Description of the upgrade

1. a new formulation of the humidity analysis (modified background-error covariances, corrected calculation of background-errors for SSMI that uses FASTEM emissivity model over sea);
2. new data streams (AIRS from Aqua, AMSU-B, AMSU-A from Aqua, Japanese wind profilers, Meteosat5, GOES9 and GOES12 WV clear sky radiances, GOES12 winds and MIPAS ozone-profile retrievals);
3. monitoring of ENVISAT data: SCIAMACHY, GOMOS, and MIPAS;
4. a new linear radiation scheme in 4D-var, a new radiation sampling (HALO) and a new aerosol climatology in the full model;
5. a relaxation of the convective mass flux limiter for long time steps (used for the EPS and monthly forecasts);
6. new model parameters (UVB, CAPE, photo-synthetically active radiation, freak waves). Details of the new parameters are:
   • Atmospheric model (Local GRIB table: 128):
     • 57 UVB Downward UV radiation at the surface w m**-2
     • 58 PAR Photosynthetically active radiation at the surface wm**-2
     • 59 CAPE Convective available potential energy J kg**-1
   • Wave model: (Local GRIB table 140):
     • 252 WSK Wave surface kurtosis -
     • 253 BFI Benjamin-Feir index -
     • 254 WSP Wave spectral peakedness s**-1

• The change to the new cycle was transparent for users apart from a change in Model identification number for the atmospheric model in GRIB headers, which was set to 121.
• Note: after reaching the end of the defined range of possible identifications numbers in cycle 26r1 with 203 it was agreed that the numbers will be recycled.
• The wave model identification numbers were not changed and continue to be 113 for the Global Wave Model and 213 for the Mediterranean Wave Model.
• Verification results gathered to date from the experimental suite and from several months of research experiments indicated that, in general, a significant and consistent improvement in the upper air (including humidity) forecasts can be expected from this new cy26r3.

Resolution

Unchanged