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D2 – L1 Basics about the atmosphere - Hennie Kelder 1
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Basics on the atmosphere
D2 – L1 Basics about the atmosphere - Hennie Kelder 2
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Overview• Climate and enhanced greenhouse effect• Stratosphere
– Background ozone chemistry– Polar ozone depletion – the ozone hole
• Troposphere– Ozone formation and destruction– Ozone budget– Air pollution
D2 – L1 Basics about the atmosphere - Hennie Kelder 3
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Atmospheric temperature distribution
Composition
N2 (~80%) and O2 (~20%)
trace gases < 0.03 % essentialrole in radiation budget and atmospheric chemistry
•
D2 – L1 Basics about the atmosphere - Hennie Kelder 4
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Temperature distribution: radiative balance earth-atmosphere system
Incoming solar radiation342 Wm-2
Reflected solar radiation102 Wm-2 (circa 30%)
Outgoing infrared radiation 240 Wm-2Te = 255 K, A = 0.30With atmosphere, Ts = 288 K, 15 C Difference 33 K due to natural greenhouse effect
D2 – L1 Basics about the atmosphere - Hennie Kelder 5
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Climate, climate changes due to natural variability and externalcauses
1. Vulcanic eruptions
2. Solar activity
D2 – L1 Basics about the atmosphere - Hennie Kelder 6
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSINGIncrease of greenhouse gasesThe greenhouse effect
D2 – L1 Basics about the atmosphere - Hennie Kelder 7
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Temperature on earth has increased globally
D2 – L1 Basics about the atmosphere - Hennie Kelder 8
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Increase of temperature in last decades mainly caused by enhanced greenhouse effect
D2 – L1 Basics about the atmosphere - Hennie Kelder 9
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSINGRadiative forcing
D2 – L1 Basics about the atmosphere - Hennie Kelder 10
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Where in the atmosphere is the ozone?
D2 – L1 Basics about the atmosphere - Hennie Kelder 11
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
What is ozone?
OxygenAtom (O)
OxygenMolecule (O2)
OzoneMolecule (O3)
D2 – L1 Basics about the atmosphere - Hennie Kelder 12
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
How ozone is formed?
D2 – L1 Basics about the atmosphere - Hennie Kelder 13
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Why is the ozone layer important?
D2 – L1 Basics about the atmosphere - Hennie Kelder 14
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSINGUV-radiation DNA-damage
Skin cancer
D2 – L1 Basics about the atmosphere - Hennie Kelder 15
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
How is ozone distributed over the world?
D2 – L1 Basics about the atmosphere - Hennie Kelder 16
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Life is due to the ozone layer and the ozone layer is due to life
D2 – L1 Basics about the atmosphere - Hennie Kelder 17
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSINGThe ozone hole aboveAntarctica
D2 – L1 Basics about the atmosphere - Hennie Kelder 18
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Ozone destruction above the North pole
D2 – L1 Basics about the atmosphere - Hennie Kelder 19
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Ozone destruction at the north- and south polar region
D2 – L1 Basics about the atmosphere - Hennie Kelder 20
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Ozone destruction
emissions accumulation transport
removal Chemicalreactions
transformation
Uitstoot Ophoping Transport
Omzetting
Chemische reactie
Verwijdering
CFC’s
Wat is hetozongat?
D2 – L1 Basics about the atmosphere - Hennie Kelder 21
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Emissions
Ozonafbraak
D2 – L1 Basics about the atmosphere - Hennie Kelder 22
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Polar stratospheric ozoneWhere do Cl and Br come from?
Stable compounds (CFCs) are photolyzed by UV in the stratosphere
D2 – L1 Basics about the atmosphere - Hennie Kelder 23
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Accumulation
Ozonafbraak
CFC’s are inert in the troposphere
Long lifetime (~100 Year)
Total amount
“effective chlorine”
D2 – L1 Basics about the atmosphere - Hennie Kelder 24
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Transport
Ozonafbraak
yearly ca. 5% of all air exchanged between the
the troposphere and the stratosphere
D2 – L1 Basics about the atmosphere - Hennie Kelder 25
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
transformation
Ozonafbraak
In the stratosphere CFC’s are destructed through the intense UV-radiation producing Cl and ClO
D2 – L1 Basics about the atmosphere - Hennie Kelder 26
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Chemical reactions
Ozonafbraak
D2 – L1 Basics about the atmosphere - Hennie Kelder 27
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Removal
Ozonafbraak
By the atmospheric circulation Cl is transported from the stratosphere to the troposphere;
By clouds and precipitation Cl is removed from the atmosphere.
D2 – L1 Basics about the atmosphere - Hennie Kelder 28
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
How is the ozone hole created?Necessary:
1) Low temperature (< -78 ºC); → polar stratospheric clouds
2) Chlorine
3) Sunlight
This happens at the end of the polar winter
D2 – L1 Basics about the atmosphere - Hennie Kelder 29
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Polar stratospheric ozone Role of PSCsCl and Br in stable reservoirs: HCl, ClONO2 , BrONO2 and HBr.
But on polar stratospheric clouds (PSCs):
ClONO2solid+ HClsas Cl2gas + HNO3solid
Cl2 + hν 2Cl sunlight !
PSCs form at sufficiently low T as ice or NAT (HNO3.3H2O)
Detailed microphysics still not completely understood!
Reformation of the reservoirs after PSCs re-evaporate:HNO3 + hν NO2 + OH
ClO + NO2+ M ClONO2 + M
Re-evaporation may occur after sedimentation !
D2 – L1 Basics about the atmosphere - Hennie Kelder 30
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSINGThe future of the ozone layer
D2 – L1 Basics about the atmosphere - Hennie Kelder 31
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
The future of the ozone layer: CFC’s
D2 – L1 Basics about the atmosphere - Hennie Kelder 32
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Observed temperature trend (1961-96)
Troposphere is warming up, butOzone layer is cooling!
D2 – L1 Basics about the atmosphere - Hennie Kelder 33
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Global mean temperature in the stratosphere,1960-2000
D2 – L1 Basics about the atmosphere - Hennie Kelder 34
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Causes cooling stratosphere-lower part: mainly increase in ozone-upper part: mainly increase in greenhouse gases
20 km
30 km
50 km
D2 – L1 Basics about the atmosphere - Hennie Kelder 35
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Hence:More greenhouse gases →lower temperature stratosphere →more polar stratospheric clouds →more ozone destruction above polar regions → delay in recovery of the ozone layer
D2 – L1 Basics about the atmosphere - Hennie Kelder 36
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Tropospheric ozone increase related to emissions
D2 – L1 Basics about the atmosphere - Hennie Kelder 37
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Tropospheric ozone budget
23.6 daysLifetime344 TgBurden
508 Tg/yrInflux from stratosphere
720 Tg/yrSurface deposition
212 Tg/yrNet chemical production
4594 Tg/yrChemical loss
4806 Tg/yrChemical production
TM resultsProcess
Zonal mean ozone (ppbv)
D2 – L1 Basics about the atmosphere - Hennie Kelder 38
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Air Pollution: Global Tropospheric NO2 from SCIAMACHY
D2 – L1 Basics about the atmosphere - Hennie Kelder 39
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Spatio-temporal variability
tropospheric NOx is high
EMEP emissions
SCIAMACHY cloud-free 2003
Model 2003
D2 – L1 Basics about the atmosphere - Hennie Kelder 40
DRAGON ADVANCED TRAINING COURSE IN ATMOSPHERE REMOTE SENSING
Summary
• Overview of the enhanced greenhouse effect• Introduction to the stratosphere
- Background ozone chemistry– Polar ozone depletion – the ozone hole
• Tropospheric composition– Ozone budget– Ozone in a changed climate– Air pollution