Surface pressure impact study: FEC and OSE

(1)

Surface pressure impact study:

FEC and OSE

(2)

Outline

DFS&FEC and OSE experiment setup

Data coverages

Standard scores:

¾ BUOY versus No-BUOY

¾ Thinning BUOYs over the Northern-Atlantic

Conclusions

(3)

BUOYS-SHIP

DFS

and

FEC

Monthly Average

0°N 30°S 60°S 30°N 60°N

150°W 120°W 90°W 60°W 30°W 0°E 30°E 60°E 90°E 120°E 150°E

0.14 0.61 0.82 1.04 1.25 1.47 1.68 1.90 2.11 2.33 2.54 2.75 2.97 3.18 3.40 3.61 3.83 4.04 4.25 4.47

DFS

1 0.7 0.5 0.3 0

FEC

_0°N 30°S 60°S 30°N 60°N 150 W 120 W 90 W 60 W 30 W 0 E 30 E 60 E 90 E 120 E 150 E

150°W 120°W 90°W 60°W 30°W 0°E 30°E 60°E 90°E 120°E 150°E

-138.46 -24.02 -21.02 -18.01 -15.01 -12.01 -9.01 -6.00 -3.00 -0.00 0.00 3.00 6.00 9.01 12.01 15.01 18.01 21.02 24.02 27.02 41.93 Min=-138 Max=41 Mean=-2.5

(4)

BUOYS

FEC Time Serie

-16 -14 -12 -10 -8 -6 -4 -2 0 2 [j ]

Feb Mar Apr May

-60 -50 -40 -30 -20 -10 0 [j ]

Feb Mar Apr May

-5 -4 -3 -2 -1 0 1 2 3 [j ]

Feb Mar Apr May

-11 -9 -7 -5 -3 -1 1 3 [j ]

Feb Mar Apr May

North Atlantic _{North Pacific}

(5)

6

th

_{November: Case of a rapidly developing cyclogenesis}

Analysis

12h Forecast

(6)

Mean sea level pressure: Evolved increments

Forecast valid at the same time but initiate from subsequent analyses

00Z 6

th

_{Nov analysis shifts the storm North West}

Increments

12-24h Forecast

36-48h Forecast

24-36h Forecast

(7)

00Z 6

th

_{November FEC}

All observations with FEC < -20 J

(8)

00Z 6

th

_{November FEC in the 30°x30°}

MSL pressure

(9)

Denial OSEs vs. Operations

Mean sea-level pressure increment at 00Z, 6

th

_November

Operations: total increment

Ship and DRIBU

(10)

OSEs

4D-Var Assimilation System : T511/T95/T159 IFS CY36R1

Experiment period: 1 Dec 2008 to 26 January 2009

3 scenarios:

¾

Control: Operational observation set

¾ SP Denial:

Control -

BUOY -

Non-Synoptic time Ship

¾

Control -

72 BUOYs in North-Atlantic -

Non-Synoptic VOS

ship data (to simulate the situation before the 2002

improved ESurfMar coverage)

(11)

Data coverage: DRIBU global (01/01/2009)

90 S 60 S 30 S 0 N 30 N 60 N 90 N

(12)

Data coverage for Ships

All data and non-synoptic time data

90 S 60 S 30 S 0 N 30 N 60 N 90 N 180 W 120 W 60 W 0 E 60 E 120 E 180 E 31-Dec-08 22:00:00 23:50:00 01-Jan-09 01:40:00 03:30:00 05:20:00 07:10:00 01-Jan-09 09:00:00

(13)

Results: SP-Denial versus Control

Relative error diff

Control

better

Denial

better

(14)

Results: SP-Denial vs Control

Difference significant up to 2

0 1 2 3 4 5 Forecast Day -1.2 -1 -0.8 -0.6 -0.4 -0.2 0 0.2 0.4 Population: 51 Confidence: 90% 1000hPa Geopotential 00UTC

Date: 20081207 00UTC to 20090126 00UTC S.hem Lat -90.0 to -20.0 Lon -180.0 to 180.0

(15)

25 N 36 N 47 N 58 N 69 N 80 N 65 W 46 W 27 W 8 W 11 E 30 E 31-Dec-08 21:00:00 23:10:00 01-Jan-09 01:20:00 03:30:00 05:40:00 07:50:00

Data coverage for DRIBU in the N.Atlantic

With and without “

EsurfMar+

“ data

25 N 36 N 47 N 58 N 69 N 80 N 65 W 46 W 27 W 8 W 11 E

CTL

Thinned

1038 Ps obs

503 Ps obs

(16)

Data coverage for DRIBU in the N.Atlantic

With and without EsurfMar+ data

5 W 46 W 27 W 8 W 11 E 30 E

W 46 W 27 W 8 W 11 E 30 E

(17)

Results: Thinned E-SurfMar versus Control

30 °N 60°N W 0°

NH=0.09 SH= -0.36 Trop= 0.79 Eur=-0.37 NAmer= 0.15 NAtl= 0.58 NPac= -0.43 Lev=1000, Par=z, fcDate=20081207-20090126 0Z, Step=36

-2.5 -2 -1 -0.5 -0.25 -0.1 -0.05 0.05 0.1 0.25 0.5 1 2 2.5

(18)

Results: Thinned E-SurfMar versus Control

Population: 51 Confidence: 90%

1000hPa Geopotential 00UTC

Date: 20081207 00UTC to 20090126 00UTC N.atl Lat 25.0 to 65.0 Lon -70.0 to -10.0

Root mean square error forecast CTRL minus THIN 0 1 2 3 4 5 Forecast Day -0.6 -0.4 -0.2 0 0.2 0.4 0.6 0.8 1

Surface pressure impact study: FEC and OSE