Wen-Chau Lee NCAR/EOL Ben Jong-Dao JOU

1. TiMREX/SoWMEX Program Overview(Terrain-influenced Monsoon Rainfall Experiment Southwest Monsoon Experiment/)A Joint US-Taiwan Monsoon Rainfall Study Wen-Chau Lee NCAR/EOL Ben Jong-Dao JOU Department of Atmospheric Sciences, National Taiwan University 15 November 2007

2. TiMREX/SoWMEX (Terrain-influenced Monsoon Rainfall Experiment/Southwest Monsoon Experiment) Goal:To improve basic understanding of the physical process associated with the terrain-influenced heavy precipitation systems and the monsoonal environment in which they are embedded through intensive observations, data assimilation and numerical modeling studies. Region:Southern Taiwan and adjacent oceans Date:15 May – 30 June 2008 NCAR PI - Wen-Chau Lee, Jim Wilson, Tammy Weckwerth, Bill Kuo, Jenny Sun, Rita Roberts, Qingnong Xiao, Chris Davis UCLA - Robert Fovell University of Hawaii - David Y.-L Chen University of Washington - Bob Houze Colorado State University - Steve Rutledge, Dick Johnson

3. Key Events of TiMREX • First discussed in 2 called TAMEX II • Opportunity was presented when both SHARE and VORTEX II were declined in 2006 • First planning meeting at NCAR on 30 Oct. 2006 • Taiwan and U.S. components were organized in Nov. 2006 • Taiwan proposal was submitted in Dec. 2006 • NCAR proposal was submitted in March 2007 • TiMREX replaced TAMEX-II • 2nd SoWMEX/TiMREX planning meeting in Taipei, April 2007 • Taiwan NSC proposal was awarded in June 2006 • NSF awarded S-Pol to TiMREX in July 2007 • 3rd TiMREX/SoWMEX planning meeting in Boulder, Sept. 2007 • 4th SoWMEX/TiMREX planning meeting in Taiwan, Nov. 2007 • 5th SoWMEX/TiMREX planning meeting in Boulder, Feb. 2008 • S-Pol departed Boulder on 21 March 2008

4. Motivation • Flash floods resulting from terrain-influenced heavy precipitation during warm seasons are extreme hazards in the U. S. [e.g., Big Thompson (1976, 12 inches in 4 hr), Rapid City (1972, 15 inches in 48 hr), Fort Collins (1997, 10 inches in 5 hr)] • Low skill in both predicting the warm season orographic heavy rainfall events and amount in numerical models impacts society, land-use, the economy, emergency manager, local government, far beyond the scope of meteorology • Improve warm season QPE and data assimilation techniques are two of the three goals of the U.S. Weather Research Program and are consistent with the NCAR cross-divisional Short Term Explicit Prediction (STEP) program • The rarely repeatable nature of these warm season flash floods at the same location in U.S. (>20-100 years) makes it difficult to design an experiment in U.S. to study these events with reasonable chances of success

5. Why TiMREX • Terrain-influenced heavy rainfall and flash floods occurred with a degree of regularity in southern Taiwan during the Mei-Yu season, a natural laboratory to study these events. • Heavy precipitation MCSs influenced by interactions among East Asian summer monsoon, Mei-Yu front, land-sea contrast, and steep terrain (>3000 m) are scientifically unique. • TiMREX nicely complements a series of field programs to improve basic understanding of orographic precipitation (COAST, MAP, IMPROVE II, and NAME) and convective precipitation forecasts (IHOP-2002, CSIP, and COPS). TiMREX provides natural progression from these prior programs into a subtropical, warm, humid and unstable environment. • TiMREX is cost effective because Taiwan operates one of the highest density meteorological observing networks in the world and already committed to a mesoscale experiment in southern Taiwan in 2008 with additional research facilities.

6. Why S-Pol • First S-Pol deployment to Asia • Polarimetric data at unattenuated frequency in the Rayleigh region: • Microphysical processes within these heavy rain producing convective systems (particle ID) • Rainfall rate • Cloud liquid water content and moisture profile • Boundary layer measurement: • Refractivity (surface moisture) • Cumulus clouds (Bragg scattering) • Boundaries and convergence lines • Storm kinematic strctures: • Key component of dual-Doppler radar network • Vertical wind profile (VAD)

7. Okinawa connection SCHeREX driftsonde PHONE08 SoWMEX-08/TiMREX Palau-08 Why 2008? 04/27~07/31 2006 FORMOSAT-3 RO (G) + rawinsonde (O)

8. Terrain and 12-Year Rainfall Statistics

9. Where Is It Going to Rain, and How Much?

10. TiMREX Scientific Questions • What are the effects of orography and the characteristics of upstream monsoonal flow on rainfall distributions in southern Taiwan? • What are the roles of the Mei-Yu front and its mesoscale circulations in the development, maintenance and regeneration of heavy rain producing convection systems in southern Taiwan? • How do boundary layer processes, such as, surface moisture distribution, land-sea contrasts and mountain-valley circulations modulate the precipitation pattern? • What are the microphysical processes within heavy rain producing convective systems that are influenced by complex terrain? • What is the potential for improving QPF skills by better understanding of multi-scale precipitation processes and the assimilation of high-resolution observations into numerical models and nowcasting systems?

11. TiMREX Scientific Questions • What are the effects of orography and the characteristics of upstream monsoonal flow on rainfall distributions in southern Taiwan? • What are the roles of the Mei-Yu front and its mesoscale circulations in the development, maintenance and regeneration of heavy rain producing convection systems in southern Taiwan? • How do boundary layer processes, such as, surface moisture distribution, land-sea contrasts and mountain-valley circulations modulate the precipitation pattern? • What are the microphysical processes within heavy rain producing convective systems that are influenced by complex terrain? • What is the potential for improving QPF skills by better understanding of multi-scale precipitation processes and the assimilation of high-resolution observations into numerical models and nowcasting systems?

12. SoWMEX/TiMREX DROPSONDE Ship sounding High Θe air Period：May 15-June 30, 2008, Area：SCS and Taiwan NCAR SPOL, Mobile XPOL, GPS Dropsonde, Shipsonde

14. ISS Potential Sites ISS Potential Site 2 Position: Chi-shan Lat./Lon.：None Altitude： None TEAM-R Site 3 TEAM-R Site 1 TEAM-R Site 2 ISS Potential Site 1 Position: Liou-Guei Jhong-Hsin Community Activities Center 六龜鄉中興社區活動中心 Lat./Lon.： N 22o59’36.45” E 120o38’39.30” Altitude：260 m

16. S-Pol Control Center 229 in . S-Pol Network SCI 1 SCI 2 ENG RDA 1 DM Rack RDA 1 RDA 2 Tape Tape Tape Tape 212 in . 39 in . 39 in . 39 in . 39 in . 56 in . Ant DM SCI 1 SCI 2 ENG UPS Work Space (1) RDA 2 Tape VIRAQ Ant

17. Work Space (2) • S-Pol Annex • Two 6-foot tables • 3 feet taken by technician computer • Room for three additional laptops • Data Analysis and Display Center • Approximately 30 ft of work space

18. Data at S-Pol (1) • S-Pol Data • SCC • Complete S-Pol data set available using CIDD • Complete set of DORADE sweep files from VIRAQ and HAWK processors available on sci1 and sci2 (viewable and translatable by soloii) • Data Analysis and Display Center • Complete S-Pol data set available using CIDD • Other Data • South-West Monsoon Experiment Field Catalog • http://61.56.10.120/

19. Data at S-Pol (2) • Other data (cont.) • CAA data (radar, satellite, winds, temperatures, etc.) • CAA data latest images are available on the web • http://wmds.aoaws.caa.gov.tw/htdocs/projects/aoaws/jmds/ • CAA data is also available through a Java application • Networking at S-Pol will limit number of Java clients • Possibility of WINS data sets from CWB WINS and/or CAA data availability dependent on permission and logistics

20. SoWMEX/TiMREX Logo

21. The End Thank you!

23. Micro rain radar ASTRA Da-Kwan NCAR-SPOL SoWMEX/TiMREX (2008)