ECMWFSeattle, 6-7 June 2005 slide 1

The role of the Pacificdownstream: Europe

Value of Targeting

Carla Cardinali

Roberto Buizza Graeme KellyJean-Noel Thepaut

ECMWFSeattle, 6-7 June 2005 slide 2

The role of the North Pacific sea for the downstream forecast has been investigated by removing all observations over sea

1.5 month assimilation ECMWF 4D-Var T511T159L60

Compare with O-suite

Targeting studies (March 2005-…) Preliminary results

Value of SVs to detect targeting areas

Ultimately, value of targeting with satellite data

Outline

ECMWFSeattle, 6-7 June 2005 slide 3

Experiment Description: North Pacific OUT

Synop Airep Satob DribuTemp Pilot Satellite Scatt

ECMWFSeattle, 6-7 June 2005 slide 4

The Role of the Pacific

EUROPE LAT 35.000 TO 75.000 LON -12.500 TO 42.500

ROOT MEAN SQUARE ERROR FORECAST

500hPa GEOPOTENTIAL

FORECAST VERIFICATION 12UTC

M'

1DECEMBER

2003

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13JANUARY

2004

20

40

60

80

100

120

140

160

180

NoPac T+144Cntrl T+144

ECMWFSeattle, 6-7 June 2005 slide 5

The Role of the Pacific

144 HOUR FORECASTS

AREA=EUROPE TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

500 hPa VECTOR WIND (M/S)

0 10 20 30

NoPac0

10

20

30

Op

er

NoPac is WORSE than Oper at the 5.0% level (t test)NoPac is WORSE than Oper at the 5.0% level (sign test)

43 CASES

MEAN

MAGICS 6.9.1 leda - dac Wed May 18 13:50:27 2005 Verify SCOCAT

144 HOUR FORECASTS

AREA=EUROPE TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

500 hPa GEOPOTENTIAL (M)

0 25 50 75 100 125 150 175 200

NoPac0

25

50

75

100

125

150

175

200

Op

er

diff has too few runs at the 10.0% level (run test)NoPac is WORSE than Oper at the 5.0% level (sign test)

43 CASES

MEAN

MAGICS 6.9.1 leda - dac Wed May 18 13:14:04 2005 Verify SCOCAT

ECMWFSeattle, 6-7 June 2005 slide 6

The Role of the Pacific

144 HOUR FORECASTS

AREA=EUROPE TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

200 hPa VECTOR WIND (M/S)

0 10 20 30

NoPac0

10

20

30

Op

er

43 CASES

MEAN

MAGICS 6.9.1 leda - dac Wed May 18 13:50:27 2005 Verify SCOCAT

144 HOUR FORECASTS

AREA=EUROPE TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

200 hPa GEOPOTENTIAL (M)

0 25 50 75 100 125 150 175 200

NoPac0

25

50

75

100

125

150

175

200

Op

er 43 CASES

MEAN

MAGICS 6.9.1 leda - dac Wed May 18 13:14:04 2005 Verify SCOCAT

ECMWFSeattle, 6-7 June 2005 slide 7

PACIFIC: NoPac forecast error – Oper forecast error at T+24

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 8

PACIFIC: NoPac forecast error – Oper forecast error at T+48

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 9

PACIFIC: NoPac forecast error – Oper forecast error at T+72

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 10

PACIFIC: NoPac forecast error – Oper forecast error at T+96

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 11

PACIFIC: NoPac forecast error – Oper forecast error at T+120

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 12

PACIFIC: NoPac forecast error – Oper forecast error at T+144

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 13

Removing all the observation over the North Pacific slightly deteriorate the day 6-7 forecast over Europe

1.5 month assimilation ECMWF 4D-Var T511T159L60

Compare with O-suite

Observations over North America recover the lack over the Pacific: the impact depends on the synoptic situation

See THORPEX picture

Preliminary Conclusion

ECMWFSeattle, 6-7 June 2005 slide 14

ECMWFSeattle, 6-7 June 2005 slide 15

Targeting studies

The key questions addressed in this study are:

Q1 - What is the value of observations taken in target areas over the ocean, and what is the ‘value’ of SVs at depicting target areas?

Q2 - Is the ‘value’ of observation regional dependent? (in other words, what is the value of observations taken over the Pacific for North-America, and the value of observations taken over the Atlantic for Europe?)

Q3 - What is the ‘value’ of different types of observations?

In particular, what is the scope of targeted satellite observations

ECMWFSeattle, 6-7 June 2005 slide 16

1) Experiment Description: IN

SV

RD

V

10 ToT Energy SVs T63L40 computed every analysis cycle

for 1.5 month

Verification region V and area where SVs have maximum

final-time total energy after 48h.

IN = All Points over Sea removed but in

SV and RD Target-Areas Grid Points = 120

ECMWFSeattle, 6-7 June 2005 slide 17

2) Experiment Description: OUT

10 ToT Energy SVs T63L40 computed every

analysis cycle for 1.5 month

OUT = All Points Removed in

SV and RD Target-Areas

Point left = 929

ECMWFSeattle, 6-7 June 2005 slide 18

Experiment Description: Data CoveragePacific OUT

SVIN

RDIN

ECMWFSeattle, 6-7 June 2005 slide 19

Target IN

N.AMER LAT 25.000 TO 60.000 LON -120.000 TO -75.000

ROOT MEAN SQUARE ERROR FORECAST

500hPa GEOPOTENTIAL

FORECAST VERIFICATION 12UTC

M'

1DECEMBER

2003

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13JANUARY

2004

5

10

15

20

25

30

35

40

45

SVinPac T+ 48RDinPac T+ 48

ECMWFSeattle, 6-7 June 2005 slide 20

Target OUT

N.AMER LAT 25.000 TO 60.000 LON -120.000 TO -75.000

ROOT MEAN SQUARE ERROR FORECAST

500hPa GEOPOTENTIAL

FORECAST VERIFICATION 12UTC

M'

1DECEMBER

2003

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13JANUARY

2004

8

10

12

14

16

18

20

22

24

26

28

SVoutPac T+ 48

RDoutPac T+ 48

ECMWFSeattle, 6-7 June 2005 slide 21

Target IN Target OUT

48 HOUR FORECASTS

AREA=N.AMER TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

850 hPa GEOPOTENTIAL (M)

0 10 20 30 40 50

SVoutPac

0

10

20

30

40

50

RD

ou

tPa

c

diff has too few runs at the .1% level (run test)SVoutPac is WORSE than RDoutPac at the 10.0% level (t test)

51 CASES

MEAN

MAGICS 6.9.1 leda - dac Thu May 26 16:58:23 2005 Verify SCOCAT

48 HOUR FORECASTS

AREA=N.AMER TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

500 hPa GEOPOTENTIAL (M)

0 10 20 30 40 50

SVoutPac

0

10

20

30

40

50

RD

ou

tPa

c

diff has too few runs at the .1% level (run test)SVoutPac is WORSE than RDoutPac at the .5% level (t test)

SVoutPac is WORSE than RDoutPac at the 5.0% level (sign test)

51 CASES

MEAN

MAGICS 6.9.1 leda - dac Thu May 26 16:58:48 2005 Verify SCOCAT

48 HOUR FORECASTS

AREA=N.AMER TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

850 hPa GEOPOTENTIAL (M)

0 10 20 30 40 50

SVinPac

0

10

20

30

40

50

RD

inP

ac

diff has too few runs at the .1% level (run test)SVinPac is BETTER than RDinPac at the .1% level (t test)

SVinPac is BETTER than RDinPac at the .1% level (sign test)

51 CASES

MEAN

MAGICS 6.9.1 leda - dac Thu May 26 17:02:07 2005 Verify SCOCAT

48 HOUR FORECASTS

AREA=N.AMER TIME=12 DATE=20031201/...

ROOT MEAN SQUARE ERROR FORECAST

500 hPa GEOPOTENTIAL (M)

0 10 20 30 40 50

SVinPac

0

10

20

30

40

50

RD

inP

ac

diff has too few runs at the .1% level (run test)diff has too small variance ratio at the 5.0% level (F test)

SVinPac is BETTER than RDinPac at the .1% level (t test)SVinPac is BETTER than RDinPac at the 1.0% level (sign test)

51 CASES

MEAN

MAGICS 6.9.1 leda - dac Thu May 26 17:02:35 2005 Verify SCOCAT

ECMWFSeattle, 6-7 June 2005 slide 22

PACIFIC: SVIN forecast error – RDIN forecast error at T+24

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 23

PACIFIC: SVIN forecast error – RDIN forecast error at T+48

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 24

PACIFIC: SVIN forecast error – RDIN forecast error at T+72

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 25

PACIFIC: SVIN forecast error – RDIN forecast error at T+96

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 26

PACIFIC: SVIN forecast error – RDIN forecast error at T+120

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 27

PACIFIC: SVIN forecast error – RDIN forecast error at T+144

NormDiff in RMS Averaged over 50 cases

ECMWFSeattle, 6-7 June 2005 slide 28

Key preliminary conclusions (based on ~1.5 months) Q1 - The value of observations taken in target areas over the ocean depends

strongly on the underlying observations.

If the underlying system has no-observations over the ocean, than observations

taken in target areas are valuable, and observations taken in SV target areas are

more valuable than observations taken in Random areas

If the underlying system has observations over the ocean, than removing

observations from SV or Random areas has smaller value

Q2 - The value is regional dependent: the value of observations taken in the

Pacific for North America is higher than the value of observations taken in the

Atlantic for Europe

Q3 – No conclusions yet on this point (if results are symmetrical, little scope to target with satellite observations).

ECMWFSeattle, 6-7 June 2005 slide 29

Value of Targeting the Pacific for Europe

EUROPE LAT 35.000 TO 75.000 LON -12.500 TO 42.500

ROOT MEAN SQUARE ERROR FORECAST

500hPa VECTOR WIND

FORECAST VERIFICATION 12UTC

M/S

1DECEMBER

2003

2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 1 2 3 4 5 6 7 8 9 10 11 12 13JANUARY

2004

6

8

10

12

14

16

18

20

22

NoPac T+144Cntrl T+144

SVinPac T+144RDinPac T+144