Mado Observatory Summer School Alain Hauchecorne - PowerPoint PPT Presentation

È È È È ­ ï ­ ­ ’ è ’ è é ‐ ­ ï ­ ­ ’ è ’ è é Maïdo Observatory Summer School ‐ é é ‐ ‐ é é Alain Hauchecorne LATMOS-IPSL, UVSQ, CNRS – alain.hauchecorne@latmos.ipsl.fr – é é ’ è é é é é ‐ ’ è ’ è é é é ‐ Middle atmosphere dynamics ’ è é é é ‐ ‐

The middle atmosphere Middle atmosphere = stratosphere + mesosphere, 12 to 90 km

The middle atmosphere Middle atmosphere = stratosphere + mesosphere, 12 to 90 km

From Haynes, 2004

From Haynes, 2004

Middle atmosphere radiative balance and general circulation

Observed zonal averaged temperature Cold Warm Polar day Polar night Brasseur and Solomon, 2005; based on Fleming et al., 1998

Radiative equilibrium temperat ure Cold Warm Polar night Polar day Brasseur and Solomon, 2005; calculated by Fels, 1985

Adiabatic heating/cooling in the atmosphere

Net adiabatic heating rate (K/day) Cooling Heating Polar day Polar night Brasseur and Solomon, 2005; from London, 1980

Residual circulation Diabatic heating (cooling)  vertical ascent (descent) of air Continuity equation  meridional wind Polar day Polar nigh t

Zonal wind: the geostrophic approximation Coriolis force equilibrates Pressure gradient force Coriolis force = 2 w sin(latitude) w : Earth rotation rate Wind blows around depression - anticlockwise in Northern Hemisphere - clockwise in Southern Hemisphere

Zonal wind Polar day Polar night Brasseur and Solomon, 2005; based on Fleming, 1988

Antarctic polar vortex evolution 1996 UKMO analysis

Atmospheric waves in the atmosphere Transport energy, momentum flux and atmospheric constituants Different kinds of waves: - planetary waves: global scale - gravity waves: local scale - atmospheric tides: global scale, diurnal period, solar heating of stratospheric ozone and tropospheric water vapour

Planetary Rossby waves Meridional gradient of Coriolis force Hemispheric extension Upward propagation possible only if zonal wind > 0 (winter conditions in the stratosphere) Interaction with zonal wind: stratospheric warming

Temperature maps at 22 km Winter 01/02/2010 Summer 07/01/2010 Non zonal structure Zonal structure Planetary waves

Rayleigh lidar observations Observatoire de Haute-Provence

Backscatter lidar principle

Temperature measurements using Rayleigh Lidar • Required pure molecular scattering • Density and pressure are relative measurements • Temperature is absolute r ( z ) = f ( N ( z ) dP ( z ) = - g ( z ) r ( z ) dz T ( z ) = MP ( z ) R r ( z ) top z å å g r ( z ') dz ' N ( z ') dz ' T ( z ) = M = Mg ( z ) z 0 r ( z ) R R N ( z )

Temperature lidar profile At Maïdo Observatory, Reunion Island

paper!on!QBO).!The!GW! ,!estimated!in!the!equatorial!band!using!GPSK RO!data!(Fig.!12), is!enhanced!along!the!zero!wind!line!! OHP temperature evolution in winter 1996/97 ! !Evolution!of!the!temperature!at!OHP!during!winter!1996K 1997.!Days!with!measurements are!indicated!with!a!vertical!bar!at!the!top!of!the!figure.!Adapted!from!Hauchecorne!et!al.!(2006).

Temperature variability Middle latitude (44 ° N) Tropics 21 ° N Leblanc et al.

Non-linear phenomenon Planetary wave forcing in the troposphee Development depending on planetary wave amplitude and stratospheric zonal wind profile

Stratospheric warming 2009 Stratospheric warming: vortex splitting

° ° ° × ° – Lidar profile evolution during a Sudden Stratospheric Warming !

Stratosphere-troposphere dynamics coupling Pressure and temperature perturbations generated in the upper stratosphere can propagate down to the troposphere and the surface Baldwin and Dunkerton, JASTP, 2005

Stratosphere-troposphere dynamics coupling Pressure and temperature perturbations generated in the upper stratosphere can propagate down to the troposphere and the surface Baldwin and Dunkerton, JASTP, 2005

Impact of SSW on medium range weather forecast Surface temperature 15 to 30 days after a Strat Warm event Averaged over 15 SSWs Charlton Perez et al., 2015

Gravity waves Gravity force Local extension (10 à 1000 km) Main sources • Orography (Lee waves) • Deep convection • Jet stream (geostrophic adjustment)

Gravity wave propagation and breaking GW breaking GW breaking Brasseur and Solomon, 2005; from Lindzen, 1981 Gravity wave breaking  wind deceleration  Vertical and meridional wind  summer mesosphere cooling and winter mesosphere warming

Lidar temperature profile with a gravity wave

(21° 55° Temperature profile evolution during one night !Consecutive!lidar!temperature!profiles!at!Ma ï do!Observatory!on!21!November!2013.! profile!is!integrated!during!15!minutes.!A!5!K!shift!is!applied!between!two!consecutive!pro

Temperature anomaly: gravity wave propagation K K

GW characterization NDACC Rayleigh Temperature lidars: from the variance of lidar signal fluctuations at OHP COSMIC-GPS radio-occultation: from the fluctuations in temperature profiles in a 10 ° longitude by 5 ° latitude box around OHP Radiosoundings: from the fluctuations in temperature profiles at Nîmes (100 km from OHP) æ ö æ ö 2 g 2 ÷ T ' E p = 1 GW potential energy per unit of mass ç ÷ ç è ø è ø N 2 T 2

Climatology of GW potential energy from OHP lidar data Mze et al., JGR, 2014

Gravity waves and thunderstorms Gravity wave potential WRF energy Infrasounds COSMIC-GPS WRF model / Lidar Costantino et al., 2015 37

Seasonal evolution of GW potential energy Mze et al., JGR, 2014

GPS radio-occultation technique From http://www.cosmic.ucar.edu/related_papers/GPS_RO_cartoon.jpg

° ° ° × ° GW potential energy from combined GPS-RO and lidar data in winter 2012-2013 Figure 2. Same as Fig. 1b for the period October 2012 – April 2013. GW potential energy at the Equator and link with the QBO from GPS-RO data

Doppler wind lidar The Doppler shift is proportionnal to the radial wind OHP wind lidar U rad ≈ (S A -S B )/(S A +S B )

Doppler wind lidar profile Zonal wind at Maïdo observed by lidar and radiosonde on 7 June 2016

Gravity wave in Doppler wind (courtesy of C. Souprayen) zonal meridional

Gravity waves observed from space Preusse, 2006

Infrared composite from geostationary satellites

Gravity waves observed from space Preusse, 2006

GOMOS principle From 10 km up to 120 km One star spectrum every 0.5 s Scintillation information 1000 Hz

GOMOS scintillation measurements towards visualization of gravity wave breaking Star scintillation Sofieva et al., 2007 2 High resolution temperature profile Turbulence structure C T

The Quasi Biennial Oscillation Periodic evolution of the equatorial zonal wind, period ≈28 months Review Baldwin et al., Rev. Geophys. 2001 QBO cycle

Equatorial waves Kelvin waves Rossby-gravity waves Purely zonal zonal and meridional Eastward phase Westward phase propagation propagation From Wheeler et al., 2000 ­ β­ ­ ­

QBO mechanism Momentum flux deposition from eastward and westward propagating waves  Kelvin waves  E  Rossby-gravity waves  W  Gravity waves  E and W

Disruption of QBO in 2016 Newman et al., GRL, 2016

Disruption of QBO in 2016 Newman et al., GRL, 2016

Conclusion The middle atmophere dynamics plays an important role in the coupling between the different atmospheric layers and in the transport and mixing of atmospheric constituents Lidars, with other instruments installed at OHP and Maïdo and satellite observations, are very efficient tools for atmospheric dynamics studies

High resolution transport model MIMOSA

Potential vorticity (PV) V In absence of diabatic effects, an air mass is moving along isntropic surfaces and its PV is conserved

Relation tracer-PV Danielsen (1968) First evidence : Increase of ozone and radioactivity in a tropopause folitation

PV and polar vortex First use of PV conservation to study the polar vortex dynamicspolaire McIntyre and Palmer, Nature, 1983

Projet EC-FP5 METRO-THESEO 1999-2000 Objective: to study the meridional transport of ozone in the lower and middle stratosphere (vortex filamentation, tropical intrusions) Tools: Lidar ozone ALTO on board French Falcon IGN-INSU Lidar ozone at Observatoire de Haute-Provence Need to have a isentropic transport model for the planning of aircraft flights and the interpretation

Advection and regridding Advection Semi-implicit method Advection during 6 hours Interpolation on initial grid

Polar filament seen by the OHP ozone lidar

MIMOSA on AERIS/ESPRI database 475 K ≈ 19 km

MIMOSA service on AERIS/ESPRI http://ether.ipsl.jussieu.fr/ether/pubipsl/mimosa_fr.jsp Scientific coordinator: Alain Hauchecorne (LATMOS) Technical coordinator: Cathy Boonne (IPSL)