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

Region: Southern Taiwan and adjacent oceans Date: 15 May – 30 June 2008 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. 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

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  Taiwan and U.S. components were organized in Nov  Taiwan proposal was submitted in Dec  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  4th SoWMEX/TiMREX planning meeting in Taiwan, Nov  5 th SoWMEX/TiMREX planning meeting in Boulder, Feb  S-Pol departed Boulder on 21 March 2008

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. (> years) makes it difficult to design an experiment in U.S. to study these events with reasonable chances of success

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.

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) Why S-Pol

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

Terrain and 12-Year Rainfall Statistics

Where Is It Going to Rain, and How Much?

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?

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?

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

ISS Potential Sites 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 22 o 59’36.45” E 120 o 38’39.30” Altitude ： 260 m ISS Potential Site 2 Position: Chi-shan Lat./Lon. ： None Altitude ： None TEAM-R Site 1 TEAM-R Site 2 TEAM-R Site 3

Work Space (1) AntVIRAQ RDA2 Tape

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

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

Data at S-Pol (2) Other data (cont.) –CAA data (radar, satellite, winds, temperatures, etc.) CAA data latest images are available on the web – / / 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

SoWMEX/TiMREX Logo

The End Thank you!

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