1. Wind Profiler Radar for diagnosis of precipitating clouds K. Krishna Reddy 1, Baio Geng 1, Ryuichi Shirooka 1, Tomoki Ushiyama 1, Hiroyuki Yamada 1, Hisayuki Kubota 1, Hiroshi Uyeda 1,2, Masanori Yoshizaki 1 1 Institute of Observational Research for Global Change (IORGC) / Japan Agency for Marine-Earth Science and Technology (JAMSTEC) 1, 2 Hydrospheric and Atmospheric Research Center (HyARC), Nagoya University Capsule: Single Wind Profiler Radar capabilities and its application for diagnosis of the vertical structure of the Precipitating clouds.

2. Background and Motivation The global atmospheric circulation is sensitive to the vertical distribution of latent heating, which is associated with different types of precipitation and hence it is important to distinguish between convective and stratiform precipitation profiles around various precipitating clouds observed during Meiyu/Baiu season and also around western Pacific Ocean region over Palau. To understand the mechanism of cloud- precipitation processes and air-sea interactions over the warm water pool, focusing on seasonal and intra-seasonal variations (ISV). Lack of long-term field experiments over Palau region in the Western Tropical Pacific Ocean. In the vicinity of Palau several tropical depression are developed. To elucidate the global climate change, focusing on the ENSO (El Nino Southern Oscillation) event around the Western Tropical Pacific Ding, 1995

3. Brief introduction to the Observational Facilities Characterization of Meiyu/Baiu Precipitating clouds observed during IOP-2001 and IOP-2002 Microphysical evidence of the transition between predominant convective/stratiform rainfall associated with intra-seasonal variations (ISV) over Palau Summary and Conclusions Outline of the Presentation

4. Aimeliik Observatory Wind profiler site AWS observations Ocean, Land and Atmosphere Interactions Integrated Research Project (IORGC/JAMSTEC)

5. Instruments at Peleliu Observation Site Potable Radiation Package Automatic Weather Station Solar panel Microwave radiometer GPS receiver Total sky imager Ceilometer JW Disdrometer November 2000 (AWS, GPS) June 2001 (Ceilometer) October 2001 (TSI, PRP) December 2001 (MWR) March 2005 (JW Disdrometer)

6. Microwave profiling Radiometer (MPR) Ceilometer JW Disdrometer AWS 1290 WP: V h (z), W(z), Cn 2 (z)Low Mode: ~30 s, 60 m 0.1 to 2-4 km High Mode: ~ 30 s, 200 m 0.3 to 12 km RASS: T V ~ 30 s, 60 m 0.1 to 1.5 km MRR: N(D,z), DSD(z), W(z) 1 min, 100 m 0.1 to 3 km Ceilometer: β(z), Cloud base 1 min, 15 m 0.015 to 7.6 km MPR: T(z), rv(Z), rc(z), integrated vapor & liquid 1 min, variable,0.1 to 10 km JW Disdrometer: N(D), DSD 1 min, surface measurements AWS: T,p,e, V h, Rain intensity 10 sec, surface measurements Micro Rain Radar (MRR) RASS Shield Wind Profiler (WP) Antenna Assembly Instrument and measured parameter Δt, Δz, height coverage Instruments at (Palau) Aimeliik Observatory Doppler Radar

7. Wind Profiler Radar (WPR) 200 m 60 m Wind profiler data Accuracy: Wind speed :  1 m/s; Wind Direction :  10 degree Reddy et al. 2004 WPR observe Vertical wind directly. Horizontal wind profiles in the Troposphere. Useful for classification of Precipitating cloud systems into Convective, mixed (convection/stratiform) and Stratiform. Characterization of convective boundary layer evolution. Air quality measurements

8. Brief introduction to the Observational Facilities Characterization of Meiyu/Baiu Precipitating clouds observed during IOP-2001 and IOP-2002 Microphysical evidence of the transition between predominant convective/stratiform rainfall associated with intra-seasonal variations (ISV) over Palau Summary and Conclusions Outline of the Presentation

9. Yangtze River Observational area Meiyu/Baiu Front Data used for the Meiyu/Baiu Precipitation Study: Wind profiler : IOP-2001  04 June – 16 July IOP-2002  11 June – 31 July Rawinsonde : - do – GMS satellite : - do –

10. Classification of precipitating cloud using Wind Profiler Radar data (a) Convection 08:03 LT Transition 08:56 LT DOPPLER VELOCITY, ms  1 Stratiform 16:38 LT Stratiform 09:07 LT Precipitation echo Turbulence echo Based on Reddy et al. 2002 Doppler Spectra of the vertical beam observed on 21 June 2002 Down ward Upward Doppler Velocity, ms  1 REFLECTIVITY (SNR), dB Convection 08:03 LT Transition 08:56 LT Stratiform 09:07 LT Precipitation echo Turbulence echo Bright Band 22 June 2001 23 June 2001 24 June 2001 19 June 2002 20 June 2002 21 June 2002 IOP-2001 IOP-2002

11. Algorithm for Classification of Vertical Structure of the Precipitating Clouds observed by the wind profiler radar Doppler Velocity, m/s

12. GMS Satellite, AWS & Wind profiler observation during IOP-2001 and 2002 15 June to 15 July 2001 15 June to 15 July 2002 Total Rain fall over Dongshan 254 mm Total Rainfall over Donghsan 140 mm Power failure T BB Meiyu/Baiu period

13. Characteristics of Meiyu/Baiu environmental conditions during the year 2001 and 2002

14. Time-height sections of reflectivities over a Doppler radar. Diurnal variation 3-4-day periodicity Stronger precipitation systems Weaker precipitation systems Geng et al. 2004

15. 20012002 Meiyu periodShorter (June 18 – June 27) Longer (June 18 – July 10) Rainfall amountMuch more (about 400 mm) Less (about 200 mm) Precipitation systemStronger (many convective echoes) Weaker (many stratiform echoes) Precipitation varietyDiurnal variationAbout 3-4 day periodicity CAPE / CIN935.2/-110.01376.07/-114.67 Precipitable Water (mm)50.3845.18 Relative humidity(%) @850 hPa 71.2364.17 Difference of Difference of Meiyu/Baiu Period):

16. Brief introduction to the Observational Facilities Characterization of Meiyu/Baiu Precipitating clouds observed during IOP-2001 and IOP-2002 Microphysical evidence of the transition between predominant convective/stratiform rainfall associated with intra-seasonal variations (ISV) over Palau Summary and Conclusions Outline of the Presentation:

17. Data-collection at Aimeliik Observatory Months DATA USED FOR THE PRESENT :

18. Westerly and Easterly (monsoon) wind regime over Palau Criteria : Westerly Wind Regime: 1. Wind Profiler observations between 1.5 and 2 km Zonal wind >5 m/s 2. Korror Radiosonde data at 850 hPa Zonal wind > 5 m/s Westerly Wind Regime: 1. Wind Profiler observations between 1.5 and 2 km Zonal wind >5 m/s 2. Korror Radiosonde data at 850 hPa Zonal wind > 5 m/s 10-days averaged Horizontal winds observed over Palau 2003 2004

20. Intra-seasonal variation (ISV) of precipitating clouds observed during Westerly Wind regime Month Easterly windswesterly windsEasterly windswesterly winds May30&3118-29 June01-06,15-3007-1413-30 July*01-1002-1801, 19-31 August12-2301-11,24-31 01-31 Sept.*10-2001-10*,21-3003-14,17-2101-02,15-16, 22-30 Oct.02-1301,14-3121-3101-20 Nov.01-2225-3001-13,21-25,2914-20,26-28,30 20032004 * 11 -22 July 2002 & 29 Aug. to 16 Sept. 2003 No data because Wind Profiler Radar site electric power failure

21. E1 W1 E2 W2 147 157 167 177 187 149 157 167 177 187 Zonal Winds and Daily mean diameter (27 May to 09 July 2003) Julian Day D Mean Diameter (mm) Velocity, (m/s) During the easterly periods had Rain drops with larger diameters since mean weighted diameter is about 0.5 and 1.5 mm, while for the westerly case drops diameter is from 0.5 to just 1.0 mm. This is evidence of a convective feature for easterly regime.

22. Daily mean Doppler Velocity and Spectral width observed between 27 May and 09 July 2003 E1 W1 E2 W2 147 157 167 177 187 Daily mean velocity was more positive for easterly regime and its standard deviation was very high, indicating the presence of strong updrafts The turbulence was concentrated below the 0 o C isotherm during westerly regimes, but during the easterly regime it exceeded this height due to strong convection, related to the strong up and downdrafts.

23.  In the passage of the cloud systems, during IOP-2001, convective and mixed types of rain systems are pre-dominant whereas during IOP-2002 convective systems embedded within a wide stratiform precipitation were observed.  Differences between the cases in IOP-2001 and in IOP-2002 are mainly due to the difference in the distribution of water vapor and local environmental conditions. Our observational results suggest that large difference in relative humidity and horizontal wind speed apart from the large scale systems disturbances. In IOP-2002, relative humidity and horizontal wind speed in the lower troposphere below about 3 km altitude are about 87 percent and 11 m/s, respectively, which are both smaller than those in IOP-2001.  The observational results also suggest that shallow convective boundary layer, low preciptiable water, lower relative humidity and the weak low level jet contributed to the shorter lifetime and the suppressed development of convective precipitating clouds over Dongshan during IOP-2002 compared with IOP-2001. Conclusions Conclusions (Meiyu/Baiu Period):

24.  The brief microphysical analysis of convective regimes associated with the ISV showed a large difference in type, size and microphysical processes of hydrometeor growth in each wind regime.  Strong spectral width is due to convective precipitation formation mechanisms (turbulence), allowing particles to rapidly grow by accretion of liquid water, while weak spectral width is due to weak turbulence, which allows ice particles to grow by deposition of vapor water, aggregation and, in a last way, by accretion. Conclusions (ISV associated Precipitating clouds over Palau)

25. Meiyu period 10 days 2001 2002 Meiyu period 23 days Time-latitude sections of infrared satellite images. Approach of the first typhoon T Three consecutive rainy days T