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A role of multi-decadal natural variability in forming weather and climate anomalies in Russia Major results in 2012 WP 5 Regional Projections of Extreme.

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Presentation on theme: "A role of multi-decadal natural variability in forming weather and climate anomalies in Russia Major results in 2012 WP 5 Regional Projections of Extreme."— Presentation transcript:

1 A role of multi-decadal natural variability in forming weather and climate anomalies in Russia Major results in 2012 WP 5 Regional Projections of Extreme Events Vladimir A. Semenov Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012

2 Outline ● Recent harsh winters as a consequence of the Arctic sea ice melt ● Impact of Atlantic Multidecadla Variability on weather and climate ● Simulation of the hypothetical Gulfstream shutdown ● Winter Arctic Sea ice and the Early 20 th Century Warming ● Projections of regional climate changes (CMIP5 models) ● Impact of model resolution on daily precipitation statistics Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012

3 Harsh winters of the 21 st century: Anomalously cold monthly temperature after a period of mild winters in 1980s and 1990s Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December period Hamburg “cold yrs” < 0 °C Moscow “cold yrs” < -9 °C NpNp (11)2 (3)0.25 (0.33)3 (4)0.36 (0.44)

4 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 SAT anomaly, KSLP anomaly, hPa Previously, using idealized simulations with an AGCM, it was found that anti-cyclonic atmospheric circulation response can be caused by reduced sea ice anomalies in the Barents and Kara Seas (Petoukhov and Semenov 2010) Can it be reproduced by using realistic sea ice anomalies? Harsh winters of the 21 st century: The most recent example of winter 2012

5 Modeling climate response to the sea ice changes corresponding to the recent extremes of the Atlantic Multidecadal Variability Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 SST anomalies in the NA (40N-60N)SST and SIC changes ( )-( ) Experimental setup

6 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Sea ice impact on circulation and temperature Sea ice reduction in the Atlantic sector of the Arctic leads to the temperature decrease due to anti-cyclonic circulation anomaly centered in the southern border of the Barents Sea (Semenov et al. 2012, FAO) winter 2012 Modeling climate response to the sea ice changes corresponding to the recent extremes of the Atlantic Multidecadal Variability winter SATwinter SLP

7 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Modeling climate response to the sea ice changes corresponding to the recent extremes of the Atlantic Multidecadal Variability Changes in probability of the anomalously cold februaries, in % (SAT less than 1.5 standard deviation)

8 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Realistic sea ice experiments: sea ice vs NAO ECHAM5-T42L19/fixedSST-SIC run781: SIC, SST : high ice, very low NAO, cold winters run782: SIC, SST : low ice, very high NAO, warm winters run783: SIC, SST : very low ice, low NAO, cold winters

9 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Realistic sea ice experiments: sea ice vs NAO NCEP Jan SLP change ( )-( ) Realistic sea ice experiments: Feb SLP change SIC ( )-( ) No significant response to sea ice change from to “Anti-cyclonic” response to sea ice changes from to similar to observations (although seasonally shifted) Semenov et al. (in preparation)

10 Impact of Atlantic Multidecadal Variability on weather and climate (work with Evgeniya Shelekhova) Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 ?

11 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of Atlantic Multidecadal Variability on weather and climate Experimental setup: Atmospheric GCM ECHAM5 coupled with mixed layer ocean model with additional Q-fluxes corresponding to Atlantic Multidecadal Variability ATLICEATLICEx2 ATLICE

12 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of Atlantic Multidecadal Variability on weather and climate Winter SLP changes, hPa ATLICEATLICEx2 ATLICE Atmospheric circulation response depends on both the amplitude and location of the additional heating. It is heat flux that is associated with sea ice changes that produces NAO-like response.

13 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of Atlantic Multidecadal Variability on weather and climate Change in probability of anomalously cold Februaries (colder than -1.5 standard deviation, in %) AMV may lead to increased probabilities of the cold winter months in large regions of Russia, in particular in European part. The increase is likely due to Arctic sea ice loss associated with the AMV. ATLICEATLICEx2 ATLICE

14 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of Atlantic Multidecadal Variability on weather and climate Experimental setup: Atmospheric GCM ECHAM5 coupled with mixed layer ocean model with additional Q-fluxes corresponding to Atlantic Multidecadal Variability The additional flux is time-varying with periodicity of 60 years Experiments: 1. ATLICEx2 flux, 60 years period 2. ATLICE flux, 60 years period 3. ATLICE flux, 40 years period

15 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of Atlantic Multidecadal Variability on weather and climate Implications for the Caspian Sea level variations Annual temperature regression on the anomalous Q-fluxes (°С / 0.1PW) Correlation and regression of annual precipitation with anomalous Q-fluxes (0.1mm / day / 0.1PW) correlation regression Volga River discharge (km 3 /year) as simulated and observed AMV can be an important factor for the Caspian Sea level variations Impact of Atlantic Multidecadal Variability on Caspian Sea level, Semenov et al., EGU 2012

16 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 The “Day after Tomorrow” revisited: Simulation of the hypothetical Gulfstream shutdown After a possibility of the Atlantic Meridional Overturning shutdown due to global warming with a threat of new Ice Age was disproved some years ago, recently, another media event has happened: Gulf of Mexico Oil Spill in spring Loop Current breaks, Gulfstream stops, Europe freezes and suffer from extremes.

17 Annual oceanic heat transport (Q-flux in the MLO model), W/m 2 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Simulation of the hypothetical Gulfstream shutdown Deviation of surface temperature from zonal means, K

18 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Simulation of the hypothetical Gulfstream shutdown Simulated January temperature change, K Atlantic sector Barents Sea January 2006 Zuev, Semenov, Shelekhova, Gulev, Koltermann, 2012, Doklady Earth Sciences

19 Winter Arctic Sea ice and the Early 20th Century Warming Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 There is a clear disagreement between temperature and sea ice HadISST1 data in the Arctic in before 1960s. Using AGCM with prescribed boundary conditions (sea ice and SST) allows us to evaluate temperature sensitivity to sea ice and estimate Arctic sea ice anomaly in the Early 20 th century Warming period Semenov, Latif, 2012, TC

20 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Winter Arctic Sea ice and the Early 20th Century Warming Difference between observed and simulated (HadISST1 ice data) Arctic land winter (November-April) temperatures, °C 0.8 млн км 2 Negative Arctic sea ice anomaly in the ETCW period is comparable to the current sea ice decrease

21 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Projections of regional climate changes Using data of 9 CMIP5 models, monthly mean temperature and precipitation, daily max and min temperature has been analyzed in simulations employing moderate climate change scenario RCP4.5. Annual SAT (°C) for Sochi region as simulated by 9 CMIP5 models in the 21 st century Ensemble mean (for 9 CMIP5 models) annual SAT (°C) for Sochi region in the 21 st century. Dashed area represents 95% confidence interval

22 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Projections of regional climate changes Same as in the previous slide but for precipitation, mm/day winterspring summerfall

23 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Projections of regional climate changes Ensemble mean annual precipitation trends and their uncertainty Trend, mm/day per 100 yr Inter-ensemble STDDEV, mm/day per 100 yr

24 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of model resolution on daily precipitation statistics What is the impact of the climate model resolution on the results we use for climate change assessments? T31T42 T63T106 T159T213

25 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of model resolution on daily precipitation statistics Summer mean precipitation, mm/daySummer rain intensity, mm/day

26 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Impact of model resolution on daily precipitation statistics Impact on extremes 20-yr return values of daily precipitation in the Gelendzhik region, mm/day as a fuction of model resolution (in degrees lat/lon)

27 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Major conclusions  Recent anomalously cold winters can be a consequence of the Arctic sea ice loss. Winter sea ice retreat plays the major role in forming anti- cyclonic atmospheric circulation anomaly leading to cold events.  Accelerated winter Sea ice loss may be linked to the Atlantic Multidecadal Variability.  Atlantic Multidecadal Variability (AMV) plays important role for climate change over Eurasia, it can be responsible for about a half of the observed climate change in the last 3-4 decades.  AMV impacts not only mean climate characteristics but also extreme events.  Global climate model projections on a regional scale have a very large spread and should be treated with caution.  To resolve regional peculiarities related to complex orography and coastal line, a higher spatial resolution is required than that provided by current generation of global climate models.

28 Спасибо за внимание! Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012

29 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012 Publications 2012 Refereed journals Зуев В.В., Семенов В.А., Шелехова Е.А., Гулев С.К., Колтерманн П. Оценки влияния океанического переноса тепла в Северной Атлантике и в Баренцевом море на климат Северного полушария // Доклады РАН Т № 5. С. 585–589. Семенов В.А., Мохов И.И., Латиф М. Влияние температуры поверхности океана и границ морского льда на изменение регионального климата в Евразии за последние десятилетия. // Изв. РАН Физика атмосферы и океана Т. 48. №4. С Semenov V.A., Latif M. The early twentieth century warming and winter Arctic sea ice // The Cryosphere V6. Doi: /tc Conferences Semenov, V.A., Mokhov, I.I., Latif, M. and K.P. Koltermann (2012) Impact of Atlantic Multidecadal Variability on Caspian Sea level, EGU General Assembly 2012, Geophysical Research Abstracts, Vol. 14, EGU Semenov, V.A. and M. Latif (2012) The early twentieth century warming and winter Arctic sea ice, EGU General Assembly 2012, Geophysical Research Abstracts, Vol. 14, EGU

30 Natural Risks Assessment Laboratory NRAL Conference, Moscow, 14 December 2012


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