Total Ozone Observations During the Past 80 Years

2008 ◽  
pp. 129-140 ◽  
Author(s):  
S. Brönnimann ◽  
C. Vogler ◽  
J. Staehelin ◽  
R. Stolarski ◽  
G. Hansen
Keyword(s):  
Total Ozone ◽  
The Past

scholarly journals Attribution of stratospheric ozone trends to chemistry and transport: a modelling study

2010 ◽  
Vol 10 (7) ◽  
pp. 17491-17525
Author(s):  
G. Kiesewetter ◽  
B.-M. Sinnhuber ◽  
M. Weber ◽  
J. P. Burrows
Keyword(s):  
Total Ozone ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Stratospheric Ozone ◽  
Weather Forecast ◽  
Medium Range Weather Forecast ◽  
The Past ◽  
Ozone Sensitivity ◽  
Ozone Trends ◽  
Ozone Depleting Substances

Abstract. The decrease of the concentration of ozone depleting substances (ODS) in the stratosphere over the past decade raises the question to what extent observed changes in stratospheric ozone over this period are consistent with known changes in chemical composition and possible changes in atmospheric transport. Here we present a series of ozone sensitivity calculations with a stratospheric chemistry transport model (CTM) driven with meteorological reanalyses from the European Centre for Medium Range Weather Forecast, covering the period 1978–2009. In order to account for the reversal in ODS trends, ozone trends are analysed in two periods, 1979–1999 and 2000–2009. Effects of ODS changes on the ozone chemistry are either accounted for or left out, allowing for a distinct attribution of ozone trends to the different factors of variability, namely ODS acting via gas phase chemistry, ODS acting via polar heterogeneous chemistry, and changes in transport and temperature. Modeled column ozone trends are in excellent agreement with observed trends from the Total Ozone Mapping Spectrometer (TOMS) and Solar Backscatter UV (SBUV/2) as well as the Global Ozone Monitoring Experiment (GOME/GOME2) and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instruments. For the 1979–1999 period we find that changes in ODS are the dominant source of the ozone trend, while changes in transport also contribute signifcantly to the overall trend. In contrast, for the period 2000–2009 the effect of ODS changes on total ozone is small. Observed ozone changes can be reproduced well with the CTM driven with meteorological reanalyses, indicating that the observed evolution of ozone over the past decade is consistent with our current understanding of chemistry and transport.

scholarly journals The Ozone Hole of 2002 as Measured by TOMS

2005 ◽  
Vol 62 (3) ◽  
pp. 716-720 ◽  
Author(s):  
Richard S. Stolarski ◽  
Richard D. McPeters ◽  
Paul A. Newman
Keyword(s):  
Total Ozone ◽  
Polar Vortex ◽  
Ozone Hole ◽  
Positive Anomaly ◽  
Total Ozone Mapping Spectrometer ◽  
Broad Area ◽  
The Past ◽  
The Earth ◽  
Weakened Form ◽  
South Polar

Abstract Since its discovery in 1985, the ozone hole has been regularly mapped using the data from Total Ozone Mapping Spectrometer (TOMS) instruments on several satellites. The current TOMS, on the Earth Probe satellite, has been taking measurements since 1996. The ozone hole first appeared during the 1980s. Since 1990, the hole has consistently developed during each Antarctic spring over a broad area with the minimum total ozone value reaching about 100 Dobson units (DU; 1 DU = 2.69 × 1016 molecules cm−2) in late September or early October. The year 2002 was markedly different from the past 12 years. A series of strong wave events weakened the South Polar vortex. In late September, a major stratospheric warming took place, reversing the direction of the polar flow and the latitudinal temperature gradient. This warming resulted in a division of the ozone hole into two pieces, one that migrated to lower latitudes and disappeared and one that reformed over the Pole in a weakened form. The development of this year’s unusual ozone hole is shown here and is contrasted to a climatology of the years since 1990. Minimum daily values of total ozone barely reached 150 DU in contrast to values nearer to 100. The area of the ozone hole briefly reached 18 × 106 km2, then dropped rapidly to only 2 × 106 km2, and finally recovered to about 8 × 106 km2 before disappearing in early November. The positive anomaly compared with the last 12 yr near the Pole was accompanied by a smaller negative anomaly north of 45°S.

scholarly journals Recent changes observed in column ozone concentrations over India

MAUSAM ◽  
2021 ◽  
Vol 51 (1) ◽  
pp. 69-74
Author(s):  
S. K. PESHIN ◽  
J. N. DEWHARE ◽  
R. C. BHATIA ◽  
S. K. SRIVASTAV
Keyword(s):  
Trend Analysis ◽  
Tropospheric Ozone ◽  
Total Ozone ◽  
Term Trend ◽  
The Past ◽  
Increasing Trend ◽  
Column Ozone ◽  
Long Term Trend ◽  
Ozone Levels

Ozone observations taken during the past 23-39 years by Dobson Spectrophotometers at Delhi, Varanasi, Pune and Kodikanal have been analysed to examine its long-term trend over Indian stations. An increasing trend of this species over the years has been noticed at all the places, except at Varanasi, where a decreasing trend has been found. The cause of these trends could be attributed, partly, to the trends of ozone in the troposphere. The results also indicate that there are certain recent changes in ozone levels at the Indian stations. These changes are less apparent in long-term trend analysis of total ozone data as the increase in tropospheric ozone has a compensating effect to the decrease in ozone at stratospheric levels.

Tropospheric ozone based on S5P-BASCOE and extension to the past based on OMI and GOME-2 observation.

2021 ◽  
Author(s):  
Klaus-Peter Heue ◽  
Christophe Lerot ◽  
Fabian Romahn ◽  
Simon Chabrillat ◽  
Yves Christophe ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Tropospheric Ozone ◽  
Total Ozone ◽  
Reanalysis Data ◽  
Data Set ◽  
The Past ◽  
Stratospheric Intrusion ◽  
Non Linear ◽  
Linear Effects

<p>Ozone in the troposphere has mainly two sources, the first one is stratospheric intrusion the second one is chemical reactions following the emissions of primary pollutions such as NOx and VOCS.</p><p>We combine TROPOMI total ozone columns with Microwave Limb Sounding ozone profiles assimilated to BASCOE to retrieve tropospheric ozone columns.</p><p>Based on a first analysis we observe a decrease of tropospheric ozone during April and May 2020. The lockdown as measure against the Corona pandemic also caused an economic shutdown, and thereby a reduction of primary pollutants mainly NOx. Within the cities centres the lack of NOx caused an increase in tropospheric ozone, due to non linear effects in the ozone NOx chemistry. Outside the cities however a decrease might be expected. Thereby the tropospheric ozone reduction in April May might be caused by the lockdown due to the COVID-19.</p><p>However the natural variabilty is high caused by metrological conditions. To redcue the influnece of indiviual metrological situation the timeseries is expanded to the past by using additional sensors like GOME-2 and OMI, combined with the BASCOE reanalysis data set BRAM. The tropospheric columns are haromized using the same time and latitude depended bias added as for harmonizing the total columns. Therby we generated a typical anual mean data set, where the exceptional year of 2020 can be compared to.</p>

Observations of the continuum near the galactic centre

1967 ◽  
Vol 31 ◽  
pp. 405
Author(s):  
F. J. Kerr
Keyword(s):  
Galactic Centre ◽  
The Past ◽  
Centre Region ◽  
The Continuum

A continuum survey of the galactic-centre region has been carried out at Parkes at 20 cm wavelength over the areal11= 355° to 5°,b11= -3° to +3° (Kerr and Sinclair 1966, 1967). This is a larger region than has been covered in such surveys in the past. The observations were done as declination scans.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

On The Possibility of an Autonomous History of Modern Southeast Asia

1961 ◽  
Vol 2 (2) ◽  
pp. 73-105 ◽  
Author(s):  
John R. W. Small
Keyword(s):  
Southeast Asia ◽  
Contemporary History ◽  
The Past ◽  
History Of

It is generally accepted that history is an element of culture and the historian a member of society, thus, in Croce's aphorism, that the only true history is contemporary history. It follows from this that when there occur great changes in the contemporary scene, there must also be great changes in historiography, that the vision not merely of the present but also of the past must change.

Stellar Evolution

1962 ◽  
Vol 11 (02) ◽  
pp. 137-143
Author(s):  
M. Schwarzschild
Keyword(s):  
Solar System ◽  
Stellar Evolution ◽  
Space Craft ◽  
New Techniques ◽  
Substantial Body ◽  
Individual Stars ◽  
The Past ◽  
Evolution Of Galaxies ◽  
History Of ◽  
Fast Flow

It is perhaps one of the most important characteristics of the past decade in astronomy that the evolution of some major classes of astronomical objects has become accessible to detailed research. The theory of the evolution of individual stars has developed into a substantial body of quantitative investigations. The evolution of galaxies, particularly of our own, has clearly become a subject for serious research. Even the history of the solar system, this close-by intriguing puzzle, may soon make the transition from being a subject of speculation to being a subject of detailed study in view of the fast flow of new data obtained with new techniques, including space-craft.

Novae in the Magellanic Clouds

1979 ◽  
Vol 46 ◽  
pp. 96-101
Author(s):  
J.A. Graham
Keyword(s):  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Magellanic Clouds ◽  
University Of Michigan ◽  
The Past ◽  
Spectroscopic Information ◽  
Objective Prism ◽  
The University ◽  
Small Cloud ◽  
Low Dispersion

During the past several years, a systematic search for novae in the Magellanic Clouds has been carried out at Cerro Tololo Inter-American Observatory. The Curtis Schmidt telescope, on loan to CTIO from the University of Michigan is used to obtain plates every two weeks during the observing season. An objective prism is used on the telescope. This provides additional low-dispersion spectroscopic information when a nova is discovered. The plates cover an area of 5°x5°. One plate is sufficient to cover the Small Magellanic Cloud and four are taken of the Large Magellanic Cloud with an overlap so that the central bar is included on each plate. The methods used in the search have been described by Graham and Araya (1971). In the CTIO survey, 8 novae have been discovered in the Large Cloud but none in the Small Cloud. The survey was not carried out in 1974 or 1976. During 1974, one nova was discovered in the Small Cloud by MacConnell and Sanduleak (1974).

Immunoferritin localization of intracellular antigens in positively stained frozen sections

1978 ◽  
Vol 36 (2) ◽  
pp. 168-169
Author(s):  
K. T. Tokuyasu
Keyword(s):  
Surface Tension ◽  
Water Surface ◽  
Thin Layers ◽  
The Other ◽  
Positive Staining ◽  
Frozen Sections ◽  
The Past ◽  
Ultrathin Frozen Sections ◽  
Definition Of

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).

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