival sources, we have further processed and analyzed the results of geomagnetic measurements made during the 1772-1775 Second World Expedition by James Cook and the 1819-1821 overseas Antarctic Expedition by Russian mariners Bellingshausen and Lazarev. Comparison with the GUFM historical model showed that there are systematic differences in the spatial structure of both the declination and its secular variation. The results obtained can serve as a basis for the construction of regional models of the geomagnetic field for the Antarctic region.

  20. Climate Change Influences on Antarctic Bird Populations

    Science.gov (United States)

    Korczak-Abshire, Małgorzata

    2010-01-01

    Rapid changes in the major environmental variables like: temperature, wind and precipitation have occurred in the Antarctic region during the last 50 years. In this very sensitive region, even small changes can potentially lead to major environmental perturbations. Then the climate change poses a new challenge to the survival of Antarctic wildlife. As important bioindicators of changes in the ecosystem seabirds and their response to the climate perturbations have been recorded. Atmospheric warming and consequent changes in sea ice conditions have been hypothesized to differentially affect predator populations due to different predator life-history strategies and substantially altered krill recruitment dynamics.

  1. Measurement of Ozone Production Sensor

    Directory of Open Access Journals (Sweden)

    M. Cazorla

    2010-05-01

    Full Text Available A new ambient air monitor, the Measurement of Ozone Production Sensor (MOPS, measures directly the rate of ozone production in the atmosphere. The sensor consists of two 11.3 L environmental chambers made of UV-transmitting Teflon film, a unit to convert NO2 to O3, and a modified ozone monitor. In the sample chamber, flowing ambient air is exposed to the sunlight so that ozone is produced just as it is in the atmosphere. In the second chamber, called the reference chamber, a UV-blocking film over the Teflon film prevents ozone formation but allows other processes to occur as they do in the sample chamber. The air flows that exit the two chambers are sampled by an ozone monitor operating in differential mode so that the difference between the two ozone signals, divided by the exposure time in the chambers, gives the ozone production rate. High-efficiency conversion of NO2 to O3 prior to detection in the ozone monitor accounts for differences in the NOx photostationary state that can occur in the two chambers. The MOPS measures the ozone production rate, but with the addition of NO to the sampled air flow, the MOPS can be used to study the sensitivity of ozone production to NO. Preliminary studies with the MOPS on the campus of the Pennsylvania State University show the potential of this new technique.

  2. Degradation of Acenaphthene by Ozone

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To investigate the oxidation of acenaphthene (Ace), a polycyclic aromatic hydrocarbon (PAH) with a saturated C-C bond by ozone and to characterize the intermediate products of ozonation. Methods Ozone was generated from filtered dry oxygen by an ozone generator and continually bubbled into a reactor containing 1g/L Ace dissolved in an acetonitrile/water solvent mixture (90/10, v/v) at a rate of 0.5 mg/s. HPLC was used to analyze the Ace concentration. Total organic carbon (TOC) was used to measure the amount of water soluble organic compounds. GC-MS was used to identify the ozonized products. Oxygen uptake rate (OUR) of activated sludge was used to characterize the biodegradability of ozonized products. Results During the ozonation process, Ace was degraded, new organic compounds were produced and these intermediate products were difficult mineralize by ozone, with increasing TOC of soluble organics. The ozonized products were degraded by activated sludge more easily than Ace. Conclusion Ozonation decomposes the Ace and improves its biodegradability. The ozonation combined with biological treatment is probably an efficient and economical way to mineralize acenaphthene in wastewater.

  3. Ozone: apocalypse or misinformation

    International Nuclear Information System (INIS)

    This paper debates about the origin of the destruction of ozone layer in the stratosphere. Chlorofluorocarbons don't seem to be the single responsible agent but chloric acid from volcanic eruptions, chlorinated compounds of oceans or biomass combustion are another major sources. 13 refs., 3 figs

  4. Ozone, greenhouse effect

    International Nuclear Information System (INIS)

    This file is made of eight general papers on environment (climates under observation, research on photo-oxidizing pollution, scientific aspects of stratospheric ozone layer, urban engineering and environment, glory of public gardens, earths not very natural, darwinism and society, economical data on environment). (A.B.). refs., 3 tabs

  5. Ozone Layer Educator's Guide.

    Science.gov (United States)

    Environmental Protection Agency, Washington, DC.

    This guide has been developed through a collaborative effort involving the U.S. Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics and Space Administration (NASA). It is part of an ongoing commitment to ensure that the results of scientific research on ozone depletion are…

  6. Ozone and Cavitation Combination

    Science.gov (United States)

    Carreon, Ernestina; Traversoni, Leonardo

    2009-09-01

    From laboratory measurements it is well known that the addition of ozone and cavitation enhances the properties of both, understanding for that the ones related to disinfection and carbon removal from waste water. This paper shows modeling of such phenomena that gives some light to the understanding of it and also provides the opportunity to improve the effectiveness of the current procedures.

  7. The effect of UV radiation on photosynthesis in an Antarctic diatom (Thalassiosira sp.): does vertical mixing matter?

    International Nuclear Information System (INIS)

    Full text: The reduction of the Antarctic stratospheric ozone resulted in significant increases in ultraviolet B radiation (UVBR, 280-320 nm) reaching the surface of the ocean. A series of laboratory and field experiments were conducted at Potter Cove (25 de Mayo Is., South Shetland Is., Antarctica) to study the effects of UVBR on photosynthesis of a typical Antarctic bloom forming diatom (Thalassiosira sp.) in fixed and moving incubations. There were three irradiance treatments: PART (with only photosynthetic active radiation, PAR, 400- 700 nm), UVAT (with PAR and ultraviolet A radiation, UVAR, 320-400 nm) and UVBT (with PAR, UVAR and UVBR). The three treatments were incubated in the field and laboratory with a solar simulator (SOLSI) in fixed frames at 0.5 and 5 m depth (Sfix and Bfix, respectively), while for the moving incubations were done within 6 h cycles (Mix). Considering the field and laboratory pooled data, results suggest an overall 45-50 % photosynthesis inhibition of Sfix incubations in relation with Mix ones. During SOLSI experiments no significant differences were found between irradiance treatments under normal and medium ozone concentrations. Under low ozone conditions, a 40 % reduction in photosynthesis was observed in the UVBT for Sfix . In contrast, no significant differences were observed between the irradiance treatments for Mix. Field experiment showed results similar to the laboratory ones, but in this case not only Sfix but Mix incubations presented a significant reduction in photosynthesis under low ozone. The differences between laboratory and field experiments are discussed in terms of the relative significance of UVBR dose and dose rate on both types of experiments. (author)

  8. Arctic chlorine monoxide observations during spring 1993 over Thule, Greenland, and implications for ozone depletion

    Science.gov (United States)

    Shindell, D. T.; Reeves, J. M.; Emmons, L. K.; De Zafra, R. L.

    1994-01-01

    We have determined the vertical distribution of chlorine monoxide (ClO), from measurements of pressure-broadened molecular-emission spectra made over Thule, Greenland, during the 1993 Arctic spring. The measurements show a weak lower stratospheric layer of chlorine monoxide inside the vortex in late February, which was, however, significantly greater in mixing ratio than that seen in observations we made in the spring of 1992. ClO was also observed in much smaller quantities in early to mid-March 1993 when Thule was outside the vortex. The amount of ClO within the vortex was severely reduced by the time it returned over Thule in late March. This reduction occurred several weeks earlier relative to the winter solstice than the decline of ClO inside the Antarctic vortex in 1993. The enhanced Arctic lower stratospheric layer seen in late February 1993 at a nearly equivalent photochemical period, and beyond. We have calculated daily ozone loss rates, due primarily to the dimer chlorine catalytic cycle, from both sets of measurements. The vertical integral of the Arctic daily percentage ozone loss when the largest ClO levels were present, at the end of February, is found to be approximately one quarter of that in the Antarctic at a photochemical period only 1 week later. The relative weakness of daily ozone depletion, combined with the early disappearance of ClO in the Arctic, suggests that hemispheric dilution by ozone-poor air from within the Arctic vortex is unlikely to be sufficient to explain the historically extreme loss of midlatitude northern hemisphere ozone which began in 1992 and persisted throughout 1993.

  9. Antarctic Data Management as Part of the IPY Legacy

    Science.gov (United States)

    de Bruin, T.

    2006-12-01

    The Antarctic Treaty states that "scientific observations and results from Antarctica shall be exchanged and made freely available". Antarctica includes the Southern Ocean. In support of this, National Antarctic Data Centres (NADC) are being established to catalogue data sets and to provide information on data sets to scientists and others with interest in Antarctic science. The Joint Committee on Antarctic Data Management (JCADM) was established by the Scientific Committee on Antarctic Research (SCAR) and the Council of Managers of National Antarctic Programs (COMNAP). JCADM comprises representatives of the National Antarctic Data Centres. Currently 30 nations around the world are represented in JCADM. JCADM is responsible for the Antarctic Master Directory (AMD), the internationally accessible, web-based, searchable record of Antarctic and Southern Ocean data set descriptions. The AMD is directly integrated into the international Global Change Master Directory (GCMD) to help further merge Antarctic science into global science. The AMD is a resource for scientists to advertise the data they have collected and to search for data they may need. JCADM is the Antarctic component of the IPY Data Infrastructure, which is presently being developed. This presentation will give an overview of the organization of Antarctic and Southern Ocean data management with sections on the organizational structure of JCADM, contents of the Antarctic Master Directory, relationships to the SCAR Scientific Research Programmes (SRP) and IPY, international embedding and connections with discipline-based peer organizations like the International Oceanographic Data and Information Exchange Committee (IODE). It will focus primarily on the role that an existing infrastructure as JCADM, may play in the development of the IPY Data Infrastructure and will provide considerations for IPY data management, based on the experiences in Antarctic and oceanographic data management.

  10. Non-Thermal Plasma Ozone Generation

    OpenAIRE

    S. Pekárek

    2003-01-01

    This paper reviews ozone properties, ozone applications and the mechanism of ozone production in non-thermal plasma. An analysis is made of the influence of a reduced electric field and discharge space temperature on ozone production. The phenomenon of discharge poisoning is also explained. Finally, a modern ozone production system based on dielectric barrier electrical discharge is described.

  11. Non-Thermal Plasma Ozone Generation

    Directory of Open Access Journals (Sweden)

    S. Pekárek

    2003-01-01

    Full Text Available This paper reviews ozone properties, ozone applications and the mechanism of ozone production in non-thermal plasma. An analysis is made of the influence of a reduced electric field and discharge space temperature on ozone production. The phenomenon of discharge poisoning is also explained. Finally, a modern ozone production system based on dielectric barrier electrical discharge is described.

  12. Mineral dust variability in central West Antarctica associated with ozone depletion

    Directory of Open Access Journals (Sweden)

    M. Cataldo

    2013-02-01

    Full Text Available We present here data of mineral dust variability retrieved from an ice core of the central West Antarctic, spanning the last five decades. Main evidence provided by the geochemical analysis is that northerly air mass incursions to the coring site, tracked by insoluble dust microparticles, have declined over the past 50 yr. This result contrasts with dust records from ice cores reported to the coastal West Antarctic that show increases since mid-20th century. We attribute this difference to regional climatic changes due to the ozone depletion and its implications to westerly winds. We found that the diameters of insoluble microparticles in the central West Antarctica ice core are significantly correlated with cyclone depth (energy and wind intensity around Antarctica.

  13. Contrasting Arctic and Antarctic sea ice temperatures

    Science.gov (United States)

    Vancoppenolle, Martin; Raphael, Marilyn; Rousset, Clément; Vivier, Frédéric; Moreau, Sébastien; Delille, Bruno; Tison, Jean-Louis

    2016-04-01

    Sea ice temperature affects the sea ice growth rate, heat content, permeability and habitability for ice algae. Large-scale simulations with NEMO-LIM suggest large ice temperature contrasts between the Arctic and the Antarctic sea ice. First, Antarctic sea ice proves generally warmer than in the Arctic, in particular during winter, where differences reach up to ~10°C. Second, the seasonality of temperature is different among the two hemispheres: Antarctic ice temperatures are 2-3°C higher in spring than they are in fall, whereas the opposite is true in the Arctic. These two key differences are supported by the available ice core and mass balance buoys temperature observations, and can be attributed to differences in air temperature and snow depth. As a result, the ice is found to be habitable and permeable over much larger areas and much earlier in late spring in the Antarctic as compared with the Arctic, which consequences on biogeochemical exchanges in the sea ice zone remain to be evaluated.

  14. Relevance of antarctic microbial ecosystems to exobiology

    Science.gov (United States)

    Mckay, Christopher P.

    1993-01-01

    Antarctic microbial ecosystems which provide biological and physical analogs that can be used in exobiology are studied. Since the access to extraterrestrial habitats is extremely difficult, terrestrial analogs represent the best opportunity for both formulation and preliminary testing of hypothesis about life. Antarctica, as one of few suitable environments on earth is considered to be a major locus of progress in exobiology.

  15. Global dynamics of the Antarctic ice sheet

    NARCIS (Netherlands)

    Oerlemans, J.

    2002-01-01

    The total mass budget of the Antarctic ice sheet is studied with a simple axi-symmetrical model. The ice-sheet has a parabolic profile resting on a bed that slopes linearly downwards from the centre of the ice sheet into the ocean. The mean ice velocity at the grounding line is assumed to be proport

  16. Dynamics of black holes

    OpenAIRE

    Hayward, Sean A.

    2008-01-01

    This is a review of current theory of black-hole dynamics, concentrating on the framework in terms of trapping horizons. Summaries are given of the history, the classical theory of black holes, the defining ideas of dynamical black holes, the basic laws, conservation laws for energy and angular momentum, other physical quantities and the limit of local equilibrium. Some new material concerns how processes such as black-hole evaporation and coalescence might be described by a single trapping h...

  17. Noncommutative black holes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-DomInguez, J C [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); Obregon, O [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico); RamIrez, C [Facultad de Ciencias FIsico Matematicas, Universidad Autonoma de Puebla, PO Box 1364, 72000 Puebla (Mexico); Sabido, M [Instituto de Fisica de la Universidad de Guanajuato PO Box E-143, 37150 Leoen Gto. (Mexico)

    2007-11-15

    We study noncommutative black holes, by using a diffeomorphism between the Schwarzschild black hole and the Kantowski-Sachs cosmological model, which is generalized to noncommutative minisuperspace. Through the use of the Feynman-Hibbs procedure we are able to study the thermodynamics of the black hole, in particular, we calculate Hawking's temperature and entropy for the 'noncommutative' Schwarzschild black hole.

  18. Black holes without firewalls

    Science.gov (United States)

    Larjo, Klaus; Lowe, David A.; Thorlacius, Larus

    2013-05-01

    The postulates of black hole complementarity do not imply a firewall for infalling observers at a black hole horizon. The dynamics of the stretched horizon, that scrambles and reemits information, determines whether infalling observers experience anything out of the ordinary when entering a large black hole. In particular, there is no firewall if the stretched horizon degrees of freedom retain information for a time of the order of the black hole scrambling time.

  19. Neogene kinematic history of Nazca-Antarctic-Phoenix slab windows beneath Patagonia and the Antarctic Peninsula

    Science.gov (United States)

    Breitsprecher, Katrin; Thorkelson, Derek J.

    2009-01-01

    The Patagonian slab window is a subsurface tectonic feature resulting from subduction of the Nazca-Antarctic spreading-ridge system (Chile Rise) beneath southern South America. The geometry of the slab window had not been rigorously defined, in part because of the complex nature of the history of ridge subduction in the southeast Pacific region, which includes four interrelated spreading-ridge systems since 20 Ma: first, the Nazca-Phoenix ridge beneath South America, then simultaneous subduction of the Nazca-Antarctic and the northern Phoenix-Antarctic spreading-ridge systems beneath South America, and the southern Phoenix-Antarctic spreading-ridge system beneath Antarctica. Spreading-ridge paleo-geographies and rotation poles for all relevant plate pairs (Nazca, Phoenix, Antarctic, South America) are available from 20 Ma onward, and form the mathematical basis of our kinematic reconstruction of the geometry of the Patagonia and Antarctic slab windows through Neogene time. At approximately 18 Ma, the Nazca-Phoenix-Antarctic oceanic (ridge-ridge-ridge) triple junction enters the South American trench; we recognize this condition as an unstable quadruple junction. Heat flow at this junction and for some distance beneath the forearc would be considerably higher than is generally recognized in cases of ridge subduction. From 16 Ma onward, the geometry of the Patagonia slab window developed from the subduction of the trailing arms of the former oceanic triple junction. The majority of the slab window's areal extent and geometry is controlled by the highly oblique (near-parallel) subduction angle of the Nazca-Antarctic ridge system, and by the high contrast in relative convergence rates between these two plates relative to South America. The very slow convergence rate of the Antarctic slab is manifested by the shallow levels achieved by the slab edge (< 45 km); thus no point on the Antarctic slab is sufficiently deep to generate "normal" mantle-derived arc-type magmas

  20. Using Transport Diagnostics to Understand Chemistry Climate Model Ozone Simulations

    Science.gov (United States)

    Strahan, S. E.; Douglass, A. R.; Stolarski, R. S.; Akiyoshi, H.; Bekki, S.; Braesicke, P.; Butchart, N.; Chipperfield, M. P.; Cugnet, D.; Dhomse, S.; Frith, S. M.; Gettleman, A.; Hardiman, S. C.; Kinnison, D. E.; Lamarque, J.-F.; Mancini, E.; Marchand, M.; Michou, M.; Morgenstern, O.; Nakamura, T.; Olivie, D.; Pawson, S.; Pitari, G.; Plummer, D. A.; Pyle, J. A.

    2010-01-01

    We demonstrate how observations of N2O and mean age in the tropical and midlatitude lower stratosphere (LS) can be used to identify realistic transport in models. The results are applied to 15 Chemistry Climate Models (CCMs) participating in the 2010 WMO assessment. Comparison of the observed and simulated N2O/mean age relationship identifies models with fast or slow circulations and reveals details of model ascent and tropical isolation. The use of this process-oriented N2O/mean age diagnostic identifies models with compensating transport deficiencies that produce fortuitous agreement with mean age. We compare the diagnosed model transport behavior with a model's ability to produce realistic LS O3 profiles in the tropics and midlatitudes. Models with the greatest tropical transport problems show the poorest agreement with observations. Models with the most realistic LS transport agree more closely with LS observations and each other. We incorporate the results of the chemistry evaluations in the SPARC CCMVal Report (2010) to explain the range of CCM predictions for the return-to-1980 dates for global (60 S-60 N) and Antarctic column ozone. Later (earlier) Antarctic return dates are generally correlated to higher (lower) vortex Cl(sub y) levels in the LS, and vortex Cl(sub y) is generally correlated with the model's circulation although model Cl(sub y) chemistry or Cl(sub y) conservation can have a significant effect. In both regions, models that have good LS transport produce a smaller range of predictions for the return-to-1980 ozone values. This study suggests that the current range of predicted return dates is unnecessarily large due to identifiable model transport deficiencies.

  1. Ozone measurements and correlations with cosmogenic radioisotopes in Italian Alpine valley. Misure di ozono in atmosfera e correlazioni con radioisotopi cosmogenici in Valtellina

    Energy Technology Data Exchange (ETDEWEB)

    Vecchi, R.; Valli, G.; Ludwig, N.; De Dosso, L. (Milan Univ. (Italy). Ist. di Fisica Generale Applicata)

    The Italian Institute of General Applied Physics since 1990 has been conducting Be-7 measurements in the atmosphere in order to use it as a tracer for air coming from the upper layers of the atmosphere and for stratospheric ozone. This paper presents the results on Be-7 and ozone concentrations obtained with a one year monitoring campaign carried out in Sondrio, an Alpine town in Northern Italy. For a few interesting events, a correlation between beryllium and ozone is observed. Be-7 reveals itself as a good marker which reaches ground level during particularly rare events, such as stratospheric intrusions. This study could have an interesting application concerning the ozone depletion layer in the Antarctic area.

  2. Degradation of carbofuran by ozonation.

    Science.gov (United States)

    Suneethi, S; Joseph, Kurian

    2009-04-01

    Degradation of commercial grade carbofuran (2, 3 dihydro-2, 2-dimethyl-7 benzo furanyl-N-methyl carbamate) in aqueous solution by ozone oxidation was investigated using bench scale experiments. The degradation rate was strongly influenced by the ozone dosage, pH, initial concentration of carbofuran and contact time of ozonation. Carbofuran solution of 200ppm concentration was degraded by 79% within 10 minutes consuming 87 mg of ozone at pH 4. The associated TOC reduction was observed to be 53%. Ammonium (20 mg/L) and nitrate (30 mg/L) ions were detected in the effluent as degradation products of ozonation. The results support the effectiveness of ozonation for degradation of organic pesticides such as carbofuran.

  3. Sound Hole Sound

    CERN Document Server

    Politzer, David

    2015-01-01

    The volume of air that goes in and out of a musical instrument's sound hole is related to the sound hole's contribution to the volume of the sound. Helmholtz's result for the simplest case of steady flow through an elliptical hole is reviewed. Measurements on multiple holes in sound box geometries and scales relevant to real musical instruments demonstrate the importance of a variety of effects. Electric capacitance of single flat plates is a mathematically identical problem, offering an alternate way to understand the most important of those effects. The measurements also confirm and illuminate aspects of Helmholtz's "bottle" resonator model as applied to musical instrument sound boxes and sound holes.

  4. Health Effects of Ozone and Particle Pollution

    Science.gov (United States)

    ... Health Risks Health Effects of Ozone and Particle Pollution Two types of air pollution dominate in the ... So what are ozone and particle pollution? Ozone Pollution It may be hard to imagine that the ...

  5. Ozonated olive oils and the troubles.

    Science.gov (United States)

    Uysal, Bulent

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. PMID:26401346

  6. The signatures of large-scale patterns of atmospheric variability in Antarctic surface temperatures

    Science.gov (United States)

    Marshall, Gareth J.; Thompson, David W. J.

    2016-04-01

    We investigate the impact that the four principal large-scale patterns of Southern Hemisphere (SH) atmospheric circulation variability have on Antarctic surface air temperature (SAT): (1) the southern baroclinic annular mode (BAM), which is associated with variations in extratropical storm amplitude; (2) the Southern Annular Mode (SAM), associated with latitudinal shifts in the midlatitude jet; and (3) the two Pacific-South American patterns (PSA1 and PSA2), which are characterized by wave trains originating in the tropical Pacific that extend across the SH extratropics. A key aspect is the use of 35 years of daily observations and reanalysis data, which affords a sufficiently large sample size to assess the signatures of the circulation patterns in both the mean and variability of daily mean SAT anomalies. The BAM exerts the weakest influence on Antarctic SAT, albeit it is still important over select regions. Consistent with previous studies, the SAM is shown to influence SAT across most of the continent throughout the year. The PSA1 also affects SAT across almost all of Antarctica. Regionally, both PSA patterns can exert a greater impact on SAT than the SAM but also have a significantly weaker influence during summer, reflecting the seasonality of the SH response to El Niño-Southern Oscillation. The SAM and PSA patterns have distinct signatures in daily SAT variance that are physically consistent with their signatures in extratropical dynamic variability. The broad-scale climate linkages identified here provide benchmarks for interpreting the Antarctic climate response to future changes in tropical sea surface temperatures, ozone recovery, and greenhouse gas increases.

  7. Protecting the ozone layer.

    Science.gov (United States)

    Munasinghe, M; King, K

    1992-06-01

    Stratospheric ozone layer depletion has been recognized as a problem by the Vienna Convention for the Protection of the Ozone Layer and the 1987 Montreal Protocol (MP). The ozone layer shields the earth from harmful ultraviolet radiation (UV-B), which is more pronounced at the poles and around the equator. Industrialized countries have contributed significantly to the problem by releasing chlorofluorocarbons (CFCs) and halons into the atmosphere. The effect of these chemicals, which were known for their inertness, nonflammability, and nontoxicity, was discovered in 1874. Action to deal with the effects of CFCs and halons was initiated in 1985 in a 49-nation UN meeting. 21 nations signed a protocol limiting ozone depleting substances (ODS): CFCs and halons. Schedules were set based on each country's use in 1986; the target phaseout was set for the year 2000. The MP restricts trade in ODSs and weights the impact of substances to reflect the extent of damage; i.e., halons are 10 times more damaging than CFCs. ODS requirements for developing countries were eased to accommodate scarce resources and the small fraction of ODS emissions. An Interim Multilateral Fund under the Montreal Protocol (IMFMP) was established to provide loans to finance the costs to developing countries in meeting global environmental requirements. The IMFMP is administered by the World Bank, the UN Environmental Program, and the UN Development Program. Financing is available to eligible countries who use .3 kg of ODS/person/year. Rapid phaseout in developed countries has occurred due to strong support from industry and a lower than expected cost. Although there are clear advantages to rapid phaseout, there were no incentives included in the MP for rapid phaseout. Some of the difficulties occur because the schedules set minimum targets at the lowest possible cost. Also, costs cannot be minimized by a country-specific and ODS-specific process. The ways to improve implementation in scheduling and

  8. Dynamic recycling of gaseous elemental mercury in the boundary layer of the Antarctic Plateau

    Directory of Open Access Journals (Sweden)

    A. Dommergue

    2012-07-01

    Full Text Available Gaseous elemental mercury (Hg(0 was investigated in the troposphere and in the interstitial air extracted from the snow at Dome Concordia station (alt. 3320 m on the Antarctic Plateau during January 2009. Measurements showed evidence of a very dynamic and daily cycling of Hg(0 inside the mixing layer with a range of values from 0.2 ng m−3 up to 2.3 ng m−3. During low solar irradiation periods, fast Hg(0 oxidation processes in a confined layer were observed leading to an enrichment of the upper snow layers in divalent Hg. Unexpectedly high Hg(0 concentrations for such a remote place were measured under higher solar irradiation due to the reemission of Hg(0 by the snowpack via photochemical reactions. Hg(0 concentrations showed a negative correlation with ozone mixing ratios, which contrasts with atmospheric mercury depletion events observed during the Arctic spring. It remains unclear whether halogens are involved in Hg(0 oxidation. We suggest that snow surfaces may play a role in promoting the heterogeneous oxidation of Hg(0. The cycling of other oxidants should be investigated together with Hg in order to clarify the complex reactivity on the Antarctic Plateau.

  9. Absence of 21st century warming on Antarctic Peninsula consistent with natural variability.

    Science.gov (United States)

    Turner, John; Lu, Hua; White, Ian; King, John C; Phillips, Tony; Hosking, J Scott; Bracegirdle, Thomas J; Marshall, Gareth J; Mulvaney, Robert; Deb, Pranab

    2016-07-21

    Since the 1950s, research stations on the Antarctic Peninsula have recorded some of the largest increases in near-surface air temperature in the Southern Hemisphere. This warming has contributed to the regional retreat of glaciers, disintegration of floating ice shelves and a 'greening' through the expansion in range of various flora. Several interlinked processes have been suggested as contributing to the warming, including stratospheric ozone depletion, local sea-ice loss, an increase in westerly winds, and changes in the strength and location of low-high-latitude atmospheric teleconnections. Here we use a stacked temperature record to show an absence of regional warming since the late 1990s. The annual mean temperature has decreased at a statistically significant rate, with the most rapid cooling during the Austral summer. Temperatures have decreased as a consequence of a greater frequency of cold, east-to-southeasterly winds, resulting from more cyclonic conditions in the northern Weddell Sea associated with a strengthening mid-latitude jet. These circulation changes have also increased the advection of sea ice towards the east coast of the peninsula, amplifying their effects. Our findings cover only 1% of the Antarctic continent and emphasize that decadal temperature changes in this region are not primarily associated with the drivers of global temperature change but, rather, reflect the extreme natural internal variability of the regional atmospheric circulation.

  10. Absence of 21st century warming on Antarctic Peninsula consistent with natural variability

    Science.gov (United States)

    Turner, John; Lu, Hua; White, Ian; King, John C.; Phillips, Tony; Hosking, J. Scott; Bracegirdle, Thomas J.; Marshall, Gareth J.; Mulvaney, Robert; Deb, Pranab

    2016-07-01

    Since the 1950s, research stations on the Antarctic Peninsula have recorded some of the largest increases in near-surface air temperature in the Southern Hemisphere. This warming has contributed to the regional retreat of glaciers, disintegration of floating ice shelves and a ‘greening’ through the expansion in range of various flora. Several interlinked processes have been suggested as contributing to the warming, including stratospheric ozone depletion, local sea-ice loss, an increase in westerly winds, and changes in the strength and location of low–high-latitude atmospheric teleconnections. Here we use a stacked temperature record to show an absence of regional warming since the late 1990s. The annual mean temperature has decreased at a statistically significant rate, with the most rapid cooling during the Austral summer. Temperatures have decreased as a consequence of a greater frequency of cold, east-to-southeasterly winds, resulting from more cyclonic conditions in the northern Weddell Sea associated with a strengthening mid-latitude jet. These circulation changes have also increased the advection of sea ice towards the east coast of the peninsula, amplifying their effects. Our findings cover only 1% of the Antarctic continent and emphasize that decadal temperature changes in this region are not primarily associated with the drivers of global temperature change but, rather, reflect the extreme natural internal variability of the regional atmospheric circulation.

  11. Absence of 21st century warming on Antarctic Peninsula consistent with natural variability.

    Science.gov (United States)

    Turner, John; Lu, Hua; White, Ian; King, John C; Phillips, Tony; Hosking, J Scott; Bracegirdle, Thomas J; Marshall, Gareth J; Mulvaney, Robert; Deb, Pranab

    2016-07-21

    Since the 1950s, research stations on the Antarctic Peninsula have recorded some of the largest increases in near-surface air temperature in the Southern Hemisphere. This warming has contributed to the regional retreat of glaciers, disintegration of floating ice shelves and a 'greening' through the expansion in range of various flora. Several interlinked processes have been suggested as contributing to the warming, including stratospheric ozone depletion, local sea-ice loss, an increase in westerly winds, and changes in the strength and location of low-high-latitude atmospheric teleconnections. Here we use a stacked temperature record to show an absence of regional warming since the late 1990s. The annual mean temperature has decreased at a statistically significant rate, with the most rapid cooling during the Austral summer. Temperatures have decreased as a consequence of a greater frequency of cold, east-to-southeasterly winds, resulting from more cyclonic conditions in the northern Weddell Sea associated with a strengthening mid-latitude jet. These circulation changes have also increased the advection of sea ice towards the east coast of the peninsula, amplifying their effects. Our findings cover only 1% of the Antarctic continent and emphasize that decadal temperature changes in this region are not primarily associated with the drivers of global temperature change but, rather, reflect the extreme natural internal variability of the regional atmospheric circulation. PMID:27443743

  12. Ringrotbestrijding met behulp van ozon

    OpenAIRE

    Wolf, de, H.; Bergervoet, J.H.W.; Kastelein, P.; Zouwen, van der, P.S.

    2009-01-01

    Door het kistenreinigingsbedrijf van Frans Renne wordt een nieuwe kistenreinigingsmachine ontwikkeld. De methode is gebaseerd op ontsmetting met Ozon van recirculerend spoelwater en van kisten. In dit rapport wordt verslag gedaan van laboratorium-onderzoek naar het effect van ozon op ringrotbacterieën en de noodzakelijke dosering en inwerktijd, en naar het effect van ozon in organisch belast (maar d.m.v. filtering gereinigd) spoelwater

  13. Stuffed Black Holes

    CERN Document Server

    Arbona, A; Carot, J; Mas, L; Massó, J; Stela, J

    1998-01-01

    Initial data corresponding to spacetimes containing black holes are considered in the time symmetric case. The solutions are obtained by matching across the apparent horizon different, conformally flat, spatial metrics. The exterior metric is the vacuum solution obtained by the well known conformal imaging method. The interior metric for every black hole is regular everywhere and corresponds to a positive energy density. The resulting matched solutions cover then the whole initial (Cauchy) hypersurface, without any singularity, and can be useful for numerical applications. The simpler cases of one black hole (Schwarzschild data) or two identical black holes (Misner data) are explicitly solved. A procedure for extending this construction to the multiple black hole case is also given, and it is shown to work for all time symmetric vacuum solutions obtained by the conformal imaging method. The numerical evolution of one such 'stuffed' black hole is compared with that of a pure vacuum or 'plain' black hole in the...

  14. Uncertainty analysis of projections of ozone-depleting substances: mixing ratios, EESC, ODPs, and GWPs

    Science.gov (United States)

    Velders, G. J. M.; Daniel, J. S.

    2014-03-01

    The rates at which ozone-depleting substances (ODSs) are removed from the atmosphere, which determine the lifetimes of these ODSs, are key factors for determining the rate of ozone layer recovery in the coming decades. We present here a comprehensive uncertainty analysis of future mixing ratios of ODSs, levels of equivalent effective stratospheric chlorine (EESC), ozone depletion potentials, and global warming potentials (GWPs), using, among other information, the 2013 WCRP/SPARC (World Climate Research Programme/Stratospheric Processes and their Role in Climate) assessment of lifetimes of ODSs and their uncertainties. The year EESC returns to pre-1980 levels, a metric commonly used to indicate a level of recovery from ODS-induced ozone depletion, is 2048 for midlatitudes and 2075 for Antarctic conditions based on the lifetimes from the SPARC assessment, which is about 2 and 4 yr, respectively, later than based on the lifetimes from the WMO (World Meteorological Organization) assessment of 2011. However, the uncertainty in this return to 1980 levels is much larger than the shift due to this change in lifetimes. The year EESC returns to pre-1980 levels ranges from 2039 to 2064 (95% confidence interval) for midlatitudes and from 2061 to 2105 for the Antarctic spring. The primary contribution to these ranges comes from the uncertainty in the lifetimes, with smaller contributions from uncertainties in other modeled parameters. The earlier years of the return estimates derived by the uncertainty analysis, i.e., 2039 for midlatitudes and 2061 for Antarctic spring, are comparable to a hypothetical scenario in which emissions of ODSs cease in 2014. The later end of the range, i.e., 2064 for midlatitudes and 2105 for Antarctic spring, can also be obtained by a scenario with an additional emission of about 7 Mt CFC-11 eq. (eq. - equivalent) in 2015, which is the same as about 2 times the projected cumulative anthropogenic emissions of all ODSs from 2014 to 2050, or about 12

  15. Hole history, rotary hole DC-3

    Energy Technology Data Exchange (ETDEWEB)

    1977-10-01

    Purpose of hole DC-3 was to drill into the Umtanum basalt flow using both conventional rotary and core drilling methods. The borehole is to be utilized for geophysical logging, future hydrological testing, and the future installation of a borehole laboratory for long-term pressure, seismic, and moisture migration or accumulation recording in the Umtanum basalt flow in support of the Basalt Waste Isolation Program. Hole DC-3 is located east of the 200 West barricaded area on the Hanford reservation.

  16. Hole history, rotary hole DC-3

    International Nuclear Information System (INIS)

    Purpose of hole DC-3 was to drill into the Umtanum basalt flow using both conventional rotary and core drilling methods. The borehole is to be utilized for geophysical logging, future hydrological testing, and the future installation of a borehole laboratory for long-term pressure, seismic, and moisture migration or accumulation recording in the Umtanum basalt flow in support of the Basalt Waste Isolation Program. Hole DC-3 is located east of the 200 West barricaded area on the Hanford reservation

  17. Encouraging Advances Made by Chinese Scientists in Antarctic Research

    Institute of Scientific and Technical Information of China (English)

    Zhang Qingsong

    2003-01-01

    @@ Chinese scientists began involving in the Antarctic research in 1980. As the first step, some 40 Chinese scientists were sent to Antarctic stations of Australia and other countries during the period from 1980 to 1984. Then,China established two Antarctic stations of its own, and purchased an icebreaker, enabling China to carry on its own independent research program both on land and at sea.

  18. Relative Changes in Krill Abundance Inferred from Antarctic Fur Seal

    OpenAIRE

    Tao Huang; Liguang Sun; John Stark; Yuhong Wang; Zhongqi Cheng; Qichao Yang; Song Sun

    2011-01-01

    Antarctic krill Euphausia superba is a predominant species in the Southern Ocean, it is very sensitive to climate change, and it supports large stocks of fishes, seabirds, seals and whales in Antarctic marine ecosystems. Modern krill stocks have been estimated directly by net hauls and acoustic surveys; the historical krill density especially the long-term one in the Southern Ocean, however, is unknown. Here we inferred the relative krill population changes along the West Antarctic Peninsula ...

  19. Stratospheric ozone depletion over Antarctica - Role of aerosols based on SAGE II satellite observations

    Science.gov (United States)

    Lin, N.-H.; Saxena, V. K.

    1992-01-01

    The physical characteristics of the Antarctic stratospheric aerosol are investigated via a comprehensive analysis of the SAGE II data during the most severe ozone depletion episode of October 1987. The aerosol size distribution is found to be bimodal in several instances using the randomized minimization search technique, which suggests that the distribution of a single mode may be used to fit the data in the retrieved size range only at the expense of resolution for the larger particles. On average, in the region below 18 km, a wavelike perturbation with the upstream tilting for the parameters of mass loading, total number, and surface area concentration is found to be located just above the region of the most severe ozone depletion.

  20. Microbial mercury methylation in Antarctic sea ice.

    Science.gov (United States)

    Gionfriddo, Caitlin M; Tate, Michael T; Wick, Ryan R; Schultz, Mark B; Zemla, Adam; Thelen, Michael P; Schofield, Robyn; Krabbenhoft, David P; Holt, Kathryn E; Moreau, John W

    2016-01-01

    Atmospheric deposition of mercury onto sea ice and circumpolar sea water provides mercury for microbial methylation, and contributes to the bioaccumulation of the potent neurotoxin methylmercury in the marine food web. Little is known about the abiotic and biotic controls on microbial mercury methylation in polar marine systems. However, mercury methylation is known to occur alongside photochemical and microbial mercury reduction and subsequent volatilization. Here, we combine mercury speciation measurements of total and methylated mercury with metagenomic analysis of whole-community microbial DNA from Antarctic snow, brine, sea ice and sea water to elucidate potential microbially mediated mercury methylation and volatilization pathways in polar marine environments. Our results identify the marine microaerophilic bacterium Nitrospina as a potential mercury methylator within sea ice. Anaerobic bacteria known to methylate mercury were notably absent from sea-ice metagenomes. We propose that Antarctic sea ice can harbour a microbial source of methylmercury in the Southern Ocean. PMID:27670112

  1. The history of Antarctic Peninsula glaciation

    Science.gov (United States)

    Barker, Peter F.

    2007-01-01

    As Co-Chief Scientist on DSDP Leg 35 in 1974, Cam Craddock (1930-2006) produced the first useful information on Cenozoic Antarctic Peninsula glaciation - an early middle Miocene (15-17 Ma) apparent glacial onset. Subsequent work, onshore and offshore, has greatly extended our knowledge but that early conclusion stands today. Cenozoic Antarctic Peninsula palaeoclimate as presently known is broadly consistent with global palaeoclimate proxies. Initial glacial onset was within the Eocene-Oligocene boundary interval (although earlier, short-lived glaciations have been proposed, from indirect measurements) and the peninsula probably became deglaciated in the earliest Miocene (ca. 24 Ma). The renewed middle Miocene glaciation probably continued to the present and, for the last 9 Myr at least, has persisted through glacial (orbital) cycles, with grounded ice advance to the shelf edge during maxima. Although orbital cyclicity affected earlier AP palaeoclimate also, the level of glaciation through a complete cycle is uncertain.

  2. Total Mercury in Six Antarctic Notothenioid Fishes.

    Science.gov (United States)

    Wintle, Nathan J P; Sleadd, Isaac M; Gundersen, Deke T; Kohl, Kristina; Buckley, Bradley A

    2015-11-01

    We analyzed white muscle samples from six species of Antarctic fish (suborder Notothenioidei) collected in 2011 from McMurdo Sound, Ross Sea, Antarctica, to assess levels of total mercury (THg). Gymnodraco acuticeps and Trematomus bernacchii exhibited the highest concentrations of THg followed by Trematomus pennellii, Trematomus nicolai, Trematomus newnesi and Pagothenia borchgrevinki, (71.3, 53.9±32.1, 45.8±27.3, 37.2±18.6, 35.7±23.6, and 21.9±2.8 ng/g wet weight, respectively). The results from this study suggest that THg has the potential to bioaccumulate from various marine Antarctic ecosystems into biota.

  3. Antarctic Meteorite Classification and Petrographic Database

    Science.gov (United States)

    Todd, Nancy S.; Satterwhite, C. E.; Righter, Kevin

    2011-01-01

    The Antarctic Meteorite collection, which is comprised of over 18,700 meteorites, is one of the largest collections of meteorites in the world. These meteorites have been collected since the late 1970's as part of a three-agency agreement between NASA, the National Science Foundation, and the Smithsonian Institution [1]. Samples collected each season are analyzed at NASA s Meteorite Lab and the Smithsonian Institution and results are published twice a year in the Antarctic Meteorite Newsletter, which has been in publication since 1978. Each newsletter lists the samples collected and processed and provides more in-depth details on selected samples of importance to the scientific community. Data about these meteorites is also published on the NASA Curation website [2] and made available through the Meteorite Classification Database allowing scientists to search by a variety of parameters

  4. Terrestrial age dating of antarctic meteorites

    International Nuclear Information System (INIS)

    During the last three antarctic field seasons, US and Japanese teams have collected several thousand meteorites. The terrestrial age of these objects is of interest because such knowledge enables the setting of lower bounds on the lower age of the ice sheet, provides information about ice movement, and aids understanding of the accumulation mechanism of the meteorites. Terrestrial ages can be established by measuring the decay of radioactive species produced by bombardment of cosmic rays while the objects are in space. After entering the Earth's atmosphere the meteorites essentially are completely shielded from cosmic rays. The radioactive products that exist at saturation values in space then decay exponentially toward zero activity. By the end of 1980, data will be established on 150 to 200 selected samples. With that large a data base we should have a fairly clear picture of the terrestrial age distribution of antarctic meteorites

  5. New and rare cephalopods from the Antarctic waters

    OpenAIRE

    Kubodera,Tsunemi/Okutani,Takeshi

    1986-01-01

    Three species of Antarctic cephalopods, Grimpoteuthis antarctica n. sp., male specimens of Megaleledone senoi TAKI and Gonatus antarcticus LONNBERG are described with some considerations to their systematic status.

  6. Gas chromatography-mass spectrometry analysis of fatty acid profiles of Antarctic and non-Antarctic yeasts.

    Science.gov (United States)

    Bhuiyan, Mohammad; Tucker, David; Watson, Kenneth

    2014-08-01

    The fatty acid profiles of Antarctic (n = 7) and non-Antarctic yeasts (n = 7) grown at different temperatures were analysed by gas chromatography-mass spectrometry. The Antarctic yeasts were enriched in oleic 18:1 (20-60 %), linoleic 18:2 (20-50 %) and linolenic 18:3 (5-40 %) acids with lesser amounts of palmitic 16:0 (Antarctic yeasts (n = 4) were enriched in 18:1 (20-55 %, with R. mucilaginosa at 75-80 %) and 18:2 (10-40 %) with lesser amounts of 16:0 (Antarctic yeasts (enriched in 18:1 and 18:2) and the third to the Antarctic yeasts (enriched in 18:2 and 18:3).

  7. Satellite magnetic anomalies of the Antarctic crust

    Directory of Open Access Journals (Sweden)

    D. E. Alsdorf

    2000-06-01

    Full Text Available Spatially and temporally static crustal magnetic anomalies are contaminated by static core field effects above spherical harmonic degree 12 and dynamic, large-amplitude external fields. To extract crustal magnetic anomalies from the measurements of NASA's Magsat mission, we separate crustal signals from both core and external field effects. In particular, we define Magsat anomalies relative to the degree 11 field and use spectral correlation theory to reduce them for external field effects. We obtain a model of Antarctic crustal thickness by comparing the region's terrain gravity effects to free-air gravity anomalies derived from the Earth Gravity Model 1996 (EGM96. To separate core and crustal magnetic effects, we obtain the pseudo-magnetic effect of the crustal thickness variations from their gravity effect via Poisson's theorem for correlative potentials. We compare the pseudo-magnetic effect of the crustal thickness variations to field differences between degrees 11 and 13 by spectral correlation analysis. We thus identify and remove possible residual core field effects in the Magsat anomalies relative to the degree 11 core field. The resultant anomalies reflect possible Antarctic contrasts due both to crustal thickness and intracrustal variations of magnetization. In addition, they provide important constraints on the geologic interpretation of aeromagnetic survey data, such as are available for the Weddell Province. These crustal anomalies also may be used to correct for long wavelength errors in regional compilations of near-surface magnetic survey data. However, the validity of these applications is limited by the poor quality of the Antarctic Magsat data that were obtained during austral Summer and Fall when south polar external field activity was maximum. Hence an important test and supplement for the Antarctic crustal Magsat anomaly map will be provided by the data from the recently launched Ørsted mission, which will yield coverage

  8. Antarctic terrestrial ecosystems: responses to environmental change

    OpenAIRE

    Convey, Peter

    2006-01-01

    The consequences of climate change are exciting considerable concern worldwide. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. This paper sets out to introduce contemporary ecosystems of the Antarctic, and the factors that have influenced them and their biodiversity over evolutionary timescales. Contemporary climate change processes significant to terrestrial biota, and the biological consequences of these changes seen t...

  9. PSEUDO MAGNETIC ANOMALIES IN THE ANTARCTIC SEA

    OpenAIRE

    マツモト, タケシ; カミヌマ, カツタダ; Takeshi, MATSUMOTO; Katsutada, Kaminuma

    1988-01-01

    Pseudo magnetic anomaly in the Antarctic Sea has been calculated using the gravity data derived from altimetric geoid. Comparison of the pseudo magnetic anomaly thus calculated with the theoretical magnetic anomaly predicted from topography has been made with respect to the large fracture zones composed of short-wavelength ridges and troughs in the Southeastern Pacific, which shows that these two anomalies coincide well with each other. Gravity anomaly calculated from topography only also coi...

  10. Tephrochronology : Methodology and correlations, Antarctic Peninsula Area

    OpenAIRE

    Molén, Mats

    2012-01-01

    Abstract Methods for tephrochronology are evaluated, in the following way: Lake sediments <500 years old from three small Antarctic lakes were analysed for identification of tephras. Subsamples were analysed for a) grain size, and identification and concentration of volcanogenic grains, b) identification of tephra horizons, c) element abundance by EPMA WDS/EDS and LA-ICP-MS, and d) possible correlations between lakes and volcanoes. Volcanogenic minerals and shards were found all through th...

  11. Measurements of 36Cl in Antarctic meteorites and Antarctic ice using a Van de Graaff accelerator

    International Nuclear Information System (INIS)

    Cosmic-ray produced 36Cl(tsub(1/2) = 3.0 X 105 years) has been measured in four Antarctic meteorites and one sample of Antarctic ice using a tandem Van de Graaff accelerator as an ultrasensitive mass spectrometer with the extremely low background level of 36Cl/Cl -16. Results from this ion counting technique (applied here to extraterrestrial materials for the first time) are used to support a two-stage irradiation model for the Yamato-7301and Allan Hills-76008 meteorites and to show a long terrestrial age (0.7 +- 0.1 m.y.) for Allan Hills-77002. Yamato-7304 has a terrestrial age of less than 0.1 m.y. The 36Cl content of the Antarctic ice sample from the Yamato Mountain area implies that the age of the ice cap at this site is less than one 36Cl half-life. (Auth.)

  12. Experimental study of ozone synthesis

    International Nuclear Information System (INIS)

    A silent discharge ozonizer has been constructed with a design that enables the study of ozone concentration behaviour as a function of different parameters when oxygen used as a working gas. The behaviour of ozone concentration as a function of discharge current density has four characteristic regions. The concentration is enhanced by more than threefold whenever gas pressure is reduced by a factor of two. The flow rate of the working gas is a more effective parameter on ozone concentration than the gas pressure. When the flow rate is kept constant, and the pressure is decreased by 100%, the ozone concentration increases by only 10%. On the other hand, when the flow rate is decreased by 13%, the ozone concentration increases by 200%, whenever the gas pressure is kept constant. The concentration is nearly doubled when the gap space is increased by four times under the same conditions. The length of the discharge region, the thickness and the dielectric constant of the insulating materials are found to have a considerable effect on the generated ozone concentration. Also, the ozone concentration is ten times less when air is used instead of oxygen as a working gas. A maximum efficiency of 185 g/kWh, is obtained for the present system

  13. Ringrotbestrijding met behulp van ozon

    NARCIS (Netherlands)

    Wolf, van der J.M.; Bergervoet, J.H.W.; Kastelein, P.; Zouwen, van der P.S.

    2009-01-01

    Door het kistenreinigingsbedrijf van Frans Renne wordt een nieuwe kistenreinigingsmachine ontwikkeld. De methode is gebaseerd op ontsmetting met Ozon van recirculerend spoelwater en van kisten. In dit rapport wordt verslag gedaan van laboratorium-onderzoek naar het effect van ozon op ringrotbacterie

  14. Stimulated Black Hole Evaporation

    CERN Document Server

    Spaans, Marco

    2016-01-01

    Black holes are extreme expressions of gravity. Their existence is predicted by Einstein's theory of general relativity and is supported by observations. Black holes obey quantum mechanics and evaporate spontaneously. Here it is shown that a mass rate $R_f\\sim 3\\times 10^{-8} (M_0/M)^{1/2}$ $M_0$ yr$^{-1}$ onto the horizon of a black hole with mass $M$ (in units of solar mass $M_0$) stimulates a black hole into rapid evaporation. Specifically, $\\sim 3 M_0$ black holes can emit a large fraction of their mass, and explode, in $M/R_f \\sim 3\\times 10^7 (M/M_0)^{3/2}$ yr. These stimulated black holes radiate a spectral line power $P \\sim 2\\times 10^{39} (M_0/M)^{1/2}$ erg s$^{-1}$, at a wavelength $\\lambda \\sim 3\\times 10^5 (M/M_0)$ cm. This prediction can be observationally verified.

  15. Extremal Hairy Black Holes

    CERN Document Server

    Gonzalez, P A; Saavedra, Joel; Vasquez, Yerko

    2014-01-01

    We consider a gravitating system consisting of a scalar field minimally coupled to gravity with a self-interacting potential and an U(1) electromagnetic field. Solving the coupled Einstein-Maxwell-scalar system we find exact hairy charged black hole solutions with the scalar field regular everywhere. We go to the zero temperature limit and we study the effect of the scalar field on the near horizon geometry of an extremal black hole. We find that except a critical value of the charge of the black hole there is also a critical value of the charge of the scalar field beyond of which the extremal black hole is destabilized. We study the thermodynamics of these solutions and we find that if the space is flat then at low temperature the Reissner-Nordstr\\"om black hole is thermodynamically preferred, while if the space is AdS the hairy charged black hole is thermodynamically preferred at low temperature.

  16. Astrophysical black holes

    CERN Document Server

    Gorini, Vittorio; Moschella, Ugo; Treves, Aldo; Colpi, Monica

    2016-01-01

    Based on graduate school lectures in contemporary relativity and gravitational physics, this book gives a complete and unified picture of the present status of theoretical and observational properties of astrophysical black holes. The chapters are written by internationally recognized specialists. They cover general theoretical aspects of black hole astrophysics, the theory of accretion and ejection of gas and jets, stellar-sized black holes observed in the Milky Way, the formation and evolution of supermassive black holes in galactic centers and quasars as well as their influence on the dynamics in galactic nuclei. The final chapter addresses analytical relativity of black holes supporting theoretical understanding of the coalescence of black holes as well as being of great relevance in identifying gravitational wave signals. With its introductory chapters the book is aimed at advanced graduate and post-graduate students, but it will also be useful for specialists.

  17. Antarctic Treaty Summit: Washington, DC (2009)

    Science.gov (United States)

    Berkman, P. A.; Young, O. R.

    2005-12-01

    Advancement in Earth system science and international cooperation have been intertwined with the International Polar Years since 1882. In particular, the 3rd International Polar Year (which was convened as the International Geophysical Year from 1 July 1957 through 31 December 1958) specifically demonstrates the role of science in international policy: Acknowledging the substantial contributions to scientific knowledge resulting from international cooperation in scientific investigation in Antarctica; Convinced that the establishment of a firm foundation for the continuation and development of such cooperation on the basis of freedom of scientific investigation in Antarctica as applied during the International Geophysical Year accords with the interests of science and the progress of all mankind; Preamble, 1959 Antarctic Treaty To commemorate the 50th anniversary of the 1959 Antarctic Treaty and to explore the complexities of the science-policy relationship through the lens of a well-constrained case study, an international and interdisciplinary Antarctic Treaty Summit is being planned for 2009 in Washington, DC in conjunction with the International Polar Year 2007-08 (http://www.ipy.org).

  18. Antarctic Meteorite Classification and Petrographic Database Enhancements

    Science.gov (United States)

    Todd, N. S.; Satterwhite, C. E.; Righter, K.

    2012-01-01

    The Antarctic Meteorite collection, which is comprised of over 18,700 meteorites, is one of the largest collections of meteorites in the world. These meteorites have been collected since the late 1970 s as part of a three-agency agreement between NASA, the National Science Foundation, and the Smithsonian Institution [1]. Samples collected each season are analyzed at NASA s Meteorite Lab and the Smithsonian Institution and results are published twice a year in the Antarctic Meteorite Newsletter, which has been in publication since 1978. Each newsletter lists the samples collected and processed and provides more in-depth details on selected samples of importance to the scientific community. Data about these meteorites is also published on the NASA Curation website [2] and made available through the Meteorite Classification Database allowing scientists to search by a variety of parameters. This paper describes enhancements that have been made to the database and to the data and photo acquisition process to provide the meteorite community with faster access to meteorite data concurrent with the publication of the Antarctic Meteorite Newsletter twice a year.

  19. Mirror seeing of the Antarctic survey telescope

    Institute of Scientific and Technical Information of China (English)

    ZHANG Kaiyuan; LI Zhengyang; YUAN Xiangyan; PEI Chong

    2014-01-01

    Site testing results indicate that Antarctic Dome A is an excellent ground-based astronomical site suitable for observations ranging from visible to infrared wavelengths. However, the harsh environment in Antarctica, especially the very low temperature and atmospheric pressure, always produces frost on the telescopes’ mirrors, which are exposed to the air. Since the Dome A site is still unattended, the Antarctic telescope tubes are always designed to be filled with dry nitrogen, and the outer surfaces of the optical system are heated by an indium-tin oxide thin film. These precautions can prevent the optical surfaces from frosting over, but they degrade the image quality by introducing additional mirror seeing. Based on testing observations of the second Antarctic Survey Telescope (AST3-2) in the Mohe site in China, mirror seeing resulting from the heated aspheric plate has been measured using micro-thermal sensors. Results comparing the real-time atmospheric seeing monitored by the Differential Image Motion Monitor and real-time examinations of image quality agree well.

  20. A paleomagnetic study of the Antarctic Peninsula

    Science.gov (United States)

    Poblete, F.; Arriagada, C.; Roperch, P.

    2009-05-01

    In the Paleozoic, South America, South Africa and Antarctica were part of Gondwana. The Weddell Sea began to form at about 146 Ma, after rifting between the Antarctic Peninsula and southernmost South America. Much uncertainty still exists about the geometrical fit and subsequent drift history between Patagonia and Antarctica. Geophysical and geological data which describe the tectonic history are sparsely distributed and often of poor quality. During the last two years we have collected more than 1000 paleomagnetic samples from 70 sites at several localities (King George Island, Robert Island, Yankee Bay, Half Moon Island, Byers Peninsula and Snow Island) from the South Shetland Islands and Anderson Island in the northern tip of Antarctic Peninsula. Our main objective was to provide first-order constraints on latitudinal displacements and the amount of tectonic rotations as an essential test of published tectonic models. Paleomagnetic results were obtained from 50 sites. All samples from sites in volcanic and intrusive rocks have well-defined univectorial magnetizations. Unfortunately, all sites in late Paleozoic sediments have been remagnetized and the magnetizations are often unstable upon thermal demagnetization. Cretaceous and Cenozoic units display very little apparent polar wander. Results from intrusive rocks of expected Jurassic age do not confirm the expected relative rotation betwen the Antarctic Peninsula and East Antarctica. Further radiometric dating are needed to confirm the age of these units.

  1. Update on terrestrial ages of Antarctic meteorites

    Energy Technology Data Exchange (ETDEWEB)

    Welten, K C; Nishiizumi, K; Caffee, M W

    2000-01-14

    Terrestrial ages of Antarctic meteorites are one of the few parameters that will help us to understand the meteorite concentration mechanism on blue-ice fields. Traditionally, terrestrial ages were determined on the basis of {sup 36}Cl in the metal phase, which has an uncertainty of about 70 ky. For young meteorites (< 40 ky), the terrestrial age is usually and most accurately determined using {sup 14}C in the stone phase. In recent years two methods have been developed which are independent of shielding effects, the {sup 10}Be-{sup 36}Cl/{sup 10}Be method and the {sup 41}Ca/{sup 36}Cl method. These methods have reduced the typical uncertainties in terrestrial ages by a factor of 2, to about 30 ky. The {sup 10}Be-{sup 36}Cl/{sup 10}Be method is quite dependent on the exposure age, which is unknown for most Antarctic meteorites. The authors therefore also attempt to use the relation between {sup 26}Al and {sup 36}Cl/{sup 26}Al to derive a terrestrial age less dependent on the exposure age. The authors have measured the concentrations of cosmogenic {sup 10}Be, {sup 26}Al and {sup 36}Cl in the metal phase of {approximately} 70 Antarctic meteorites, from more than 10 different ice-fields, including many new ones. They then discuss the trends in terrestrial ages of meteorites from different ice-fields.

  2. Simulation of stratospheric water vapor trends: impact on stratospheric ozone chemistry

    Directory of Open Access Journals (Sweden)

    A. Stenke

    2005-01-01

    Full Text Available A transient model simulation of the 40-year time period 1960 to 1999 with the coupled climate-chemistry model (CCM ECHAM4.L39(DLR/CHEM shows a stratospheric water vapor increase over the last two decades of 0.7 ppmv and, additionally, a short-term increase after major volcanic eruptions. Furthermore, a long-term decrease in global total ozone as well as a short-term ozone decline in the tropics after volcanic eruptions are modeled. In order to understand the resulting effects of the water vapor changes on lower stratospheric ozone chemistry, different perturbation simulations were performed with the CCM ECHAM4.L39(DLR/CHEM feeding the water vapor perturbations only to the chemistry part. Two different long-term perturbations of lower stratospheric water vapor, +1 ppmv and +5 ppmv, and a short-term perturbation of +2 ppmv with an e-folding time of two months were applied. An additional stratospheric water vapor amount of 1 ppmv results in a 5–10% OH increase in the tropical lower stratosphere between 100 and 30 hPa. As a direct consequence of the OH increase the ozone destruction by the HOx cycle becomes 6.4% more effective. Coupling processes between the HOx-family and the NOx/ClOx-family also affect the ozone destruction by other catalytic reaction cycles. The NOx cycle becomes 1.6% less effective, whereas the effectiveness of the ClOx cycle is again slightly enhanced. A long-term water vapor increase does not only affect gas-phase chemistry, but also heterogeneous ozone chemistry in polar regions. The model results indicate an enhanced heterogeneous ozone depletion during antarctic spring due to a longer PSC existence period. In contrast, PSC formation in the northern hemisphere polar vortex and therefore heterogeneous ozone depletion during arctic spring are not affected by the water vapor increase, because of the less PSC activity. Finally, this study shows that 10% of the global total ozone decline in the transient model run

  3. Skip spawning as a reproductive strategy in Antarctic fish species: the Antarctic silverfish (Pleuragramma antarctica) case study

    OpenAIRE

    Eva Pisano; Stuart Hanchet; Marino Vacchi

    2015-01-01

    The Antarctic silverfish Pleuragramma antarctica (Notothenioidei, Nototheniidae) is the most abundant pelagic fish inhabiting the frigid Antarctic coastal waters. It plays relevant roles in the local ecosystems, where it is often considered a keystone species connecting lower and upper trophic levels within the coastal marine food web. Despite its ecological relevance, and although many aspects of the Antarctic silverfish biology have already been elucidated, knowledge on important components...

  4. Source attribution of tropospheric ozone

    Science.gov (United States)

    Butler, T. M.

    2015-12-01

    Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both

  5. Perturbations around black holes

    CERN Document Server

    Wang, B

    2005-01-01

    Perturbations around black holes have been an intriguing topic in the last few decades. They are particularly important today, since they relate to the gravitational wave observations which may provide the unique fingerprint of black holes' existence. Besides the astrophysical interest, theoretically perturbations around black holes can be used as testing grounds to examine the proposed AdS/CFT and dS/CFT correspondence.

  6. Plant injury induced by ozone

    Energy Technology Data Exchange (ETDEWEB)

    Hill, A.C.; Pack, M.R.; Treshow, M.; Downs, R.J.; Transtrum, L.G.

    1961-06-01

    Phytotoxicity of ozone to 34 plant species was studied in controlled-atmosphere greenhouses. Plants were subjected at various stages of growth to 0.13-0.72 ppm ozone for 2-hour periods. Injury symptoms developed on 28 species. Some of the most sensitive species were small grains, alfalfa, spinach, and tobacco. There was a general tendency for sensitivity to increase with maturity of tissue. Palisade cells were most readily injured by ozone. On plants with adaxial palisade parenchyma, chlorotic spots and bleached necrotic areas developed on the upper leaf surface. Injury was equally apparent from either leaf surface of plants with undifferentiated mesophyll. Necrotic spots extending completely through the leaf developed on plants with either mesophyll structure when injury was severe. Ozone caused conspicuous tumors to develop on broccoli leaves. Symptoms similar to those produced by ozone fumigations have been observed on a wide range of plant species growing near several large metropolitan centers. 18 references, 8 figures, 2 tables.

  7. Evidence for black holes.

    Science.gov (United States)

    Begelman, Mitchell C

    2003-06-20

    Black holes are common objects in the universe. Each galaxy contains large numbers-perhaps millions-of stellar-mass black holes, each the remnant of a massive star. In addition, nearly every galaxy contains a supermassive black hole at its center, with a mass ranging from millions to billions of solar masses. This review discusses the demographics of black holes, the ways in which they interact with their environment, factors that may regulate their formation and growth, and progress toward determining whether these objects really warp spacetime as predicted by the general theory of relativity. PMID:12817138

  8. Asymptotic Black Holes

    CERN Document Server

    Ho, Pei-Ming

    2016-01-01

    Following earlier works on the KMY model of black-hole formation and evaporation, we construct the metric for a matter sphere in gravitational collapse, with the back-reaction of pre-Hawking radiation taken into consideration. The mass distribution and collapsing velocity of the matter sphere are allowed to have an arbitrary radial dependence. We find that a generic gravitational collapse asymptote to a universal configuration which resembles a black hole but without horizon. This approach clarifies several misunderstandings about black-hole formation and evaporation, and provides a new model for black-hole-like objects in the universe.

  9. A Black Hole Levitron

    CERN Document Server

    Arsiwalla, Xerxes D

    2009-01-01

    We study the problem of spatially stabilising four dimensional extremal black holes in background electric/magnetic fields. Whilst looking for stationary stable solutions describing black holes kept in external fields we find that taking a continuum limit of Denef et al's multi-center solutions provides a supergravity description of such backgrounds within which a black hole can be trapped in a given volume. This is realised by levitating a black hole over a magnetic dipole base. We comment on how such a construction resembles a mechanical Levitron.

  10. Deforming regular black holes

    CERN Document Server

    Neves, J C S

    2015-01-01

    In this work, we have deformed regular black holes which possess a general mass term described by a function which generalizes the Bardeen and Hayward mass terms. Using linear constraints in the energy-momentum tensor, the solutions are either regular or singular. That is, with this approach, it is possible to generate singular black holes from regular black holes and vice versa. Moreover, contrary to the Bardeen and Hayward regular solutions, the regular deformed metrics may violate the weak energy condition despite the presence of the spherical symmetry. Some comments on accretion of deformed black holes in cosmological scenarios are made.

  11. The ARM West Antarctic Radiation Experiment (AWARE)

    Science.gov (United States)

    Lubin, Dan; Bromwich, David; Vogelmann, Andrew; Verlinde, Johannes; Russell, Lynn

    2016-04-01

    West Antarctica is one of the most rapidly warming regions on Earth, and its changing climate in both atmosphere and ocean is linked to loss of Antarctic ice mass and global sea level rise. The specific mechanisms for West Antarctic Ice Sheet (WAIS) warming are not fully understood, but are hypothesized to involve linkage between moisture from Southern Ocean storm tracks and the surface energy balance over the WAIS, and related teleconnections with subtropical and tropical meteorology. This present lack of understanding has motivated a climate science and cloud physics campaign jointly supported by the US National Science Foundation (NSF) and Department of Energy (DOE), called the Atmospheric Radiation Measurement Program (ARM) West Antarctic Radiation Experiment (AWARE). The DOE's second ARM Mobile Facility (AMF2) was deployed to McMurdo Station on Ross Island in November 2015 and will operate through December 2016. The AMF2 includes (1) cloud research radars, both scanning and zenith, operating in the Ka- and X-bands, (2) high spectral resolution and polarized micropulse lidars, and (3) a suite of shortwave and longwave broadband and spectral radiometers. A second suite of instruments is deployed at the WAIS Divide Ice Camp on the West Antarctic plateau during December 2015 and January 2016. The WAIS instrument suite provides (1) measurement of all surface energy balance components, (2) a polarized micropulse lidar and shortwave spectroradiometer, (3) microwave total water column measurement, and (4) four times daily rawinsonde launches which are the first from West Antarctica since 1967. There is a direct linkage between the WAIS instrument suite and the AMF2 at McMurdo, in that air masses originating in Southern Ocean storm tracks that are driven up over the WAIS often subsequently descend over the Ross Ice Shelf and arrive at Ross Island. Preliminary data are already illustrating the prevalence of mixed-phase clouds and their role in the surface energy balance

  12. Options to accelerate ozone recovery: ozone and climate benefits

    Directory of Open Access Journals (Sweden)

    J. S. Daniel

    2010-08-01

    Full Text Available Hypothetical reductions in future emissions of ozone-depleting substances (ODSs and N2O are evaluated in terms of effects on equivalent effective stratospheric chlorine (EESC, globally-averaged total column ozone, and radiative forcing through 2100. Due to the established success of the Montreal Protocol, these actions can have only a fraction of the impact on ozone depletion that regulations already in force have had. If all anthropogenic ODS and N2O emissions were halted beginning in 2011, ozone is calculated to be higher by about 1–2% during the period 2030–2100 compared to a case of no additional restrictions. Direct radiative forcing by 2100 would be about 0.23 W/m2 lower from the elimination of anthropogenic N2O emissions and about 0.005 W/m2 lower from the destruction of the chlorofluorocarbon (CFC bank. Due to the potential impact of N2O on future ozone levels, we provide an approach to incorporate it into the EESC formulation, which is used extensively in ozone depletion analyses. The ability of EESC to describe total ozone changes arising from additional ODS and N2O controls is also quantified.

  13. Black holes and beyond

    International Nuclear Information System (INIS)

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for instance, the UK

  14. A summary of research on the NASA-Global Atmospheric Sampling Program performed by the Atmospheric Sciences Research Center. [ozone transport theory

    Science.gov (United States)

    Falconer, P. D.; Pratt, R. W.

    1979-01-01

    The annual variations of ozone near the tropopause are derived from aircraft exhibit year-to-year differences which are not explicitly accounted for by the simple, classical ozone transport theory. Phenomena such as tropopause lifting, interannual variations in the rates of stratospheric-tropospheric exchange and meridional mixing, contribute differently to the distribution of ozone in this altitude region. Ozone encounter climatologies have been represented by global maps which show the probabilities of exceeding ambient ozone levels of 200, 300, and 400 ppbV along flight routes during the year. Continuous ozone records obtained from the GASP system revealed the presence of gravity waves whose wavelength is of the order 20 km. The GASP data cannot, however, be utilized for the evaluation of horizontal fluxes of such quantities as ozone, sensible heat, and zonal momentum; the data are too sparsely and irregularly distributed for the computation of stable correlations. Multiple species data from the unique circumglobal flight of a Pan American airliner on 28-30 October 1977 are discussed with particular regard to the apparent interhemispheric differences in tropospheric species concentrations, variation between the Arctic and Antarctic stratospheres, to possible covariations between species, and to potential source regions for various constituents.

  15. Sensitivity of Polar Stratospheric Ozone Loss to Uncertainties in Chemical Reaction Kinetics

    Science.gov (United States)

    Kawa, S. Randolph; Stolarksi, Richard S.; Douglass, Anne R.; Newman, Paul A.

    2008-01-01

    Several recent observational and laboratory studies of processes involved in polar stratospheric ozone loss have prompted a reexamination of aspects of our understanding for this key indicator of global change. To a large extent, our confidence in understanding and projecting changes in polar and global ozone is based on our ability to simulate these processes in numerical models of chemistry and transport. The fidelity of the models is assessed in comparison with a wide range of observations. These models depend on laboratory-measured kinetic reaction rates and photolysis cross sections to simulate molecular interactions. A typical stratospheric chemistry mechanism has on the order of 50- 100 species undergoing over a hundred intermolecular reactions and several tens of photolysis reactions. The rates of all of these reactions are subject to uncertainty, some substantial. Given the complexity of the models, however, it is difficult to quantify uncertainties in many aspects of system. In this study we use a simple box-model scenario for Antarctic ozone to estimate the uncertainty in loss attributable to known reaction kinetic uncertainties. Following the method of earlier work, rates and uncertainties from the latest laboratory evaluations are applied in random combinations. We determine the key reactions and rates contributing the largest potential errors and compare the results to observations to evaluate which combinations are consistent with atmospheric data. Implications for our theoretical and practical understanding of polar ozone loss will be assessed.

  16. DMAH ozone measurement net

    Directory of Open Access Journals (Sweden)

    D. Pagès

    2006-01-01

    Full Text Available The complexity of the study of tropospheric ozone lies in the fact that it is a secondary pollutant. It is not emitted by a source, instead its concentration in the air depends on other compounds (especially the nitrogen oxides emitted by motor vehicles and the volatile organic compounds emitted by the industry and the vegetation and meteorological factors (especially solar radiation and temperature. The European legislation compells to make measurements of the tropospheric ozone due to its effects on people (fatigue, irritation of the mucous membranes, aggravation of asthma ... and on environment (decrease of the production of cereals, synergy with plagues .... The measuring net in Catalonia belongs to the Department of Environment and Housing (DMAH. It has a pyramidal structure and it allows a surveillance to notify in case of exceeding a certain threshold. From the registered data of last years it is shown that the number of incidences is related to meteorology. They are more frequent during afternoon and the behaviour of this pollutant is different according to the proximity of the point of measurement to the sources of its precursors.

  17. Ozonated olive oils and the troubles

    OpenAIRE

    Bulent Uysal

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financ...

  18. Hole-hole propagation and saturation

    International Nuclear Information System (INIS)

    Ladder contributions to the effective interaction are calculated with inclusion of hole-hole (hh) propagation to all orders. For a correct calculation of the self-energy resulting from the ladder-summed effective interaction, ΓL, dispersion relations are used numerically. The single-particle (sp) energy is calculated self-consistently from the real on-shell self-energy. The contribution of the hh terms leads to a repulsive contribution to the energy per particle which increases with density. This saturation mechanism has not been identified previously and results are presented for the ν2 homework potential. (orig.)

  19. Black holes matter

    DEFF Research Database (Denmark)

    Kragh, Helge Stjernholm

    2016-01-01

    Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015).......Review essay, Marcia Bartusiak, Black Hole: How an Idea Abandoned by Newtonians, Hated by Einstein, and Gambled On by Hawking Became Loved (New Haven: Yale University Press, 2015)....

  20. Scattering by Black Holes

    CERN Document Server

    Andersson, N

    2000-01-01

    This is a chapter on Black-hole Scattering that was commissioned for an Encyclopaedia on Scattering edited by Pike and Sabatier, to be published by Academic Press. The chapter surveys wave propagation in black-hole spacetimes, diffraction effects in wave scattering, resonances, quasinormal modes and related topics.

  1. Noncommutative Singular Black Holes

    International Nuclear Information System (INIS)

    In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t - r) dependence of solution in terms of the noncommutative parameter σ. In this setup, there is no black hole remnant at long times.

  2. Noncommutative Singular Black Holes

    Science.gov (United States)

    Hamid Mehdipour, S.

    2010-11-01

    In this paper, applying the method of coordinate coherent states to describe a noncommutative model of Vaidya black holes leads to an exact (t — r) dependence of solution in terms of the noncommutative parameter σ. In this setup, there is no black hole remnant at long times.

  3. Black Hole Dynamic Potentials

    Indian Academy of Sciences (India)

    Koustubh Ajit Kabe

    2012-09-01

    In the following paper, certain black hole dynamic potentials have been developed definitively on the lines of classical thermodynamics. These potentials have been refined in view of the small differences in the equations of the laws of black hole dynamics as given by Bekenstein and those of thermodynamics. Nine fundamental black hole dynamical relations have been developed akin to the four fundamental thermodynamic relations of Maxwell. The specific heats , and , have been defined. For a black hole, these quantities are negative. The d equation has been obtained as an application of these fundamental relations. Time reversible processes observing constancy of surface gravity are considered and an equation connecting the internal energy of the black hole , the additional available energy defined as the first free energy function , and the surface gravity , has been obtained. Finally as a further application of the fundamental relations, it has been proved for a homogeneous gravitational field in black hole space times or a de Sitter black hole that $C_{\\Omega,\\Phi}-C_{J,Q}=\\kappa \\left[\\left(\\dfrac{\\partial J}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial \\Omega}{\\partial \\kappa}\\right)_{J,Q}+\\left(\\dfrac{\\partial Q}{\\partial \\kappa}\\right)_{\\Omega,\\Phi}\\left(\\dfrac{\\partial\\Phi}{\\partial \\kappa}\\right)_{J,Q}\\right]$. This is dubbed as the homogeneous fluid approximation in context of the black holes.

  4. Newborn Black Holes

    Science.gov (United States)

    Science Teacher, 2005

    2005-01-01

    Scientists using NASA's Swift satellite say they have found newborn black holes, just seconds old, in a confused state of existence. The holes are consuming material falling into them while somehow propelling other material away at great speeds. "First comes a blast of gamma rays followed by intense pulses of x-rays. The energies involved are much…

  5. UV radiation and primary production in the Antarctic waters

    Digital Repository Service at National Institute of Oceanography (India)

    LokaBharathi, P.A.; Krishnakumari, L.; Bhattathiri, P.M.A.; Chandramohan, D.

    obtained between pp and the above parameters in the Antarctic sub-surface waters determined at discrete depths of 10, 20, 30 and 40 m. However, when the primary productivity values were normalised for PAR, a more negative effect was noticed at the Antarctic...

  6. Challenges to the Future - Conservation of the Antarctic

    NARCIS (Netherlands)

    Chown, S.L.; Lee, J.E.; Hughes, K.A.; Barnes, J.; Bergstrom, D.M.; Convey, P.; Cowan, D.A.; Crosbie, K.; Dyer, G.; Frenot, Y.; Grant, S.M.; Herr, D.; Kennicutt, M.C.; Lamers, M.A.J.; Murray, A.; Possingham, H.P.; Reid, K.; Riddle, M.J.; Ryan, P.G.; Sanson, L.; Shaw, J.D.; Sparrow, M.D.; Summerhayes, C.; Terauds, A.; Wall, D.H.

    2012-01-01

    The Antarctic Treaty System, acknowledged as a successful model of cooperative regulation of one of the globe's largest commons (1), is under substantial pressure. Concerns have been raised about increased stress on Antarctic systems from global environmental change and growing interest in the regio

  7. The distribution of Fe in the Antarctic Circumpolar Current

    NARCIS (Netherlands)

    Löscher, B.M.; Baar, H.J.W. de; Jong, J.T.M. de; Veth, C.; Dehairs, F.

    1997-01-01

    The large-scale distributions of dissolved and total Fe in surface and deep waters of the Antarctic Circumpolar Current exhibit strong relationships with hydrography and biological processes. The mean dissolved Fe concentrations are low in surface waters of the Antarctic Circumpolar Current (0.31–0.

  8. Transcriptome of the Antarctic brooding gastropod mollusc Margarella antarctica.

    Science.gov (United States)

    Clark, Melody S; Thorne, Michael A S

    2015-12-01

    454 RNA-Seq transcriptome data were generated from foot tissue of the Antarctic brooding gastropod mollusc Margarella antarctica. A total of 6195 contigs were assembled de novo, providing a useful resource for researchers with an interest in Antarctic marine species, phylogenetics and mollusc biology, especially shell production.

  9. Biological studies in the Antarctic waters: A review

    Digital Repository Service at National Institute of Oceanography (India)

    Dhargalkar, V.K.

    stream_size 12 stream_content_type text/plain stream_name Proc_Workshop_Antarct_Stud_1990_407.pdf.txt stream_source_info Proc_Workshop_Antarct_Stud_1990_407.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset...

  10. Reaching for the Horizon: Enabling 21st Century Antarctic Science

    Science.gov (United States)

    Rogan-Finnemore, M.; Kennicutt, M. C., II; Kim, Y.

    2015-12-01

    The Council of Managers of National Antarctic Programs' (COMNAP) Antarctic Roadmap Challenges(ARC) project translated the 80 highest priority Antarctic and Southern Ocean scientific questionsidentified by the community via the SCAR Antarctic Science Horizon Scan into the highest prioritytechnological, access, infrastructure and logistics needs to enable the necessary research to answer thequestions. A workshop assembled expert and experienced Antarctic scientists and National AntarcticProgram operators from around the globe to discern the highest priority technological needs includingthe current status of development and availability, where the technologies will be utilized in the Antarctic area, at what temporal scales and frequencies the technologies will be employed,and how broadly applicable the technologies are for answering the highest priority scientific questions.Secondly the logistics, access, and infrastructure requirements were defined that are necessary todeliver the science in terms of feasibility including cost and benefit as determined by expected scientific return on investment. Finally, based on consideration of the science objectives and the mix oftechnologies implications for configuring National Antarctic Program logistics capabilities andinfrastructure architecture over the next 20 years were determined. In particular those elements thatwere either of a complexity, requiring long term investments to achieve and/or having an associated cost that realistically can only (or best) be achieved by international coordination, planning and partnerships were identified. Major trends (changes) in logistics, access, and infrastructure requirements were identified that allow for long-term strategic alignment of international capabilities, resources and capacity. The outcomes of this project will be reported.

  11. Antarctic bacteria inhibit growth of foodborne microorganisms at low temperatures.

    NARCIS (Netherlands)

    A.C. O'Brien; R. Sharp; N.J. Russell; S. Roller

    2004-01-01

    The aim of this study was to identify Antarctic microorganisms with the ability to produce cold-active antimicrobial compounds with potential for use in chilled food preservation. Colonies (4496) were isolated from 12 Antarctic soil samples and tested against Listeria innocua, Pseudomonas fragi and

  12. Anodic Materials for Electrocatalytic Ozone Generation

    OpenAIRE

    Yun-Hai Wang; Qing-Yun Chen

    2013-01-01

    Ozone has wide applications in various fields. Electrocatalytic ozone generation technology as an alternative method to produce ozone is attractive. Anodic materials have significant effect on the ozone generation efficiency. The research progress on anodic materials for electrocatalytic ozone generation including the cell configuration and mechanism is addressed in this review. The lead dioxide and nickel-antimony-doped tin dioxide anode materials are introduced in detail, including their st...

  13. Fluctuating Black Hole Horizons

    CERN Document Server

    Mei, Jianwei

    2013-01-01

    In this paper we treat the black hole horizon as a physical boundary to the spacetime and study its dynamics following from the Gibbons-Hawking-York boundary term. Using the Kerr black hole as an example we derive an effective action that describes, in the large wave number limit, a massless Klein-Gordon field living on the average location of the boundary. Complete solutions can be found in the small rotation limit of the black hole. The formulation suggests that the boundary can be treated in the same way as any other matter contributions. In particular, the angular momentum of the boundary matches exactly with that of the black hole, suggesting an interesting possibility that all charges (including the entropy) of the black hole are carried by the boundary. Using this as input, we derive predictions on the Planck scale properties of the boundary.

  14. Lifshitz Topological Black Holes

    CERN Document Server

    Mann, R B

    2009-01-01

    I find a class of black hole solutions to a (3+1) dimensional theory gravity coupled to abelian gauge fields with negative cosmological constant that has been proposed as the dual theory to a Lifshitz theory describing critical phenomena in (2+1) dimensions. These black holes are all asymptotic to a Lifshitz fixed point geometry and depend on a single parameter that determines both their area (or size) and their charge. Most of the solutions are obtained numerically, but an exact solution is also obtained for a particular value of this parameter. The thermodynamic behaviour of large black holes is almost the same regardless of genus, but differs considerably for small black holes. Screening behaviour is exhibited in the dual theory for any genus, but the critical length at which it sets in is genus-dependent for small black holes.

  15. Ozone Applications in Food Industry

    Directory of Open Access Journals (Sweden)

    Elif Savaş

    2014-03-01

    Full Text Available Known as active oxygen Ozone (O3, are among the most effective antimicrobials. The sun's ultraviolet rays and ozone caused by electric arcs of lightning occurring instantly around the world, and is available as a protective shield protects the animals against the effects of the sun's radiation. In the food industry, directly or indirectly in contact with food during processing of foods and chemical treatment of water disinfection bacteriological emerges as an alternative protection method. In this study, the effects of the ozone applications will evaluated as an alternative to conventional disinfectants in food industry.

  16. Ozone and Ozonated Oils in Skin Diseases: A Review

    Directory of Open Access Journals (Sweden)

    V. Travagli

    2010-01-01

    Full Text Available Although orthodox medicine has provided a variety of topical anti-infective agents, some of them have become scarcely effective owing to antibiotic- and chemotherapeutic-resistant pathogens. For more than a century, ozone has been known to be an excellent disinfectant that nevertheless had to be used with caution for its oxidizing properties. Only during the last decade it has been learned how to tame its great reactivity by precisely dosing its concentration and permanently incorporating the gas into triglycerides where gaseous ozone chemically reacts with unsaturated substrates leading to therapeutically active ozonated derivatives. Today the stability and efficacy of the ozonated oils have been already demonstrated, but owing to a plethora of commercial products, the present paper aims to analyze these derivatives suggesting the strategy to obtain products with the best characteristics.

  17. Ozone and Ozonated Oils in Skin Diseases: A Review

    Science.gov (United States)

    Travagli, V.; Zanardi, I.; Valacchi, G.; Bocci, V.

    2010-01-01

    Although orthodox medicine has provided a variety of topical anti-infective agents, some of them have become scarcely effective owing to antibiotic- and chemotherapeutic-resistant pathogens. For more than a century, ozone has been known to be an excellent disinfectant that nevertheless had to be used with caution for its oxidizing properties. Only during the last decade it has been learned how to tame its great reactivity by precisely dosing its concentration and permanently incorporating the gas into triglycerides where gaseous ozone chemically reacts with unsaturated substrates leading to therapeutically active ozonated derivatives. Today the stability and efficacy of the ozonated oils have been already demonstrated, but owing to a plethora of commercial products, the present paper aims to analyze these derivatives suggesting the strategy to obtain products with the best characteristics. PMID:20671923

  18. Evolution of massive black holes

    OpenAIRE

    Volonteri, Marta

    2007-01-01

    Supermassive black holes are nowadays believed to reside in most local galaxies. Accretion of gas and black hole mergers play a fundamental role in determining the two parameters defining a black hole: mass and spin. I briefly review here some of the physical processes that are conducive to the evolution of the massive black hole population. I'll discuss black hole formation processes that are likely to place at early cosmic epochs, and how massive black hole evolve in a hierarchical Universe...

  19. Black Hole Critical Phenomena Without Black Holes

    CERN Document Server

    Liebling, S L

    2000-01-01

    Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical phenomena, discuss some recent results, and describe a model which demonstrates similar phenomena without gravity.

  20. The interaction of ozone and nitrogen dioxide in the stratosphere of East Antarctica

    Science.gov (United States)

    Bruchkouski, Ilya; Krasouski, Aliaksandr; Dziomin, Victar; Svetashev, Alexander

    2016-04-01

    At the Russian Antarctic station "Progress" (S69°23´, E76°23´) simultaneous measurements of trace gases using the MARS-B (Multi-Axis Recorder of Spectra) instrument and PION-UV spectro-radiometer for the time period from 05.01.2014 to 28.02.2014 have been performed. Both instruments were located outdoors. The aim of the measurements was to retrieve the vertical distribution of ozone and nitrogen dioxide in the atmosphere and to study their variability during the period of measurements. The MARS-B instrument, developed at the National Ozone Monitoring Research and Education Centre of the Belarusian State University (NOMREC BSU), successfully passed the procedure of international inter-comparison campaign MAD-CAT 2013 in Mainz, Germany. The instrument is able to record the spectra of scattered sunlight at different elevation angles within a maximum aperture of 1.3°. 12 elevation angles have been used in this study, including the zenith direction. Approximately 7000 spectra per day were registered in the range of 403-486 nm, which were then processed by DOAS technique aiming to retrieve differential slant columns of ozone, nitrogen dioxide and oxygen dimer. Furthermore, total nitrogen dioxide column values have been retrieved employing the Libradtran radiative transfer model. The PION-UV spectro-radiometer, also developed at NOMREC BSU, is able to record the spectra of scattered sunlight from the hemisphere in the range of 280-430 nm. The registered spectra have been used to retrieve the total ozone column values employing the Stamnes method. In this study observational data from both instruments is presented and analyzed. Furthermore, by combining analysis of this data with model simulations it is shown that decreases in nitrogen dioxide content in the upper atmosphere can be associated with increases in total ozone column values and rising of the ozone layer upper boundary. Finally, the time delay between changes in nitrogen dioxide and ozone values is

  1. Atmospheric blocking signatures in total ozone and ozone miniholes

    OpenAIRE

    Barriopedro Cepero, David; Antón Martínez, Manuel; García García, José Agustín

    2010-01-01

    This paper analyzes the statistical relationship between the total ozone column (TOC) and atmospheric blocking using 40-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-40) data for the 1978-98 period, with special emphasis on winter and the European and eastern Pacific sectors. Regional blocking occurrence is accompanied by a decrease of TOC within the anticyclonic circulation region and a distinctive ozone increase upstream and downstream (upstream and south) i...

  2. Screening of microorganisms from Antarctic surface water and cytotoxicity metabolites from Antarctic microorganisms.

    Science.gov (United States)

    Zheng, Lanhong; Yang, Kangli; Liu, Jia; Sun, Mi; Zhu, Jiancheng; Lv, Mei; Kang, Daole; Wang, Wei; Xing, Mengxin; Li, Zhao

    2016-03-01

    The Antarctic is a potentially important library of microbial resources and new bioactive substances. In this study, microorganisms were isolated from surface water samples collected from different sites of the Antarctic. 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay-based cytotoxicity-tracking method was used to identify Antarctic marine microorganism resources for antitumor lead compounds. The results showed that a total of 129 Antarctic microorganism strains were isolated. Twelve strains showed potent cytotoxic activities, among which a Gram-negative, rod-shaped bacterium, designated as N11-8 was further studied. Phylogenetic analysis based on 16S rRNA gene sequence showed that N11-8 belongs to the genus Bacillus. Fermented active products of N11-8 with molecular weights of 1-30 kDa had higher inhibitory effects on different cancaer cells, such as BEL-7402 human hepatocellular carcinoma cells, U251 human glioma cells, RKO human colon carcinoma cells, A549 human lung carcinoma cells, and MCF-7 human breast carcinoma cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. However, they displayed lower cytotoxicity against HFL1 human normal fibroblast lung cells. Microscopic observations showed that the fermented active products have inhibitory activity on BEL-7402 cells similar to that of mitomycin C. Further studies indicated that the fermented active products have high pH and high thermal stability. In conclusion, most strains isolated in this study may be developed as promising sources for the discovery of antitumor bioactive substances. The fermented active products of Antarctic marine Bacillus sp. N11- 8 are expected to be applied in the prevention and treatment of cancer.

  3. Emerging spatial patterns in Antarctic prokaryotes

    Directory of Open Access Journals (Sweden)

    Chun Wie eChong

    2015-09-01

    Full Text Available Recent advances in knowledge of patterns of biogeography in terrestrial eukaryotic organisms have led to a fundamental paradigm shift in understanding of the controls and history of life on land in Antarctica, and its interactions over the long term with the glaciological and geological processes that have shaped the continent. However, while it has long been recognized that the terrestrial ecosystems of Antarctica are dominated by microbes and their processes, knowledge of microbial diversity and distributions has lagged far behind that of the macroscopic eukaryote organisms. Increasing human contact with and activity in the continent is leading to risks of biological contamination and change in a region whose isolation has protected it for millions of years at least; these risks may be particularly acute for microbial communities which have, as yet, received scant recognition and attention. Even a matter apparently as straightforward as Protected Area designation in Antarctica requires robust biodiversity data which, in most parts of the continent, remain almost completely unavailable. A range of important contributing factors mean that it is now timely to reconsider the state of knowledge of Antarctic terrestrial prokaryotes. Rapid advances in molecular biological approaches are increasingly demonstrating that bacterial diversity in Antarctica may be far greater than previously thought, and that there is overlap in the environmental controls affecting both Antarctic prokaryotic and eukaryotic communities. Bacterial dispersal mechanisms and colonization patterns remain largely unaddressed, although evidence for regional evolutionary differentiation is rapidly accruing and, with this, there is increasing appreciation of patterns in regional bacterial biogeography in this large part of the globe. In this review, we set out to describe the state of knowledge of Antarctic prokaryote diversity patterns, drawing analogy with those of eukaryote

  4. Ocean processes at the Antarctic continental slope.

    Science.gov (United States)

    Heywood, Karen J; Schmidtko, Sunke; Heuzé, Céline; Kaiser, Jan; Jickells, Timothy D; Queste, Bastien Y; Stevens, David P; Wadley, Martin; Thompson, Andrew F; Fielding, Sophie; Guihen, Damien; Creed, Elizabeth; Ridley, Jeff K; Smith, Walker

    2014-07-13

    The Antarctic continental shelves and slopes occupy relatively small areas, but, nevertheless, are important for global climate, biogeochemical cycling and ecosystem functioning. Processes of water mass transformation through sea ice formation/melting and ocean-atmosphere interaction are key to the formation of deep and bottom waters as well as determining the heat flux beneath ice shelves. Climate models, however, struggle to capture these physical processes and are unable to reproduce water mass properties of the region. Dynamics at the continental slope are key for correctly modelling climate, yet their small spatial scale presents challenges both for ocean modelling and for observational studies. Cross-slope exchange processes are also vital for the flux of nutrients such as iron from the continental shelf into the mixed layer of the Southern Ocean. An iron-cycling model embedded in an eddy-permitting ocean model reveals the importance of sedimentary iron in fertilizing parts of the Southern Ocean. Ocean gliders play a key role in improving our ability to observe and understand these small-scale processes at the continental shelf break. The Gliders: Excellent New Tools for Observing the Ocean (GENTOO) project deployed three Seagliders for up to two months in early 2012 to sample the water to the east of the Antarctic Peninsula in unprecedented temporal and spatial detail. The glider data resolve small-scale exchange processes across the shelf-break front (the Antarctic Slope Front) and the front's biogeochemical signature. GENTOO demonstrated the capability of ocean gliders to play a key role in a future multi-disciplinary Southern Ocean observing system.

  5. Automatic focusing system of BSST in Antarctic

    Science.gov (United States)

    Tang, Peng-Yi; Liu, Jia-Jing; Zhang, Guang-yu; Wang, Jian

    2015-10-01

    Automatic focusing (AF) technology plays an important role in modern astronomical telescopes. Based on the focusing requirement of BSST (Bright Star Survey Telescope) in Antarctic, an AF system is set up. In this design, functions in OpenCV is used to find stars, the algorithm of area, HFD or FWHM are used to degree the focus metric by choosing. Curve fitting method is used to find focus position as the method of camera moving. All these design are suitable for unattended small telescope.

  6. Fast recession of a West Antarctic glacier

    OpenAIRE

    Rignot, EJ

    1998-01-01

    Satellite radar interferometry observations of Pine Island Glacier, West Antarctica, reveal that the glacier hinge-line position retreated 1.2 ± 0.3 kilometers per year between 1992 and 1996, which in turn implies that the ice thinned by 3.5 ± 0.9 meters per year. The fast recession of Pine Island Glacier, predicted to be a possible trigger for the disintegration of the West Antarctic Ice Sheet, is attributed to enhanced basal melting of the glacier floating tongue by warm ocean waters.

  7. Ozone emergency in Venetian land

    International Nuclear Information System (INIS)

    The events exceeding the level of attention for ozone detected on the venetian land on a period of 6 and 4 years respectively by two stationary observatories, the ones located in the industrial zone and the other in a semi-rural, completed by data detected by three mobile observatories, have been correlated with space-temporal, atmospheric and relative chemical pollution parameters. The analysis of the data allowed: a) the estimation of the state of the air of the venetian land, with reference to the ozone pollution; b) the information of the hours, days and month of greatest risk and the meteorological situations which give high concentration levels of this polluting substance; c) the suggestion of a model of formation and dispersion of the ozone; d) the ascertainment of a higher ozone risk on zone relatively remote from the polluting sources

  8. Ozonation of cooling tower waters

    Science.gov (United States)

    Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

    1979-01-01

    Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

  9. Delayed Macular Hole Closure

    Directory of Open Access Journals (Sweden)

    Peter Distelmaier

    2014-04-01

    Full Text Available Purpose: The presented case raises questions regarding the favorable scheduling of planned postoperative care and the ideal observation interval to decide for reoperations in macular hole surgery. Furthermore a discussion about the use of short- and long-acting gas tamponades in macular hole surgery is encouraged. Methods: We present an interventional case report and a short review of the pertinent literature. Results: We report a case of spontaneous delayed macular hole closure after vitreoretinal surgery had been performed initially without the expected success. A 73-year-old male Caucasian patient presented at our clinic with a stage 2 macular hole in his left eye. He underwent 23-gauge pars plana vitrectomy and internal limiting membrane peeling with a 20% C2F6-gas tamponade. Sixteen days after the procedure, an OCT scan revealed a persistent stage 2 macular hole, and the patient was scheduled for reoperation. Surprisingly, at the date of planned surgery, which was another 11 days later, the macular hole had resolved spontaneously without any further intervention. Conclusions: So far no common opinion exists regarding the use of short- or long-acting gas in macular hole surgery. Our case of delayed macular hole closure after complete resorption of the gas tamponade raises questions about the need and duration of strict prone positioning after surgery. Furthermore short-acting gas might be as efficient as long-acting gas. We suggest to wait with a second intervention at least 4 weeks after the initial surgery, since a delayed macular hole closure is possible.

  10. Ozone as an ecotoxicological problem

    Energy Technology Data Exchange (ETDEWEB)

    Mortensen, L. [National Environmental Research Inst., Dept. of Atmospheric Environment, Roskilde (Denmark)

    1996-11-01

    Ozone is quantitatively the dominating oxidant in photochemical air pollution. Other compounds like hydrogen peroxide, aldehydes, formate, peroxyacetyl nitrate (PAN) and nitrogen dioxide are present too, and several of these are known to be phytotoxic, but under Danish conditions the concentration of these gases are without significance for direct effects on vegetation. Therefore, it is the effects of ozone on plant growth that will be described below. (EG) 65 refs.

  11. New challenges threatening the ozone layer

    Science.gov (United States)

    Abubakar, Babagana

    Since the beginning of the 1990's when the importation of fairly used Refrigerators, Airconditioners and propellants that can easily go broken containing chlorofluorocarbon substances that is capable of destroying the Ozone layer started in commercial quantity in Africa, the African refuse mountains began metamorphosing into mountains of dumped broken Refrigerators, Air-conditioners and Propellants which are collectively becoming a threat to the Ozone layer, because of the continuous discharging of the Chlorofluorocarbon gases by the refuse in to the atmosphere in each passing second.. Nobody can actually quantify the numbers of Refrigerators, Air-conditioners and Propellants imported and disposed in Africa over the last fifteen years, but the facts still remains that the numbers of metamorphosing mountains keeps on increasing in both size and numbers in each passing day. They have even become sources of raw materials for the local blacksmiths, children and refrigerators repairers who use parts of the dumped refrigerators, Air-conditioners and Propellants for their constructions, toys and repairs respectively. This explains the reason why despite the global efforts toward protecting the Ozone layer by the United Nations (UN), governments, International Organizations and climatologist among many others, but yet the hole in the Ozone layer keeps on expanding and the global temperature keeps on rising which resulted in the unusual phenomenon like the hurricanes "Katrina" and "Rita" the unusual floods in China, Thailand, Mozambique and to some extent even the Tsunami disaster that claims millions of lives in 2004.The Rapid rising in temperature of the Tropical world countries and increase in the cases of cancer patients among many other unusual happenings over the last eight years. It was in review of the above situation that this research work was conducted and came up with the under listed suggestions/Recommendations: 1. The UN should use its capacity to discourage

  12. Scalarized Hairy Black Holes

    CERN Document Server

    Kleihaus, Burkhard; Yazadjiev, Stoytcho

    2015-01-01

    In the presence of a complex scalar field scalar-tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and ordinary hairy black holes. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  13. Noncommutative Solitonic Black Hole

    CERN Document Server

    Chang-Young, Ee; Lee, Daeho; Lee, Youngone

    2012-01-01

    We investigate solitonic black hole solutions in three dimensional noncommutative spacetime. We do this in gravity with negative cosmological constant coupled to a scalar field using the Moyal product expanded up to first order in the noncommutativity parameter in the two noncommutative spatial directions. By numerical simulation we look for black hole solutions by increasing the non- commutativity parameter value starting from regular solutions with vanishing noncommutativity. We find that even a regular soliton solution in the commutative case becomes a black hole solution when the noncommutativity parameter reaches a certain value.

  14. Scalarized hairy black holes

    Energy Technology Data Exchange (ETDEWEB)

    Kleihaus, Burkhard, E-mail: b.kleihaus@uni-oldenburg.de [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Kunz, Jutta [Institut für Physik, Universität Oldenburg, Postfach 2503, D-26111 Oldenburg (Germany); Yazadjiev, Stoytcho [Department of Theoretical Physics, Faculty of Physics, Sofia University, Sofia 1164 (Bulgaria)

    2015-05-11

    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  15. Scalarized hairy black holes

    Directory of Open Access Journals (Sweden)

    Burkhard Kleihaus

    2015-05-01

    Full Text Available In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn.

  16. Black holes new horizons

    CERN Document Server

    Hayward, Sean Alan

    2013-01-01

    Black holes, once just fascinating theoretical predictions of how gravity warps space-time according to Einstein's theory, are now generally accepted as astrophysical realities, formed by post-supernova collapse, or as supermassive black holes mysteriously found at the cores of most galaxies, powering active galactic nuclei, the most powerful objects in the universe. Theoretical understanding has progressed in recent decades with a wider realization that local concepts should characterize black holes, rather than the global concepts found in textbooks. In particular, notions such as trapping h

  17. Scalarized hairy black holes

    International Nuclear Information System (INIS)

    In the presence of a complex scalar field scalar–tensor theory allows for scalarized rotating hairy black holes. We exhibit the domain of existence for these scalarized black holes, which is bounded by scalarized rotating boson stars and hairy black holes of General Relativity. We discuss the global properties of these solutions. Like their counterparts in general relativity, their angular momentum may exceed the Kerr bound, and their ergosurfaces may consist of a sphere and a ring, i.e., form an ergo-Saturn

  18. Corona Discharge Influences Ozone Concentrations Near Rats

    Energy Technology Data Exchange (ETDEWEB)

    Goheen, Steven C.; Gaither, Kari A.; Anantatmula, Shantha M.; Mong, Gary M.; Sasser, Lyle B.; Lessor, Delbert L.

    2004-02-26

    Ozone is produced by corona discharge in air. Its production is enhanced near grounded water. Whether grounded animals behave like grounded water, producing more ozone was investigated. Rats were exposed to corona discharge in a plastic cage. The concentration of ozone in the gas phase was monitored. The ozone concentration exceeded ambient levels only in the presence of corona discharge and either rats or water. When water or rats were exposed to corona discharge, ozone levels were more than 10 times higher than controls. Ozone levels increased rapidly with applied voltage. There was also a correlation between the distance of the corona needle to the rats and the amount of ozone produced. As the distance increased, ozone production decreased. These results are discussed in relation to the potential exposure of mammals to ozone in the vicinity of corona discharge and electric fields.

  19. CHAMP Magnetic Anomalies of the Antarctic Crust

    Science.gov (United States)

    Kim, Hyung Rae; Gaya-Pique, Luis R.; vonFrese, Ralph R. B.; Taylor, Patrick T.; Kim, Jeong Woo

    2003-01-01

    Regional magnetic signals of the crust are strongly masked by the core field and its secular variations components and hence difficult to isolate in the satellite measurements. In particular, the un-modeled effects of the strong auroral external fields and the complicated- behavior of the core field near the geomagnetic poles conspire to greatly reduce the crustal magnetic signal-to-noise ratio in the polar regions relative to the rest of the Earth. We can, however, use spectral correlation theory to filter the static lithospheric and core field components from the dynamic external field effects. To help isolate regional lithospheric from core field components, the correlations between CHAMP magnetic anomalies and the pseudo magnetic effects inferred from gravity-derived crustal thickness variations can also be exploited.. Employing these procedures, we processed the CHAMP magnetic observations for an improved magnetic anomaly map of the Antarctic crust. Relative to the much higher altitude Orsted and noisier Magsat observations, the CHAMP magnetic anomalies at 400 km altitude reveal new details on the effects of intracrustal magnetic features and crustal thickness variations of the Antarctic.

  20. Extremophiles in an Antarctic Marine Ecosystem

    Science.gov (United States)

    Dickinson, Iain; Goodall-Copestake, William; Thorne, Michael A.S.; Schlitt, Thomas; Ávila-Jiménez, Maria L.; Pearce, David A.

    2016-01-01

    Recent attempts to explore marine microbial diversity and the global marine microbiome have indicated a large proportion of previously unknown diversity. However, sequencing alone does not tell the whole story, as it relies heavily upon information that is already contained within sequence databases. In addition, microorganisms have been shown to present small-to-large scale biogeographical patterns worldwide, potentially making regional combinations of selection pressures unique. Here, we focus on the extremophile community in the boundary region located between the Polar Front and the Southern Antarctic Circumpolar Current in the Southern Ocean, to explore the potential of metagenomic approaches as a tool for bioprospecting in the search for novel functional activity based on targeted sampling efforts. We assessed the microbial composition and diversity from a region north of the current limit for winter sea ice, north of the Southern Antarctic Circumpolar Front (SACCF) but south of the Polar Front. Although, most of the more frequently encountered sequences  were derived from common marine microorganisms, within these dominant groups, we found a proportion of genes related to secondary metabolism of potential interest in bioprospecting. Extremophiles were rare by comparison but belonged to a range of genera. Hence, they represented interesting targets from which to identify rare or novel functions. Ultimately, future shifts in environmental conditions favoring more cosmopolitan groups could have an unpredictable effect on microbial diversity and function in the Southern Ocean, perhaps excluding the rarer extremophiles. PMID:27681902

  1. Solar power for an Antarctic rover

    Science.gov (United States)

    Lever, J. H.; Ray, L. R.; Streeter, A.; Price, A.

    2006-03-01

    Sensors mounted on mobile robots could serve a variety of science missions in Antarctica. Although weather conditions can be harsh, Antarctic snowfields offer unique conditions to facilitate long-distance robot deployment: the absence of obstacles, firm snow with high albedo, and 24 h sunlight during the summer. We have developed a four-wheel-drive, solar-powered rover that capitalizes on these advantages. Analyses and field measurements confirm that solar power reflected from Antarctic snow contributes 30-40% of the power available to a robot consisting of a five-side box of solar panels. Mobility analyses indicate that the 80 kg rover can move at 0.8 m s-1 during clear sky conditions on firm snow into a 5 m s-1 headwind, twice the speed needed to achieve the design target of 500 km in 2 weeks. Local winter tests of the chassis demonstrated good grade-climbing ability and lower than predicted rolling resistance. Tests of the completed robot occurred in Greenland in 2005.

  2. Longitudinal surface structures (flowstripes on Antarctic glaciers

    Directory of Open Access Journals (Sweden)

    N. F. Glasser

    2011-11-01

    Full Text Available Longitudinal surface structures (''flowstripes'' are common on many glaciers but their origin and significance are poorly understood. In this paper we present observations of the development of these longitudinal structures from four different Antarctic glacier systems (the Lambert Glacier/Amery Ice Shelf area, outlet glaciers in the Ross Sea sector, ice-shelf tributary glaciers on the Antarctic Peninsula, and the onset zone of a tributary to the Recovery Glacier Ice Stream in the Filchner Ice Shelf area. Mapping from optical satellite images demonstrates that longitudinal surface structures develop in two main situations: (1 as relatively wide flow stripes within glacier flow units and (2 as relatively narrow flow stripes where there is convergent flow around nunataks or at glacier confluence zones. Our observations indicate that the confluence features are narrower, sharper, and more clearly defined features. They are characterised by linear troughs or depressions on the ice surface and are much more common than the former type. Longitudinal surface structures within glacier flow units have previously been explained as the surface expression of localised bed perturbations but a universal explanation for those forming at glacier confluences is lacking. Here we propose that these features are formed at zones of ice acceleration and extensional flow at glacier confluences. We provide a schematic model for the development of longitudinal surface structures based on extensional flow that can explain their ridge and trough morphology as well as their down-ice persistence.

  3. Extremophiles in an Antarctic Marine Ecosystem

    Directory of Open Access Journals (Sweden)

    Iain Dickinson

    2016-01-01

    Full Text Available Recent attempts to explore marine microbial diversity and the global marine microbiome have indicated a large proportion of previously unknown diversity. However, sequencing alone does not tell the whole story, as it relies heavily upon information that is already contained within sequence databases. In addition, microorganisms have been shown to present small-to-large scale biogeographical patterns worldwide, potentially making regional combinations of selection pressures unique. Here, we focus on the extremophile community in the boundary region located between the Polar Front and the Southern Antarctic Circumpolar Current in the Southern Ocean, to explore the potential of metagenomic approaches as a tool for bioprospecting in the search for novel functional activity based on targeted sampling efforts. We assessed the microbial composition and diversity from a region north of the current limit for winter sea ice, north of the Southern Antarctic Circumpolar Front (SACCF but south of the Polar Front. Although, most of the more frequently encountered sequences  were derived from common marine microorganisms, within these dominant groups, we found a proportion of genes related to secondary metabolism of potential interest in bioprospecting. Extremophiles were rare by comparison but belonged to a range of genera. Hence, they represented interesting targets from which to identify rare or novel functions. Ultimately, future shifts in environmental conditions favoring more cosmopolitan groups could have an unpredictable effect on microbial diversity and function in the Southern Ocean, perhaps excluding the rarer extremophiles.

  4. Interhemispheric coupling and warm Antarctic interglacials

    Directory of Open Access Journals (Sweden)

    P. B. Holden

    2009-12-01

    Full Text Available Ice core evidence indicates that even though atmospheric CO2 concentrations did not exceed ~300 ppm at any point during the last 800 000 years, East Antarctica was at least ~3–4 °C warmer than pre-industrial (CO2 ~280 ppm in each of the last four interglacials. During the previous three interglacials, this anomalous warming was short lived (~3 000 years and apparently occurred before the completion of Northern Hemisphere deglaciation. Hereafter, we refer to these periods as "Warmer than Present Transients" (WPTs. We here present transient 800 kyr simulations using the intermediate complexity model GENIE-1 which suggest that WPTs could be explained as a consequence of the meltwater-forced slowdown of the Atlantic Meridional Overturning Circulation (AMOC during glacial terminations. It is well known that a slowed AMOC would increase southern Sea Surface Temperature (SST through the bipolar seesaw. Observational data supports this hypothesis, suggesting that the AMOC remained weak throughout the terminations preceding WPTs, strengthening rapidly at a time which coincides closely with peak Antarctic temperature. In order to investigate model and boundary condition uncertainty, we additionally present three ensembles of transient GENIE-1 simulations across Termination II (135 000 to 124 000 BP and three snapshot HadCM3 simulations at 130 000 Before Present (BP. These simulations together reproduce both the timing and magnitude of WPTs, and point to the potential importance of an albedo feedback associated with West Antarctic Ice Sheet (WAIS retreat.

  5. Basic Principle of Advanced Oxidation Technology : Hybrid Technology Based on Ozone and Titania

    International Nuclear Information System (INIS)

    One of problems in health environment is organic liquid waste from many pollutant resources. Environmental friendly technology for degrading this waste is ozone which produced by plasma discharge technology, but its capability is limited. However, it is needed a new environmental friendly technology which has stronger capability. This new technology is so called advanced oxidation technology. Advanced oxidation technology is a hybrid of ozone, peroxide, UV light and photo catalyst. In this paper, it is introduced basic principle of hybrid of ozone and titania photo catalyst semiconductor. The capability of organic liquid degradation will be stronger because there is new radical which is produced by chemical reaction between electron-hole pair from photo catalyst titania and water or oxygen. This new radical then degrades this organic pollutant. This technology is used to degrade phenol. (author)

  6. Rapid Access Ice Drill: A New Tool for Exploration of the Deep Antarctic Ice Sheets and Subglacial Geology

    Science.gov (United States)

    Goodge, J. W.; Severinghaus, J. P.

    2014-12-01

    The Rapid Access Ice Drill (RAID) will penetrate the Antarctic ice sheets in order to core through deep ice, the glacial bed, and into bedrock below. This new technology will provide a critical first look at the interface between major ice caps and their subglacial geology. Currently in construction, RAID is a mobile drilling system capable of making several long boreholes in a single field season in Antarctica. RAID is interdisciplinary and will allow access to polar paleoclimate records in ice >1 Ma, direct observation at the base of the ice sheets, and recovery of rock cores from the ice-covered East Antarctic craton. RAID uses a diamond rock-coring system as in mineral exploration. Threaded drill-pipe with hardened metal bits will cut through ice using reverse circulation of Estisol for pressure-compensation, maintenance of temperature, and removal of ice cuttings. Near the bottom of the ice sheet, a wireline bottom-hole assembly will enable diamond coring of ice, the glacial bed, and bedrock below. Once complete, boreholes will be kept open with fluid, capped, and made available for future down-hole measurement of thermal gradient, heat flow, ice chronology, and ice deformation. RAID will also sample for extremophile microorganisms. RAID is designed to penetrate up to 3,300 meters of ice and take sample cores in less than 200 hours. This rapid performance will allow completion of a borehole in about 10 days before moving to the next drilling site. RAID is unique because it can provide fast borehole access through thick ice; take short ice cores for paleoclimate study; sample the glacial bed to determine ice-flow conditions; take cores of subglacial bedrock for age dating and crustal history; and create boreholes for use as an observatory in the ice sheets. Together, the rapid drilling capability and mobility of the drilling system, along with ice-penetrating imaging methods, will provide a unique 3D picture of the interior Antarctic ice sheets.

  7. Introducing the Black Hole

    Science.gov (United States)

    Ruffini, Remo; Wheeler, John A.

    1971-01-01

    discusses the cosmology theory of a black hole, a region where an object loses its identity, but mass, charge, and momentum are conserved. Include are three possible formation processes, theorized properties, and three way they might eventually be detected. (DS)

  8. Black hole critical phenomena without black holes

    Indian Academy of Sciences (India)

    Steven L Liebling

    2000-10-01

    Studying the threshold of black hole formation via numerical evolution has led to the discovery of fascinating nonlinear phenomena. Power-law mass scaling, aspects of universality, and self-similarity have now been found for a large variety of models. However, questions remain. Here I briefly review critical phenomena, discuss some recent results, and describe a model which demonstrates similar phenomena without gravity.

  9. Microbial biomass and basal respiration in Sub-Antarctic and Antarctic soils in the areas of some Russian polar stations

    Directory of Open Access Journals (Sweden)

    E. Abakumov

    2014-03-01

    Full Text Available Antarctica is the unique place for pedological investigations. Soils of Antarctica have been studied intensively during the last century. Antarctic logistic provides the possibility to scientists access the terrestrial landscapes mainly in the places of polar stations. That is why the main and most detailed pedological investigations were conducted in Mc Murdo Valleys, Transantarctic Mountains, South Shetland Islands, Larsemann hills and Schirmacher Oasis. Investigations were conducted during the 53rd and 55th Russian Antarctic expeditions on the base of soil pits and samples collected in Sub-Antarctic and Antarctic regions. Soils of diverse Antarctic landscapes were studied with aim to assess the microbial biomass level, basal respiration rates and metabolic activity of microbial communities. The investigation conducted shows that soils of Antarctic are quite different in profile organization and carbon content. In general, Sub-Antarctic soils are characterized by more developed humus (sod organo-mineral horizons as well as the upper organic layer. The most developed organic layers were revealed in peat soils of King-George Island, where its thickness reach even 80 cm. These soils as well as soils under guano are characterized by the highest amount of total organic carbon (TOC 7.22–33.70%. Coastal and continental soils of Antarctic are presented by less developed Leptosols, Gleysols, Regolith and rare Ornhitosol with TOC levels about 0.37–4.67%. The metabolic ratios and basal respiration were higher in Sub-Antarctic soils than in Antarctic ones which can be interpreted as result of higher amounts of fresh organic remnants in organic and organo-mineral horizons. Also the soils of King-George island have higher portion of microbial biomass (max 1.54 mg g−1 than coastal (max 0.26 mg g−1 and continental (max 0.22 mg g−1 Antarctic soils. Sub-Antarctic soils mainly differ from Antarctic ones in increased organic layers thickness and total

  10. Scientific assessment of ozone depletion: 1991

    Science.gov (United States)

    1991-01-01

    Over the past few years, there have been highly significant advances in the understanding of the impact of human activities on the Earth's stratospheric ozone layer and the influence of changes in chemical composition of the radiative balance of the climate system. Specifically, since the last international scientific review (1989), there have been five major advances: (1) global ozone decreases; (2) polar ozone; (3) ozone and industrial halocarbons; (4) ozone and climate relations; and (5) ozone depletion potentials (ODP's) and global warming potentials (GWP's). These topics and others are discussed.

  11. Cosmological Black Holes

    OpenAIRE

    Stornaiolo, Cosimo

    2001-01-01

    In this paper we propose a model for the formation of the cosmological voids. We show that cosmological voids can form directly after the collapse of extremely large wavelength perturbations into low-density black holes or cosmological black holes (CBH). Consequently the voids are formed by the comoving expansion of the matter that surrounds the collapsed perturbation. It follows that the universe evolves, in first approximation, according to the Einstein-Straus cosmological model. We discuss...

  12. Cosmic Black Holes

    OpenAIRE

    Ahn, Eun-Joo; Cavaglia, Marco

    2003-01-01

    Production of high-energy gravitational objects is a common feature of gravitational theories. The primordial universe is a natural setting for the creation of black holes and other nonperturbative gravitational entities. Cosmic black holes can be used to probe physical properties of the very early universe which would usually require the knowledge of the theory of quantum gravity. They may be the only tool to explore thermalisation of the early universe. Whereas the creation of cosmic black ...

  13. Quantum black holes

    International Nuclear Information System (INIS)

    No particle theory can be complete without gravity. Einstein's theory of gravity is of the Euler-Lagrange form, but standard quantization procedure fails. In quantum gravity the higher order interactions have a dimensionality different form the fundamental ones, because Newton's constant G has dimensions and the renormalization procedure fails. Another problem with quantum gravity is even more mysterious. Suppose that we had regularized the gravitational forces at the small distance end in the way that the weak intermediate vector boson regularized the fundamental 4-fermion interaction vertex of the weak interactions. Then what we discover is that the gravitational forces are unstable. Given sufficiently large amount of matter, it can collapse under its own weight. Classical general relativity tells us what will happen: a black hole is formed. But how is this formulated in quantum theory. S. Hawking observed that when a field theory is quantized in the background metric of a black hole, the black hole actually emits particles in a completely random thermal way. Apparently black holes are just another form of matter unstable against Hawking decay. Unfortunately this picture cannot be complete. The problem is that the quantum version of black holes has infinite phase space, and other symptoms of a run-away solution. Black holes are the heaviest and most compact forms of matter that can be imagined. A complete particle theory can have nothing but a spectrum of black-hole like objects at it high-energy end. This is why it is believed that a resolution of the black hole problem will in time disclose the complete small-distance structure of our world. 6 references

  14. Modelling quantum black hole

    CERN Document Server

    Govindarajan, T R

    2016-01-01

    Novel bound states are obtained for manifolds with singular potentials. These singular potentials require proper boundary conditions across boundaries. The number of bound states match nicely with what we would expect for black holes. Also they serve to model membrane mechanism for the black hole horizons in simpler contexts. The singular potentials can also mimic expanding boundaries elegantly, there by obtaining appropriately tuned radiation rates.

  15. The impacts of local human activities on the Antarctic environment

    Science.gov (United States)

    Tin, T.; Fleming, Z. L.; Hughes, K. A.; Ainley, D. G.; Convey, P.; Moreno, C. A.; Pfeiffer, S.; Scott, J.; Snape, I.

    2009-04-01

    An overview of a recently published review of the scientific literature from the past decade on the impacts of human activities on the Antarctic environment is presented. An assessment of the cumulative effects of scientists and accompanying base construction, tourists and fishery activities in Antarctica is timely given a decade since the Protocol on Environmental Protection to the Antarctic Treaty came into force in 1998 and the increasing attention given to and human presence in Antarctica during this 2007-2009 IPY. A range of impacts has been identified at a variety of spatial and temporal scales. Chemical contamination and sewage disposal on the continent have been found to be long-lived, with contemporary sewage management practices at many coastal stations insufficient to prevent local contamination. Human activities, particularly construction and transport, have affected Antarctic flora and fauna and a small number of non-indigenous plant and animal species has become established on some of the Antarctic Peninsula and sub Antarctic islands. There is little indication of recovery of overexploited fish stocks, and ramifications of fishing activity on bycatch species and the ecosystem could also be far-reaching. The Antarctic Treaty System and its instruments, in particular the Convention for the Conservation of Antarctic Marine Living Resources (CCAMLR) and the Environmental Protocol, provide a framework within which management of human activities take place. In order to ensure comprehensive protection of the Antarctic environment, including its intrinsic, wilderness and scientific values in the face of the continuing expansion of human activities in Antarctica, a more effective implementation of a wide range of measures is essential. These include effective environmental impact assessments, long-term monitoring, mitigation measures for non-indigenous species, ecosystem-based management of living resources, and increased regulation of National Antarctic

  16. On Noncommutative Black Holes Thermodynamics

    CERN Document Server

    Faizal, Mir; Ulhoa, S C

    2015-01-01

    In this paper, we will analyze noncommutative deformation of the Schwarzschild black holes and Kerr black holes. We will perform our analysis by relating the commutative and the noncommutative metrics using an Moyal product. We will also analyze the thermodynamics of these noncommutative black hole solutions. We will explicitly derive expression for the corrected entropy and temperature of these black hole solutions.

  17. The Thermodynamics of Black Holes

    Directory of Open Access Journals (Sweden)

    Wald Robert M.

    2001-01-01

    Full Text Available We review the present status of black hole thermodynamics. Our review includes discussion of classical black hole thermodynamics, Hawking radiation from black holes, the generalized second law, and the issue of entropy bounds. A brief survey also is given of approaches to the calculation of black hole entropy. We conclude with a discussion of some unresolved open issues.

  18. Charged Galileon black holes

    Science.gov (United States)

    Babichev, Eugeny; Charmousis, Christos; Hassaine, Mokhtar

    2015-05-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematically compatible with the field equations. This opens up the possibility for novel searches of hairy black holes in a far more general setting of Horndeski theory.

  19. Ultramassive Black Hole Coalescence

    CERN Document Server

    Khan, Fazeel; Berczik, Peter

    2015-01-01

    Although supermassive black holes (SMBHs) correlate well with their host galaxies, there is an emerging view that outliers exist. Henize 2-10, NGC 4889, and NGC1277 are examples of SMBHs at least an order of magnitude more massive than their host galaxy suggests. The dynamical effects of such ultramassive central black holes is unclear. Here, we perform direct N-body simulations of mergers of galactic nuclei where one black hole is ultramassive to study the evolution of the remnant and the black hole dynamics in this extreme regime. We find that the merger remnant is axisymmetric near the center, while near the large SMBH influence radius, the galaxy is triaxial. The SMBH separation shrinks rapidly due to dynamical friction, and quickly forms a binary black hole; if we scale our model to the most massive estimate for the NGC1277 black hole, for example, the timescale for the SMBH separation to shrink from nearly a kiloparsec to less than a parsec is roughly 10 Myr. By the time the SMBHs form a hard binary, gr...

  20. Ozone depletion and climate change: impacts on UV radiation.

    Science.gov (United States)

    Bais, A F; McKenzie, R L; Bernhard, G; Aucamp, P J; Ilyas, M; Madronich, S; Tourpali, K

    2015-01-01

    might affect UV-B radiation at the surface indirectly through changes induced in stratospheric ozone. (2) The projected changes in cloud cover would lead to relatively small effects (less than 3%), except at northern high latitudes where increases in cloud cover could lead to decreases in UVery by up to 7%. (3) Reductions in reflectivity due to the melting of sea-ice in the Arctic would lead to decreases of UVery by up to 10%, while at the margins of the Antarctic the decreases would be smaller (2-3%). The melting of the sea-ice would expose the ocean surface formerly covered by ice to UV-B radiation up to 10 times stronger than before. (4) The expected improvement of air-quality and reductions of aerosols over the most populated areas of the northern hemisphere may result in 10-20% increases in UVery, except over China where even larger increases are projected. The projected aerosol effect for the southern hemisphere is generally very small. Aerosols are possibly the most important factor for future UV levels over heavily populated areas, but their projected effects are the most uncertain. PMID:25380284

  1. Topics in black hole evaporation

    International Nuclear Information System (INIS)

    Two major aspects of particle creation by gravitational fields of black holes are studied: the neutrino emission from rotating black holes; and interactions between scalar particles emitted by a black hole. Neutrino emission is investigated under three topics: The asymmetry of the angular dependence of neutrino emission from rotating black holes; the production of a local matter excess by rotating black holes in a baryon symmetric universe; and cosmological magnetic field generation by neutrinos from evaporating black holes. Finally the author studies the effects of interactions on the black hole evaporation process

  2. Antarctic Treaty Summit to Focus on Global Science Policy Lessons

    Science.gov (United States)

    Berkman, Paul Arthur; Walton, David W. H.; Weiler, C. Susan

    2008-10-01

    The Antarctic Treaty Summit, which will coincide with the fiftieth anniversary of the treaty's signing, will be held at the Smithsonian Institution's National Museum of Natural History, in Washington, D. C., from 30 November to 3 December 2009. The summit will provide an open international forum for scientists, legislators, lawyers, administrators, educators, students, corporate executives, historians, and other members of global civil society to explore science policy achievements from the first 50 years of the Antarctic Treaty. In addition, the summit will complement official government celebrations of the Antarctic Treaty anniversary that do not include public participation.

  3. Antarctic Porifera database from the Spanish benthic expeditions

    OpenAIRE

    Pilar Rios; Javier Cristobo

    2014-01-01

    The information about the sponges in this dataset is derived from the samples collected during five Spanish Antarctic expeditions: Bentart 94, Bentart 95, Gebrap 96, Ciemar 99/00 and Bentart 2003. Samples were collected in the Antarctic Peninsula and Bellingshausen Sea at depths ranging from 4 to 2044 m using va­rious sampling gears.The Antarctic Porifera database from the Spanish benthic expeditions is unique as it provides in­formation for an under-explored region of the Southern Oc...

  4. Changes in the occurence of heavy metals in Antarctic ice during the last climatic cycles

    Science.gov (United States)

    Gabrielli, P.; Barbante, C.; Planchon, F.; Ferrari, C.; Delmonte, B.; Boutron, C. F.

    2003-04-01

    During the last decades ice cores drilled in Antarctica and in Greenland have provided time series of data that have allowed the characterisation of variations of natural and anthropogenic heavy metals in the past atmosphere. Nevertheless, the interactions of heavy metals with climate change and their transport patterns remain largely unknown for the last climatic cycles. Our aim is to assess past changes of various heavy metals in polar ice during the past ª500 kyr. Special emphasis is given to Pt, Pd, Rh, Ir, Os and Ru which are tracers of interplanetary dust particles (IDPs). It has in fact been shown that the accretion flux of IDPs would change in parallel with the period of 100 kyr, possibly affecting climate and/or contributing to the observed 100 kyr cycle in climate records. These tracers could also allow us to identify the impact of larger size bodies which might have strongly influenced the stratospheric ozone layer. Tracers of crustal material (Pb isotopes, Pb, Ba, Fe, Co, Ti, Mn, V), volcanic activity (Cd, Bi, Sb, As) and ocean paleoproductivity (Hg, Se) are also investigated. At the moment we are focusing especially on the ongoing EPICA Dome C Antarctic ice core. We are decontaminating mechanically each section and we are performing preliminary measurements of Zn and Al using Graphite Furnace Atomic Absorption Spectrometry and ultraclean procedures. These data confirm the prominent continental origin of Zn in the East Antarctic ice during the last and penultimate glacial period back to about 200,,000 years B.P.. The other analyses are going to be performed using Inductively Coupled Plasma Sector Field Mass Spectrometry, Thermal Ionisation Mass Spectrometry, and Cold Vapour Atomic Absorption Spectrometry, adopting ultraclean procedures.

  5. Tropospheric ozone columns and ozone profiles for Kiev in 2007

    CERN Document Server

    Shavrina, A V; Sheminova, V A; Synyavski, I I; Romanyuk, Ya O; Eremenko, N A; Ivanov, Yu S; Monsar, O A; Kroon, M

    2010-01-01

    We report on ground-based FTIR observations being performed within the framework of the ESA-NIVR-KNMI project 2907 entitled "OMI validation by ground based remote sensing: ozone columns and atmospheric profiles" for the purpose of OMI data validation. FTIR observations were performed during the time frames August-October 2005, June-October 2006 and March-October 2007, mostly under cloud free and clear sky conditions and in some days from early morning to sunset covering the full range of solar zenith angles possible. Ozone column and ozone profile data were obtained for the year 2005 using spectral modeling of the ozone spectral band profile near 9.6 microns with the MODTRAN3 band model based on the HITRAN-96 molecular absorption database. The total ozone column values retrieved from FTIR observations are biased low with respect to OMI-DOAS data by 8-10 DU on average, where they have a relatively small standard error of about 2%. FTIR observations for the year 2006 were simulated by MODTRAN4 modeling. For the...

  6. Study of ozone "weekend effect" in Shanghai

    Institute of Scientific and Technical Information of China (English)

    TANG WenYuan; ZHAO ChunSheng; GENG FuHai; PENG Li; ZHOU GuangQiang; GAO Wei; XU JianMing; TIE XueXi

    2008-01-01

    Analysis of observed ozone data in 2006 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in Shanghai reveals that ozone (O3) concentrations in Xujiahui are higher at weekends than those on weekdays, despite the fact that emissions of ozone precursor substances, such as oxides of nitrogen (NOX), carbon monoxide (CO) and volatile organic compounds (VOCs) are lower at weekends than those on weekdays.The possible chemical cause of ozone "weekend effect" is that NO2/NO ratio increases at weekends by 25.61% compared with those on weekdays.In addition, because of an average 12.13% reduction in NOx (NO + NO2) in the early morning (05:00-09:00) at weekends compared with that on weekdays, the ozone inhibition period ends 0.5 h earlier at weekends resulting in the longer duration of ozone accumulation and the higher ozone production rate.The rate of ozone production is a function of VOCs and NOx in the atmosphere.VOCs/NOx ratio in Xujiahui is 4.55 at weekends, and 4.37 on weekdays, belonging to the "NOx-limited".The increasing VOCs/NOx ratio at weekends leads to ozone enhancement from 73 ppbv to 80 ppbv, which are consistent with ozone "weekend effect" in Xujiahui.Furthermore, combining with MICAPS cloud amount data, the fact that ozone "weekend effect" in Xujiahui weakens gradually along with the increasing of cloud amount indicates that ozone photochemical production leads to ozone "weekend effect" in Xujiahui of Shanghai.

  7. Adjustment of pigment composition in Desmarestia (Desmarestiaceae species along a sub-Antarctic to Antarctic latitudinal gradient

    Directory of Open Access Journals (Sweden)

    Andrés Mansilla

    2016-08-01

    Full Text Available Photosynthesis at high latitudes demands efficient strategies of light utilization to maintain algal fitness and performance. The fitness, and physiological adaptation, of a plant or algae species depends in part on the abundance and efficiency of the pigments it can produce to utilize the light resource from its environment. We quantified pigment composition and concentration in six species of the brown macroalgal genus Desmarestia, collected from sub-Antarctic sites (Strait of Magellan, Beagle Channel–Cape Horn Province and sites on the Antarctic Peninsula and adjacent islands. Sub-Antarctic Desmarestia species exhibited lower concentrations of chlorophyll a, chlorophyll c and fucoxanthin than endemic Antarctic species. Antarctic samples of D. menziesii and D. antarctica collected along a decreasing latitudinal gradient showed spatial and interspecific differences in light-harvesting pigment composition. Our results suggest distinct physiological adjustments in Desmarestia species in response to heterogeneous abiotic environmental conditions. The marine sub-Antarctic and Antarctic ecosystems are characterized by harsh environments (e.g., extreme irradiance, photoperiod, temperature, salinity to which the physiology of macroalgal species must adapt.

  8. Different adaptations of Chinese winter-over expeditioners during prolonged Antarctic and sub-Antarctic residence

    Science.gov (United States)

    Chen, Nan; Wu, Quan; Li, Hao; Zhang, Tao; Xu, Chengli

    2016-05-01

    Prolonged residence in Antarctica is characterized by exposure to isolated, confined, and extreme (ICE) environment. Winter-over expeditioners at research stations often exhibit a complex of psychophysiological symptoms, which varied by stations and sociocultural backgrounds. To understand the different patterns of psychophysiological responses provoked by environmental stress, we conducted a longitudinal assessment of mood and endocrine function in two groups of Chinese expeditioners who were deployed to sub-Antarctic (Great Wall Station, 62°S, N = 12) and Antarctic (Zhongshan Station, 66°S, N = 16) from December 2003 to 2005. Measures of mood, thyroid function, the levels of plasma catecholamine, and circulating interleukins were obtained at departure from China, mid-winter (Antarctica), end of winter (Antarctica), and return to China, respectively. The Zhongshan Station crew experienced significant increases in fatigue, anger, tension, confusion, and decrease in free thyroxine (FT4), norepinephrine (NE), and epinephrine (E) during the winter, increase in thyrotropin (TSH) and total triiodothyronine (TT3) when returning, whereas their counterparts at Great Wall Station only experienced increased TT3 after deployment. Moreover, compared with the Great Wall Station crew, the Zhongshan Station crew exhibited greater increase in anger, greater decrease in FT4, total thyroxine (TT4), NE and E over the winter, and greater increase in TSH when returning. Chinese expeditioners who lived and worked at the Antarctic station and the sub-Antarctic station for over a year showed different change patterns in mood and endocrine hormones. Negative mood and endocrine dysfunction were positively associated with the severity of environment. The study is a supplement to scientific knowledge on psychophysiological variation under ICE environment, which has certain applied value for the development of preventive countermeasures or interventions.

  9. Different adaptations of Chinese winter-over expeditioners during prolonged Antarctic and sub-Antarctic residence.

    Science.gov (United States)

    Chen, Nan; Wu, Quan; Li, Hao; Zhang, Tao; Xu, Chengli

    2016-05-01

    Prolonged residence in Antarctica is characterized by exposure to isolated, confined, and extreme (ICE) environment. Winter-over expeditioners at research stations often exhibit a complex of psychophysiological symptoms, which varied by stations and sociocultural backgrounds. To understand the different patterns of psychophysiological responses provoked by environmental stress, we conducted a longitudinal assessment of mood and endocrine function in two groups of Chinese expeditioners who were deployed to sub-Antarctic (Great Wall Station, 62°S, N = 12) and Antarctic (Zhongshan Station, 66°S, N = 16) from December 2003 to 2005. Measures of mood, thyroid function, the levels of plasma catecholamine, and circulating interleukins were obtained at departure from China, mid-winter (Antarctica), end of winter (Antarctica), and return to China, respectively. The Zhongshan Station crew experienced significant increases in fatigue, anger, tension, confusion, and decrease in free thyroxine (FT4), norepinephrine (NE), and epinephrine (E) during the winter, increase in thyrotropin (TSH) and total triiodothyronine (TT3) when returning, whereas their counterparts at Great Wall Station only experienced increased TT3 after deployment. Moreover, compared with the Great Wall Station crew, the Zhongshan Station crew exhibited greater increase in anger, greater decrease in FT4, total thyroxine (TT4), NE and E over the winter, and greater increase in TSH when returning. Chinese expeditioners who lived and worked at the Antarctic station and the sub-Antarctic station for over a year showed different change patterns in mood and endocrine hormones. Negative mood and endocrine dysfunction were positively associated with the severity of environment. The study is a supplement to scientific knowledge on psychophysiological variation under ICE environment, which has certain applied value for the development of preventive countermeasures or interventions.

  10. Cosmic censorship inside black holes

    CERN Document Server

    Thorlacius, L

    2006-01-01

    A simple argument is given that a traversable Cauchy horizon inside a black hole is incompatible with unitary black hole evolution. The argument assumes the validity of black hole complementarity and applies to a generic black hole carrying angular momentum and/or charge. In the second part of the paper we review recent work on the semiclassical geometry of two-dimensional charged black holes.

  11. Black holes and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-02-01

    Belief in the existence of black holes is the ultimate act of faith for a physicist. First suggested by the English clergyman John Michell in the year 1784, the gravitational pull of a black hole is so strong that nothing - not even light - can escape. Gravity might be the weakest of the fundamental forces but black-hole physics is not for the faint-hearted. Black holes present obvious problems for would-be observers because they cannot, by definition, be seen with conventional telescopes - although before the end of the decade gravitational-wave detectors should be able to study collisions between black holes. Until then astronomers can only infer the existence of a black hole from its gravitational influence on other matter, or from the X-rays emitted by gas and dust as they are dragged into the black hole. However, once this material passes through the 'event horizon' that surrounds the black hole, we will never see it again - not even with X-ray specs. Despite these observational problems, most physicists and astronomers believe that black holes do exist. Small black holes a few kilometres across are thought to form when stars weighing more than about two solar masses collapse under the weight of their own gravity, while supermassive black holes weighing millions of solar masses appear to be present at the centre of most galaxies. Moreover, some brave physicists have proposed ways to make black holes - or at least event horizons - in the laboratory. The basic idea behind these 'artificial black holes' is not to compress a large amount of mass into a small volume, but to reduce the speed of light in a moving medium to less than the speed of the medium and so create an event horizon. The parallels with real black holes are not exact but the experiments could shed new light on a variety of phenomena. The first challenge, however, is to get money for the research. One year on from a high-profile meeting on artificial black holes in London, for

  12. Mechanism of Fixation of Ozone and Its Medical Value

    Institute of Scientific and Technical Information of China (English)

    ZHU Lei; MIN Xinmin; WANG Xuchao

    2014-01-01

    Because of both ozone gas and ozone solution are instable which limits the application of ozone, to solve the storage problem, it is necessary to find a kind of ideal ozone carrier which can combine ozone as an “ozonic compound” in which the bond strength between ozone and carrier should not be too high or too low, to appropriately release ozone from the ozonic compound. Combining Criegee’s three-step reaction mechanism of ozone and olefins, the charge, covalent bond levels and energy levels of ozone, ethylene, butadiene and their ozonic compounds were calculated by the first-principles calculation method based on density functional theory methods. The stability of the ozonide, or the bond strength between ozone and ions of carrier were controlled felicitously to release ozone from the ozonide with proper velocity. Ozone antimicrobial was composed on the above principle. It can be used conveniently, especially for common families.

  13. Biomarkers and Microbial Fossils In Antarctic Rocks

    Science.gov (United States)

    Wierzchos, J.; Ascaso, C.

    Lithobiontic microbial communities living within Antarctic rocks are an example of survival in an extremely cold and dry environment. Any unfavourable change in ex- ternal conditions can result in the death and disappearance of microscopic organisms, and this may be followed by the appearance of trace biomarkers and microbial fossils. The extinction of these microorganisms in some zones of the Ross Desert, probably provoked by the hostile environment, might be considered a good terrestrial analogue of the first stage of the disappearance of possible life on early Mars. Granite samples from maritime Antarctica (Granite Harbour) and sandstone rocks from the continental Ross Desert were collected with the aim of searching for biomarkers and microbial fossils at the microscopic level of observation. To this end, a novel in situ applica- tion of scanning electron microscopy with backscattered electron imaging was com- bined with the simultaneous use of X-ray energy dispersive spectroscopy techniques. Our findings confirm the existence of inorganic biomarkers in the form of physico- chemically bioweathered minerals within the granitic rocks. The presence of Fe-rich diagenetic minerals, such as iron hydroxide nanocrystals and biogenic clays around chasmoendolithic hyphae and bacterial cells was also observed. Others biomarkers, including inorganic deposits such as calcium oxalates and silica accumulations, are clear signs of endolithic microorganism activity. The interior of the sandstone rocks (Ross Desert, Mt. Fleming) reveal the presence of microbial fossils of algae and other endolithic microorganisms. These microbial fossils, detected for the first time within Antarctic rocks, contain well preserved and morphologically distinguishable relics of ultrastructural cytoplasm elements, such as cell walls, chloroplast membranes, and oc- casionally, pyrenoids and traces of organic matter. These structures are similar to those observed in live cells also found in Antarctic

  14. Ozone, Air Quality, and Asthma (For Parents)

    Science.gov (United States)

    ... with chemicals produced by cars, power plants, and factories. That's why ground-level ozone, a main component ... Lung Association included not only ozone but particle pollution levels in its annual "State of the Air" ...

  15. [Ozone decline and UV increase].

    Science.gov (United States)

    Winkler, P; Trepte, S

    2004-02-01

    The following results have been obtained from long-term observations on the ozone layer and UV at the Meteorological Observatory Hohenpeigenberg:The seasonally varying decline of the ozone layer determines the maximum exposure to UV. Since ozone decline shows the highest rates in the spring months the UV exposure has most strongly increased in this time of the year. This is especially important because in spring the human skin is not adapted to UV exposure. Weather changes from day to day can induce rapid ozone reductions in spring about -30% which in turn is followed by an increase in UV of about 40%. Clouds, especially the transparent cirrus clouds (high clouds consisting of ice particles) have increased in frequency during spring and fall while a decrease is observed in summer. This change in cloudiness reduces the daily UV dose in spring and fall while it is enhanced in summer. With increasing height above sea level UV rises by roughly 10% per 1000 m (rule of thumb). Snow reflects the UV-radiation by up to 80% enhancing the UV-doses at relevant conditions. Strong volcano eruptions destroy ozone in the stratosphere additionally during 1-2 years after the eruption. Therafter the ozone layer recovers. In April 1993, after the eruption of Mt. Pinatubo (1991), the UV burden was still 40% higher than average. Miniholes and streamers can appear unexpected on a short-time scale and cross over Central Europe within 1-2 days, thus enhancing UV irradiation. The human skin reacts to UV exposure depending on the type of skin. The campaign "Sonne(n) mit Verstand" of the Bavarian Ministries for Environment, for Health and for Education informs about the danger of UV radiation (see www.sonne-mit-ver-stand.de). The German Weather Service informs the public on present developments of the ozone layer and relevant topics byits ozone bulletin, which is also available via internet under (www.dwd.de/deFundE/Observator/MOHp/hp2/ozon/bulletin.htm). PMID:14770335

  16. Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM

    Directory of Open Access Journals (Sweden)

    M. M. Hurwitz

    2011-03-01

    Full Text Available A new formulation of the Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM, with an improved general circulation model and an internally generated quasi-biennial oscillation (QBO, is used to investigate the response of the Antarctic stratosphere to (1 warm pool El Niño (WPEN events and (2 the sensitivity of this response to the phase of the QBO. Two 50-yr time-slice simulations are forced by repeating annual cycles of sea surface temperatures and sea ice concentrations composited from observed WPEN and neutral ENSO (ENSON events. In these simulations, greenhouse gas and ozone-depleting substance concentrations represent the present-day climate. The modelled responses to WPEN, and to the phase of the QBO during WPEN, are compared with NASA's Modern Era Retrospective-Analysis for Research and Applications (MERRA reanalysis.

    WPEN events enhance poleward planetary wave activity in the central South Pacific during austral spring, leading to relative warming of the Antarctic lower stratosphere in November/December. During the easterly phase of the QBO (QBO-E, the GEOS V2 CCM reproduces the observed 3–5 K warming of the polar region at 50 hPa, in the WPEN simulation relative to ENSON.

    In the recent past, the response to WPEN events was sensitive to the phase of the QBO: the enhancement in planetary wave driving and the lower stratospheric warming signal were mainly associated with WPEN events coincident with QBO-E. In the GEOS V2 CCM, however, the Antarctic response to WPEN events is insensitive to the phase of the QBO: the modelled response is always easterly QBO-like. OLR, streamfunction and Rossby wave energy diagnostics are used to show that the modelled QBO does not extend far enough into the lower stratosphere and upper troposphere to modulate convection and thus planetary wave activity in the south central Pacific.

  17. Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM

    Directory of Open Access Journals (Sweden)

    M. M. Hurwitz

    2011-09-01

    Full Text Available The Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM is used to investigate the response of the Antarctic stratosphere to (1 warm pool El Niño (WPEN events and (2 the sensitivity of this response to the phase of the QBO. A new formulation of the GEOS V2 CCM includes an improved general circulation model and an internally generated quasi-biennial oscillation (QBO. Two 50-yr time-slice simulations are forced by repeating annual cycles of sea surface temperatures and sea ice concentrations composited from observed WPEN and neutral ENSO (ENSON events. In these simulations, greenhouse gas and ozone-depleting substance concentrations represent the present-day climate. The modelled responses to WPEN, and to the phase of the QBO during WPEN, are compared with NASA's Modern Era Retrospective-Analysis for Research and Applications (MERRA reanalysis.

    WPEN events enhance poleward tropospheric planetary wave activity in the central South Pacific region during austral spring, leading to relative warming of the Antarctic lower stratosphere in November/December. During the easterly phase of the QBO (QBO-E, the GEOS V2 CCM reproduces the observed 4–5 K warming of the polar region at 50 hPa, in the WPEN simulation relative to ENSON.

    In the recent past, the response to WPEN events was sensitive to the phase of the QBO: the enhancement in planetary wave driving and the lower stratospheric warming signal were mainly associated with WPEN events coincident with QBO-E. In the GEOS V2 CCM, however, the Antarctic response to WPEN events is insensitive to the phase of the QBO: the modelled response is always easterly QBO-like. The QBO signal does not extend far enough into the lower stratosphere and upper troposphere to modulate convection and thus planetary wave activity in the south central Pacific.

  18. Ozone Damages to Mediterranean Crops: Physiological Responses

    OpenAIRE

    Massimo Fagnano; Albino Maggio

    2011-01-01

    In this brief review we analyzed some aspects of tropospheric ozone damages to crop plants. Specifically, we addressed this issue to Mediterranean environments, where plant response to multiple stresses may either exacerbate or counteract deleterious ozone effects. After discussing the adequacy of current models to predict ozone damages to Mediterranean crops, we present a few examples of physiological responses to drought and salinity stress that generally overlap with seasonal ozone peaks i...

  19. A Comparative Study of Antarctic Arctic and Himalayan Ice

    Directory of Open Access Journals (Sweden)

    R. C. Pathak

    1989-07-01

    Full Text Available Arctic, Antarctic and inaccessible lofty regions of Himalayas,which are geographically diverse areas and have been a constant source of inspiration, envisages a challenging field of study 'by early adventurers and scientists of the world. Characteristics of ice obtained at Arctic and Antarctic do not possess similar properties. Even thesalient properties of snow and ice of western and central Himalayas vary due to its differing free water content. A study has been carriedout based on recent Antarctic Expedition by Indian scientists and the data gathered along litha-tectonic regions of Himalayas and their characteristics have been compared, wkich brings out stratigraphic and metamorphic characteristics of the ice and snow. In the present paper,an analysis of the ice and snow properties of Arctic, Antarctic and Himalayan regions has been presented.

  20. Photosynthesis in a sub-Antarctic shore-zone lichen

    NARCIS (Netherlands)

    Smith, V.; Gremmen, N.J.M.

    2001-01-01

    Photosynthetic responses to moisture, light, temperature, salinity and inorganic nitrogen fertilization are reported for a shore-zone lichen Turgidiusculum complicatulum (formerly Mastodia tesselata), a possible recent introduction to sub-Antarctic Marion Island. Optimum moisture contents for net ph

  1. STRATEGIES AND KINETICS OF PHOTOACCLIMATION IN 3 ANTARCTIC NANOPHYTOFLAGELLATES

    NARCIS (Netherlands)

    BUMA, AGJ; NOORDELOOS, AAM; LARSEN, J

    1993-01-01

    Three Antarctic nanophytoflagellates (two cryptophyte species and a Pyramimonas sp.) were compared for their capacity to photoacclimate and for their kinetic responses in changing photic environments. Division rate, cell size, cellular fluorescence, and chlorophyll a content were measured during ste

  2. Climate Prediction Center (CPC) Daily Antarctic Oscillation Index

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Antarctic Oscillation (AAO) is a leading teleconnection pattern in the Southern Hemisphere circulation. It is calculated as the first Empirical Orthogonal...

  3. Searching for eukaryotic life preserved in Antarctic permafrost

    DEFF Research Database (Denmark)

    Zucconi, L.; Selbmann, L.; Buzzini, P.;

    2012-01-01

    Fungi and yeasts isolated in pure culture from Antarctic permafrost collected at different depths in the McMurdo Dry Valleys were identified with cultural, physiological and molecular methods. Fungi belonged to the genera Penicillium, Eurotium, Cladosporium, Alternaria, Engyodonthium, Aureobasidium...

  4. German Antarctic Receiving Station (GARS) O'Higgins

    Science.gov (United States)

    Neidhardt, Alexander; Ploetz, Christian; Kluegel, Thomas

    2013-01-01

    In 2012, the German Antarctic Receiving Station (GARS) O'Higgins contributed to the IVS observing program with four observation sessions. Maintenance and upgrades were made, and a new replacement dewar is under construction in the observatory at Yebes, Spain.

  5. Biological invasions in the Antarctic: extent, impacts and implications.

    Science.gov (United States)

    Frenot, Yves; Chown, Steven L; Whinam, Jennie; Selkirk, Patricia M; Convey, Peter; Skotnicki, Mary; Bergstrom, Dana M

    2005-02-01

    Alien microbes, fungi, plants and animals occur on most of the sub-Antarctic islands and some parts of the Antarctic continent. These have arrived over approximately the last two centuries, coincident with human activity in the region. Introduction routes have varied, but are largely associated with movement of people and cargo in connection with industrial, national scientific program and tourist operations. The large majority of aliens are European in origin. They have both direct and indirect impacts on the functioning of species-poor Antarctic ecosystems, in particular including substantial loss of local biodiversity and changes to ecosystem processes. With rapid climate change occurring in some parts of Antarctica, elevated numbers of introductions and enhanced success of colonization by aliens are likely, with consequent increases in impacts on ecosystems. Mitigation measures that will substantially reduce the risk of introductions to Antarctica and the sub-Antarctic must focus on reducing propagule loads on humans, and their food, cargo, and transport vessels.

  6. Joint Antarctic School Expedition - An International Collaboration for High School Students and Teachers on Antarctic Science

    Science.gov (United States)

    Botella, J.; Warburton, J.; Bartholow, S.; Reed, L. F.

    2014-12-01

    The Joint Antarctic School Expedition (JASE) is an international collaboration program between high school students and teachers from the United States and Chile aimed at providing the skills required for establishing the scientific international collaborations that our globalized world demands, and to develop a new approach for science education. The National Antarctic Programs of Chile and the United States worked together on a pilot program that brought high school students and teachers from both countries to Punta Arenas, Chile, in February 2014. The goals of this project included strengthening the partnership between the two countries, and building relationships between future generations of scientists, while developing the students' awareness of global scientific issues and expanding their knowledge and interest in Antarctica and polar science. A big component of the project involved the sharing by students of the acquired knowledge and experiences with the general public. JASE is based on the successful Chilean Antarctic Science Fair developed by Chile´s Antarctic Research Institute. For 10 years, small groups of Chilean students, each mentored by a teacher, perform experimental or bibliographical Antarctic research. Winning teams are awarded an expedition to the Chilean research station on King George Island. In 2014, the Chileans invited US participation in this program in order to strengthen science ties for upcoming generations. On King George Island, students have hands-on experiences conducting experiments and learning about field research. While the total number of students directly involved in the program is relatively small, the sharing of the experience by students with the general public is a novel approach to science education. Research experiences for students, like JASE, are important as they influence new direction for students in science learning, science interest, and help increase science knowledge. We will share experiences with the

  7. Effects of UV on photosynthesis of Antarctic phytoplankton: models and their application to coastal and pelagic assemblages Efecto de la radiación UV sobre la fotosíntesis de fitoplancton antártico: modelos y su aplicación a ensambles costeros y pelágicos

    OpenAIRE

    Neale, Patrick J.; JENNIFER J. FRITZ; Davis, Richard F.

    2001-01-01

    We have characterized the photosynthetic response to ultraviolet radiation (UV) of natural phytoplankton assemblages in Antarctic (Southern Ocean) waters. Biological weighting functions (BWFs) and exposure response curves for inhibition of photosynthesis by UV were measured during spring-time ozone depletion (October-November). Two different models were developed to relate photosynthesis to UV exposure. A model that is a function of the duration of exposure (BWF H) applied to assemblages in t...

  8. Charged Galileon black holes

    CERN Document Server

    Babichev, Eugeny; Hassaine, Mokhtar

    2015-01-01

    We consider an Abelian gauge field coupled to a particular truncation of Horndeski theory. The Galileon field has translation symmetry and couples non minimally both to the metric and the gauge field. When the gauge-scalar coupling is zero the gauge field reduces to a standard Maxwell field. By taking into account the symmetries of the action, we construct charged black hole solutions. Allowing the scalar field to softly break symmetries of spacetime we construct black holes where the scalar field is regular on the black hole event horizon. Some of these solutions can be interpreted as the equivalent of Reissner-Nordstrom black holes of scalar tensor theories with a non trivial scalar field. A self tuning black hole solution found previously is extended to the presence of dyonic charge without affecting whatsoever the self tuning of a large positive cosmological constant. Finally, for a general shift invariant scalar tensor theory we demonstrate that the scalar field Ansatz and method we employ are mathematic...

  9. Morphogenesis of Antarctic Paleosols: Martian Analogue

    Science.gov (United States)

    Mahaney, W. C.; Dohm, J. M.; Baker, V. R.; Newsom, Horton E.; Malloch, D.; Hancock, R. G. V.; Campbell, Iain; Sheppard, D.; Milner, M. W.

    2001-11-01

    Samples of horizons in paleosols from the Quartermain Mountains of the Antarctic Dry Valleys (Aztec and New Mountain areas) were analyzed for their physical characteristics, mineralogy, chemical composition, and microbiology to determine the accumulation and movement of salts and other soluble constituents and the presence/absence of microbial populations. Salt concentrations are of special interest because they are considered to be a function of age, derived over time, in part from nearby oceanic and high-altitude atmospheric sources. The chemical composition of ancient Miocene-age paleosols in these areas is the direct result of the deposition and weathering of airborne-influxed salts and other materials, as well as the weathering of till derived principally from local dolerite and sandstone outcrops. Paleosols nearer the coast have greater contents of Cl, whereas near the inland ice sheet, nitrogen tends to increase on a relative basis. The accumulation and vertical distribution of salts and other soluble chemical elements indicate relative amounts of movement in the profile over long periods of time, in the order of several million years. Four of the six selected subsamples from paleosol horizons in two ancient soil profiles contained nil concentrations of bacteria and fungi. However, two horizons at depths of between 3 and 8 cm, in two profiles, yielded several colonies of the fungi Beauveria bassiana and Penicillium brevicompactum, indicating very minor input of organic carbon. Beauveria bassiana is often reported in association with insects and is used commercially for the biological control of some insect pests. Penicillium species are commonly isolated from Arctic, temperate, and tropical soils and are known to utilize a wide variety of organic carbon and nitrogen compounds. The cold, dry soils of the Antarctic bear a close resemblance to various present and past martian environments where similar weathering could occur and possible microbial populations

  10. Effects of stratospheric ozone recovery on photochemistry and ozone air quality in the troposphere

    OpenAIRE

    Zhang, H.; Wu, S.; Huang, Y.; Wang, Y.

    2014-01-01

    There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). W...

  11. IDENTIFICATION OF BROMOHYDRINS IN OZONATED WATERS

    Science.gov (United States)

    Because ozonation is becoming a popular alternative to chlorination for disinfection of drinking water and because little is known about the potential adverse effects of ozonation disinfection by-products (DBPs), we have sought to identify ozone DBPs, particularly brominated orga...

  12. Plant Species Sensitivity Distributions for ozone exposure

    International Nuclear Information System (INIS)

    This study derived Species Sensitivity Distributions (SSD), representing a cumulative stressor-response distribution based on single-species sensitivity data, for ozone exposure on natural vegetation. SSDs were constructed for three species groups, i.e. trees, annual grassland and perennial grassland species, using species-specific exposure–response data. The SSDs were applied in two ways. First, critical levels were calculated for each species group and compared to current critical levels for ozone exposure. Second, spatially explicit estimates of the potentially affected fraction of plant species in Northwestern Europe were calculated, based on ambient ozone concentrations. We found that the SSD-based critical levels were lower than for the current critical levels for ozone exposure, with conventional critical levels for ozone relating to 8–20% affected plant species. Our study shows that the SSD concept can be successfully applied to both derive critical ozone levels and estimate the potentially affected species fraction of plant communities along specific ozone gradients. -- Highlights: ► Plant Species Sensitivity Distributions were derived for ozone exposure. ► Annual grassland species, as a species assemblage, tend to be most sensitive to ozone. ► Conventional critical levels for ozone relate to 8–20% affected plant species. ► The affected fraction of plant species for current ozone exposure in Northwestern Europe is estimated. -- Species Sensitivity Distributions offer opportunities in ozone risk assessment to both derive critical levels and estimate the affected fraction of a plant community

  13. Tropospheric Ozone and Photochemical Smog

    Science.gov (United States)

    Sillman, S.

    2003-12-01

    The question of air quality in polluted regions represents one of the issues of geochemistry with direct implications for human well-being. Human health and well-being, along with the well-being of plants, animals, and agricultural crops, are dependent on the quality of air we breathe. Since the start of the industrial era, air quality has become a matter of major importance, especially in large cities or urbanized regions with heavy automobile traffic and industrial activity.Concern over air quality existed as far back as the 1600s. Originally, polluted air in cities resulted from the burning of wood or coal, largely as a source of heat. The industrial revolution in England saw a great increase in the use of coal in rapidly growing cities, both for industrial use and domestic heating. London suffered from devastating pollution events during the late 1800s and early 1900s, with thousands of excess deaths attributed to air pollution (Brimblecombe, 1987). With increasing use of coal, other instances also occurred in continental Europe and the USA. These events were caused by directly emitted pollutants (primary pollutants), including sulfur dioxide (SO2), carbon monoxide (CO), and particulates. They were especially acute in cities with northerly locations during fall and winter when sunlight is at a minimum. These original pollution events gave rise to the term "smog" (a combination of smoke and fog). Events of this type have become much less severe since the 1950s in Western Europe and the US, as natural gas replaced coal as the primary source of home heating, industrial smokestacks were designed to emit at higher altitudes (where dispersion is more rapid), and industries were required to install pollution control equipment.Beginning in the 1950s, a new type of pollution, photochemical smog, became a major concern. Photochemical smog consists of ozone (O3) and other closely related species ("secondary pollutants") that are produced photochemically from directly

  14. Perspectives on the economic history of the Antarctic region

    OpenAIRE

    Basberg, Bjørn L.

    2005-01-01

    This paper starts out by indicating how the economic history of the Antarctic could be conceptualized, given the peculiarities of the continent and the region (no permanent population, no sovereignty in a traditional sense, extreme remoteness, rigorous climate etc.). Second, it describes the main industries throughout Antarctic history. Third, it examines the quantitative data available on economic activity in the region, suggests how we should proceed to analyse the economic a...

  15. Holocene subsurface temperature variability in the eastern Antarctic continental margin

    OpenAIRE

    Kim, J. H.; Crosta, X.; Willmott, V.; Renssen, H.; Bonnin, J.; Helmke, P.; Schouten, S.; Sinninghe Damsté, J. S.

    2012-01-01

    We reconstructed subsurface (similar to 45-200 m water depth) temperature variability in the eastern Antarctic continental margin during the late Holocene, using an archaeal lipid-based temperature proxy (TEX86 L). Our results reveal that subsurface temperature changes were probably positively coupled to the variability of warmer, nutrient-rich Modified Circumpolar Deep Water (MCDW, deep water of the Antarctic circumpolar current) intrusion onto the continental shelf. The TEX86 L record, in c...

  16. Obliquity-paced Pliocene West Antarctic ice sheet oscillations

    OpenAIRE

    Naish, T.; Antarctic Research Centre, Victoria University of Wellington, Kelburn Parade, PO Box 600, Wellington 6012, New Zealand; Powell, R.; Department of Geology & Environmental Geosciences, Northern Illinois University, DeKalb, Illinois 60115, USA.; Levy, R.; ANDRILL Science Management Office, University of Nebraska-Lincoln, Lincoln, USA; Wilson, G.; University of Otago, Department of Geology, PO Box 56, Leith Street, Dunedin, Otago 9001, New Zealand; Scherer, R.; Department of Geology & Environmental Geosciences, Northern Illinois University, DeKalb, Illinois 60115, USA.; Talarico, F.; Universita` di Siena, Dipartimento di Scienze delle Terra, Via Laterina 8, I-53100 Siena, Italy; Krissek, L.; Ohio State University, Department of Geological Sciences, 275 Mendenhall Lab, 125 South Oval Mall, Columbus, Ohio 43210, USA; Niessen, F.; Alfred Wegener Institute, Department of Geosciences, Postfach 12 01 6, Am Alten Hafen 26, D-27515 Bremerhaven, Germany; Pompilio, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Pisa, Pisa, Italia; Wilson, T.; Ohio State University, Department of Geological Sciences, 275 Mendenhall Lab, 125 South Oval Mall, Columbus, Ohio 43210, USA; Carter, L.; Antarctic Research Centre, Victoria University of Wellington, Kelburn Parade, PO Box 600, Wellington 6012, New Zealand; DeConto, R.; Department of Geosciences, 233 Morrell Science Centre, University of Massachusetts, Amherst, Massachusetts 01003-9297, USA; Huybers, P.; Department of Earth and Planetary Sciences, Harvard University, Massachusetts 02138, USA; McKay, R.; Antarctic Research Centre, Victoria University of Wellington, PO Box 600, Wellington - New Zealand; Pollard, D.; Earth and Environmental Systems Institute, 2217 Earth-Engineering Science Bldg, University Park, PA 16802, USA

    2009-01-01

    Thirty years after oxygen isotope records frommicrofossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth’s orbital geometry control the ice ages1, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles2. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the ‘warmer-than- present’ early-Pliocene epoch (̃5–3Myr ago) is needed to better constrain the possibl...

  17. The relationship between solar UV irradiance and total ozone from observations over southern Argentina

    Science.gov (United States)

    Bojkov, Rumen D.; Fioletov, Vitali E.; Diaz, Susana B.

    1995-05-01

    Solar ultraviolet (UV) radiation at 300 and 305 nm, measured by a Biospherical Instruments high resolution scanning spectroradiometer at Ushuaia, southern Argentina (55 deg S, 68 deg W), as a part of the US National Science Foundation network for Polar Regions, was compared with total ozone satellite measurements. A statistical relationship between UV and total ozone was derived. On the basis of this relationship, the differences in 300 and 305 nm irradiance between 1979-1983 and 1989-1993 intervals are estimated; for October, the 15% observed decline of total ozone has led to irradiance increases of 80% at 300 nm and 35% at 305 nm. During the days with 'ozone hole' conditions, the 300 nm irradiance is as high as it would be at the summer solstice three months later, and is approximately 4 times higher than the UV irradiance corresponding to the 'normal ozone condition for early October, as further illustrated for October 1994. Inclusion of the 340 nm cloudy-dependent predictor is discussed.

  18. Ozone's impact on public health: Contributions from indoor exposures to ozone and products of ozone-initiated chemistry

    DEFF Research Database (Denmark)

    Weschler, Charles J.

    2006-01-01

    , if any, threshold for ozone's impact on mortality. Additionally, the present study estimates that average daily indoor intakes of ozone oxidation products are roughly one-third to twice the indoor inhalation intake of ozone alone. Some of these oxidation products are known or suspected to adversely...... affect human health (e.g., formaldehyde, acrolein, hydro-peroxides, fine and ultrafine particles). Indirect evidence supports connections between morbidity/mortality and exposures to indoor ozone and its oxidation products. For example, cities with stronger associations between outdoor ozone...

  19. Antarctic marine biodiversity and deep-sea hydrothermal vents.

    Science.gov (United States)

    Chown, Steven L

    2012-01-01

    The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  20. Transcriptomics and comparative analysis of three antarctic notothenioid fishes.

    Directory of Open Access Journals (Sweden)

    Seung Chul Shin

    Full Text Available For the past 10 to 13 million years, Antarctic notothenioid fish have undergone extraordinary periods of evolution and have adapted to a cold and highly oxygenated Antarctic marine environment. While these species are considered an attractive model with which to study physiology and evolutionary adaptation, they are poorly characterized at the molecular level, and sequence information is lacking. The transcriptomes of the Antarctic fishes Notothenia coriiceps, Chaenocephalus aceratus, and Pleuragramma antarcticum were obtained by 454 FLX Titanium sequencing of a normalized cDNA library. More than 1,900,000 reads were assembled in a total of 71,539 contigs. Overall, 40% of the contigs were annotated based on similarity to known protein or nucleotide sequences, and more than 50% of the predicted transcripts were validated as full-length or putative full-length cDNAs. These three Antarctic fishes shared 663 genes expressed in the brain and 1,557 genes expressed in the liver. In addition, these cold-adapted fish expressed more Ub-conjugated proteins compared to temperate fish; Ub-conjugated proteins are involved in maintaining proteins in their native state in the cold and thermally stable Antarctic environments. Our transcriptome analysis of Antarctic notothenioid fish provides an archive for future studies in molecular mechanisms of fundamental genetic questions, and can be used in evolution studies comparing other fish.

  1. Turbulent black holes.

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-27

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability-which is triggered above a certain perturbation amplitude threshold-akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies-a phenomenon reminiscent of the inverse cascade displayed by (2+1)-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids.

  2. Janus black holes

    Science.gov (United States)

    Bak, Dongsu; Gutperle, Michael; Janik, Romuald A.

    2011-10-01

    In this paper Janus black holes in A dS 3 are considered. These are static solutions of an Einstein-scalar system with broken translation symmetry along the horizon. These solutions are dual to interface conformal field theories at finite temperature. An approximate solution is first constructed using perturbation theory around a planar BTZ blackhole. Numerical and exact solutions valid for all sets of parameters are then found and compared. Using the exact solution the thermodynamics of the system is analyzed. The entropy associated with the Janus black hole is calculated and it is found that the entropy of the black Janus is the sum of the undeformed black hole entropy and the entanglement entropy associated with the defect.

  3. Black hole entropy quantization

    CERN Document Server

    Corichi, A; Fernandez-Borja, E; Corichi, Alejandro; Diaz-Polo, Jacobo; Fernandez-Borja, Enrique

    2006-01-01

    Ever since the pioneer works of Bekenstein and Hawking, black hole entropy has been known to have a quantum origin. Furthermore, it has long been argued by Bekenstein that entropy should be quantized in discrete (equidistant) steps given its identification with horizon area in (semi-)classical general relativity and the properties of area as an adiabatic invariant. This lead to the suggestion that black hole area should also be quantized in equidistant steps to account for the discrete black hole entropy. Here we shall show that loop quantum gravity, in which area is not quantized in equidistant steps can nevertheless be consistent with Bekenstein's equidistant entropy proposal in a subtle way. For that we perform a detailed analysis of the number of microstates compatible with a given area and show that an observed oscillatory behavior in the entropy-area relation, when properly interpreted yields an entropy that has discrete, equidistant values that are consistent with the Bekenstein framework.

  4. Black-hole astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Bender, P. [Univ. of Colorado, Boulder, CO (United States); Bloom, E. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Cominsky, L. [Sonoma State Univ., Rohnert Park, CA (United States). Dept. of Physics and Astronomy] [and others

    1995-07-01

    Black-hole astrophysics is not just the investigation of yet another, even if extremely remarkable type of celestial body, but a test of the correctness of the understanding of the very properties of space and time in very strong gravitational fields. Physicists` excitement at this new prospect for testing theories of fundamental processes is matched by that of astronomers at the possibility to discover and study a new and dramatically different kind of astronomical object. Here the authors review the currently known ways that black holes can be identified by their effects on their neighborhood--since, of course, the hole itself does not yield any direct evidence of its existence or information about its properties. The two most important empirical considerations are determination of masses, or lower limits thereof, of unseen companions in binary star systems, and measurement of luminosity fluctuations on very short time scales.

  5. Black Hole Bose Condensation

    Science.gov (United States)

    Vaz, Cenalo; Wijewardhana, L. C. R.

    2013-12-01

    General consensus on the nature of the degrees of freedom responsible for the black hole entropy remains elusive despite decades of effort dedicated to the problem. Different approaches to quantum gravity disagree in their description of the microstates and, more significantly, in the statistics used to count them. In some approaches (string theory, AdS/CFT) the elementary degrees of freedom are indistinguishable, whereas they must be treated as distinguishable in other approaches to quantum gravity (eg., LQG) in order to recover the Bekenstein-Hawking area-entropy law. However, different statistics will imply different behaviors of the black hole outside the thermodynamic limit. We illustrate this point by quantizing the Bañados-Teitelboim-Zanelli (BTZ) black hole, for which we argue that Bose condensation will occur leading to a "cold", stable remnant.

  6. Turbulent black holes.

    Science.gov (United States)

    Yang, Huan; Zimmerman, Aaron; Lehner, Luis

    2015-02-27

    We demonstrate that rapidly spinning black holes can display a new type of nonlinear parametric instability-which is triggered above a certain perturbation amplitude threshold-akin to the onset of turbulence, with possibly observable consequences. This instability transfers from higher temporal and azimuthal spatial frequencies to lower frequencies-a phenomenon reminiscent of the inverse cascade displayed by (2+1)-dimensional fluids. Our finding provides evidence for the onset of transitory turbulence in astrophysical black holes and predicts observable signatures in black hole binaries with high spins. Furthermore, it gives a gravitational description of this behavior which, through the fluid-gravity duality, can potentially shed new light on the remarkable phenomena of turbulence in fluids. PMID:25768746

  7. Noncommutative black hole thermodynamics

    International Nuclear Information System (INIS)

    We give a general derivation, for any static spherically symmetric metric, of the relation Th=(K/2π) connecting the black hole temperature (Th) with the surface gravity (K), following the tunneling interpretation of Hawking radiation. This derivation is valid even beyond the semi-classical regime, i.e. when quantum effects are not negligible. The formalism is then applied to a spherically symmetric, stationary noncommutative Schwarzschild space-time. The effects of backreaction are also included. For such a black hole the Hawking temperature is computed in a closed form. A graphical analysis reveals interesting features regarding the variation of the Hawking temperature (including corrections due to noncommutativity and backreaction) with the small radius of the black hole. The entropy and tunneling rate valid for the leading order in the noncommutative parameter are calculated. We also show that the noncommutative Bekenstein-Hawking area law has the same functional form as the usual one

  8. Parasites of the Antarctic toothfish (Dissostichus mawsoni Norman, 1937 (Perciformes, Nototheniidae in the Pacific sector of the Antarctic

    Directory of Open Access Journals (Sweden)

    Ilya I. Gordeev

    2016-06-01

    Full Text Available The Antarctic toothfish (Dissostichus mawsoni Norman, 1937 is one of the main target species of commercial fisheries in the Antarctic. It is an endemic and is found along the shelf of Antarctica, as well as on the slopes of seamounts, underwater elevations and islands in the sub-Antarctic. It feeds on a variety of fish and cephalopods and can be an intermediate/paratenic host of some helminthes, whose final hosts are whales, seals, large rays and sharks. This article presents new data on toothfish infection in the Pacific sector of the Antarctic. Specimens were examined during commercial longline fishing in the Ross Sea and the Amundsen Sea in January–February 2013. Fourteen species of parasites were found using standard parasitological methods and genetic analysis.

  9. Slowly balding black holes

    International Nuclear Information System (INIS)

    The 'no-hair' theorem, a key result in general relativity, states that an isolated black hole is defined by only three parameters: mass, angular momentum, and electric charge; this asymptotic state is reached on a light-crossing time scale. We find that the no-hair theorem is not formally applicable for black holes formed from the collapse of a rotating neutron star. Rotating neutron stars can self-produce particles via vacuum breakdown forming a highly conducting plasma magnetosphere such that magnetic field lines are effectively ''frozen in'' the star both before and during collapse. In the limit of no resistivity, this introduces a topological constraint which prohibits the magnetic field from sliding off the newly-formed event horizon. As a result, during collapse of a neutron star into a black hole, the latter conserves the number of magnetic flux tubes NB=eΦ∞/(πc(ℎ/2π)), where Φ∞≅2π2BNSRNS3/(PNSc) is the initial magnetic flux through the hemispheres of the progenitor and out to infinity. We test this theoretical result via 3-dimensional general relativistic plasma simulations of rotating black holes that start with a neutron star dipole magnetic field with no currents initially present outside the event horizon. The black hole's magnetosphere subsequently relaxes to the split-monopole magnetic field geometry with self-generated currents outside the event horizon. The dissipation of the resulting equatorial current sheet leads to a slow loss of the anchored flux tubes, a process that balds the black hole on long resistive time scales rather than the short light-crossing time scales expected from the vacuum no-hair theorem.

  10. Over spinning a black hole?

    Energy Technology Data Exchange (ETDEWEB)

    Bouhmadi-Lopez, Mariam; Cardoso, Vitor; Nerozzi, Andrea; Rocha, Jorge V, E-mail: mariam.bouhmadi@ist.utl.pt, E-mail: vitor.cardoso@ist.utl.pt, E-mail: andrea.nerozzi@ist.utl.pt, E-mail: jorge.v.rocha@ist.utl.pt [CENTRA, Department de Fisica, Instituto Superior Tecnico, Av. Rovisco Pais 1, 1049 Lisboa (Portugal)

    2011-09-22

    A possible process to destroy a black hole consists on throwing point particles with sufficiently large angular momentum into the black hole. In the case of Kerr black holes, it was shown by Wald that particles with dangerously large angular momentum are simply not captured by the hole, and thus the event horizon is not destroyed. Here we reconsider this gedanken experiment for black holes in higher dimensions. We show that this particular way of destroying a black hole does not succeed and that Cosmic Censorship is preserved.

  11. Growth of Primordial Black Holes

    Science.gov (United States)

    Harada, Tomohiro

    Primordial black holes have important observational implications through Hawking evaporation and gravitational radiation as well as being a candidate for cold dark matter. Those black holes are assumed to have formed in the early universe typically with the mass scale contained within the Hubble horizon at the formation epoch and subsequently accreted mass surrounding them. Numerical relativity simulation shows that primordial black holes of different masses do not accrete much, which contrasts with a simplistic Newtonian argument. We see that primordial black holes larger than the 'super-horizon' primordial black holes have decreasing energy and worm-hole like struture, suggesting the formation through quamtum processes.

  12. OZONE CONCENTRATION ATTRIBUTABLE PREMATURE DEATH IN POLAND

    Directory of Open Access Journals (Sweden)

    Krzysztof Skotak

    2010-03-01

    Full Text Available Ozone in the lower part of the atmosphere (troposphere, strong photochemical oxidant, is not directly emitted to the atmosphere but formed through a series of complex reactions. Ozone concentrations depends on ozone precursors air contamination (mainly nitrogen dioxide and non-methane volatile organic compounds and meteorological conditions (temperature and solar radiation. The main sectors emitted ozone precursors are road transport, power and heat generation plants, household (heating, industry, and petrol storage and distribution. Ozone and some of its precursors are also transported long distances in the atmosphere and are therefore considered a transboundary problem. As a result, the ozone concentrations are often low in busy urban areas and higher in suburban and rural areas. Nowadays, instead of particulate matter, ozone is one of the most widespread global air pollution problems. In and around urban areas, relatively large gradients of ozone can be observed. Because of its high reactivity in elevated concentrations ozone causes serious health problems and damage to ecosystems, agricultural crops and materials. Main ill-health endpoints as a results of ozone concentrations can be characterised as an effect of pulmonary and cardiovascular system, time morbidity and mortality series, development of atherosclerosis and asthma and finally reduction in life expectancy. The associations with increased daily mortality due to ozone concentrations are confirmed by many researches and epidemiological studies. Estimation of the level selected ill-health endpoints (mortality in total and due to cardiovascular and respiratory causes as a result of the short-term ozone exposure in Poland was the main aim of the project. Final results have been done based on estimation method elaborated by WHO, ozone measurements from National Air Quality Monitoring System and statistical information such as mortality rate and populations. All analysis have been done in

  13. Are Black Holes Springy?

    CERN Document Server

    Good, Michael R R

    2014-01-01

    A $(3+1)$-dimensional asymptotically flat Kerr black hole angular speed $\\Omega_+$ can be used to define an effective spring constant, $k=m\\Omega_+^2$. Its maximum value is the Schwarzschild surface gravity, $k = \\kappa $, which rapidly weakens as the black hole spins down and the temperature increases. The Hawking temperature is expressed in terms of the spring constant: $2\\pi T = \\kappa - k$. Hooke's law, in the extremal limit, provides the force $F = 1/4$, which is consistent with the conjecture of maximum force in general relativity.

  14. Noncommutative solitonic black hole

    International Nuclear Information System (INIS)

    We investigate solitonic black hole solutions in three-dimensional noncommutative spacetime. We do this in gravity with a negative cosmological constant coupled to a scalar field. Noncommutativity is realized with the Moyal product which is expanded up to first order in the noncommutativity parameter in two spatial directions. With numerical simulation we study the effect of noncommutativity by increasing the value of the noncommutativity parameter starting from commutative solutions. We find that even a regular soliton solution in the commutative case becomes a black hole solution when the noncommutativity parameter reaches a certain value. (paper)

  15. Noncommutative solitonic black hole

    Science.gov (United States)

    Chang-Young, Ee; Kimm, Kyoungtae; Lee, Daeho; Lee, Youngone

    2012-05-01

    We investigate solitonic black hole solutions in three-dimensional noncommutative spacetime. We do this in gravity with a negative cosmological constant coupled to a scalar field. Noncommutativity is realized with the Moyal product which is expanded up to first order in the noncommutativity parameter in two spatial directions. With numerical simulation we study the effect of noncommutativity by increasing the value of the noncommutativity parameter starting from commutative solutions. We find that even a regular soliton solution in the commutative case becomes a black hole solution when the noncommutativity parameter reaches a certain value.

  16. Horndeski black hole geodesics

    CERN Document Server

    Tretyakova, D A

    2016-01-01

    We examine geodesics for the scalar-tensor black holes in the Horndeski-Galileon framework. Our analysis shows that first kind relativistic orbits may not be present within some model parameters range. This is a highly pathological behavior contradicting to the black hole accretion and Solar System observations. We also present a new (although very similar to those previously known) solution, which contains the orbits we expect from a compact object, admits regular scalar field at the horizon and and can fit into the known stability criteria.

  17. Dancing with black holes

    CERN Document Server

    Aarseth, Sverre J

    2007-01-01

    We describe efforts over the last six years to implement regularization methods suitable for studying one or more interacting black holes by direct N-body simulations. Three different methods have been adapted to large-N systems: (i) Time-Transformed Leapfrog, (ii) Wheel-Spoke, and (iii) Algorithmic Regularization. These methods have been tried out with some success on GRAPE-type computers. Special emphasis has also been devoted to including post-Newtonian terms, with application to moderately massive black holes in stellar clusters. Some examples of simulations leading to coalescence by gravitational radiation will be presented to illustrate the practical usefulness of such methods.

  18. Modeling black hole evaporation

    CERN Document Server

    Fabbri, Alessandro

    2005-01-01

    The scope of this book is two-fold: the first part gives a fully detailed and pedagogical presentation of the Hawking effect and its physical implications, and the second discusses the backreaction problem, especially in connection with exactly solvable semiclassical models that describe analytically the black hole evaporation process. The book aims to establish a link between the general relativistic viewpoint on black hole evaporation and the new CFT-type approaches to the subject. The detailed discussion on backreaction effects is also extremely valuable.

  19. Superfluid Black Holes

    CERN Document Server

    Hennigar, Robie A; Tjoa, Erickson

    2016-01-01

    We present what we believe is the first example of a "$\\lambda$-line" phase transition in black hole thermodynamics. This is a line of (continuous) second order phase transitions which in the case of liquid $^4$He marks the onset of superfluidity. The phase transition occurs for a class of asymptotically AdS hairy black holes in Lovelock gravity where a real scalar field is conformally coupled to gravity. We discuss the origin of this phase transition and outline the circumstances under which it (or generalizations of it) could occur.

  20. Black holes and quasiblack holes: Some history and remarks

    CERN Document Server

    Lemos, José P S

    2011-01-01

    A brief reference to the two Schwarzschild solutions and what Petrov had to say about them is given. Comments on how the Schwarzschild vacuum solution describes a black hole are also provided. Then we compare the properties, differences and similarities between black holes and quasiblack holes. Black holes are well known. Quasiblack hole is a new concept. A quasiblack hole, either nonextremal or extremal, can be broadly defined as the limiting configuration of a body when its boundary approaches the body's own gravitational radius (the quasihorizon). They are objects that are on the verge of being black holes but actually are distinct from them in many ways. We display some of their properties: there are infinite redshift whole regions; the curvature invariants remain perfectly regular everywhere, in the quasiblack hole limit; a free-falling observer finds in his own frame infinitely large tidal forces in the whole inner region, showing some form of degeneracy; outer and inner regions become mutually impenetr...