Improving the NOAA Joint global OSSE System for Lidar data impact evaluationImproving the NOAA Joint global OSSE System for Lidar data impact evaluation

1Forecast Applications Branch2AOML

Yuanfu Xie1, Yu Zhang1 Zoltan Toth1, and Bob Atlas2

Global Systems Division

OutlineReview the joint global OSSE system;

Some regional OSSE effort;

Development of a new regional nature run;

Improvement for global OSSE system;

Future work

Joint Global OSSE systemThe OSSE system is based on the NCEP

operational system, GFS and GSI (3DVAR);Nature Run (“truth”) is from ECMWF’s 13

month free forecast (May 1, 2005 to June 31, 2006) at T511 and 91 levels;

Synthetic observations: Conventional observation data (NCEP);Satellite radiance data (NCEP and NASA GMAO);UAS and WISDOM data (ESRL).

Calibration through data denial (ESRL).

Joint Global OSSE ApplicationsUAS OSSE (ESRL): a report of data impact;

WISDOM OSSE (ESRL): some results but further improvement needed with targeting obs schemes;

Wind lidar OSSE (NCEP and JCSDA): presented in May LWG

Atmospheric river OSSE: planning.

WISDOM OSSE110 WISDOM launch sites; every 30 min: 21312 data

Impact of WISDOM on Track

The impact of WISDOM data on hurricane track forecast at different forecast time

Issues for Lidar OSSET511 resolution of NR may need upgrade

Higher resolution ECMWF nature run;FIM or other global model forecast for a new NR;

The current data assimilation system needs upgradeHybrid GSI for taking advantage of flow dependency;Other fine scale data assimilation with hotstart

capability;

Existing ensemble forecast cannot be used for hybrid data assimilation or targeting observation.

Acknowledgment: Riishojgaard et al: May LWG meeting

500hPa HGT anomaly correlation coefficients (T382)

1.2%

NH1.8%

SH

Impact of DWL observations is larger at the higher resolution (T382), even though skill of control is higher

Lidar Working Group, Miami, May 1-2 2012

Regional OSSEsTo address the resolution issue, one solution is regionalAOML and UM have developed a regional NR for hurricane applications embedded in the global OSSE;

ESRL is studying a new nature run approach for regional OSSEs

Fine scale NWP model forecasts nudged towards large scale analysis;

All existing ensemble forecasts can be used for targeting or hybrid data assimilation.

Nudged Nature Run towards Global Analysis

Initial/Boundary GFS 0.5 degree analysis data

Run time From 11th Mar. to 18th Mar. grid points: 402×468

Domain D3, but the resolution is 3km

Nudging effectsupper level

Improving Global OSSE for LidarUpgrade the nature runs to finer resolution as

discussed above;

Upgrade the data assimilation system from GSI to GSI hybrid systemThe hybrid can take flow dependent covariance to

improve lidar data impact;Ensemble forecasts are needed for the current

nature run.

Upgrade GFS to higher resolution with fine NRs.

Acknowledgment: Daryl T. Kleist at NCEP

Single 850mb Tv observation (1K O-F, 1K error)

Future WorksDevelop a comprehensive Lidar OSSE plan with

this Lidar Working Group;

Adapt the hybrid GSI data assimilation system into the current global OSSE system;

Develop new and fine resolution OSSE nature runs;

Calibrate improved global and new regional OSSEs.