Experiment Name: T254 L64
| When | Who | What |
|---|---|---|
| 2002/04/08/06 | Kistler,Iredell | Use snow analysis only when it is updated at 00Z, as was implemented in operations last October. |
| 2002/04/05/12 | Moorthi | Make snow over glacier (that is, Greenland and Antarctica) at least as deep as 55 m of water equivalent in the surface analysis. |
| 2002/03/14/12 | Iredell | All satellite data missing for 12Z and 18Z cycles in both operational and parallel cycles due to a 13-hour outage in NESDIS. |
| 2002/01/23/12 | Treadon | Two minor global_ssi bug fixes: (1) correctly account for dry temperature in calculation of saturation vapor pressure, and (2) correct precipitation quality control decision (wrong parameter was adjusted). |
| 2002/01/15/06 | Yu, Keyser | QuikSCAT winds are now implemented in both the operational and parallel. The winds are currently superobbed to 1 degree resolution. |
| 2002/01/10/06 | Iredell | Again increase horizontal diffusion in stratosphere to increase by a factor 1.8 every scale height for extra stability. |
| 2002/01/08/06 | Iredell | Return Rayleigh damping to values previous to December 17, i.e. 5 day damping starting at 2 mb. Also, increase horizontal diffusion in stratosphere to increase by a factor 1.4 every scale height. This should restore stratospheric jets to reasonable values while hopefully maintaining stability. |
| 2002/01/04/06 | Derber | Update background error covariances and vertical structure functions. |
| 2002/01/03/12 | White, Kistler | Resume use of profiler stations PSGAL and PSPIU. |
| 2001/12/31/12 | Liu | Fix bug in relocation program. |
| 2001/12/28/12 | Derber, Treadon | Correct tropical transition problem in background error variance file. |
| 2001/12/24/00 | Treadon | Decrease model timestep to 180s (was 300s) due to CFL problem with stratospheric jet. 180s timestep used only in fcstf step from 2001122400 analysis. |
| 2001/12/23/00 | Treadon | Decrease model timestep to 240s (was 300s) due to CFL problem with stratospheric jet. 240s timestep used only in fcstf step from 2001122300 analysis. |
| 2001/12/21/12 | Kistler, Treadon | Exclude two profiler stations, PSGAL and PSPIU, from analysis by reseting quality mark to 15 in gdasa step. |
| 2001/12/21/00 | Moorthi | Increase Rayleigh damping of stratospheric jet. |
| 2001/12/19/12 | White, Treadon | Exclude two profiler stations, PSGAL and PSPIU, from analysis to examine impact on tropical wind forecast error. |
| 2001/12/17/06 | Iredell | Begin level of Rayleigh damping at 3 mb rather than 2 mb, effectively doubling the damping at the stratospheric jet. |
| 2001/12/13/12 | Treadon | Reduce divten error scaling parameter ampdivt=1e-9, effectively turn off divergence tendency constraint |
| 2001/12/10/12 | Moorthi | Recompiled the model after correcting a bug in sfcsub.f for vegfrac |
| 2001/12/03/12 | Derber, Treadon | Increase use of GOES and HIRS channel 12 radiances. Reduce divten error scaling parameter (ampdivt) by one order of magnitude (now, 0.03) |
| 2001/12/03/00 | Iredell | Run T254L64 to hour 84, T170L42 to hour 180, and T126L28 to hour 384. Each resolution change has a 12-hour overlap to reduce spinup. |
| 2001/11/27/12 | Derber | Increase use of radiance data over land. |
| 2001/11/20/18 | Treadon | Add 1 degree superob'd TRMM TMI rain rates as assimilated data type. |
| 2001/11/16/12 | Treadon | Update time mean, angle dependent radiance bias correction file based on T254L64 Parallel-X radiance diagnostic files from 2001/10/30/12 to 2001/11/16/06. (Did not spin up biascr file.) |
| 2001/11/13/18 | Iredell | Major amount of satellite data was lost due to network problems from 2001/11/12/18 to 2001/11/13/12 in both operations and parallel. |
| 2001/11/13/12 | Treadon | Reformulate super-saturation portion of moisture constraint to avoid convergence problems due to small saturation values in upper troposphere. |
| 2001/11/09/00 | Iredell | Run T254 L64 to hour 84, but truncate to T126 L28 at hour 72. The first forecast product of the truncated forecast will be at hour 96. |
| 2001/11/07/18 | Treadon | Turn on NOAA-16 HIRS data (use same channels as NOAA-14 HIRS) |
| 2001/11/05/12 | Treadon | Turn on divergence tendency constraint. Scale divten error by ampdivt=0.3 (weaker than operations). Also relax constraint by setting dampdivt=1.0 (permit larger divten field in absolute sense). Turn SSM/I precipitation back on. |
| 2001/11/01/12 | Derber | Correct bug in cloud liquid water bias correction of AMSU-A radiances. |
| 2001/11/01/00 | Iredell | Begin to archive 24 and 48 hour sigma forecast files. |
| 2001/10/30/12 | Derber | Update background error variance file. Remove bias in construction of structure functions. Reduce leading eigenvalue for wavenumber 0 q variance by 1 order or magnitude. Replace guess humidity between 500 mb and 30 mb from operations again. |
| 2001/10/29/12 | Moorthi | Corrected diagnostic cloud top temperatures. |
| 2001/10/22/12 | Iredell | Replaced the humidity in the guess between 500 mb and 30 mb to match the relative humidity from operations again. Consolidated gravitational acceleration to 9.80665 m/s**2. |
| 2001/10/19/12 | Derber | Correct error in background error variance file, also affects structure functions for background error. |
| 2001/10/17/06 | Iredell | Replaced the humidity in the guess between 500 mb and 30 mb to match the relative humidity from operations. The humidity around the tropopause had errantly drifted way too small. Investigation is continuing into the cause of this drift. |
| 2001/10/16/12 | Treadon | Turned off precipitation assimilation to improve analysis convergence. |
| 2001/10/15/12 | Moorthi | Corrected three radiation bugs. |
| 2001/10/11/12 | Treadon | Turned off divergence tendency constraint to improve analysis convergence. |
| 2001/10/10/12 | Treadon | Negligible rain situations no longer contribute to the precipitation analysis. This change should help analysis convergence. |
| 2001/10/05/06 | Yang,Iredell | An analysis bug was fixed that had been causing intermittent aborts.
The post processor now makes fields up to 1 mb. |
| 2001/09/28/12 | Derber | The analysis will now use AMSU-A channels 12 and 13 from NOAA-15 and NOAA-16. The observation error is assumed to be large at 5.0 degrees K. |
| 2001/09/27/06 | Iredell | Begin parallel run. |
Page Last Modified: April 9, 2001