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Comparison of Key Characteristics of Remarkable SSW Events in the Southern and Northern Hemisphere. ATMOSPHERE 2020. [DOI: 10.3390/atmos11101063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
An exceptionally strong sudden stratospheric warming (SSW) in the Southern Hemisphere (SH) during September 2019 was observed. Because SSW in the SH is very rare, comparison with the only recorded major SH SSW is done. According to World Meteorological Organization (WMO) definition, the SSW in 2019 has to be classified as minor. The cause of SSW in 2002 was very strong activity of stationary planetary wave with zonal wave-number (ZW) 2, which reached its maximum when the polar vortex split into two circulations with polar temperature enhancement by 30 K/week and it penetrated deeply to the lower stratosphere and upper troposphere. On the other hand, the minor SSW in 2019 involved an exceptionally strong wave-1 planetary wave and a large polar temperature enhancement by 50.8 K/week, but it affected mainly the middle and upper stratosphere. The strongest SSW in the Northern Hemisphere was observed in 2009. This study provides comparison of two strongest SSW in the SH and the strongest SSW in the NH to show difference between two hemispheres and possible impact to the lower or higher layers.
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Varotsos C, Efstathiou M, Christodoulakis J. The lesson learned from the unprecedented ozone hole in the Arctic in 2020; A novel nowcasting tool for such extreme events. JOURNAL OF ATMOSPHERIC AND SOLAR-TERRESTRIAL PHYSICS 2020; 207:105330. [DOI: 10.1016/j.jastp.2020.105330] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Varotsos CA, Krapivin VF. Modeling the state of marine ecosystems: A case study of the Okhotsk Sea. JOURNAL OF MARINE SYSTEMS 2019; 194:1-10. [DOI: 10.1016/j.jmarsys.2019.02.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Varotsos CA, Efstathiou MN, Cracknell AP. Sharp rise in hurricane and cyclone count during the last century. THEORETICAL AND APPLIED CLIMATOLOGY 2015; 119:629-638. [DOI: 10.1007/s00704-014-1136-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Efstathiou MN, Varotsos CA. On the 11 year solar cycle signature in global total ozone dynamics. METEOROLOGICAL APPLICATIONS 2013; 20:72-79. [DOI: 10.1002/met.1287] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Efstathiou MN, Varotsos CA. Intrinsic properties of Sahel precipitation anomalies and rainfall. THEORETICAL AND APPLIED CLIMATOLOGY 2012; 109:627-633. [DOI: 10.1007/s00704-012-0605-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Varotsos CA, Cracknell AP, Tzanis C. The exceptional ozone depletion over the Arctic in January–March 2011. REMOTE SENSING LETTERS 2012; 3:343-352. [DOI: 10.1080/01431161.2011.597792] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Varotsos C, Tzanis C. A new tool for the study of the ozone hole dynamics over Antarctica. ATMOSPHERIC ENVIRONMENT 2012; 47:428-434. [DOI: 10.1016/j.atmosenv.2011.10.038] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Varotsos C, Cracknell A, Tzanis C. Major atmospheric events monitored by deep underground muon data. REMOTE SENSING LETTERS 2010; 1:169-178. [DOI: 10.1080/01431161003680961] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
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Efstathiou MN, Varotsos CA. On the altitude dependence of the temperature scaling behaviour at the global troposphere. INTERNATIONAL JOURNAL OF REMOTE SENSING 2010; 31:343-349. [DOI: 10.1080/01431160902882702] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- M. N. Efstathiou
- a Department of Applied Physics , University of Athens , Panepistimioupolis, PHYS-V, ATH, 157 84, Greece
| | - C. A. Varotsos
- a Department of Applied Physics , University of Athens , Panepistimioupolis, PHYS-V, ATH, 157 84, Greece
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Efstathiou MN, Tzanis C, Varotsos CA. Long-term memory dynamics of total ozone content. INTERNATIONAL JOURNAL OF REMOTE SENSING 2009; 30:3897-3905. [DOI: 10.1080/01431160902821817] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- M. N. Efstathiou
- a Department of Applied Physics , University of Athens , Panepistimioupolis, PHYS-V, ATH 157 84, Greece
| | - C. Tzanis
- a Department of Applied Physics , University of Athens , Panepistimioupolis, PHYS-V, ATH 157 84, Greece
| | - C. A. Varotsos
- a Department of Applied Physics , University of Athens , Panepistimioupolis, PHYS-V, ATH 157 84, Greece
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Tzanis C, Christodoulakis J, Efstathiou M, Varotsos C. Comparison of the Athens Dobson spectrophotometer with World Standard Instruments. INTERNATIONAL JOURNAL OF REMOTE SENSING 2009; 30:3943-3950. [DOI: 10.1080/01431160902822005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- C. Tzanis
- a Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
| | - J. Christodoulakis
- a Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
| | - M. Efstathiou
- a Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
| | - C. Varotsos
- a Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
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Tzanis C, Varotsos CA, Asimakopoulos DN, Cracknell AP. Surface ultraviolet radiation and ozone content in Europe as indicators of environment quality. INTERNATIONAL JOURNAL OF REMOTE SENSING 2009; 30:4123-4143. [DOI: 10.1080/01431160902822856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- C. Tzanis
- a Department of Applied Physics , University of Athens , Panepistimioupolis Build. Phys. 5, Athens, 15784, Greece
| | - C. A. Varotsos
- a Department of Applied Physics , University of Athens , Panepistimioupolis Build. Phys. 5, Athens, 15784, Greece
| | - D. N. Asimakopoulos
- a Department of Applied Physics , University of Athens , Panepistimioupolis Build. Phys. 5, Athens, 15784, Greece
| | - A. P. Cracknell
- b Division of Electronic Engineering and Physics , University of Dundee , Dundee, DD1 4HN, Scotland, UK
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Varotsos CA, Milinevsky G, Grytsai A, Efstathiou M, Tzanis C. Scaling effect in planetary waves over Antarctica. INTERNATIONAL JOURNAL OF REMOTE SENSING 2008; 29:2697-2704. [DOI: 10.1080/01431160701767559] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- C. A. Varotsos
- a Department of Applied Physics , University of Athens , Panepistimiopolis, Athens 15784, Greece
| | - G. Milinevsky
- b Department of Astronomy and Space Physics , National Taras Shevchenko University of Kyiv , Kyiv, 03680 MSP, Ukraine
| | - A. Grytsai
- b Department of Astronomy and Space Physics , National Taras Shevchenko University of Kyiv , Kyiv, 03680 MSP, Ukraine
| | - M. Efstathiou
- a Department of Applied Physics , University of Athens , Panepistimiopolis, Athens 15784, Greece
| | - C. Tzanis
- a Department of Applied Physics , University of Athens , Panepistimiopolis, Athens 15784, Greece
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Tzanis C, Varotsos CA. Tropospheric aerosol forcing of climate: a case study for the greater area of Greece. INTERNATIONAL JOURNAL OF REMOTE SENSING 2008; 29:2507-2517. [DOI: 10.1080/01431160701767575] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- C. Tzanis
- a Department of Energy Technology , Technological Education Institute of Athens , Ag. Spyridonos Str., 12210, Athens, Greece
| | - C. A. Varotsos
- b Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
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Varotsos C, Tzanis C, Tsitomeneas S, Assimakopoulos M, Mammis A. Surface solar ultraviolet irradiance and total ozone during summertime. INTERNATIONAL JOURNAL OF REMOTE SENSING 2008; 29:2667-2673. [DOI: 10.1080/01431160701767567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Affiliation(s)
- C. Varotsos
- a Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
| | - C. Tzanis
- b Department of Energy Technology , Technological Education Institute of Athens , Ag. Spyridonos Str., 12210, Athens, Greece
| | - S. Tsitomeneas
- c Department of Electronics , Technological Education Institution of Piraeus , 250 Thivon & P. Ralli, Aigaleo‐12244, Greece
| | - M‐N. Assimakopoulos
- a Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
| | - A. Mammis
- a Department of Applied Physics , University of Athens , Panepistimiopolis Build. Phys. 5, 15784, Athens, Greece
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Heinrich A. Analysis of the Trend and Seasonal Cycle of Carbon Monoxide Concentrations in an Urban Area (4 pp). ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2007; 14 Suppl 1:19-22. [PMID: 21959536 DOI: 10.1065/espr2006.09.342] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2005] [Accepted: 09/13/2006] [Indexed: 05/31/2023]
Abstract
BACKGROUND, AIM AND SCOPE Air quality is an field of major concern in large cities. This problem has led administrations to introduce plans and regulations to reduce pollutant emissions. The analysis of variations in the concentration of pollutants is useful when evaluating the effectiveness of these plans. However, such an analysis cannot be undertaken using standard statistical techniques, due to the fact that concentrations of atmospheric pollutants often exhibit a lack of normality and are autocorrelated. On the other hand, if long-term trends of any pollutant's emissions are to be detected, meteorological effects must be removed from the time series analysed, due to their strong masking effects. MATERIALS AND METHODS The application of statistical methods to analyse temporal variations is illustrated using monthly carbon monoxide (CO) concentrations observed at an urban site. The sampling site is located at a street intersection in central Valencia (Spain) with a high traffic density. Valencia is the third largest city in Spain. It is a typical Mediterranean city in terms of its urban structure and climatology. The sampling site started operation in January 1994 and monitored CO ground level concentrations until February 2002. Its geographic coordinates are W0º22'52\ N39º28'05\ and its altitude is 11 m. Two nonparametric trend tests are applied. One of these is robust against serial correlation with regards to the false rejection rate, when observations have a strong persistence or when the sample size per month is small. A nonparametric analysis of the homogeneity of trends between seasons is also discussed. A multiple linear regression model is used with the transformed data, including the effect of meteorological variables. The method of generalized least squares is applied to estimate the model parameters to take into account the serial dependence of the residuals of this model. This study also assesses temporal changes using the Kolmogorov-Zurbenko (KZ) filter. The KZ filter has been shown to be an effective way to remove the influence of meteorological conditions on O3 and PM to examine underlying trends. RESULTS The nonparametric tests indicate a decreasing, significant trend in the sampled site. The application of the linear model yields a significant decrease every twelve months of 15.8% for the average monthly CO concentration. The 95% confidence interval for the trend ranges from 13.9% to 17.7%. The seasonal cycle also provides significant results. There are no differences in trends throughout the months. The percentage of CO variance explained by the linear model is 90.3%. The KZ filter separates out long, short-term and seasonal variations in the CO series. The estimated, significant, long-term trend every year results in 10.3% with this method. The 95% confidence interval ranges from 8.8% to 11.9%. This approach explains 89.9% of the CO temporal variations. DISCUSSION The differences between the linear model and KZ filter trend estimations are due to the fact that the KZ filter performs the analysis on the smoothed data rather than the original data. In the KZ filter trend estimation, the effect of meteorological conditions has been removed. The CO short-term component is attributable to weather and short-term fluctuations in emissions. There is a significant seasonal cycle. This component is a result of changes in the traffic, the yearly meteorological cycle and the interactions between these two factors. There are peaks during the autumn and winter months, which have more traffic density in the sampled site. There is a minimum during the month of August, reflecting the very low level of vehicle emissions which is a direct consequence of the holiday period. CONCLUSIONS The significant, decreasing trend implies to a certain extent that the urban environment in the area is improving. This trend results from changes in overall emissions, pollutant transport, climate, policy and economics. It is also due to the effect of introducing reformulated gasoline. The additives enable vehicles to burn fuel with a higher air/fuel ratio, thereby lowering the emission of CO. The KZ filter has been the most effective method to separate the CO series components and to obtain an estimate of the long-term trend due to changes in emissions, removing the effect of meteorological conditions. RECOMMENDATIONS AND PERSPECTIVE . Air quality managers and policy-makers must understand the link between climate and pollutants to select optimal pollutant reduction strategies and avoid exceeding emission directives. This paper analyses eight years of ambient CO data at a site with a high traffic density, and provides results that are useful for decision-making. The assessment of long-term changes in air pollutants to evaluate reduction strategies has to be done while taking into account meteorological variability.
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Affiliation(s)
- Almut Heinrich
- Scientific Journals, ecomed publishers, 86899, Landsberg, Germany,
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Varotsos C. The extraordinary events of the major, sudden stratospheric warming, the diminutive antarctic ozone hole, and its split in 2002. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2004; 11:405-411. [PMID: 15603531 DOI: 10.1007/bf02979661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
GOAL, SCOPE AND BACKGROUND Great interest in the unprecedented events of the major, sudden stratospheric warming and the ozone hole split over Antarctica in September 25, 2002 motivates a necessity to analyze the current understanding on the dynamics, chemistry and climate impacts that are associated with both events. METHODS Significant progress in the analysis of the observational data obtained, as well as successful development and application of dynamical modeling, which have been achieved very recently, create a basis for the first survey on the role of the major, sudden stratospheric warming observed in the southern hemisphere and its relationship to the diminutive Antarctic ozone hole and its break up into two parts. RESULTS AND DISCUSSION Special attention has been paid to assessments of the causes of the major warming event and the future expectations concerning the stratospheric ozone depletion effect. Among the principal results is the fact that, as the polar vortex elongated, it became hydrodynamically unstable, and this insta-, bility affected the upper troposphere and stratosphere. During the major, sudden stratospheric warming, the middle stratospheric vortex split into two pieces; one piece rapidly mixed with extra vortex air, while the other returned to the pole as a much weaker and smaller vortex. The polar night jet was considerably weaker than normal, and was displaced more poleward than has been observed in previous winters, resulting from a series of wave events (propagated from the troposphere) that took place over the course of the winter. Finally, the relative ozone decrease (increase) in the eastern Antarctic is tightly associated with westerly (easterly) zonal wind anomalies near the southern tip of South America, and the unusual behavior of the ozone hole in 2002 therefore appears to be caused by great easterlies in this region. CONCLUSIONS The main conclusion is that the southern polar vortex and the diminutive ozone hole split into two parts in September 2002, due to the prevalence of very strong planetary waves, led to the appearance of a major, sudden stratospheric warming. Although there is evidence that sea surface temperature anomalies contributed to the excitation of the quite strong planetary waves over Antarctica in 2002, there is not yet a widely approved mechanism supporting that. RECOMMENDATIONS AND OUTLOOK The appearance of the near-record size of the 2003 ozone hole confirmed that the 'no-ozone-hole' episode observed in the year 2002 does not denote a recovery of the ozone layer. Despite the current successful attempts to get a sufficient understanding for the genesis of both extraordinary events, more observations and further modeling efforts are necessary to more reliably assess the contribution of various dynamic mechanisms to the recently observed tropo-stratospheric surprises.
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Affiliation(s)
- Costas Varotsos
- University of Athens, Department of Applied Physics, Panepistimiopolis, GR-157 84 Athens, Greece.
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