3rd thorpex international science symposium, monterey, usa, 14 sept. 2009 overview of t-parc falcon...

3rd THORPEX International Science Symposium, Monterey, USA, 14 Sept. 2009

Overview of T-PARC Falcon operations and ECMWF data denial experiments

Martin Weissmann, Florian Harnisch, Stephan Rahm, Martin WirthInstitut für Physik der Atmosphäre, DLR Oberpfaffenhofen, Germany

Pat Harr, Naval Postgraduate School, USATetsuo Nakazawa and Kotaro Bessho, MRI-JMA, Japan

Sarah Jones and Doris Anwender, Universität Karlsruhe/Forschungszentrum Karlsruhe, GermanyDavid Parsons, World Meteorological Organization

Hee-Sang Lee, National Institute for Meteorologial Research, KoreaRon McTaggert-Cowan, Environment Canada

Carla Cardinali, ECMWF, United Kingdom


Falcon flights

Falcon objectives:- typhoon targeting- extratropical transition of tropical cylcones- lidar observations for NWP

Falcon funding institutionsDLR (Germany), NSF (USA), JMA (Japan) Forschungszentrum Karlsruhe (Germany), NIMR (Korea)Environment Canada, EUCOS

Falcon operations23 August - 3 October 2008 in Japan25 research flights 93 flight hours in total

hosted by US Navy @ NAF Atsugi (near Tokyo)

Overview of Falcon operations


source of satellite images: https://www.fnmoc.navy.mil/tcweb/cgi-bin/tc_home.cgi/

Sinlaku

Japan

IR Satellite Image09/11/08 2030 LT

Highlight 1: Water vapour lidar observations in typhoon environment (11 Sept. 2008)

16W

S-Korea Japan

OkinawaIR Satellite Image09/11/08 1830 LT

contentrations of 0.01-15 g/kg measured by new worldwide unique 4-wavelength DIAL


Highlight 2: Wind lidar observations

30 Sept 2008: flight into jet for ET objectives

A-TReC 2003

A-TReC 2003: ~ 3% reduction of mean forecast error over Europe by lidar (Weissmann and Cardinali, QJ 2007)GOAL: investigate the general validity of these results with larger data set (60 flight hours during T-PARC)T-PARC: twice the amount of A-TReC lidar data

A-TReC 2003


Highlight 3: Joint mission for typhoon targeting (TY center, surrounding and sensitive area)

Concept for ideal mission: joint mission on 11 September WC-130 observations in typhoon center (green) DOTSTAR observations in typhoon surrounding (blue) Falcon obs. in sensitive area highlighted by e.g. SV, ETKF (red)

sensitivity experiments by Florian Harnisch --> poster in the afternoon ECMWF experiments for center, surrounding, sensitive area

Japan

China

ETKF

SV


Tracks of typhoons Sinlaku and Jangmi with flight times


Influence of T-PARC observations an ECMWF typhoon track prediction

gray: no dropsondesgreen: operational dropsonde data (two different model versions)magenta: with time-corrected dropsondes

on average, forecast error reduction with corrected dropsondeson average, operational setup has similar errors as without dropsondes

improvements at a high level of forecast skill, no real forecast busts

Sinlaku Jangmi

smallsample

significant


Influence of T-PARC observations an ECMWF typhoon track prediction

gray: no dropsondesgreen: operational dropsonde data (two different model versions)magenta: with time-corrected dropsondes

on average, forecast error reduction with corrected dropsondeson average, operational setup has similar errors as without dropsondes

improvements at a high level of forecast skill, no real forecast busts

Sinlaku Jangmi

smallsample

from Jim Doyle, Navy Research Lab., USAsignificant


Examples of improving cases

uncertainties of recurvature point --> improvement with dropsondes

largest improvement with DOTSTAR dropsondes, degradation with WC-130 observations at 2008091000

(for details see poster by F. Harnisch in the afternoon)


Examples of neutral and slightly deteriorating cases

- very good forecast without observations

- remaining errors are supposedly rather connected to problems with land interaction than initial condition errors

(for details see poster by F. Harnisch in the afternoon)


Dropsonde observation statistics for WC-130 flight through typhoon center

Dropsondes within the typhoon are successfully assimilated in the ECMW model, but only a relatively small part of the information can be used with current DA systems due to large differences to the model first guess field

Potential for further improvements through flow dependant covariance matrix, e.g. ensemble 4D-Var

Center observations led to significant analysis differences, mainly typhoon intensification, but relatively little forecast improvements


Period: 2008090900 - 2008100112

driftsondes

ET

recurvature

T-PARC data coverage @ ECMWF

formation


Influence on mid-latitude forecast error

Z 500 hPa Pacific: 30-65N, 155E - 130W

Z 500 hPa northern hemisphere 20-90N

reduction of mid-range forecast error over the Pacific and long range northern hemisphere forecast error


Influence on mid-latitude forecast error (uncycled)

Z 500 hPa Pacific: 30-65N, 155E - 130W

no improvement without "cycling", i.e. when the analysis uses the first-guess from the control run


on average, improved typhoon track prediction with additional dropsondes

improvements in particular at early typhoon stages before recurvature

largest improvements through observations in the surrounding of the storm (DOTSTAR strategy) rather than in the typhoon center or sensitive areas indicated by singular vectors or ETKF (see poster)

timing errors in operational dropsonde data set at ECMWF, corrected for the future and to my knowledge no other NWP center is affected

in mid-latitudes, improved mid-range forecast over the Pacific and long range forecast on the northern hemisphere

nearly no improvement without "cycling", i.e. when the analysis uses the first-guess from the control run

improvements are moderate, ECMWF forecasts without dropsondes are already relatively accurate

studies to investigate the influence of airborne lidar observations will follow

Thanks to:- all people involved in T-PARC- Milan Dragosavac, Ioannis Mallas and all others at ECMWF involved

Conclusions (preliminary results)

3rd thorpex international science symposium, monterey, usa, 14 sept. 2009 overview of t-parc falcon...

Documents

usa significant slide

typhoon center dropsondes

parc observations

nsf usa

dropsondes green

dropsondes improvements

afternoon slide

typhoon environment