ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20031

1

Chemical forecastsChemical forecasts

D. Fonteyn (@oma.be)Belgisch Instituut voor Ruimte-Aëronomie (BIRA-IASB)

2

OUTLINEOUTLINE

• Introduction: stratospheric chemistry overview• Diagnostic capability of chemicaldata assimilation• Operational set-up & forecasts• Scientific issues

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20032

3

Operational implementation Operational implementation

Operational chemical data assimilation

Daily best estimate of chemical composition

Chemical forecasts based on dynamical forecastsbased on dynamical forecasts

4

Operational implementation Operational implementation

� � � � � � � Forecast

24 hr0 hr 24 hr0 hr

ECMWF fields

MIPAS NRT observations

24 hr Chemical analysis10 day Chemical forecast

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20033

5

Operational implementation Operational implementation

Chemical forecast 6

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20034

7

Gas phase chemistry1. Chapman Cycle

2. Catalytic cycles1. Hydrogen radicals (HOx)

OH + O → H + O2

H + O3 → OH + O 2

Net: O + O3 → 2 O2

OH + O → H + O2

H + O2 + M → HO2+ M

HO2 + O → OH + O2

Net: O + O3 → O2

HO2 + O → OH + O2

OH + O3 → HO2 + O2

Net: O + O3 → 2 O2

Hydrogen Source Gases: H2O, CH4

• Long term trends

• HOx chemistry in the upperstratosphere and mesosphere

StratosphericStratospheric chemistrychemistry

8

StratosphericStratospheric chemistrychemistry2. Nitrogen radicals (NOy)

NO2 + O → NO + O2

NO + O3 → NO2 + O2

Net: O + O3 → 2 O2

3. Chlorine radicals (Cly)ClO + O → Cl + O2

Cl + O3 → ClO + O2

Net: O + O3 → 2 O2

Chlorine Source Gases: Organic Chlorine• Long term trends• Cly partitioning (in the lower

stratosphere: aerosols )

Nitrogen Source Gas: N2O (and …)

• Long term trends• NOy partitioning (in the lower

stratosphere: aerosols )

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20035

9

Ozone lossOzone loss

35°N,September 1993

24 hour average

WMO, 1998

10

Lower StratosphereLower Stratosphere

Gas phase chemistry triggered by heterogeneousprocessing

ClO + ClO + M → ClOOCl + M

ClOOCl + h í → 2 Cl + O2

2 ( Cl + O3 → ClO + O2 )

Net: 2 O3 → 3 O2

BrO + ClO → Br + Cl + O2

→ BrCl + O2

BrCl + h í → Br + Cl

Br + O3 → BrO + O2

Cl + O3 → ClO + O2

Net: 2 O3 → 3 O2

ClOx/Cly & NOx/NOy

Polar Stratospheric Clouds

Aerosols (Pinatubo)

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20036

11

Lower Stratosphere Ozone LossLower Stratosphere Ozone Loss

12

Why CDA & Forecast?Why CDA & Forecast?

Dispersion of tracer advection:(Schoeberl et al., JGR 2003)

↓↓

25 Day free model run: N2O and comparison with analyses

↓↓

“Chemical species drift”

Analysis – forecast

ppbv

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20037

13

Operational forecasts Operational forecasts

• Operational chemical data assimilation: (BASCOE) – CTM, 57 species, PSCs, ECMWF dynamics– 4D-VAR, MIPAS NRT data

• Chemical analyses: initial state for forecast• CTM must be driven by dynamical forecast

• Now mainly winter periods

• This course: – Examples to get a feeling

• N2O, O3, HNO3, NAT particles, ClO– Quantitative “forecast skill”?

14

Forecast

Analysis

20030705 20030707

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20038

15

Forecast

2003071120030709

Analysis

16

O3 / MIP_NRT_v2b41_1284 / θ ≈ 500K / z ≈ 21.1km / mjd = 1284.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_NRT_v2b41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1283.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1283.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1284.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

Forecast

20030707 20030708

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 20039

17

O3 / MIP_NRT_v2b41_1286 / θ ≈ 500K / z ≈ 21.1km / mjd = 1286.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_NRT_v2b41_1285 / θ ≈ 500K / z ≈ 21.1km / mjd = 1285.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1285.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1286.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

Forecast

2003071020030709

Analysis

18

O3 / MIP_NRT_v2b41_1287 / θ ≈ 500K / z ≈ 21.1km / mjd = 1287.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 7 . 5

[ v m r ]

1 1 . 5 2 2 . 5 3 3 . 5 4 4 . 5 5

x 10-6

O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 8 . 5

[ v m r ]

1 1 . 5 2 2 . 5 3 3 . 5 4 4 . 5 5

x 10-6

Forecast

2003071220030711

Analysis

O3 / MIP_NRT_v2b41_1288 / θ ≈ 500K / z ≈ 21.1km / mjd = 1288.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200310

19

O3 / MIP_NRT_v2b41_1290 / θ ≈ 500K / z ≈ 21.1km / mjd = 1290.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_NRT_v2b41_1289 / θ ≈ 500K / z ≈ 21.1km / mjd = 1289.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1289.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1290.5

[vmr]

1 1.5 2 2.5 3 3.5 4 4.5 5

x 10-6

Forecast

2003071420030713

Analysis

20

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 3 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 4 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1283.5

[vmr]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1284 / θ ≈ 500K / z ≈ 21.1km / mjd = 1284.5

[vmr]

2 4 6 8 10 12

x 10-9

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200311

21

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 5 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 6 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1285 / θ ≈ 500K / z ≈ 21.1km / mjd = 1285.5

[vmr]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1286 / θ ≈ 500K / z ≈ 21.1km / mjd = 1286.5

[vmr]

2 4 6 8 10 12

x 10-9

Forecast

Analysis

22

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 7 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 8 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1287 / θ ≈ 500K / z ≈ 21.1km / mjd = 1287.5

[vmr]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1288 / θ ≈ 500K / z ≈ 21.1km / mjd = 1288.5

[vmr]

2 4 6 8 10 12

x 10-9

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200312

23

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 8 9 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

H N O 3 / M I P _ F O R _ v 2 B 4 1 _ 1 2 8 3 / θ ≈ 5 0 0 K / z ≈ 2 1 . 1 k m / m j d = 1 2 9 0 . 5

[ v m r ]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1289 / θ ≈ 500K / z ≈ 21.1km / mjd = 1289.5

[vmr]

2 4 6 8 10 12

x 10-9

HNO3 / MIP_NRT_v2b41_1290 / θ ≈ 500K / z ≈ 21.1km / mjd = 1290

[vmr]

2 4 6 8 10 12

x 10-9

Forecast

Analysis

24

NAT / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1283.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

NAT / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1284.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8NAT / MIP_NRT_v2b41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1283.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

NAT / MIP_NRT_v2b41_1284 / θ ≈ 500K / z ≈ 21.1km / mjd = 1284.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200313

25

NAT / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1285.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

NAT / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1286.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8NAT / MIP_NRT_v2b41_1285 / θ ≈ 500K / z ≈ 21.1km / mjd = 1285.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

NAT / MIP_NRT_v2b41_1286 / θ ≈ 500K / z ≈ 21.1km / mjd = 1286.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

Forecast

Analysis

26

NAT / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1287.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

NAT / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1288.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8NAT / MIP_NRT_v2b41_1287 / θ ≈ 500K / z ≈ 21.1km / mjd = 1287.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

NAT / MIP_NRT_v2b41_1288 / θ ≈ 500K / z ≈ 21.1km / mjd = 1288.5

[cm2 /cm3]

0 0.5 1 1.5 2

x 10- 8

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200314

27

CLO / MIP_NRT_v2b41_1284 / θ ≈ 500K / z ≈ 21.1km / mjd = 1284.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_NRT_v2b41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1283.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1283.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1284.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

Forecast

Analysis

28

CLO / MIP_NRT_v2b41_1286 / θ ≈ 500K / z ≈ 21.1km / mjd = 1286.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_NRT_v2b41_1285 / θ ≈ 500K / z ≈ 21.1km / mjd = 1285.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1285.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1286.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200315

29

CLO / MIP_NRT_v2b41_1288 / θ ≈ 500K / z ≈ 21.1km / mjd = 1288.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_NRT_v2b41_1287 / θ ≈ 500K / z ≈ 21.1km / mjd = 1287.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1287.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1288.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

Forecast

Analysis

30

CLO / MIP_NRT_v2b41_1290 / θ ≈ 500K / z ≈ 21.1km / mjd = 1290.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_NRT_v2b41_1289 / θ ≈ 500K / z ≈ 21.1km / mjd = 1289.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1289.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

CLO / MIP_FOR_v2B41_1283 / θ ≈ 500K / z ≈ 21.1km / mjd = 1290.5

[ v m r ]

2 4 6 8 10 1 2 14

x 10-10

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200316

31

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1283.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1284.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1283 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1283.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1284 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1284.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

Forecast

Analysis

32

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1285.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.2km / mjd = 1286.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1285 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1285.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1286 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1286.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200317

33

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.2km / mjd = 1287.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.2km / mjd = 1288.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1287 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1287.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1288 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1288.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

Forecast

Analysis

34

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.2km / mjd = 1289.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_FOR_v2B41_1283 / θ ≈ 2000K / z ≈ 49.2km / mjd = 1290.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1289 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1289.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

O3 / MIP_NRT_v2b41_1290 / θ ≈ 2000K / z ≈ 49.3km / mjd = 1290.5

[vmr]

1 1.5 2 2.5 3 3.5 4

x 10-6

Forecast

Analysis

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200318

35

Forecast skill: first estimateForecast skill: first estimateILLUSTRATIVEILLUSTRATIVE

• H. Eskes Atmos.Chem.Phys., 2, 271-278, 2002• Root Mean Square Error; f=forecast,a=analysis,c=climatology

• Anomaly correlation coefficient:

• Climatology: H. Eskes; modified climatology (running monthly mean)

2

2

)(

)(

ca

afRMSE

−

−=

22 )()(

))((

cacf

caafACC

−−

−−=

36

11 22 33 44 55 66 77 88 9900

0.20.2

0.40.4

0.60.6

0.80.8

11

1.21.2

1.41.4

F o r e c a s t D a yF o r e c a s t D a y

NN22

O RMSE @ 500KO RMSE @ 500K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

11 22 33 44 55 66 77 88 9900

0.10.1

0.20.2

0.30.3

0.40.4

0.50.5

0.60.6

0.70.7

0.80.8

0.90.9

11

F o r e c a s t D a yF o r e c a s t D a y

NN22O A C C @ 5 0 0 KO A C C @ 5 0 0 K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

Forecast skill NForecast skill N22O, Lower Strat. SH winterO, Lower Strat. SH winter

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200319

37

11 22 33 44 55 66 77 88 9900

0.20.2

0.40.4

0.60.6

0.80.8

11

1.21.2

1.41.4

1.61.6

1.81.8

F o r e c a s t D a yF o r e c a s t D a y

OO33 RMSE @ 500K RMSE @ 500K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

11 22 33 44 55 66 77 88 9900

0.10.1

0.20.2

0.30.3

0.40.4

0.50.5

0.60.6

0.70.7

0.80.8

0.90.9

11

F o r e c a s t D a yF o r e c a s t D a y

OO33 A C C @ 5 0 0 K A C C @ 5 0 0 K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

Forecast skill OForecast skill O33, Lower Strat. SH winter, Lower Strat. SH winter

38

11 22 33 44 55 66 77 88 9900

0.20.2

0.40.4

0.60.6

0.80.8

11

1.21.2

1.41.4

F o r e c a s t D a yF o r e c a s t D a y

C l O R M S E @ 5 0 0 KC l O R M S E @ 5 0 0 K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

11 22 33 44 55 66 77 88 990.40.4

0.50.5

0.60.6

0.70.7

0.80.8

0.90.9

11

F o r e c a s t D a yF o r e c a s t D a y

C l O A C C @ 5 0 0 KC l O A C C @ 5 0 0 K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

Forecast skill ClO, Lower Strat. SH winterForecast skill ClO, Lower Strat. SH winter

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200320

39

11 22 33 44 55 66 77 88 9900

0.20.2

0.40.4

0.60.6

0.80.8

11

1.21.2

1.41.4

F o r e c a s t D a yF o r e c a s t D a y

HNOHNO33

R M S E @ 2 0 0 0 K R M S E @ 2 0 0 0 K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

11 22 33 44 55 66 77 88 990.30.3

0.40.4

0.50.5

0.60.6

0.70.7

0.80.8

0.90.9

11

F o r e c a s t D a yF o r e c a s t D a y

H N OH N O33

A C C @ 2 0 0 0 K A C C @ 2 0 0 0 K

lat < -60°la t < -60°-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < la t < 60°20° < la t < 60°6 0 < l a t6 0 < l a t

Forecast skill HNOForecast skill HNO33, Lower Strat. SH winter, Lower Strat. SH winter

40

11 22 33 44 55 66 77 88 990.20.2

0.40.4

0.60.6

0.80.8

11

1.21.2

1.41.4

1.61.6

1.81.8

22

2.22.2

F o r e c a s t D a yF o r e c a s t D a y

OO33 R M S E @ 2 0 0 0 K R M S E @ 2 0 0 0 K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

11 22 33 44 55 66 77 88 990.10.1

0.20.2

0.30.3

0.40.4

0.50.5

0.60.6

0.70.7

0.80.8

0.90.9

F o r e c a s t D a yF o r e c a s t D a y

OO33

A C C @ 2 0 0 0 K A C C @ 2 0 0 0 K

l a t < - 6 0 °l a t < - 6 0 °-60° < lat < -20°-60° < lat < -20°-20° < lat < 20°-20° < lat < 20°20° < lat < 60°20° < lat < 60°6 0 < l a t6 0 < l a t

Forecast skill OForecast skill O33, Lower Strat. SH winter, Lower Strat. SH winter

ESA-ESRIN, Frascati, Rome, Italy

Chemical forecasts18th – 29th August 200321

41

Forecast skill: first estimateForecast skill: first estimateconclusionconclusion

• H. Eskes Atmos.Chem.Phys., 2, 271-278, 2002• RMSE & ACC give similar picture• ClO non-observed species: very good forecast skill?• HNO3 better than O3 , N2O (tracer)• Latitudinal & species dependence:

– Assimilation & observational quality (biases, noise)– Effect of photo-chemistry

• A larger number of forecasts, investigation on modified climatology

• First illustration of stratospheric chemical forecast skill

• STILL A LONG WAY TO GO

42

Chemical stratospheric forecastsChemical stratospheric forecastsconclusionconclusion

• Chemical forecasts set-up like NWP set-up• “More expensive” (computer time) than NWP (3-5 times)• First set-up for Cal/Val• Scientific value• Other domains:

– A priori information for retrieval– Precursor of chemical weather