outline objectives results

Post campaign Meeting - Eureka 2005,- 30 May 2005

SAOZ EUREKA Feb-Mar 05

Outline• Objectives• Results

Florence Goutail Service d’Aeronomie / CNRS, France

SAOZ at Eureka



OBJECTIVES

• Ozone and NO2 monitoring O3, NO2 Slant columns

- One reference spectrum for the whole campaign

Converted Vertical columns - Using an Arctic winter AMF

(from SAOZ balloon profile at 67 °N)- SZA selection: 86 - 91 °

• Ozone loss during winter 2004/05

• Using REPROBUS and/or SLIMCAT 3D CTM



Instrument

Ground-based SAOZUV-Visible spectrometer looking at zenith(270 -620 nm, 1nm resolution) Columns: O3, NO2, ( Color index - clouds)



30

25

20

15

10

5

90807060504030

AMF O3

NO2

25

20

15

10

919089888786

AMF O3

NO2

O3 and NO2 AMF



O3 and NO2 vertical columns

Ozone:-Large day to day variations-Between day 55 and day 72 difference between morning and evening why?

NO2:After day 69, more sunlight, NO2 is increasing and diurnal variation is observed

550

500

450

400

350

300

Tot

al C

olum

n (

DU

)

9080706050

O3

6

4

2

0Co

lum

n (

101

5 mo

l/cm

2)

9080706050

Day of Year

NO2Morning

Evening



Why O3 sunset larger than O3 sunrise ?

One explanation could bebecause Eureka is located

atthe edge of the vortex.

Here is a map of PV at 475K

(by Mimosa contour advection

model) yellow inside vortex and

red outside.

Eureka is represented byblue star

PV at 475K10/3/ 2005

Mimosa: A. Hauchecorne, CNRS/SA



Why O3 sunset larger than O3 sunrise ?

As an example:On day 69, March 10,

2005O3sr = 364 DUO3ss = 439 DU

Sunrise: SAOZ is looking toward east that is inside vortex

Sunset: SAOZ is looking toward west that is outside vortex

PV at 475K10/3/ 2005



Ozone loss during Arctic winter

Method:Difference between measurements and passive ozone from a 3D CTM in which ozone is considered as a passive tracer

Model 3D CTM (chemical transport model):Reprobus (F. Lefevre)Slimcat (M. Chipperfield, W Feng)



Ozone loss above Eureka- Slimcat 3D CTMcorrectly

reproducesday to day

variations

-A large differenceis observed

betweentransported

passiveOzone (black) andSAOZ (pink): it isattributed to

chemicalloss.

At the end of winter

the difference reach

135 DU= ~25%

600

500

400

300

Ozo

ne (D

U)

1209060300-30

Day of Year 2005

SLIMCAT full chemistry SLIMCAT passive ozone SAOZ

O3 loss135 DU

EUREKA



Zhigansk(CNRS/CAO)

Salekhard(CNRS/CAO)

Sodankyla(CNRS/FMI)

Harestua(BIRA)

NyAlesund(NILU)

Thule(DMI)

ScoresbySund(CNRS/DMI)

Zhigansk(CNRS/CAO)

Salekhard(CNRS/CAO)

Sodankyla(CNRS/FMI)

Harestua(BIRA)

NyAlesund(NILU)

Thule(DMI)


Zhigansk(CNRS/CAO)

Salekhard(CNRS/CAO)

Sodankyla(CNRS/FMI)

Harestua(BIRA)

NyAlesund(NILU)

Thule(DMI)


Comparison to other SAOZ Arctic stations

Eureka(Canada)

Measurements and associated model data are selected only when the station is located inside vortex.



Comparison to other SAOZ stations

-Loss above Eureka (green) seems similar to that of other Stations

-Cumulative loss at the end of winter: 25% according to Slimcat

-with REPROBUS 3D CTM 22%

-40

-30

-20

-10

0

10

Ozo

ne

loss

(%

)

-25 + 2%

JAN FEB

Zhigansk Sodankyla Salekhard ScoresbySund Thule NyAlesund Harestua Eureka

DEC MAR APR

SAOZ/SLIMCAT



Conclusion

Ozone and NO2 morning and evening vertical columns recorded for the whole campaign.

Ozone loss during winter 2004/05above SAOZ stations 25%at Eureka: 25% -> 135 DU

outline objectives results

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