1. Joint OSSE Nature Run by ECMWF
Based on recommendations/requirements from JCSDA, NCEP, GMAO, GLA, SIVO, SWA, NESDIS, ESRL
“Low Resolution” Nature Run
Free-running T511 L91 w. 3-hourly dumps
May through June (13 mnth long)
Two “High Resolution” periods of 35 days each
Hurricane season: Starting at 12z September 27,2005,
Convective precipitation over CONUS: starting at 12Z April 10, 2006
T799 L91 levels, one-hourly dump
Initial condition from T511 NR

2. Archive and Distribution
The Complete data set
saved at ECMWF, NCEP, ESRL, and NASA/GSFC
ECMWF:
Archived in the MARS system as expver=etwu
NASA/GSFC portal:
ID and password required
contact: Harper Prior
Gradsdods access is available for T511 NR. The data can be down loaded  in grib1, NetCDF, binary. The data can be retrieved globally or selected region.
Provide IP number to :Arlindo da Silva
NCEP: Require account at NCEP
Nature Runs are available to designated users for research purpose& users known to ECMWF
The user list outside of the EC is maintained by :Michiko Masutani and reported to ECMWF

3. Supplemental low resolution regular lat lon data
Archive and Distribution
Supplemental data
Supplemental low resolution regular lat lon data
1degx1deg for T511 NR, 0.5degx0.5deg for T799 NR
Pressure level data: 31 levels,
Potential temperature level data: 315,330,350,370,530K
Selected surface data for T511 NR: Convective precip, Large scale precip, MSLP,T2m,TD2m, U10,V10, HCC, LCC, MCC, TCC, Sfc Skin Temp
Complete surface data for T799 NR
Available from NCAR CISL Research Data Archive. Data set ID ds621.0
Currently NCAR account is required for access.
(Also available from NCEP hpss, NASA/GSFC Portal, ESRL, NCAR/MMM, NRL/MRY, JMA, MSU, Utah)
Note: This data must not be used for commercial purposes and re-distribution rights are not given.

4. Squall line / cold front case event from T799 NR
Mississippi State University
Hill_MSU_case_event_T799_ ppt

5. An Observing System Simulation Experiment to Evaluate ATMS and CrIS Observations
Christopher M. Hill Patrick J. Fitzpatrick Valentine G. Anantharaj
Mississippi State University
Lars-Peter Riishojgaard/NASA
T799 NR case event May UTC MSU
Out of season storm over Mississippi. Provide good sample for MSU. 5

6. Evaluation of Tropics in T511
Oreste Reale
Reale_Evaluation_ECMWF_T511NR.ppt
The NR shows a stronger than climatology TEJ, but a very credible and realistic decrease of easterly speed with the progress of the monsoon season. As a consequence, the environment becomes conducive to more development
First Nature Run to simulate one entire season
Twelve tropical cyclones develop
Realistic variability of tracks
Most intense reaches 957 hPa
Binary vortices, looping and singularities are observed (good from OSSE perspective)

7. Concluding remarks on the African Monson region and tropical Atlantic (T511NR)
A synoptic assessment of the NR over the AM region and the tropical Atlantic shows an overall very realistic African Monsoon, AEJ and wave activity
Several weak tropical and sub-tropical systems are present, together with `major’ tropical cyclones
In spite of a tendency of creating several early recurvers, it can be stated that the NR, given the resolution limitation, does have a very good representativeness of tropical cyclone track variability in the Atlantic, as it would occur in an active season
This Nature Run represents a very promising tool to perform OSSEs over the tropical Atlantic

8. Summary of Tropics of T799 NR Oreste Reale
Reale_T799_October_Nature_Run.ppt
AEJ is 40% weaker than climatology
Atlantic TC activity contains some highly suspicious tracks
Eastern Pacific seems to present excessive proliferation of weak TCs
The intensity of the strongest ATL systems is not superior to T511
Different behavior in different basins
Structure of some intense system not very satisfactory in terms of scale and size of eye-like feature

9. Preliminary conclusions
The increased resolution does not necessarily provide stronger confidence in a much better Nature Run for the tropics
Representation of TC activity does not immediately appear superior to the T511
Caution should perhaps be used in adopting this NR for applications centered on future instruments targeting hurricanes
Further investigation is needed

10. Summary: Extratropical Cyclones 31R1 @ T511 (DJFM)
Thomas Jung
Jung_ECMWF_Nature_Run_TJ.ppt
Synoptic activity (extratropics):
Generally well represented
Distribution of storm frequency quite realistic
Problems in the Gulf Stream/Kurushio area?
Too many systems in the eastern Atlantic (blocking)

11. Summary: Tropical Cyclones 31R1 @ T511 (DJFM)
T511 model produces quite realistic frequency of occurrence of TS/Hurricanes in the Atlantic.
North African Monsoon too strong + northward shifted.
AEJ is too weak (problem at higher resolution).
Perhaps slightly too much AEW activity.
Strong problems in the western tropical Pacific (too little atmospheric upwelling). Problem larger at higher resolution.

12. Some Other Issues: Model Climate 31R1 @ T511
Amplitude of the MJO is underestimated (better in recent cycles but still an issue).
Convectively coupled Kelvin waves in the tropics are underestimated (better from 32R3 onwards).
Too little (much) precipitation over the tropical continents (oceans) (improved in recent cycles).
No QBO
Euro-Atlantic blocking significantly underestimated (large improvements in 33R1).
Anti-cyclonic circulation bias in the North Pacific (fixed in 32R3)

13. Tropical Cyclones in Recent Model Cycles
Generally there is an increase in the number/intensity of tropical cyclones/hurricanes.
Particularly lower resolution versions perform better than older cycles (e.g., US landfall).
Large increases in the western tropical Pacific (partly due changes in the large-scale atmospheric circulation). Too large?

14. Sensitivity to Horizontal Resolution Thomas Jung Jung_ECMWF_Nature_Run_TJ.ppt
Short-range and medium-range forecasts suggest that T799, if anything, produces stronger hurricanes than T511.
Resolution studies, however, suggests, that some aspects of the tropical climate (i.e., beyond the medium-range) of 31R1 deteriorate when increasing horizontal resolution (T159->T511). So it may be possible that T799 performs worse than T511.
In the extratropics the largest changes occur when going from T95 to T159. Rather little changes occur beyond T159 (T159->T511). Hence, it seems reasonable to assume that T511 and T799 perform similar.

15. Colder surface in Both poles (T799NR)
Michiko Masutani
Masutani_T799_T ppt
Transient eddy kinetic energy become activs in SH toward summer
Both Poles are colder in T799 NR
10 day average sfc skin temperature

16. Zonal mean high pass eddy KE at 250hPa
Three day running mean subtracted
Interpolated to 1degree
3 hour sampling
Toward end of October, SH become erroneously active in T799 NR.

17. Arctic in T511 NR Nikki Prive
2008//Jan-Mar08/Prive_arctic_ice_ ppt
Stratospheric ‘cold pole’ - without input from obs, model develops abnormally cold polar region in winter with strong polar vortex. Common problem with global models.
Surface temperatures are strangely high over the arctic
Disconnect with temperatures above surface layer?
Low level inversion too weak - impacted by many processes
What is energy balance over ice? SHF/LHF/longwave/cloud impacts?
Sea ice and SST are applied from 2005/6 fields, not interactive with model atmosphere
Is it worth investigating causes of strange behavior in arctic? Lots of number crunching/time needed.
Have not yet looked closely at synoptic/mesoscale dynamics in arctic.

18. Omega fields in Hurricane (T511 NR)
Nikki Prive
A mage from the storm that hits Florida, with the 850 mb omega in full colors (blue = up), and the 250 mb omega in red contours (solid lines = up)
The upper level upward maximum seems to wobble around, displaced about one degree from the lower level area of strong vertical velocities.  It doesn't really look like an artifact of the low resolution interpolation.  I would have expected stronger stacking of the omega field - maybe this is not a problem, though?  I haven't looked at the full reduced gaussian data yet because it is messy, and I'm certainly not any kind of expert on hurricanes....

19. T799 T511 Quick look using 1degree data Min MSLP T799 OCT05 period
By Michiko Masutani

20. T799 T511 Quick look using 1degree data Convective Precipitation
3 hour mean 12z-15Z Oct
T511
T799
By Michiko Masutani

21. T799 T511 Quick look using 1degree data Min MSLP T799 APR06 period
By Michiko Masutani

22. T799 Convective Precipitation in Spring T511
Quick look using 3 hour mean 1degree data
T511
06Z Apr 25, 2006
T799
01Z May 2, 2005
By Michiko Masutani

23. Plot by Yoshiaki Sato Quick satellite view IR T799 NR 2006041106
datTB(ix,iy)=datTB(ix,iy)*(1.0-datC(ix,iy,iz))+datT(ix,iy,iz)*datC(ix,iy,iz) # datC: CC, datT: T IR
T799 NR