[PPT] - Evaluation of seven different atmospheric reanalysis products in the PowerPoint Presentation

SLIDE 1

Evaluation of seven different atmospheric reanalysis products in the Arctic

R. Lindsay and M. Wensnahan

Polar Science Center, Applied Physics Laboratory University of Washington, Seattle WA Modeling, Analysis, Predictions, and Projections (MAPP) Seminar September 25, 2012

SLIDE 2

Reanalysis Models

NCEP-R1

NCEP-R2 CFSR 20CR MERRA ERA-Int JRA-25 Time interval

1948–p 1979–p 1979–p 1871-2008 1979–p 1979–p 1979-p

Spatial Resolution

T62 (209 km) T62 (209 km) T382 (38 km) T62 (209 km) 0.5º x 0.66º (65 km) T255 (79 km) T106 (125 km)

Vertical levels

28 to 3 hPa 28 to 3 hPa 63 to 0.26 hPa 28 to 0.2 hPa 72 to 0.1 hPa 60 to 0.1 hPa 40 to 0.4 hPa

Data assimilation method

3D Var 3D Var 3D Var Ensemble Kalman Filter IAU 4D-Var 3D-Var

Sea Ice and SST

Prescribed Prescribed Interactive Prescribed Prescribed Prescribed Prescribed

SLIDE 3

2-m Air Temperatures

SLIDE 4

T2m, Winter

Median T2M, Winter, 1980-2009 Median, C/yr

40.0
10.0

20.0 NCEP_R1 T2M Anomaly Anomaly, C

5.00

0.00 5.00 NCEP_R2 T2M Anomaly Anomaly, C

5.00

0.00 5.00 20CR T2M Anomaly Anomaly, C

5.00

0.00 5.00 CFSR T2M Anomaly Anomaly, C

5.00

0.00 5.00 MERRA T2M Anomaly Anomaly, C

5.00

0.00 5.00 ERA_I T2M Anomaly Anomaly, C

5.00

0.00 5.00 JRA25 T2M Anomaly Anomaly, C

5.00

0.00 5.00

SLIDE 5

T2m, Spring

Median T2M, Spring, 1980-2009 Median, C/yr

40.0
10.0

20.0 NCEP_R1 T2M Anomaly Anomaly, C

5.00

0.00 5.00 NCEP_R2 T2M Anomaly Anomaly, C

5.00

0.00 5.00 20CR T2M Anomaly Anomaly, C

5.00

0.00 5.00 CFSR T2M Anomaly Anomaly, C

5.00

0.00 5.00 MERRA T2M Anomaly Anomaly, C

5.00

0.00 5.00 ERA_I T2M Anomaly Anomaly, C

5.00

0.00 5.00 JRA25 T2M Anomaly Anomaly, C

5.00

0.00 5.00

SLIDE 6

T2m Annual Temperature Trends

T2M, 1980-2009 Annual Trend Median, C/decade

0.5

0.0 0.5 NCEP_R1 T2M Trend C/decade

0.5

0.0 0.5 NCEP_R2 T2M Trend C/decade

0.5

0.0 0.5 20CR T2M Trend C/decade

0.5

0.0 0.5 CFSR T2M Trend C/decade

0.5

0.0 0.5 MERRA T2M Trend C/decade

0.5

0.0 0.5 ERA_I T2M Trend C/decade

0.5

0.0 0.5 JRA25 T2M Trend C/decade

0.5

0.0 0.5

SLIDE 7

Downwelling Surface Radiative Fluxes

Longwave Bias

2 4 6 8 10 12 Month

60
40
20

20 40 60 W/m2

Shortwave Bias

2 4 6 8 10 12 Month

100
50

50 100 W/m2

NCEP_R1 NCEP_R2 20CR CFSR MERRA ERA_I JRA25

Longwave Correlation

2 4 6 8 10 12 Month 0.0 0.2 0.4 0.6 0.8 1.0 R

Shortwave Correlation

2 4 6 8 10 12 Month 0.0 0.2 0.4 0.6 0.8 1.0 R

SLIDE 8

Longwave Flux, Winter

Median DWLWRFB, Winter, 1980-2009 Median, W/m2/yr 129 237 346 NCEP_R1 DWLWRFB Anomaly Anomaly, W/m2

16.6

0.0 16.6 NCEP_R2 DWLWRFB Anomaly Anomaly, W/m2

16.6

0.0 16.6 20CR DWLWRFB Anomaly Anomaly, W/m2

16.6

0.0 16.6 CFSR DWLWRFB Anomaly Anomaly, W/m2

16.6

0.0 16.6 MERRA DWLWRFB Anomaly Anomaly, W/m2

16.6

0.0 16.6 ERA_I DWLWRFB Anomaly Anomaly, W/m2

16.6

0.0 16.6 JRA25 DWLWRFB Anomaly Anomaly, W/m2

16.6

0.0 16.6

SLIDE 9

Longwave Flux, Summer

Median DWLWRFB, Summer, 1980-2009 Median, W/m2/yr 150 250 350 NCEP_R1 DWLWRFB Anomaly Anomaly, W/m2

20.0

0.0 20.0 NCEP_R2 DWLWRFB Anomaly Anomaly, W/m2

20.0

0.0 20.0 20CR DWLWRFB Anomaly Anomaly, W/m2

20.0

0.0 20.0 CFSR DWLWRFB Anomaly Anomaly, W/m2

20.0

0.0 20.0 MERRA DWLWRFB Anomaly Anomaly, W/m2

20.0

0.0 20.0 ERA_I DWLWRFB Anomaly Anomaly, W/m2

20.0

0.0 20.0 JRA25 DWLWRFB Anomaly Anomaly, W/m2

20.0

0.0 20.0

SLIDE 10

Shortwave Flux, Spring

Median DWSWRFB, Spring, 1980-2009 Median, W/m2/yr 150 225 300 NCEP_R1 DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 NCEP_R2 DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 20CR DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 CFSR DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 MERRA DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 ERA_I DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 JRA25 DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0

SLIDE 11

Shortwave Flux, Summer

Median DWSWRFB, Summer, 1980-2009 Median, W/m2/yr 150 225 300 NCEP_R1 DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 NCEP_R2 DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 20CR DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 CFSR DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 MERRA DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 ERA_I DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0 JRA25 DWSWRFB Anomaly Anomaly, W/m2

50.0

0.0 50.0

SLIDE 12

Precipitation

SLIDE 13

Annual Precipitation

Median Annual Precipitation, 1980-2009 Median, m/yr 0.00 1.00 2.00 NCEP_R1 PRECIP Anomaly Anomaly, m/yr

0.50

0.00 0.50 NCEP_R2 PRECIP Anomaly Anomaly, m/yr

0.50

0.00 0.50 20CR PRECIP Anomaly Anomaly, m/yr

0.50

0.00 0.50 CFSR PRECIP Anomaly Anomaly, m/yr

0.50

0.00 0.50 MERRA PRECIP Anomaly Anomaly, m/yr

0.50

0.00 0.50 ERA_I PRECIP Anomaly Anomaly, m/yr

0.50

0.00 0.50 JRA25 PRECIP Anomaly Anomaly, m/yr

0.50

0.00 0.50

SLIDE 14

10-m Wind Speed at SHEBA

SLIDE 15

10-m Wind Speed, Winter

Median AVG_SPD, Winter, 1980-2009 Median, m/s/yr 2.0 6.0 10.0 NCEP_R1 AVG_SPD Anomaly Anomaly, m/s

2.00

0.00 2.00 NCEP_R2 AVG_SPD Anomaly Anomaly, m/s

2.00

0.00 2.00 20CR AVG_SPD Anomaly Anomaly, m/s

2.00

0.00 2.00 CFSR AVG_SPD Anomaly Anomaly, m/s

2.00

0.00 2.00 MERRA AVG_SPD Anomaly Anomaly, m/s

2.00

0.00 2.00 ERA_I AVG_SPD Anomaly Anomaly, m/s

2.00

0.00 2.00 JRA25 AVG_SPD Anomaly

No Data

SLIDE 16

 2-m Temperature: MERRA does best in bias, MERRA, CFSR, and JRA-25 do well in correlations. Trends are much stronger in the NCEP-R1 and R2 models.  Radiative fluxes: MERRA, CFSR, and ERA-Interim all do well in both bias and correlations.  Precipitation: JRA-25 has the smallest bias. The anomaly correlations is best for ERA-Interim. But MERRA, JRA25, and CFSR. are also good. CFSR is much wetter over the oceans, though not in the Arctic.  Wind speed: NCEP-R2 has a low bias except in winter. All the

thers have a high bias in winter. Otherwise they do quite well.

NCEP-R1 is markedly higher than the others over land.

Conclusions

SLIDE 17

Seasonal trends vs height for temperatures N of 70N.

SLIDE 18

Surface Downwelling Longwave Trends, Fall

DWLWRFB, Fall, 1980-2009 Trend Median W/m2 / dec

10

10 NCEP_R1 DWLWRFB Trend W/m2 / dec

10

10 NCEP_R2 DWLWRFB Trend W/m2 / dec

10

10 20CR DWLWRFB Trend W/m2 / dec

10

10 CFSR DWLWRFB Trend W/m2 / dec

10

10 MERRA DWLWRFB Trend W/m2 / dec

10

10 ERA_I DWLWRFB Trend W/m2 / dec

10

10 JRA25 DWLWRFB Trend W/m2 / dec

10

10

SLIDE 19

Surface Downwelling Longwave Trends, Winter

DWLWRFB, Winter, 1980-2009 Trend Median W/m2 / dec

10

10 NCEP_R1 DWLWRFB Trend W/m2 / dec

10

10 NCEP_R2 DWLWRFB Trend W/m2 / dec

10

10 20CR DWLWRFB Trend W/m2 / dec

10

10 CFSR DWLWRFB Trend W/m2 / dec

10

10 MERRA DWLWRFB Trend W/m2 / dec

10

10 ERA_I DWLWRFB Trend W/m2 / dec

10

10 JRA25 DWLWRFB Trend W/m2 / dec

10

10

SLIDE 20

Surface Downwelling Longwave Trends, Spring

DWLWRFB, Spring, 1980-2009 Trend Median W/m2 / dec

10

10 NCEP_R1 DWLWRFB Trend W/m2 / dec

10

10 NCEP_R2 DWLWRFB Trend W/m2 / dec

10

10 20CR DWLWRFB Trend W/m2 / dec

10

10 CFSR DWLWRFB Trend W/m2 / dec

10

10 MERRA DWLWRFB Trend W/m2 / dec

10

10 ERA_I DWLWRFB Trend W/m2 / dec

10

10 JRA25 DWLWRFB Trend W/m2 / dec

10

10

SLIDE 21

Surface Downwelling Longwave Trends, Summer

DWLWRFB, Summer, 1980-2009 Trend Median W/m2 / dec

10

10 NCEP_R1 DWLWRFB Trend W/m2 / dec

10

10 NCEP_R2 DWLWRFB Trend W/m2 / dec

10

10 20CR DWLWRFB Trend W/m2 / dec

10

10 CFSR DWLWRFB Trend W/m2 / dec

10

10 MERRA DWLWRFB Trend W/m2 / dec

10

10 ERA_I DWLWRFB Trend W/m2 / dec

10

10 JRA25 DWLWRFB Trend W/m2 / dec

10

10