ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 1

Challenges for Upper AtmosphereResearch

Erkki KyröläFinnish Meteorological Institute

ContentsMesosphere structure and features

Ozone distributionSolar proton events

NLCSummary

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 2

Atmospheric layers

Lutgens and Tarbuck's The Atmosphere, 2001

Structure and features

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 3

protonselectrons photons

Gravitywaves

Tides

Chemistry

Non-LTE Atoms, Ions

Mesospheric phenomena

Vertical transport and diffusion

Mesosphericcirculation

Emissionsmeteor dustShuttleexhaust

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 4

Temperature distribution: JanuarySources: ECMWF (z<45 km), MSIS90 (z>45 km)

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 5

Temperature distribution: March

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 6

Temperature distribution: June

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 7

Factors affecting mesosphereGravity wave breaking: -> Meridional circulation from the summer pole to the winter pole• Climate change may change the wave intensity and breaking• Distribution of long-lived constituents• Adiabatic cooling and warming

Tides: Winds, vertical transport, temperature variations

Increase of GHG: CO2, H2O and CH4• Cooling of the mesosphere

Ionization by particles: Solar proton events-> local and non-local changes in chemistry

Ionization by photons: solar EUV, Lyman alpha

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 8

Observing mesosphere

Only 1/10000 of ozone is in mesosphere99% of neutral density is below 40 km

GOMOS: UV absorptionMIPAS: IR (non-LTE) emissionSCIAMACHY: UV limb scattering and emissionsOSIRIS: UV limb scattering and emissionsSABER: IR (non-LTE) emissionMLS: microwave emission

EISCAT: incoherent scattering, electron densitySounding rockets

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 9

Ozone distribution

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 10

Ozone GOMOS-MIPAS comparison

From Verronen et al., Adv. Space Res., 2005

Ozone distribution

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 11

Smith et al., JGR113, D17312, 2008

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 12

Stratosphere: O3 number density in 2003 (1012cm-3)

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 13

CFC+hv

Cl2+HNO3Cl2+hvCl+Cl

Catalytic O3 destruction

Reservoirs

Polar stratospheric clouds

Ozone generation and loss

Cl

Liberation of chlorine

Stratospheric ozone chemistry

Heterogenous chemistry

Extra chlorine from CFCs

O3+hν O+O2

O+O2 O3

Cl+O3NO+O3Br+O3

ClO+O2NO2+O2BrO+O2

ClO+ONO2+O2BrO+O3

Cl+O2NO+O2Br+O2

...

ClO+NO2H+Cl

ClONO2HCl

ClONO2+HCl

T<-85 C

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 14

Ozoneproduction

SummerWinter

Long lived: O3

Brewer-Dobson meridional circulation explains thelatitudinal and seasonal distribution of ozone

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 15

Mesospheric ozone number density (108cm-3) in 2003

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 16

Mesosphere: log10 O3 mixing ratio in 2003

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 17

Zoom to ozone minimum

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 18

Ozone number density (108cm-3) (30 day median)

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 19

Ozone mixing ratio

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 20

Total ozone column at 80 km

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 21

Catalytic O3 destruction

Ozone generation and loss

Mesospheric ozone chemistry

O3+hν

O+O3

O+O2

2O2

O+O2+M O3

H+O3 OH+O2 OH+O H+O2

!

O3[ ] =k1 O[ ] O2[ ] M[ ]

J

!

O3[ ] =k1 O[ ] O2[ ] M[ ]k2 O[ ] + k3 H[ ]

J

k3

k1

k2

Day Night

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 22

!

O3[ ] =k1 O[ ] O2[ ] M[ ]k2 O[ ] + k3 H[ ]

!

k1= 6 "10#34 "300

T

$

% &

'

( )

2.4

!

k2 =1.4 "10#10e#(470

T)

!

k3 = 8 "10#12e#(2060

T)

Mesospheric ozone at night

If T decreases, k1 increases, k2 and k3 decreases:O3 increases

O3 and T anticorrelation!

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 23

!

O3[ ] =k1 O[ ] O2[ ] M[ ]k2 O[ ] + k3 H[ ]

!

k1= 6 "10#34 "300

T

$

% &

'

( )

2.4

!

k2 =1.4 "10#10e#(470

T)

!

k3 = 8 "10#12e#(2060

T)

Diffusion +tides

Mesospheric ozone at night

Transport

You really need a chemical transport model to understand the situation.

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 24

Ozoneproduction

Stratopause

SummerWinter

H2O

Long lived: O3

GW

H+O3 OH+O2 OH+O H+O2

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 25

Meridional circulation

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 26

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 27

Solar Proton Events

With contributions fromA. Seppälä, FMIP. Verronen, FMI

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 28

Movies from http://sohowww.nascom.nasa.gov/ EIT

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 29

Movies from http://sohowww.nascom.nasa.gov/ LASCO

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 30

Energetic particles and their sources

● Cosmic rays: ions 100MeV-10GeV

● Solar Energetic Particles: p,e10MeV-100MeV

● Radiation belt particles: e,p1MeV-100MeV

● Auroral particles: e,p 100eV-100keV

NASA

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 31

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 32

Modelling mesosphere

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 33

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 34

Chemical modelling of the IMPACT -SIC

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 35

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 36

Energetic Particles and the AtmosphereCharged particles precipitate in the polar areas producing HOx

and NOx gases in mesosphere and stratosphere

HOx (H + OH + HO2)Short lifetimeHOx cycle, upper-stratosphere

+ lower-mesosphereOH + O3 -> HO2 + O2

HO2 + O -> OH + O2

Net: 2Ox -> 2O2

NOx (N + NO + NO2)Loss: photodissociation -> longlived

during night -> transported tostratosphere and lower latitudes

NOx cycle, upper-stratosphere2(NO + O3) -> 2(NO2+ O2)NO2 + hv -> NO + ONO2 + O ->NO + O2

Net: 2O3 -> 3O2

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 37

A. Seppälä, FMI

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 38

GOMOS NO2 2003-2004 winter (movie)

A. Seppälä, FMI

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 39

Northern polar regions NOx from GOMOS

A. Seppälä, FMI

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 40

Solar Proton Events – Jan 2005 SPE andthe Tertiary Ozone Maximum

• TOM first reported by Marsh et al. 2001

• Occurs ~72km near the polar nightterminator

• Result of decreased Ox loss by catalyticHOx cycles after decreased HOxproduction with reduced UV radiation.(Less UV ->Less HOx from H2Ophotolysis -> Less catalytic Ox loss)

GOMOS O3 [ppmv]

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 41

Third ozone peak in January

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 42

GOMOS O3 observations and model results

Seppälä et al., Geophys. Res. Lett. 2006

1D ion and neutral chemistry model SIC

log[HOx(ppbv)]

log[NOx(ppbv)]

[O3] %-change from background[O3] %-change from 10-14 Jan

GOMOS [O3(ppmv)] Lat 65N-75N

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 43

Solar proton events and odd H ozone loss

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 44

P. Verronen, FMI

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 45

Noctilucent clouds

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 46

Photograph taken by Mika Yrjölä in August2003. This image portraits a bright noctilucentcloud over Lake Saimaa.Source: english wikipedia (upload 13. Jul 2004by en:User:Explo)

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 47

J. Stegman, MISU

NLC movie

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 48

GOMOS photometer measurements

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 49

OSIRISB. KarlssonD. Degensteinetc.

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 50

RESEARCH CHALLENGES FOR THE MESOSPHERE

• Waves, wave breaking

• General mesospheric circulation

• Tides

• Particle events

• Solar EUV variation

• Increased GHG, cooling

• NLC

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 51

Summary and references

• Mesosphere is sensitive to external natural forcings and climatechange. There is a need to understand the different components ofchange.

• Measurements are difficult and rare. Need for new measurements.• Modelling of mesosphere is difficult. Modelling needs to include neutral

and ion chemistry and meridional circulation.

Review: A. Smith: Physics and chemistry of the mesopause region,

J. Atmospheric and Solar-Terrestrial Physics, 66. 839, 2004

A. K. Smith and D. R. Marsh: Processes that account for the ozonemaximum at the mesopause, JGR,110, D23305, 2005

ESA AATC Oxford 2008 Upper Atmosphere - Erkki Kyrölä 52

Thank you. You have been a wonderful audience!