Coupling of the polar stratosphere and mesosphere during stratospheric sudden warmings - Relevance for solar-terrestrial coupling -

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1 Coupling of the polar stratosphere and mesosphere during stratospheric sudden warmings - Relevance for solar-terrestrial coupling - Yvan J. Orsolini NILU - Norwegian Institute for Air Research and Birkeland Centre for Space Science, University of Bergen, Norway Varavut Limpasuvan, Olga Tweedy Coastal Carolina University, South Carolina, USA Doug Kinnison NCAR, Colorado, USA

2 Satellite observations of NO x mesospheric descent: 1. ACE Capturing the wintertime mesospheric descent of NOx in polar regions is a key aspect to modelling the EPP indirect effect in the stratosphere Inter-annual variability in the NH winter linked to stratospheric sudden warmings (SSW) and elevated stratopause events (ESE) Strong descent of NO x -rich air during 2004, 2006 and 2009 Strong descent after early winter SSWs (Orsolini et al., JGR, 2010; Holt et al, JGR 2013) ACE satellite obs. of NO x See: Randall, C.E., V.L. Harvey, G.L. Manney, Y. J. Orsolini, M. Codrescu, C. Sioris, S. Brohede and C. Haley, L.L. Gordley, J.M. Zawodny and J.M. Russell III, Stratospheric effects of energetic particle precipitation in , Geophys. Res. Lett., 32, No. 5, L05802, doi: /2004gl022003, Randall et al., Geophys. Res. Lett., 2009.

3 Temperature ~ 90km 2007/2008 NO (ppb) 2. Odin-SMR more recent years ~ 40km 2008/ / /2011 strong descent after elevated stratopause events (ESEs) 2011/ /2013 (70-90 N) Nov Dec Jan Feb Mar Nov Dec Jan Feb Mar From Perot K. et al., ACP, 2014

4 (70-90 N) 2007 / 2008 H 2 O 2008 / Odin-SMR more recent years ~ 90km 1 Nov > 1 May 2009 / / 2011 ~ 40km Anomalous descent of mesospheric dry air into the stratosphere following ESE / / 2013 ppmv 2013 / ppmv Orsolini, Y.J., J. Urban, D. Murtagh, S. Lossow, V. Limpasuvan, J. Geophys. Res., 115, D12305, 2010 Perot K., et al., ACP 2014.

5 Stratospheric sudden warmings and ESEs Zonal Mean Temperature [T] Vortex s Edge Zonal Mean Zonal Wind [u] Thermosphere Mesosphere Stratosphere Summer Winter Summer Winter Troposphere Strong SSWs associated large displacement of stratopause and its reformation at mesospheric heights Perturbation of the «layered» temperature structure SSWs impact on the whole middle/upper atmosphere: strat warming, mesospheric cooling, thermospheric warming, ionosphere impacts

6 Observed Elevated Stratopause Event (ESE) in 2012/13 Plunging of polar stratopause down to 30km Aura MLS Satellite Observations Re-formation of elevated stratopause near 75km SSW on 6 JAN 2013 Temperature Geostrophic Zonal Wind t=0: day of [U] reversal at 50km

7 Whole-Atmosphere chemistry-climate model WACCM with Specified Dynamics (WACCM-SD) Whole-Atmosphere Community-Climate Model (ground to ~140 km), developed at NCAR (Colorado) Comprehensive chemistry-climate model with stratospheric chemistry, gravity wave parametrization, some MLT processes WACCM-SD (Specified Dynamics) : Nudged winds and temperature with NASA MERRA Re-Analyses up to 55 km (realistic meteorology in stratosphere, to look at real events in calendar year) Free-running above 60 km Runs for 2012/13 event : 3-hourly output Enhanced vertical diffusion in MLT

8 Recent studies on ESEs using WACCM or WACCM_SD - Such ESEs events are fairly well represented in WACCM - Role of gravity wave vs planetary wave forcings in case studies of ESEs in WACCM Limpasuvan, Richter, Orsolini, Kvissel, Stordal, JASTP2012 (Special Issue MLT) Variability in minor constituents like CO or O 3 in case studies of ESEs in WACCM Kvissel, Orsolini, Stordal, Limpasuvan and Marsh et al, JASTP2012 (Special Issue MLT) Enhancement in 2nd O 3 layer during ESEs in WACCM_SD Tweedy, O., V. Limpasuvan,Y. J. Orsolini, A. K. Smith, R. R. Garcia, D. Kinnison,C. E. Randall, O.-K. Kvissel, F. Stordal, V. L. Harvey and A. Chandran, Nighttime secondary ozone layer during major stratospheric sudden warmings in specified-dynamics WACCM, JGR, Gravity waves - Planetary waves in MLT during ESEs: Comparison with radar Stray, Orsolini, Espy, Hibbins, Limpasuvan, Comparisons with SuperDARN winds during ESEs, in ACPD 2014 De Wit, Hibbins, Espy, Orsolini, Limpasuvan, Kinnison, ESE in 2012/13 in meteor radar observations, GRL July, 2014 Other papers at NCAR : ESE characteristics in WACCM De La Torre et al., JGR, 2012, Chandran et al., JGR 2013 ESE in 2012 in WACCM_SD Chandran et al., GRL, 2013 ESEs and NOx descent Holt et al., JGR 2013

9 Modelled Elevated Stratopause Event (ESE) in 2012/13 U T C W* brief mesospheric cooling and ascent around reversal date followed by elevated stratopause around 2 weeks later Polar cap average

10 Modelled ESE in 2012/13: total wave forcing forcing of the mean meridional residual circulation Gravity Waves (non-orographic) Planetary Waves (EP flux divergence) Reversed (eastward forcing): ascent Planetary Waves appear in MLT Limpasuvan, Richter, Orsolini, Kvissel, Stordal, JASTP2012

11 Gravity wave forcing in 2012/2013 : comparison with radar observations above Trondheim (Norway) (Parameterized) local GWF in WACCM_SD compares well with radar observations ( km) Peak eastward forcing around reversal time of ESE See: De Wit, R. J., R. E. Hibbins, P. J. Espy, Y. J. Orsolini, V. Limpasuvan, and D. Kinnison, 2014: Observations of gravity wave forcing of the mesopause region during the January 2013 major Sudden Stratospheric Warming, Geophysical Research Letters, 41, doi: /2014gl

12 Modelled ESE in 2012/13: O 3, NO x & CO W* Enhancement in 2 nd O 3 layer O 3 NO x CO Enhanced vertical diffusion

13 Composite of 13 ESEs in WACCM_SD: descent, O 3, NO x & CO W* O 3 NO x CO

14 2 nd O 3 layer 3 rd O 3 layer Main O 3 layer ESEs: origin of peak in mesospheric O 3 Cold Low H Warm High H ********* Stratopause (Polar average) 2 nd O 3 layer O 3 anti-correlated with Temperature ppmv O 3 :Chemical equilibrium Short Chem. Lifetime w* (mm/s) Source: O & O2 Sink: O & H Main sink is H

15 Modelled ESE in 2012/13 : origin of peak in mesospheric O 3 O (/1E3 ppmv) T (K) O 3 (ppmv) H (x10 ppmv) 97 km 15 JAN 2013 Cause of the O 3 peak: cold anomaly and low H

16 2 nd O 3 layer : peak during elevated stratopause events Main finding : Top of mesospheric ascent cooling and low H, favouring high O 3 Tweedy, O., V. Limpasuvan,Y. J. Orsolini, A. K. Smith, R. R. Garcia, D. Kinnison,C. E. Randall, O.-K. Kvissel, F. Stordal, V. L. Harvey and A. Chandran (2013), Nighttime secondary ozone layer during major stratospheric sudden warmings in specifieddynamics WACCM, J. Geophys. Res. Atmos., 118, doi: /jgrd

17 Meridional wind 48N-65N Planetary waves in MLT during ESEs (WACCM_SD composites) PW1 ESE MLT PWs At onset of ESEs Distinct from upwardpropagating PWs causing the SSWs PW2 Confirmation of such PWs SuperDarn radar data (near 97km) PW 1+2 Stray, Orsolini, Espy, Hibbins, Limpasuvan, Observations of PW activity in the MLT during SSW events using a chain of SuperDARN radars and SD-WACCM, ACPD 2014

18 Modelled ESE in 2012/13: Qualitative comparison with satellite observations of NO WACCM_SD ESE From Perot et al., ACPD, N-90N SMR Enhanced vertical diffusion 100 Obs: ppb Model: 5-10 ppb SOFIE From Bayley., et al., GRL 2014 (near 70N)

19 Older WACCM_SD (No Enhanced vertical diffusion) NO x SPEs (DIRECT EFFECT) SPEs clear Nox enhancements Bastille Nov 2001 Major SPEs Mesospheric descent Halloween Jan 2005 Mesospheric descent (INDIRECT EFFECT) Despite the ESE being wellrepresented (see composites) Not bringing down enough Nox into stratosphere stratopause

20 CONCLUSIONS ESEs and in particular the 2012/13 event well-captured by WACCM_SD PWs in the MLT region at onset of ESEs are important to initiate stratopause descent Origin of O 3 enhancement at onset of ESEs (cooling, low H) NO x transport into the stratosphere is still much weaker than observed during the ESE 2012/13 event, despite increased MLT diffusion Further causes for this deficiency are going to be examined: Downward residual circulation : not reaching high enough into NOx reservoir or too weak (?) FURTHER WORK WITH WACCM Representation of energetic electron precipitation at medium and high energies

21 RESERVE SLIDES

22 Chemical equilibrium: Case of JAN 2010 [ O 3 ] = k [ O][ O ] n 1 2 k [ O] + k [ H ] 2 where k 1, k 2, k 3 are reaction rates, and n is the background number density 3 H O T Time series of zonal-mean variables averaged from 70N-90N w* 97 km (solid line) and 80 km (dotted line) Volume mixing ratio of O is scaled by w* T H O 97 km nighttime O 3

23 Descent of CO during an ESE (WACCM) 50km CO winter descent interrupted by ESE stratopause drop In WACCM : CO descent during ESEs works, but not NO x Formation of a CO drop in stratosphere i.e. CO-rich air of mesospheric origin isolated in the midstratosphere at 60N Kvissel, Orsolini et al, JASTP km