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Joint OSSE Nature Run by ECMWF

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Joint OSSE Nature Run by ECMWF Based on recommendations/requirements from JCSDA, NCEP, GMAO, GLA, SIVO, SWA, NESDIS, ESRL Low Resolution Nature Run – PowerPoint PPT presentation

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Title: Joint OSSE Nature Run by ECMWF


1
Joint OSSE Nature Runby 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 12 2005 through June 1 2006 (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
expveretwu NASA/GSFC portal ID and password
required contact Harper Prior
(Harper.Pryor_at_nasa.gov) 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
(Arlindo.Dasilva_at_nasa.gov) 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 (michiko.masutani_at_noaa.gov)
and reported to ECMWF
3
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 Selec
ted 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_080731.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 3 06 UTC MSU
Out of season storm over Mississippi. Provide
good sample for MSU.
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 NROreste 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 _at_ 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 _at_ 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 _at_ 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 ResolutionThomas
JungJung_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-gtT511). 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-gtT511). Hence, it
    seems reasonable to assume that T511 and T799
    perform similar.

15
Colder surface in Both poles (T799NR) Michiko
Masutani
Masutani_T799_T511.080410.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 NRNikki Prive
2008//Jan-Mar08/Prive_arctic_ice_080221.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

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
Quick look using 1degree data
Min MSLP T799 OCT05 period
T511
T799
By Michiko Masutani
20
Quick look using 1degree data
Convective Precipitation
3 hour mean 12z-15Z Oct05 2005
T511
T799
By Michiko Masutani
21
Quick look using 1degree data
Min MSLP T799 APR06 period
T511
T799
By Michiko Masutani
22
Convective Precipitation in Spring
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
datTB(ix,iy)datTB(ix,iy)(1.0-datC(ix,iy,iz))dat
T(ix,iy,iz)datC(ix,iy,iz) datC CC, datT T
IR
T799 NR 2006041106
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