Spaceborne Doppler Wind Lidars - Scientific motivation and impact studies for ADM/Aeolus

Slide 1

Wind Lidar working group February 2010 Slide 1

Spaceborne Doppler Wind Lidars-

Scientific motivation and impact studies for ADM/Aeolus

Erland Källén

with help from

David Tan, Carla Cardinali, Paul Berrisford

ECMWF

Slide 2

Wind Lidar working group February 2010 Slide 2

OutlineADM/Aeolus

Scientific motivation Present observing system

Forecast error Sensitivity to Observations

Re-analysis uncertainties

ADM/Aeolus impact study

Conclusions

Slide 3

Wind Lidar working group February 2010 Slide 3

Atmospheric Dynamics Mission ADM/Aeolus

Slide 4

Wind Lidar working group February 2010 Slide 4

[H]LOS

ADM-Aeolus

•Doppler Lidar

•Aerosol and molecular scattering

•Intermittent pulses

•Only one wind component

•Dawn-dusk polar orbit

•Measurement error < 2 m/s

Slide 5

Wind Lidar working group February 2010 Slide 5

ADM/Aeolus

Slide 6

Wind Lidar working group February 2010 Slide 6

Main scientific objectives of ADM/Aeolus

Improve representation of wind field

in atmospheric analyses Tropics: Wind field governs dynamics Mid-latitudes: Intense storm developments

and meso-scale circulation systems

Numerical weather prediction

Climate sensitivity

Slide 7

Wind Lidar working group February 2010 Slide 7

Additional objectives

Aerosol information

Cloud properties

Slide 8

Wind Lidar working group February 2010 Slide 8

Outline

ADM/Aeolus

Scientific motivation Present observing system

Forecast error Sensitivity to Observations

Re-analysis uncertainties

ADM/Aeolus impact study

Conclusions

Slide 9

Wind Lidar working group February 2010 Slide 9

Present observing system

Radiosondes

Pilot balloons and profilers

Buoys

Satellites

Aircraft data

Slide 10

Wind Lidar working group February 2010 Slide 10

Radiosondes1 Nov 2004, ECMWF Total: 590

Slide 11

Wind Lidar working group February 2010 Slide 11

Satellite polar orbiting1 Nov 2004, ECMWF Total: 247309

Slide 12

Wind Lidar working group February 2010 Slide 12

Aircraft data1 Nov 2004, ECMWF Total 26219

Slide 13

Wind Lidar working group February 2010 Slide 13

Outline

ADM/Aeolus

Scientific motivation Present observing system

Forecast error Sensitivity to Observations

Re-analysis uncertainties

ADM/Aeolus impact study

Conclusions

Slide 14

Wind Lidar working group February 2010 Slide 14

Forecast error Sensitivity to Observations

a b bx = x + K(y - Hx )Analysis solution:

a

a

J J

x

y y x

Forecast error sensitivity to the analysis xa:

a

Jx

, ( )b

J JFEC J

y y Hxy y

1

a

J J

R HA

y x

Rabier F, et al. 1996.

Compute the δJ:

Forecast error J (“dry energy norm” ps, T, u, v)

1Ta

x

K R HAy

The tool provides the

Forecast Error Contribution

for each assimilated observation, which can be accumulated by observation type, subtype, variable or level

→ (y: observations)

→

Slide 15

Wind Lidar working group February 2010 Slide 15

24 H Forecast Error Contribution of GOS

Slide 16

Wind Lidar working group February 2010 Slide 16

Mass versus Wind contributions

0

10

20

30

40

50

60

70

Conventional-wind Conventional-mass Satellite-wind Satellite-mass

FC

E %

Total per OBS

Slide 17

Wind Lidar working group February 2010 Slide 17

Outline

ADM/Aeolus

Scientific motivation Present observing system

Forecast error Sensitivity to Observations

Re-analysis uncertainties

ADM/Aeolus impact study

Conclusions

Slide 18

Wind Lidar working group February 2010 Slide 18

Re-analyses of zonal winds

Kistler et al., 2001

NCEP ERA-15

Difference

NCEP/ERA-15

Slide 19

Wind Lidar working group February 2010 Slide 19

ERA-InterimZonal mean wind 1989-2001

m/s

>15

>30

30>25

<-10

Slide 20

Wind Lidar working group February 2010 Slide 20

Difference ERA-Interim vs. ERA-40 Zonal mean wind 1989-2001

m/s

>2

<-4

Slide 21

Wind Lidar working group February 2010 Slide 21

Outline

ADM/Aeolus

Scientific motivation Present observing system

Forecast error Sensitivity to Observations

Re-analysis uncertainties

ADM/Aeolus impact study

Conclusions

Slide 22

Wind Lidar working group February 2010 Slide 22

Assimilation study for ADM/Aeolus

Assimilation ensembles for data impact assessment

Use ensemble spread as proxy for short-range forecast errors (background errors)

By extension, good data reduce ensemble spread

DWL impact

Radiosonde/profiler impact - provides calibration

Tan et al., QJRMS 133:381-390 (2007)

Slide 23

Wind Lidar working group February 2010 Slide 23

Reference ResultVerificationNWP-SystemObservations

Reference ResultAn & FcDiagnostics

NWP-SystemEnsembleObservations

OSEOSE

Assimilation EnsembleAssimilation Ensemble

Real atmosphere

Assimilation/ forecast

Assimilation/ forecast

Compare to reference

Compare to reference

Impact assessment

Ref. run

Assimilation/ forecast

Assimilation/ forecast

Ensemble spread

Ensemble spread

Assimilation/ forecast Ensemble spread

Calibrate

Impact assessment

Slide 24

Wind Lidar working group February 2010 Slide 24

-0.1

0.1 0.1

0.1

80 S 80 S

60 S60 S

40 S 40 S

20 S20 S

0 0

20 N20 N

40 N 40 N

60 N60 N

80 N 80 N

120 W

120 W 60 W

60 W 0

0 60 E

60 E 120 E

120 E

Thursday 16 January 2003 12UTC ECMWF Forecast t+12 VT: Friday 17 January 2003 00UTC 500hPa **u-velocity

-2.6

-2.2

-1

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

1

2.2

2.6

-0.1

-0.1

0.1

80 S 80 S

60 S60 S

40 S 40 S

20 S20 S

0 0

20 N20 N

40 N 40 N

60 N60 N

80 N 80 N

120 W

120 W 60 W

60 W 0

0 60 E

60 E 120 E

120 E

Thursday 16 January 2003 12UTC ECMWF Forecast t+12 VT: Friday 17 January 2003 00UTC 500hPa **u-velocity

-2.6

-2.2

-1

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

1

2.2

2.6

-0.1

0.1 0.1

0.1

80 S 80 S

60 S60 S

40 S 40 S

20 S20 S

0 0

20 N20 N

40 N 40 N

60 N60 N

80 N 80 N

120 W

120 W 60 W

60 W 0

0 60 E

60 E 120 E

120 E

Thursday 16 January 2003 12UTC ECMWF Forecast t+12 VT: Friday 17 January 2003 00UTC 500hPa **u-velocity

-2.6

-2.2

-1

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

1

2.2

2.6

-0.1

-0.1

0.1

80 S 80 S

60 S60 S

40 S 40 S

20 S20 S

0 0

20 N20 N

40 N 40 N

60 N60 N

80 N 80 N

120 W

120 W 60 W

60 W 0

0 60 E

60 E 120 E

120 E

Thursday 16 January 2003 12UTC ECMWF Forecast t+12 VT: Friday 17 January 2003 00UTC 500hPa **u-velocity

-2.6

-2.2

-1

-0.4

-0.3

-0.2

-0.1

0.1

0.2

0.3

0.4

1

2.2

2.6

Data impact on ensemble forecasts - zonal wind spread at 500 hPa

Sondes

60°S60°S

30°S 30°S

0°0°

30°N 30°N

60°N60°N

150°W

150°W 120°W

120°W 90°W

90°W 60°W

60°W 30°W

30°W 0°

0° 30°E

30°E 60°E

60°E 90°E

90°E 120°E

120°E 150°E

150°E

Thursday 16 January 2003 12UTC ECMWF Forecast t+12 VT: Friday 17 January 2003 00UTC 500hPa **u-velocity

0.75

0.9

1.05

1.2

1.35

1.5

1.65

1.8

1.95

2.1

2.25

Control

ADM-Aeolus

Radiosondes and wind

profilers over Japan,

Australia, N.Amer, Europe

DWL over oceans & tropics

Slide 25

Wind Lidar working group February 2010 Slide 25

60°S60°S

30°S 30°S

0°0°

30°N 30°N

60°N60°N

150°W

150°W 120°W

120°W 90°W

90°W 60°W

60°W 30°W

30°W 0°

0° 30°E

30°E 60°E

60°E 90°E

90°E 120°E

120°E 150°E

150°E

NH=-0.03 SH= -0.04 Trop= -0.17 Eur=-0.02 NAmer= 0.02 NAtl= -0.02 NPac= -0.04Lev=200, Par=u, FcDate=20030116-20030228 12Z, Step=12

RMS of Ensemble fcspread: RMS(fcspread_emi1_emi2_emi3_emi4) - RMS(fcspread_em9l_em9m_em9n_em9o)

-1

-0.8

-0.6

-0.4

-0.2

-0.1

-0.040.04

0.1

0.2

0.4

0.6

0.8

1

60°S60°S

30°S 30°S

0°0°

30°N 30°N

60°N60°N

150°W

150°W 120°W

120°W 90°W

90°W 60°W

60°W 30°W

30°W 0°

0° 30°E

30°E 60°E

60°E 90°E

90°E 120°E

120°E 150°E

150°E

NH=-0.03 SH= -0.05 Trop= -0.09 Eur=-0.06 NAmer= -0.03 NAtl= 0 NPac= -0.04Lev=200, Par=u, FcDate=20030116-20030228 12Z, Step=12

RMS of Ensemble fcspread: RMS(fcspread_em9l_em9m_em9n_em9o) - RMS(fcspread_embd_embe_embf_embg)

-1

-0.8

-0.6

-0.4

-0.2

-0.1

-0.040.04

0.1

0.2

0.4

0.6

0.8

1

Data impact on ensemble forecasts - zonal wind spread at 200 hPa

Sondes

60°S60°S

30°S 30°S

0°0°

30°N 30°N

60°N60°N

150°W

150°W 120°W

120°W 90°W

90°W 60°W

60°W 30°W

30°W 0°

0° 30°E

30°E 60°E

60°E 90°E

90°E 120°E

120°E 150°E

150°E

Thursday 16 January 2003 12UTC ECMWF Forecast t+12 VT: Friday 17 January 2003 00UTC 200hPa **u-velocity

0.75

0.8

1

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

Control

ADM-Aeolus

Radiosondes and wind

profilers over Japan,

Australia, N.Amer, Europe

DWL over oceans and

tropics

Slide 26

Wind Lidar working group February 2010 Slide 26

Conclusions

Wind data is lacking in present global

observing system Tropical analyses suffer

Climate system re-analyses uncertain in tropics, polar areas and stratosphere

ADM/Aeolus will provide vertical wind

profiles with global coverage

Slide 27

Wind Lidar working group February 2010 Slide 27

Thank you for your attention– questions?