Transcript Allgemein - COSMO model

Status of WG1
Science Plan Issues
Christoph Schraff
Deutscher Wetterdienst, Offenbach, Germany
•
KENDA
•
LETKF at CNMCA :
•
3DVar at HMC (Sochi area):
•
ARPA-SIM (Virginia Poli): comparison of 1D-Var+nudging and LHN
talk by Lucio Torrisi
not (yet) as good as interpolated GME analyses;
will test use of radar radial winds
1D-Var not as good as LHN
Problem: bias between moist physics of COSMO and diagnostic scheme used in 1D-Var
 work will be stopped
•
at DWD:
• Direct nudging of radial velocity
• LHN for COSMO-EU
• Nudging of GPS-IWV
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
1
nudging of radar radial velocity:
verif. vs. radar precipitation (1 – 27 May 2012)
threshold:
0.1 mm / h
ETS
FSS, 11 g.pts. (30 km)
control (C-DE setup, with LHN)
use of radial velocity added
00-UTC
forecast
runs
12-UTC
forecast
runs
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
2
nudging of radar radial velocity:
summary
•
experiment May 2012 with additional use of vr (control with LHN !) :
 small positive impact on (mainly strong) precipitation
 otherwise neutral
 no show cases with strong positive impact
•
next:
 check and improve efficiency,
 add few more tests,
 make it operational
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
3
Latent Heat Nudging for COSMO-EU
Motivation
•
Reanalysis Project of HErZ would like to use LHN also on its larger domain
configuration (COSMO-CORDEX, x = 7km)
•
Does it work ?
Is there a negative interaction between LHN and the deep convection scheme ?
Experiments
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2 periods:
Summer: August 2012 (incl. convective cases)
Winter: 1 Nov. – 15 Dec. 2012 (incl. snow cases)
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operational COSMO-EU setup (Cosmo V4_27, tk?min=0.4)
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operational LHN setup except:
• no blacklist information used
• no bright band detection
• LHN within first 25 minutes of forecast (will be ~ 2.5h in operational run)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
4
LHN for COSMO-EU:
radar data coverage
•
same data as for COSMO-DE,
currently
•17 German Doppler radar stations
quality controlled
•2 Dutch stations
•2 Belgian stations
•9 France stations
•3 Swiss stations
•2 Czech stations
soon extended by 2 Polish stations
•
every 5 minutes
•
future: can be extended by OPERA
composite outside COSMO-DE domain
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
5
LHN for COSMO-EU:
case study
hourly precipitation at 2 Aug. 2012, 00 UTC + 4h
Radar
Control (rout)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
LHN Experiment
[email protected]
6
LHN for COSMO-EU:
verif. vs. radar precipitation (August 2012)
00 UTC
12 UTC
0.1 mm/h
0.1 mm/h
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
00 UTC
12 UTC
2.0 mm/h
2.0 mm/h
[email protected]
7
LHN for COSMO-EU:
Summary
•
LHN in COSMO-EU is beneficial; forecast impact:
• Summer:
• precipitation improved (esp. convective cases)
• most surface parameters slightly improved
• Winter: neutral
•
Work started to extend data coverage using OPERA radar composite
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
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Status of OPERA
•
three 2-D composites are available every 15 minutes:
• current rain rate, sum over last hour, current maximum reflectivity
• Phillipe Lopez (ECMWF) found out:
• quality has increased in 2013 (with Baltrad QC) but is still not sufficient
everywhere
• best quality over UK, France, Poland and Germany
• underestimation over southern Europe
• underestimation in snow cases
• lots of spurious ground echoes
• software transforming it to COSMO grids available (Stephan)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
9
Status of OPERA
ODC composite
12 Aug 2013,
15 UTC
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
10
Status of OPERA
OPERA DC composite (C-DE domain):
1 Z-R relationship
‘EY composite: Input for LHN at DWD,
4 different storm-dep. Z-R relationships
12 Aug.
2013
15 UTC
differences particularly for low precip rates; (erroneous spaital alignment ?)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
11
Status of OPERA
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3-D reflectivity and radial wind:
• reflectivity sent by almost all member states,
radial wind only by few
(but increasing)
(Courtesy Hidde Leijnse,
* indicates max. number)
• HIRLAM already gets access to volume data, but possible also for other
consortia
• dissemination of volume data to member states planned for end of 2014
(to be decided: with or without quality information ?)
• discussion about meta data / quality issues are ongoing
(e.g. to distinguish ‘zero echo’ – ‘no data’ (compare with raw data))
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
12
COSMO Science Plan Issues on DA:
General strategy
• overall strategic goals of COSMO: convective-scale EPS
 convective-scale ensemble-based DA
• other consortia: focus on 3D-/4D-Var for deterministic, EnKF for EPS
hybrid
• Hybrid ‘4D-EnVar’ : without need of TL / adjoint
Environment Canada !
UKMO ?
• DWD: hybrid 3D-EnVar for global ICON

HIRLAM ?
 for COSMO ?
•
advantages of EnVar over LETKF (for deterministic run !) :
 localization on B, not in obs space  better for non-local obs
 hybrid approach mitigates sampling error
•
disadvantages of EnVar over LETKF:
 4D approach limited: Use only obs times where Grib fields used
 costs
COSMO: continue with LETKF
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
13
COSMO Science Plan Issues on DA:
Action items 2015  2017 (and beyond !)
•
consolidation of LETKF scheme,
wherever found required,
may include extensions:
– intrinsic stochastic physics (links to WG3a, WG7)
– (other types of) additive covariance inflation
– iterative (e.g. running in place like) approaches or latent heat nudging (LHN)
in view of improving convection initiation
– use of ensemble members with lagged valid time to reduce phase errors
– blending techniques to combine information from the larger scales of the
nesting model
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
14
COSMO Science Plan Issues on DA:
Action items 2015  2017 (and beyond !)
•
integrated forecasting system for nowcasting (NWC) and
very short-range-forecasting based on NWP
– towards very high resolution (1 km / sub-km)
(link to SFP project COSMO-Airport, incl. Mode-S data; sub-km)
– towards very high frequent analysis and forecast update
(link to HErZ TB1, KENDA with 5-min update using 3-d radar data)
– main issue: quality !
(need to match obs, but maintain balance)
– optional: ‘higher weights for latest observations’ (smaller obs errors, weaker data
thinning) ? smaller localization scales ?
– optional: evaluation of assimilation of NWC products as pseudo-obs
such as stability indices and objects (using non-conventional metrics)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
15
COSMO Science Plan Issues on DA:
Action items 2015  2017 (and beyond !)
•
extended use of obs
(particularly PBL, low-level humidity, cloud, precip)
– consolidate obs focused in KENDA PP: radar, GPS slant path, SEVIRI cloud
– improved use of screen-level obs (T2m, RH2m, uv10m)
– SEVIRI WV (water vapour) channels
– AMDAR humidity ; high-resolution aircraft Mode-S (wind) data
– microwave radiometer (+ Raman lidar) T-, q- profiles, Doppler wind lidar,
ceilometer cloud base height
– (SEVIRI VIS for cloud properties, cloud radar data (CALIPSO, EarthCARE 2015)
– renewable energy: power data from wind mill farms and solar power systems satellite
• no aerosol assimilation :
– for COSMO-ART : accurate description of aerosol sources
– would require substantial resources
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
16
COSMO Science Plan Issues on DA:
Action items 2015  2017 (and beyond !)
•
lower BC (analysis (link to WG3b) + perturbations (link to WG7) !)
– soil moisture SM (soil temperature, etc.), e.g. by:
– include SM in control vector, add SMOS / ASCAT satellite SM
– separate 2-D column analysis: LETKF, or EPS used in Var-SMA
– snow cover and depth
– SST (perturbations e.g. by pattern generator)
•
diagnosis:
(explore in EnKF framework) use of
 FSO (Forecast Sensitivity to Observations) (→ link to HErZ project)
 DFS (Degrees of Freedom for Signal) diagnostics
(to assess usefulness of different observation types)
•
2017+ : adapt LETKF to ICON-LAM (review decision LETKF – EnVar)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
17
COSMO Science Plan Issues on DA:
Action items 2018  2020
•
… see previous slides
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MTG-IRS
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MW + IR radiance over land + in cloudy areas (dep. on experience in global DA)
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parameter estimation ?
•
observation error correlations ?
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
18
COSMO Science Plan Issues on DA:
risks
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insufficient quality of LETKF ( develop EnVar ?)
•
need to maintain / increase (often temporary) human resources !
Depends on:
 continuation of HErZ after 2014
 new fixed position for radar DA
 new temporary positions ?
 EUMETSAT fellowship submitted by CNMCA: sat data on soil moisture
 further increase of involvement e.g. by MCH, ARPA-SIM, CNMCA, …
… new projects / collaboration with academia
 new flexible portable scripts may facilitate experimentation + collaboration
with other institutes on a technical level observation error correlations ?
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
19
Science Plan issues on data assimilation:
Summary
•
consolidate / refine LETKF wherever required
(enhancement techniques e.g. to correct phase errors; RIP, LHN …)
•
integrated forecasting system for NWC – (V)SRNWP
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obs: radar, GPS slant, cloud; screen-level; SEVIRI WV, MTG IRS, …
•
lower BC
•
diagnosis: FSO , DFS
•
adapt to ICON-LAM
(develop EnVar ?)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
20
Science Plan issues on data assimilation:
Summary
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
21
developments / plans
at other consortia
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AROME:
– EDA: 3DVar with perturbed obs incl. surface ana (AROME 2014, Arpege LBC)
later: revisit breeding / ETKF
– multiplicative inflation of forecast perturbations: 1.15 (every 3 hrs)
– stochastic physics tendencies (SPPT): large-scale, slowly evolving
– also tried: microphysics & turbulence parameter perturbations
– perturbed surface initial conditions (SST, SM, Rsmin, LAI, Cveg, Z0oro)
– coupling with large-scale analysis: tests with Jk term in Var
(weak constraint towards coupling data in Var, truncate Jk info at k=20)
– Tests with 1-hrly cycles (3DVar)
– use of SEVIRI WV over land
– issue: model bias with strong diurnal cycle
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
22
developments / plans
at other consortia
•
UKMO:
– NWP nowcasting system: Nowcasting Demonstration Project (NDP)
– 1hrly 4DVar with sub-hrly obs (…, MSG WV + AMVs, radar radial winds;
hourly cloud obs (sat + surf), T2m, RH2m, uv10m) + LHN (!)
– 12-hour forecast every hour
– 40km-FSS beats STEPS (Lagrangian-extrapolation NWC) after 1.8 hrs
– forms basis for next-generation UK NWP nowcasting system
– generally: towards 4D-EnVar (without need of TL / adjoint ?)
Status of WG1 and Science Plan Issues
COSMO General Meeting, Sibiu, 2 – 5 Sept. 2013
[email protected]
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