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TESTING THE REALISM OF THE MMF (or any GCM) REPRESENTATION OF THE MJO

This study aims to assess the accuracy of the representation of the Madden-Julian Oscillation (MJO) by the Multiscale Modeling Framework (MMF) or any General Circulation Model (GCM). It examines various indices and analyzes the variations in diabatic heating, wind, and cloud properties during MJO events. The results will help identify key processes in the model and compare them to observations.

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TESTING THE REALISM OF THE MMF (or any GCM) REPRESENTATION OF THE MJO

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  1. TESTING THE REALISM OF THE MMF (or any GCM) REPRESENTATION OF THE MJO William B. Rossow Eric Tromeur City College of New York CMMAP Meeting 29-31 July 2008

  2. MJO Index Index based on the first extended EOF analysis of 200hPa velocity potential anomalies from equatorward of 30N • Maloney E. and D. L. Hartmann, J.Climate, 1998 Index based on the first two EOFs of the bandpass-filtered (20 - 80 days) 850hPa zonal wind averaged from 5N to 5S every 2.5 around the equator • Wheeler M. C. and H. H. Hendon, Monthly Weather Review, 2004 Index based on the first two EOFs of the combined fields of 850hPa zonal wind, 200hPa zonal wind, and OLR data averaged from 15N to 15S every 2.5 around the equator • Tian B., Waliser D. E., and E. J. Fetzer, GRL, 2006 Index based on the first extended EOF analysis of the bandpass-filtered (30 - 90 days) rainfall anomalies from 30N to 30S every 1 around the equator • Chen Y. and A. D. Del Genio, Climate Dynamics, 2008 Index based on the first extended EOF analysis of 200hPa velocity potential anomalies from equatorward of 30N

  3. MJO Index in Tropics MJO index : 10 components Positive values : suppressed convection Negative values : enhanced convection National Weather Service / Climate Prediction Center Composite of cloud regimes function of MJO phase (Chen and Del Genio, 2008) Consider a strong MJO event to be one when index < -1 Focus on the Indo-Pacific warm pool and the boreal winter (November-April) Ten time-lagged patterns of the first EEOF of pentad CHI200 anomalies

  4. RFO of MJO Index in 60E - 180 E region (1983 - 2004) Jan-Dec periods Continuum of MJO index values MJO signal all over the year Stronger anomalies during the Boreal Winter

  5. ISCCP WEATHER STATES • Cloud Properties 2. Diabatic Heating 3. Variations of RFO and Large-Scale Circulation during MJO

  6. PC - TAU histogram pattern and Map in Tropics over 21.5 years Cluster Analysis + ISCCP D1 data WS1 : Deep cumulus clouds WS2 : Cirrostratus Anvil clouds WS3 : Congestus clouds WS4 : Cirrus clouds WS5 : Shallow cumulus clouds WS6 : Stratocumulus clouds 1983 - 2004 time period Rossow et al, GRL, 2005

  7. Composite of precipitation in Tropics (1997 - 2004)

  8. Composite of Radiative net fluxes in ATM in Tropics (1997 - 2004) Shortwave net flux Longwave net flux

  9. Composite of Surface Fluxes in Tropics (1989 - 2000) Latent Heat Flux Sensible Heat Flux

  10. RFO of each cloud regime in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1983 - 2004) WS1 WS2 Cloud regimes WS3 WS4 WS5 Convective cloud regimes WS6 WS7 Cirrus regime Suppressed cloud regimes Clear sky Weak MJO (index < -1) Strong MJO (index < -2.2)

  11. Peak Ratio of each cloud regime in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1983 - 2004) I2 I1 I1 I2 I3 I4 I5 I6 di = 0.1 -2.2

  12. VARIATIONS OF DIABATIC HEATING AND WINDS DURING MJO

  13. Composite of Total Precipitation Anomalies in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 2: rfo(n,lag)*pcp(n)

  14. GPCP Precipitation and cloud regimes in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Weak MJO (index < -1) Method 2: rfo(n,lag)*pcp(n) Strong MJO (index < -2.2)

  15. Composite of Total Surface Flux Anomalies in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1989 - 2000) Method 2: rfo(n,lag)*srf(n) Latent Heat Flux Sensible Heat Flux

  16. Weak MJO (index < -1) Strong MJO (index < -2.2)

  17. Composite of Omega in Tropics (1983 - 2004) NCEP/NCAR Reanalysis a/ Omega at 200mb b/ Omega at 500mb c/ Omega at 850mb a/ b/ c/

  18. Composite of Omega in 60E-180E region / 5S-5N latitude band (1983 - 2004) 850 mb 200 mb 500 mb 200 mb 200 mb 850 mb 500 mb 500 mb 500 mb 850 mb 850 mb 200 mb Method 1 : om(n,lag) Method 2 : rfo(n,lag)*om(n) Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  19. THE TESTS • Verify Large-Scale Circulation Variations √√ • Verify Associated Changes in Cloud Property Distributions (WS – slide 14) • Verify Associated Variations of Diabatic Heating and Winds – Amplitude & Phase • Identify Key Process(es) in Model • Verify Behavior in Observations

  20. THINGS TO DO Finer Time Resolution (Lags, ITA) Storm Size – Lifetime Distributions Tracks and Evolution Vertical Structure

  21. BACKUP SLIDES

  22. Composite of Radiative net fluxes in ATM in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 2: rfo(n,lag)*rad(n) Longwave net flux Shortwave net flux Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  23. Composite of Surface Fluxes in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1989 - 2000) Method 2: rfo(n,lag)*srf(n) Latent Heat Flux Sensible Heat Flux Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  24. Composite of precipitation in Tropics (1997 - 2004) Composite of Precipitation Cloud regimes MJO phase Method 1 pcp(n,lag) Method 2 rfo(n,lag)*pcp(n) No change of precip with WS

  25. Composite of Radiative net fluxes in ATM in Tropics (1997 - 2004) Shortwave net flux Longwave net flux

  26. Composite of Surface Fluxes in Tropics (1989 - 2000) Latent Heat Flux Sensible Heat Flux

  27. GPCP Precipitation and cloud regimes in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 1 : pcp(n,lag) Method 2 : rfo(n,lag)*pcp(n) Weak MJO (index < -1) Strong MJO (index < -2.2)

  28. Composite of Longwave net fluxes in ATM in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 1: lw(n,lag) Method 2: rfo(n,lag)*lw(n) Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  29. Composite of Shortwave net fluxes in ATM in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 1: sw(n,lag) Method 2: rfo(n,lag)*sw(n) Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  30. Composite of Latent Heat Fluxes in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1989 - 2000) Method 1: lhf(n,lag) Method 2: rfo(n,lag)*lhf(n) Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  31. Composite of Sensible Heat Fluxes in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1989 - 2000) Method 1: shf(n,lag) Method 2: rfo(n,lag)*shf(n) Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  32. Composite of Omega in 60E-180E region / 5S-5N latitude band (1983 - 2004) 850 mb 200 mb 500 mb 200 mb 200 mb 850 mb 500 mb 500 mb 500 mb 850 mb 850 mb 200 mb Method 1 : om(n,lag) Method 2 : rfo(n,lag)*om(n) Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

  33. Composite of Anomalies of Total LW net flux in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 2: rfo(n,lag)*lw(n) Weak MJO (index < -1) Strong MJO (index < -2.2)

  34. Composite of Anomalies of Total SW net flux in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 2: rfo(n,lag)*sw(n) Weak MJO (index < -1) Strong MJO (index < -2.2)

  35. RFO of each cloud regime in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1983 - 2004) Index < -1 Index < -1.4 Index < -1.8 Index < -2.2 Index < -2.6 Index < -3

  36. Composite of Radiative net fluxes in TOA in 60E-180E region / 5S-5N latitude band (MJO events in November-April periods from 1997 - 2004) Method 2: rfo(n,lag)*rad(n) Longwave net flux Shortwave net flux Weak MJO (index < -1) Strong MJO (index < -2.2) Weak MJO (index < -1) Strong MJO (index < -2.2)

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