slide 1the wave model - last part validation of wind & wave analysis using satellite & buoy....

The Wave Model - Last part Slide 1

Validation of wind & wave analysis using satellite & buoy.

Altimeters onboard ERS-1/2, ENVISAT and Jason

Quality is monitored daily.

Monthly collocation plots

SD 0.5 0.3 m for waves (recent SI 12-

15%)

SD 2.0 1.2 m/s for wind (recent SI 16-

18%)

Wave Buoys (and other in-situ instruments)

Monthly collocation plots

SD 0.85 0.45 m for waves (recent SI 16-

20%)

SD 2.6 1.2 m/s for wind (recent SI 16-

21%)


WAM first-guess wave height againstENVISAT Altimeter measurements

(June 2003 – May 2004)

0 2 4 6 8 10 12 WAM WAVE HEIGHTS (M)

0

2

4

6

8

10

12

EN

VIS

AT

WA

VE

HE

IGH

TS

(M

)

SYMMETRIC SLOPE CORRELATION SCATTER INDEX STANDARD DEVIATION BIAS (ENVISAT - WAM) MEAN ENVISAT MEAN WAM ENTRIES STATISTICS

REGR. CONSTANT REGR. COEFFICIENT

1 . 0 5 0 9 . 9 6 5 7 . 1 3 3 4 . 3 3 8 9 . 1 0 5 5

2 . 6 4 5 3 2 . 5 3 9 8 7 3 2 1 1 0

- . 0 3 8 3 1 . 0 5 6 6

1 5 15 30 50 100 300 500 1000 30000


Global wave height RMSE between ERS-2 Altimeter and WAM FG (thin navy line is 5-day running mean ….. thick red line is 30-day running mean)

0.25

0.30

0.35

0.40

0.45

0.50

0.55

01/08/97 01/08/98 01/08/99 01/08/00 01/08/01 01/08/02 02/08/03

Wav

e H

eig

ht

RM

SE

(E

RS

2 -

WA

M F

G)

[

m]

4D

VA

R (

25/

11

/97

)

T3

19

(0

1/0

4/9

8)

Co

up

ling

(28

/06

/98

)

Use

of

U1

0 (0

9/0

3/9

9)

NG

co

rre

ctio

n (

13

/07

/99

)

60

Le

vels

(1

2/1

0/9

9)

Pe

aki

ne

ss Q

C (

11

/04

/00

)

12

Hr

4D

VA

R (

11

/09

/00

)

T5

11

(2

0/1

1/0

0)

ZG

M (

01

/06

/01

)

Qu

ikS

CA

T (

21

/01

/02

)

Ya

w c

on

trol

(0

4/0

3/0

2)

Gu

stin

ess

(0

8/0

4/0

2)

SA

R a

ssim

ilatio

n (

13

/01

/03

)

1998

2000

1999

2001

2002

2003

No

ER

S-2

full

cove

rag

e (

22

/06

/03

)


Analysed wave height and periods against buoy measurements for February to April 2002

2

4

6

8

10

12

14

HS (

m)

mo

de

l

0 2 4 6 8 10 12 14

H S (m) buoy

0

HS ENTRIES:

1 - 3

3 - 8

8 - 22

22 - 62

62 - 173

173 - 482

482 - 1350

0 2 4 6 8 10 12 14 16 18 20

Peak Period Tp (sec.) buoy

0

2

4

6

8

10

12

14

16

18

20

Pea

k P

erio

d T

p

(se

c.)

m

od

el

TP ENTRIES:

1 - 3

3 - 6

6 - 14

14 - 33

33 - 79

79 - 188

188 - 450

SYMMETRIC SLOPE = 0.932CORR COEF = 0.956 SI = 0.175RMSE = 0.438 BIAS = -0.150LSQ FIT: SLOPE = 0.879 INTR = 0.134BUOY MEAN = 2.354 STDEV = 1.389MODEL MEAN = 2.204 STDEV = 1.278ENTRIES = 29470

SYMMETRIC SLOPE = 1.008CORR COEF = 0.801 SI = 0.190RMSE = 1.746 BIAS = 0.072LSQ FIT: SLOPE = 0.813 INTR = 1.785BUOY MEAN = 9.160 STDEV = 2.743MODEL MEAN = 9.232 STDEV = 2.784ENTRIES = 17212

0 2 4 6 8 10 12 14

Mean Period Tz (sec.) buoy

0

2

4

6

8

10

12

14

Me

an

Pe

rio

d T

z (s

ec

.) m

od

el

TZ ENTRIES:

1 - 3

3 - 6

6 - 12

12 - 26

26 - 59

59 - 133

133 - 300

SYMMETRIC SLOPE = 0.985CORR COEF = 0.931 SI = 0.105

RMSE = 0.779 BIAS = -0.149LSQ FIT: SLOPE = 0.989 INTR = -0.069

BUOY MEAN = 7.306 STDEV = 1.979MODEL MEAN = 7.157 STDEV = 2.102

ENTRIES = 6105

Wave height Peak period Mean period


J93 j J94 j J95 j J96 j J97 j J98 j J99 j J00 j J01 j J02 j J03 j J04 j J05

months (3 month running average)

0.2

0.3

0.4

0.5

0.6

0.7

0.8

RM

SE

(m)

0001 WAVE HEIGHT R.M.S.E. from January 1993 to March 2005

all

MAGICS 6.9.1 muspell - wab Thu May 5 10:02:40 2005 J-R BIDLOT

Global wave height RMSE between buoys and WAM analysis


Quality of wave forecast

Compare forecast with verifying analysis.

Forecast error, standard deviation of error ( ), persistence.

Period: three months (January-March 1995).

Tropics is better predictable because of swell:

Daily errors for July-September 1994Note the start of Autumn.

New: 1. Anomaly correlation

2. Verification of forecast against buoy data.

N.H. Tropics S.H.

tHs1 0.08 0.05 0.08


Significant wave heightanomaly correlationandst. deviation of errorover 365 daysfor years 1997-2004

Northern Hemisphere (NH)

0 1 2 3 4 5 6 7 8 9 10

Forecast Day

20

30

40

50

60

70

80

90

100%DATE = 20040101 TO 20041231

AREA=N.HEM TIME=12 MEAN OVER 366 CASES

ANOMALY CORRELATION FORECAST

HEIGHT OF WAVES SURFACE LEVEL

FORECAST VERIFICATION 20042003200220012000199919981997

MAGICS 6.7 icarus - dax Tue Jan 11 08:59:01 2005 Verify SCOCOM

0 1 2 3 4 5 6 7 8 9 10

Forecast Day

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1DATE = 20040101 TO 20041231

AREA=N.HEM TIME=12 MEAN OVER 366 CASES

STANDARD DEVIATION OF ERROR FORECAST



MAGICS 6.7 icarus - dax Tue Jan 11 08:59:01 2005 Verify SCOCOM * 1 ERROR(S) FOUND *



Tropics

0 1 2 3 4 5 6 7 8 9 10

Forecast Day

40

50

60

70

80

90

100%DATE = 20040101 TO 20041231

AREA=TROPICS TIME=12 MEAN OVER 366 CASES





0 1 2 3 4 5 6 7 8 9 10

Forecast Day

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5DATE = 20040101 TO 20041231

AREA=TROPICS TIME=12 MEAN OVER 366 CASES







Southern Hemisphere (SH)

0 1 2 3 4 5 6 7 8 9 10

Forecast Day

20

30

40

50

60

70

80

90

100%DATE = 20040101 TO 20041231

AREA=S.HEM TIME=12 MEAN OVER 366 CASES





0 1 2 3 4 5 6 7 8 9 10

Forecast Day

0

0.2

0.4

0.6

0.8

1

1.2

1.4DATE = 20040101 TO 20041231

AREA=S.HEM TIME=12 MEAN OVER 366 CASES






RMSE of * significant wave height, * 10m wind speed and * peak wave period of different models as compared to buoy measurements for February to April 2005

0 1 2 3 4 53rd generation fc data only, fc from 0 and 12Z for 0502 to 0504

0

0.10.20.3

0.40.50.6

0.70.80.9

1

RM

SE

(m

)

SIGNIFICANT W AVE HEIGHT ROOT MEAN SQUARE ERROR at all 69 buoys

ECMWF METOF FNMOC MSC NCEP METFR DWD


0

0.4

0.8

1.2

1.6

2

2.4

2.8

3.2

3.6

4

RM

SE

(m

/s)

10m W IND SPEED ROOT MEAN SQUARE ERROR at all 69 buoys



0

0.3

0.6

0.9

1.2

1.5

1.8

2.1

2.4

2.7

RM

SE

(s

ec

.)

PEAK PERIOD ROOT MEAN SQUARE ERROR at all 63 non UK buoys



3. Benefits for Atmospheric Modelling 3.1. Use as Diagnostic Tool

Discovered inconsistency between wind speed and stress and resolved it.

Over-activity of atmospheric model during the forecast: mean forecast error versus time.


3.2. Coupled Wind-Wave Modelling

Coupling scheme:

Impact on depression (Doyle).

Impact on climate [extra tropic].

Impact on tropical wind field ocean circulation.

Impact on weather forecasting.

ATM

WAM

t

u10

u10

t

u10

time

time

windww Skk

d,101.0


WAM – IFS Interface

A t m o s p h e r i c M o d e l

q T P

air

zi / L (U10, V10)

W a v e M o d e l


Simulated sea-level pressure for uncoupled and coupled simulations for the 60 h time

uncoupled coupled

956.4 mb 963.0 mb

Ulml > 25 m/s1000 km


Scores of FC 1000 and 500 mb geopotential for SH(28 cases in ~ December 1997)

coupleduncoupled


Standard deviation of error and systematic error of forecast wave height for Tropics

(74 cases: 16 April until 28 June 1998).

coupled


Global RMS difference between ECMWF and ERS-2 scatterometer winds

(8 June – 14 July 1998)

coupling

~20 cm/s (~10%) reduction


Change from 12 to 24 directional bins:Scores of 500 mb geopotential for NH and SH

(last 24 days in August 2000)

slide 1the wave model - last part validation of wind & wave analysis using satellite & buoy....

Documents

mean slide

time slide

uncoupled slide

reduction slide

model mean

wave buoys

guess wave height

analysed wave height