SCILOV Limb OZONE

Nabiz Rahpoe, Katja Weigel, Alexei Rozanov, Mark Weber

FINAL REPORT WE LOVE

SCIA

overview• Introduction• Comparison instruments• Methods & Criterion• Results• Summary & Conclusion• Recommendation

Introduction

Introduction• Validation of SCIAMACHY limb ozone• DLR/ESA processor version 5.02• Collocation and comparison to 9 instruments• Quality of the data sets• Possible improvements &

InstrumentsComparison instruments used for the validation

SCIAMACHY ESA 5.02

GOMOS V 5

OSIRIS V 5.7

MIPAS V 6

MLS V 3.3

SMR V 2.1

IUP V 2.5

HALOE V19

ACE-FTS V 3.0

SAGE IIV 6.02

SCIAMACHY ESA 5.02

GOMOS V 5

OSIRIS V 5.7

MIPAS V 6

MLS V 3.3

SMR V 2.1

IUP V 2.5

HALOE V19

ACE-FTS V 3.0

SAGE IIV 6.02

Method & CriterionCollocation, MPV, and calculation of the differences

CollocationModified Potential Vorticity (MPV)

dMPV > 3 PVU

30 PVU <MPV< 40 PVU

Polar Vortex35° Poleward

6 -24 h

100 - 1000 km

resultsRelative Differences, Timeseries, Profiles

39 km• High Amplitudes for

midlat34 km• SH & NH increase in

amplitudes after 200625 km

• SH min < NH

15 km• High Amplitudes• High Variability

39 km• Low bias

34 km• Smaller values for

NH with seasonality25 km • Amplitudes increase

with time15 km• High Amplitudes• Negative bias

39 km

34 km• Decrease of bias

25 km • Tropics > Midlat• Midlat 20%15 km• Positive bias• > 40%

39 km• Anomaly and gap

2004/200534 km• Spread of latitude

bands25 km • Low bias with

spikes in SH15 km• Positive bias Midlat

39 km• A change in bias

after 201134 km• Tropics > Midlat

25 km • Stable and small

bias with seasonality15 km

• Smallest variation in bias

39 km• Drift

34 km• Seasonal amplitude

inTropics• Pronounced drift

25 km • Small bias with drift

for NH15 km• Positive bias

39 km• Variable, peak at

around 200434 km• Tropics > SH > NH

25 km • Low bias for

NH/Trop15 km• NH > SH

39 km• Larger amplitudes

34 km• NH seasonality

25 km • Low bias• SH seasonality15 km• SH > 0• Tropics < 0

39 km• NH seasonality with

increasing amplitudes34 km

• NH seasonality

25 km • Constant bias 20%• SH seasonality15 km• High Amplitudes• Tropics < 40%

Bias profiles Vertically resolved bias profiles for all 9 instruments

60° N – 60° SPositive bias < 20 %

HALOE < 40 % 20 - 30 kmBump at 30 km

20°N-20°SPositive bias = 20 %

HALOE > 40 % 20 - 30 kmBump at 30 km pronounced

60° N – 30° NPositive bias < 10 %

SMR & HALOE < 20,30 % 20 - 30 km Spread below 20 km

30° S – 60° SPositive bias < 20 %

Change of sign < 22 kmSpread below 20 km

90° N – 60° NPositive bias < 30 %

GOMOS < 35 % 20 - 30 kmLarge overall spread

60° S – 90° SBias gradient for GOMOS, ACE & SMR

Bias < 10% Above 30 km > 0, Below25 km < 0

Summary & Recommendation

Summary

Instruments

9 Different instruments have been collocated with SCIAMACHY ESA V 5.02

Collocation

100 - 1000 km collocation radius and time difference criterion for intercomparison

Validation Performed by calculating the relative differences for collocated ozone profiles using the selection cirterion

Results Timeseries and vertical profiles for different latitude bins for detailed analysis

CONCLUSION

Mid Lat. NH

• < 10 %

• HALOE

Mid Lat. SH

• < 10 %

• HALOE, SMR, MIPAS < 20%

Antarctic

• < 10 %

• Gradient

• GOMOS & ACE

Near Global

• < 20 %

• HALOE <40%

Tropics

• < 10 %

• HALOE > 40%

• Bump @ 30 km

Arctic

• < 20 %

• GOMOS < 30 %

• Large spread

RECOMMENDATION

Tropics

• Bump @ 30 km• High positive bias anomaly

observed for SCIA ESA toward all of the instruments at 30 km in the tropical band 20N-20S.

• Possible VIS band spectral issues

Arctic • Large spread• A large spread is observed

toward most of the instruments in the 20 – 25 km altitude range. Possible explanation?