Report from DAOS-WG

Presented by Richard Swinbank

Prepared by Roger Saunders with input from WG members

Current membershipRon Gelaro(D), Co-chair

NASA, USA

Roger Saunders(O), Co-chair

Met Office, UK

Stefan Klink(O)

DWD, Germany

Carla Cardinali(D)ECMWF

Chris Velden(O)Univ Wisconsin-CIMSS,

USA

Tom Hamill(D)NOAA, USA

Tom Keenan(O)CAWCR, Australia

Rolf Langland(D)NRL, USA

Bertrand Calpini (O) MeteoSwiss, Switzerland

Andrew Lorenc(D)MetOffice, UK

Florence Rabier(D/O)Météo-France

Prof. Bin Wang(D), Chinese Academy of Sciences, China

Michael Tsyroulnikov(D)HydroMet Centre, Russia

Mark Buehner (D)Environment Canada

Sharan Majumdar (D) RSMAS, Univ Miami,

USA

O=Observations D=Data Assimilation

DAOS-4 WG meeting Exeter 27-28 June 2011

• Review targetting paper

• Updates on THORPEX campaigns

• Review observing systems

• Review developments in data assimilation

• WG matters

METOP : MetOp ATOVS,MetOp IASI, MetOp ASCAT NOAA : NOAA15 ATOVS AMSUA, NOAA17 ATOVS HIRS, NOAA18 ATOVS, NOAA19 ATOVSOTHER LEO: EOS AIRS, F16 SSMIS, ERS, WINDSATGEO : GOES, MTSAT, MSGAircraft : AMDAR, AIREPSONDE : PILOT, TEMPSFC Land : SYNOP, BOGUSSFC Sea : BUOY,SHIP

Total Impact = Number of soundings/profiles * mean observation Impact of each sounding/profile

Observation Impacts to NWP forecast

-16-12-8-40

Ob

serv

atio

n T

ypes

Total Observation Impact[J/kg]

METOP

NOAA

OTHER LEO

GEO

AIRCRAFT

SONDE

SFC LAND

SFC SEA

Impact of different observation platformsfrom forecast sensitivity diagnostic

Relative Contribution of Observations to NWP forecast

3.1

15.3

13.2

9.9

5.9

7.9

20.4

24.3

0 5 10 15 20 25 30

Ob

serv

atio

n T

ypes

Relative Observation Impact[%]

METOP

NOAA

OTHER LEO

GEO

AIRCRAFT

SONDE

SFC LAND

SFC SEA

5

The Concordiasi Project

Additional observations over Antarctica for NWP

F. Rabier, V. Guidard, S. Noton-Haurot, A. Doerenbecher, D. Puech, P. Brunel, A. Vincensini, H. Bénichou, Météo-FrancePh Cocquerez, CNESA. Hertzog, F. Danis, IPSL/LMDT. Hock, S. Cohn, J. Wang NCARC. Sahin, A. Garcia-Mendez, J-N Thépaut ECMWFA. Cress, U. Pfluger, DWD R. Langland, NRLG. Verner, P. Koclas, CMCR. Gelaro, NASA/GMAOC. Parrett, R. Saunders Met OfficeY. Sato JMA

6

CONCORDIASIFlights overview Sept 2010-January 2011

2010, a stable Austral Winter Polar Vortex

7

Sea-Ice limit

640 Dropsondes (20100923-20101201)

ParticipantsCMCDWDECMWFGMAOMétéo-FranceMet OfficeJMA

Data Assimilation Monitoring Statistics over the Antarctic

RMS(O-F) Raob T Obs Count Raob T

Radiosonde Background Temperature Departures (O-F)

Courtesy F. Rabier, Météo-France

All models have difficulty predicting lowest-level temperatures

9

Concluding remarks on ConcordIASI

Concordiasi provided an unprecedented data coverage of meteorological observations over Antarctica

Both dropsonde and gondola information seem to have a positive impact on forecast performance (preliminary results from NRL, DWD and MF)

Gondola temperature data at 60hPa shows the largest model errors in areas of strong gravity-wave activity

Dropsonde information confirms statistics obtained with radiosondes and provide a more global view

Most models have problems predicting the lowest level temperatures

In –situ MeasurementsIssues for THORPEX

• Transition to BUFR for radiosondes provide new opportunities

• GPS total zenith delay gobal coverage

• In-situ soil moisture and temp

• Common format for precip radar data

•To improve estimates of solid precipitation and develop guidance on the accuracy and temporal resolution of solid precipitation parameters

• New observations needed for mesoscale

Ground-based GPSObservations available from E-GVAP

Global Extent

ASSESS THE CURRENT AND POTENTIAL CAPABILITIES OF WEATHER RADARS FOR THE USE IN WMO INTEGRATED GLOBAL OBSERVERING SYSTEM (WIGOS )by Ercan Büyükbaş, Turkish State Meteorological Service (TSMS)

Radars now used to Verify NWP model Precipitation forecasts

Need to advocate a common format worldwide to enablewider verification of precipitation

NCEP Stage IV obs (mm/day)

CTRL – NCEP Stage IV

NEW – NCEP Stage IV

Impact of NCEP Stage IV assimilation on 12h forecasts of precipitation.

Sept-Oct 2009 average(CY35R2; T511 L91)

ECMWF 2011

Mean bias and RMS error are reduced

Impact on forecast scores for other parameters (Z, T, wind, RH):

- neutral or slightly positive impact on the global scale. - some hint of positive impact over Europe (days 4-5) and Asia (days 8-10).

Direct 4D-Var assimilation of NCEP Stage IV rain data

E

CM

WF

201

1

RMSE South. Hemis. 500hPa wind

RMSE North. Hemis. 500hPa wind RMSE Europe 500hPa temperature

RMSE Asia 850hPa Temperature

good Forecast Root Mean Square Error changes due to direct 4D-Var assimilation of NCEP Stage IV rain data

1 April – 6 June 2010, T1279 (~15 km global) L91

Satellite MeasurementsIssues for THORPEX• Extended life of some research satellites helps to mitigate losses elsewhere

•Reduced thinning of AMSU-A shown to beneficial

•Hyperspectral sounder in GEO orbit now approved by Europe on MTG

•Contribution to GOS by nations increasing (e.g. FY-3, Oceansat-2) to fill future gaps in GOS

•Challenge of assimilation of satellite data in high resolution local area models and extend use of advanced IR sounders (cloudy rads, use PCs,..)

• ASCAT winds for Irene and model background

• Only one scat now used for NWP

• Trials using scatterometer on Oceansat-2

Importance of Scatterometer winds

A. Doerenbecher, Météo France

The targeting

procedure

Impact of dropsonde data for Irene

Comparison of different models

Tropical cyclone track forecast errors during the Summer T-PARC period for four assimilation-forecast systems. The solid (dashed) lines represent parallel analysis-forecast cycles excluding (including) T-PARC dropwindsonde data.

DAOS-WG Statement on impact of targeted data

• For mid-latitude systems, the value of targeted data is found to be positive but small on average. The WSR programme has found that targeting results in some improvement in 2-3 day forecasts over N. America.

•Observations in dynamically sensitive areas have a bigger average impact per observation than those deployed randomly. The cumulative benefit of a small number of targeted aircraft observations to forecast accuracy over broad verification regions is smaller than that of other observing systems that provide observations with a more complete coverage.

• For forecasts of the track of TCs targeted observations have proven to be beneficial statistically. A simple sampling strategy of observing uniformly around the TC has been shown to be effective, with most models exhibiting an improvement. • There is a need to assess the impact of targeted observations with more user-focused measures of the value of forecast improvements to society, while retaining the ability to get significant results from relatively short experiments.

DAOS-WG Future Directions• Maintain links with ET-EGOS, WGNE, etc

• Next meeting in Madison 19-20 Sep 2012

• Joint meeting with MFWR under discussion

• DAOS remains a global focus not mesoscale

• Continue mix of Observations and DA

• Leading group for DA in WMO together with WGNE. What is future post THORPEX?