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The prediction of equatorial total ozone up to the end of 2018 basing on the

The prediction of equatorial total ozone up to the end of 2018 basing on the exact seasonal synchronization of the quasi-biennial oscillation (QBO) of equatorial stratospheric zonal wind Irina P. Gabis and Oleg A. Troshichev. Arctic and Antarctic Research Institute St. Petersburg.

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The prediction of equatorial total ozone up to the end of 2018 basing on the

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  1. The prediction of equatorial total ozone up to the end of 2018 basing on the exact seasonal synchronization of the quasi-biennial oscillation (QBO) of equatorial stratospheric zonal wind Irina P. Gabis and Oleg A. Troshichev Arctic and Antarctic Research Institute St. Petersburg

  2. QBO affects the atmosphere globally polar stratospheric warmings trace gas distribution meridional circulation equatorialQBO modulation of solar activity effects atmosphericozonelayer ……… Antarctic ozone hole QBO influence on the weather and climate motivates the prediction ofQBO cycle evolution

  3. Long-term prediction is based on the exact seasonal synchronization of the QBO 1. Easterly descends with stagnationin each QBO cycle. 2. Stagnation starts always near solstice and ends always near equinox.

  4. Quasi – Biennial Oscillation (QBO) is a quasi-periodic alternation of zonal wind direction in the tropical stratosphere as a consequence of descent of EASTERLY and WESTERLY wind regimes in a layer from ~16 to ~50 km. Time–height section of zonal winds (m/s) at the equatorial stations for 1993 - 2008; westerlies are shaded. http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo/index.html Freie Universität Berlin,Department of Earth Sciences, Institute of Meteorology, Physics of the Middle Atmosphere • Accordingtocommon belief: • QBO period varies from cycle to cycle in range from 17 to 38 months, mean QBO period is ~28 months; • There is only some tendency for the QBO-phase changes to occur in specific seasons – “seasonal modulation”; • The predictability of the QBO is reduced due to the unpredictableEASTERLY delaysin a layer20–25km (40 –50 hPa); • QBO of zonal wind can be accurately predicted for several months in advance.

  5. Analysis of the height profiles of wind speed using the measurements at equatorial stations for pressure levels from 70 to 10 hPa (~ 16-31 km) in 1953-2015. The Quasi-Biennial-Oscillation (QBO) Data Serie http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo/index.html Freie Universität Berlin,Department of Earth Sciences,Institute of Meteorology, Physics of the Middle Atmosphere U > 0 m/s:Westerly U < 0 m/s:Easterly

  6. Easterly descent from August 2006 to August 2007 Easterly descentstops at P ~28 hPa. The stagnation lasts one seasonfrom December 2006 to March 2007. Easterly descends in August 2006 - December 2006. The lowest pressure level P of easterly decreasesfrom10 hPa to ~28 hPa. Easterly descent is resumed after March 2007. The pressure level decreases from~29 hPa in March 2007 to ~70 hPa in August 2007. From January 1953 to February 2015 27 events of easterly wind regime descent from ~10 to ~70 hPa were observed. The stagnation of easterly downward propagation (marked by yellow) was observed during each QBO cycle, not just occasionally in some QBO cycles, as is commonly believed.

  7. Four types of easterly stagnation SHORT stagnation – one season from solstice to firstequinox. Easterly halts near solstice in December – January and is resumed about equinox in March – April. LONG stagnation – three seasons from solstice to secondequinox Easterly halts near solstice in December – January and is resumed about equinox in September – October. Easterly halts near solsticein June – July and is resumed about equinox in March-April of the next year. Very LONG stagnation – five seasons from solstice to thirdequinox Easterly halts near solstice in December – January and is resumed about equinox in March-April of the next year.

  8. Summary Experimental analysis of the zonal wind changes has shown: 1:The stagnation (delay) during descent of the easterly wind regime is typical feature inherent to eachQBO cycle. 2:The stagnationalways starts near the solstice(in January or July)and always ends in subsequent first, second or thirdequinox(in April or October). 3:As a result, the duration of stagnation turns out to be one, three or five seasons (3, 9 or 15 months). 4.Four types of the easterly stagnationcan be observed (depending on the duration and the time of start/end). 5:The stagnation pressure level varies from ~20 to ~ 40 hPa in different QBO cycles.

  9. Seasonal regularities of the easterlystagnation results in the discretely varying period of the QBO cycle Four types of the easterly stagnation results in four types of the QBO cycle scenario. The length of each QBO cycle is unambiguously associated with duration of the corresponding stagnation Interval between the beginnings of successive stagnations STAGNATION: start in solstice end in equinox Interval between the end of the stagnation and the start of the next stagnation 7seasons April – December 24-monthQBO cycle: start in January end in December 1 season January-March 7seasons October – June 3 seasons January-September 30-month QBO cycle: start in January end in June 3 seasons July-March 7seasons April – December 30-month QBO cycle: start in July end in December 7seasons April – December 5 seasons January-March 36-month QBO cycle: start in January end in December

  10. All QBO cycles of different periods in interval from 1953 to 2018

  11. All QBO cycles of different periods in interval from 1953 to 2014 ElevenQBO cycles of 24-month scenario SixQBO cycles of 30-month scenario (start in January) 30-month QBO cycle, which began in January, is followed, evidently, by the QBO cycle, which began in July. SevenQBO-cycles of 30-month scenario (start in July) Profiles for first, second and third month during each season are shown by bold, dashed and thin lines, respectively. Time periods corresponding to stagnation stage are marked by light yellow fill. 36-month QBO cycles are not shown.

  12. The average patterns of the wind structure evolution for QBO cycles of different periods The mean height wind profiles typical of different QBO scenarios have been derived. Each group of three profiles shows the changes during a single season, the standard error of the mean value being shown by a horizontal line at each altitude along the profiles. Stagnation stage Intervals are marked by lightyellow. FORECAST The mean wind profiles are used as a base for prediction of the QBO cycle evolution and times of changes of QBO phase at different pressure levels. The stagnation stage is identified by a steady halt in descent of EASTERLY. Stagnation stage length plus the seven-season interval determine the QBO-cycle duration. THE METHOD WAS VERIFIED FOR QBO CYCLES PROCEEDED IN 2005-2014.

  13. Verification of the previous forecasts. Black profiles are those that werepredicted, red profilesare the really observed profiles. Wind profiles for period from January 2005 to December 2006. QBO-cyclewas developed according to 24-month scenario and completed in December 2006.The next QBO cycle should start in January 2007 (Gabis, I.P., Troshichev, O.A., J. Atmos. Sol. Terrestrial Phys. v.68. pp.1987-1999.2006). Wind profiles for period from January 2007 to December 2008. QBO-cyclewas developed according to 24-month scenario and completed in December 2008.The next QBO cycle should start in January 2009 (Gabis, Troshichev, in: Wang, P. (Ed.), Solar Physics Research Trends. Nova Science Publishers, Inc., New York, 165-194, 2008).

  14. Verification of the previous forecasts. Black profiles are those that werepredicted, red profilesare the really observed profiles. Wind profiles for period from January 2009 to June 2011. QBO-cyclewas developed according to 30-month scenario and completed in June 2011.The next QBO cycle should start in July 2011 (Gabis, I.P., Troshichev, O.A., Geomagnetism and Aeronomy. v.51. 501-512, 2011). Wind profiles for period from July 2011 to December 2013. QBO-cyclewas developed according to 30-month scenario and completed in December 2013.The next QBO cycle should start inJanuary 2014 (Gabis, I.P., J. Atmos. Sol. Terrestrial Phys. v.80. 79-91. 2012).

  15. Verification of the previous forecasts shows a very well agreement between the predicted and really observed variations Now the prediction is possible up to the end of 2018

  16. Forecast of the next QBO cycle onset based on the observed duration of the stagnation If the stagnation, starting in January, is not completed in 3 months, the forecast is real for two subsequent QBO cycles, i.e. for 5 years in advance (since the OBO cycles starting in July always last 30 months). After the onset of 30-month QBO cycle in January 2014 the prediction is possible for the next 5 years The 36-month QBO cycle is apparently anomalous, and its probability is low.

  17. Prediction for thenext two QBO cycles in 2014-2018 Basing on the total regularities of the QBO cycle evolution we predict that: QBO-cycle, starting in January 2014, will last 30 months and will complete in June 2016. QBO-cycle, starting in July 2016, will last 30 months and will complete in December 2018 The predicted wind profiles are marked byblack. The reallyobserved wind profiles in January 2014 - March 2015 are marked by red.

  18. As the next QBO cycle should have started in January 2019, it could develop in two alternative ways: Two options of QBO evolution: (1) 24-month scenario: the stagnation stage terminates in April 2019 and EASTERLY descent lower 40-50 hPa resumes inMay-June 2019; (2) 30-month scenario: the stagnation stage does not terminate in April2019 and EASTERLY descent to 50 hPa is put off until September 2019. Before 24-month QBO cycle the EASTERLY descends more quickly than before 30-month QBO cycle. Consequently, in the end of 2018 the reliable prediction ofQBO cycle evolution will be possible only for the initial part of this cycle – as far as April 2019.

  19. The long-term predictability of QBO in equatorial total ozone (TOZ) In figure: Mean ΔTOZ during QBO cycles of different scenarios. (ΔTOZ – deseasonalized TOZ at latitudes from 5°S to 5°N) The wind QBO affects the ΔTOZ variations in equatorial region: WESTERLY descent associated with growth of ΔTOZ, EASTERLY descent associated with decrease of ΔTOZ The increase phase of ΔTOZ has approximately the same duration in all types of QBO scenarios and continues always within one year. The duration of ΔTOZ decrease phase can be equal to one year or one and half a yeardepending on the sequence of the QBO cycles of different scenarios. The decrease phase of ΔTOZ continues abouthalf a yearin course of the current QBO cycle and later duringhalf a yearor one yearin course of the next 24-month or 30-month QBO cycle, respectively. This is in accordance with the more prolonged stage of stagnation in 30-month scenarios.

  20. Total ozone variations during the sequence of QBO cycles in 1978-2014 Actually observed ΔTOZ changes (5°N-5°S) are shown by black thin line with circles, Mean ΔTOZ variations are shown by thick red and blue lines. The mean ΔTOZ is aligned in agreement with the actually occurred sequence of QBO scenarios. Calculated mean ΔTOZ variations accord well with the experimental ΔTOZ: R=0.83. During series of 24-month QBO cycles the minima and maxima of ozone alternate with one year interval, so the phases of ozone increase and decrease are of the same length. During series of 30-month QBO cycles the increase in ozone continues within a year,butthe decrease continues one and half a year. The forecast of the wind QBO allows a prediction of the QBO related anomalies in total ozone.

  21. Predictionof the total ozoneup to the end of 2018 The mean ΔTOZ variations can be used as empirical model of the ozone QBO in course of the sequenceof different scenario QBO cycles. From January 2014 to June 2016 – 30 month QBO cycle. From July 2016 to December 2018 – 30 month QBO cycle. In January 2019 – the onset of the next QBO-cycle, which can develop in two alternative options: 24-or 30-month QBO scenario.

  22. Predictionof maximum and minimum ΔTOZin 2015-2018 Maximum ΔTOZ – at the end of 2015/beginning of 2016 and in the middle of 2018. Minimum ΔTOZ – at the end of 2014/beginning of 2015 and in the middle of 2017. The next minimum ΔTOZ will be observed in themiddle or at theend of 2019 depending on the type of next wind QBO-scenario.

  23. Predictionof maximum and minimum ΔTOZin 2015-2018 The wind profile changes during last months before 24-month and 30-month QBO-scenarios. Before 24-month QBO-cycle the EASTERLY descends more quickly than before 30-month QBO-cycle. Therefore the decrease of ΔTOZ is faster and minimum of ΔTOZ is observed earlier in 24-month QBO cycle (in the middle2019), than in 30-month QBO cycle (at the end of 2019).

  24. CONCLUSIONS • 1. The EASTERLY wind regime descent demonstrates an invariable relation to seasons: • The EASTERLY halts near the solstice and is resumed in one of subsequent equinoxes. Seasonal attachment of the stagnation causes its discrete length: one, three, or five seasons. • The discrete duration of stagnation predetermines the discreteness of the QBO periods: 24, 30, or 36 months. • 2. The discretely varying length of the EASTERLY stagnation and the discreteness of QBO period cause the quite definite duration of decrease and increase phases of the QBO related anomalies of equatorial total ozone (TOZ). • The increase phase of TOZ has the same duration in all types of QBO scenarios and continues always within a year. • The length of TOZ decrease phase varies discretely and can be equal to one year or one and half a year depending on the sequence of the QBO scenarios. • 3. Seasonal regularity of the EASTERLY descent and arising from it the discreteness of the QBO period makes it possible to forecast the duration of current QBO cycle and the starting date of next QBO cycle. • The technique for prediction of the QBO cycle evolution has been elaborated basing on the wind height profiles data and verified for QBO cycle proceeded during 2005-2014. • 4. Basing on the total regularities of QBO cycle evolution the prediction has been made for the next two QBO cycles in 2014-2018: • The current QBO cycle starting in January 2014 will last 30 months and will end in June 2016. • The subsequent QBO cycle will begin in July 2016 and will complete in December 2018. • Hereafter the next QBO cycle will begin in January 2019, and regular stagnation will continue at least until March-April 2019. • 5. The forecast of the wind QBO provides the ability to predict the QBO related variations of equatorial total ozone up to the end of 2018: • Maximum TOZ will be observed at the end of 2015/beginning of 2016 and in the middle of 2018, • Minimum TOZ will be observed at the end of 2014/beginning of 2015 and in the middle of 2017. • The next minimum TOZ will be observed in the middle or at the end of 2019 depending on the type of next wind QBO scenario.

  25. Questions At present the questions remain open: (1) what causes the stagnation during each easterly wind regime descent? (2) why are the stagnations with beginning in July always long? (3) what is the reason of two alternative durations (long or short) of stagnations with beginning in January? The additional investigations are necessary to further elucidate the physical mechanism of the stagnation in course of the easterly wind regime descent.

  26. The occurrence of short and long stagnations (and, correspondingly, 24- , 30- and 36-month cycles) with respect to the phase of the 11-year solar cycle contradicts the conclusion about the relationship of the QBO period with the11-year cycle (correlation and anticorrelation)

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