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Atmospheric transport and ozone chemistry

Lecture SS 2006Thursday, 14:15h (sharp)-15:45h

Miriam SinnhuberU3225Tel. -8101miriam@iup.physik.uni-bremen.de

Mark Weber S4350 Tel. -2362 weber@uni-bremen.de

Lecture material:www.iup.uni-bremen.de/~miriam/lecture

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20th Apr Introduction W

27th Atmospheric dynamics W

4th May Radiative transfer, heating, and vertical transport W

11th Trace gases S

18th NO CLASS

25th HOLIDAY

1st Jun General middle atmospheric chemistry S

8th Ozone chemistry and catalytic cycles S

15th Heterogeneous chemistry, stratospheric particles,

and the ozone hole S

22nd The tropical tropopause W

29th Solar (decadal) variability and dynamical coupling W,S

6th Jul Solar (decadal) variability and dynamical coupling W,S

13th Greenhouse gasses and climate-chemistry interaction W

20th Student presentations

Lecture schedule and time table

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Andrews, D. G., J. R. Holton, and C.B. Leovy, Middle Atmosphere Dynamics, Academic Press, Orlando, 1990.

Holton, J. R., An Introduction to Dynamic Meteorology, 3rd ed., Academic Press, San Diego, 1992.

Brasseur G., et al., Atmospheric Chemistry and Global Change, Oxford University Press, Oxford, 1999.

Seinfeld, J. H., Pandis, S. N., Atmospheric Chemistry and Physics – From Air Pollution to Climate Change, John Wiley & Sons, New York, 1998.

Wayne, R. P., Chemistry of Atmospheres, 3rd Ed., Clarendon Press, Oxford, 2003.

Brasseur, G., and Solomon, S., Aeronomy of the Middle Atmosphere, 3rd ed., Springer, Dordrecht, 2005.

Literature

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Master/Certificate students:Small presentation (~ 15 min) and oral examination (~30 min)

Diplom Wahlfach/Nebenfach students:Sucessful participation small presentation (~ 15 min)

No exercises !

Criterias for succesful participation in lecture

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student presentations

Summary of selected chapters/sections from WMO scientific assessment of ozone depletion

Selection of topics until 11th May lecture (first come –first serve basis)

15 minute presentations on 20th July

www.unep.ch/ozone/Publications/index.asp

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student presentations (2)

www.iup.uni-bremen.de/~weber/WMO2002/

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I. Introduction

II. Fundamental concepts in atmospheric dynamics: Brewer-Dobson circulation and waves

III. Radiative transfer, heating and vertical transport

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Climate and chemistry

Brasseur et al., 1999

Only parts are covered in this lecture

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Stratospheric chemistry

Brasseur et al., 1999

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Tropospheric chemistry

Up to 50% of free tropospheric ozone may be from the stratosphere Free troposphere ranges from abt. 2 km (above PBL) to the tropopause

Brasseur et al., 1999

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Chemistry & transport of short-lived species

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Chemical pathways for VSLS

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Annual cycle in total ozone

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wave driventransport

Photochem. summer decay

Photochem. summer decay

ozone hole

Annual cycle in total ozone

Transport (dynamics) and chemistry leads to seasonal ozone variability in tropics, middle and high latitudes

Lati

tude

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The global picture: middle atmosphere dynamics

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Stratospheric circulation

after Holton et al. 1995

planetary wave driving by momentum and heat flux transfer from the troposhere

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Inter-annual ozone variability

63°N-90°N

63°S-90°S

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Inter-annual ozone variability

63°N-90°N

63°S-90°S

chemical ozone loss

inter-hemispheric differences in transport

inter-annual variability in ozone chemistry & transportin each hemisphere

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Ozone variability in northern hemisphere

63°N-90°N

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Ozone variability

High inter-annual ozone variability in winter/spring NH

Cold (stratospheric) Arctic winters with low ozone:

1996, 1997, 2000, (2003), 2005Warm Arctic winters with high ozone

1998, 1999, 2001, 2002, 2004

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Ozone hole and polar vortex

GOME total ozone above Antarctica 1996-2002 Low inter-annual ozone variability in SH winter/spring

cold Antarctic stratospheric winters with low ozone („hole“) and large polar vortex every year

exception 2002, rather warm with higher ozone, but 2003 and 2004 are cold again like before (not shown)

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Polar stratospheric temperature anomalies

Correlation of stratospheric temperatures and polar ozone, e.g. low temperatures and low ozone

analysis datasatellite dataradiosondes

Note: here are anomalies shown (differences to long-term mean)

Polar stratospheric T are lower in SH winter than in NH winter (about 15 K)

50 hPa/ ca. 18 km altitude

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15-23 km8-15 km 23-30 km

Ozone minihole„dynamics“

ozone inside polar vortex„dynamics and chemistry“

Eichmann et al. 1999

Height resolved ozone from GOME

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Transport and changes in chemical composition

Transport and chemical composition: subtropical streamer (high tropopause) in NH mid latitudes

low ozone above Europe (mini-hole)

Geopotential height in dekameter at 300 hPa (ca. 9 km altitude)

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Tropospheric weather patterns and stratospheric ozone

North Atlantic Oscillation (NAO) is the normalised (surface) pressure difference between Lisbon (Portugal) and Stykkisholmur (Island) for the winter months December-March

Connection between tropospheric weather patterns (surface) and stratospheric ozone (~22 km altitude)

90% of ozone in stratosphere total ozone mainly stratospheric ozone

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Relationship between climate elements

energy budget

temperature

wind, cloud, precipitation,atmospheric waves

atm

os

ph

ere

solar radiationheat flux from

ocean

topography,

geography

soil composition,

vegetation, albedo

human activities, natural emission,volcanism

Impact ontrace gases

chemistrytransport

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Chemical composition and global change

What causes the large chemical ozone depletion in SH spring?

High stratospheric chlorine (halogen) loading from CFC emissions

Cold temperatures inside the polar vortex

However, past and future stratospheric temperatures also depend on climate changes

Globalwarming

emissions

deforrestation

pytoplanctondestruction

troposphericozone formation

stratospheric ozone depletion

modification of tropospheric chemistry

CFCs

equivalent effective stratospheric chlorine

(EESC)

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Can we learn from the past?

Note today:

[CO2] 370 ppmv

[CH4] 1700 ppbv

Age in kyears

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Can we learn from the past?

Note today:

[CO2] 370 ppmv

[CH4] 1700 ppbv

Mouna Loa Hawaii

Ahrens 1999

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Can we learn from the past?

Note today:

[CO2] 370 ppmv

[CH4] 1700 ppbv

IPCC 2001

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Surface temperetures from the past to the future

Mann et al, 1998

Mann et al., 1998: temperature proxy dataECHO-G1: climate model result

Cubash

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Atmospheric scales

terminology scale phenomenas

Synoptic global, > 1000km cyclonic wavesplanetary waves

mesoscale <1000 km sea wind circulation, frontal systems,gravity waves

regional ~100 km mountain winds, foehn, hurricanes

micro < 100 km turbulence, lightning, tornadoes

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Atmospheric scales

terminology scale phenomenas

Synoptic global, > 1000km cyclonic wavesplanetary waves

mesoscale <1000 km sea wind circulation, frontal systems,gravity waves

regional ~100 km mountain winds, foehn, hurricanes

micro < 100 km turbulence, lightning, tornadoes

troposphere

stratosphere

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Atmospheric space and time scales

Glossary: planetarische Wellen=planetary scale waves, Wolken Cluster=cloud cluster, kleinräumige Turbulenz= small scale turbulence, Schwerewellen=gravity waves, Schallwellen=sound waves, kleinräumig=micro scale, grossräumig=synoptic

tim

e s

cale

spatial scale

Warn

eke 1

99

7

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Chemical time scales