Videosonde Observation in the Tropics The Third International SOWER Meeting Lake Shikotsu July 18-2, 26 Kyukamura Shikotsuko, Lake Shikotsu, Japan Kenji Suzuki Yamaguchi University, Japan 1
Table of Contents 1. Motivation 2. Videosonde 3. Previous videosonde observation 4. R/V Mirai MR4-8 cruise 5. Summary and future plan 2
Motivation 1 In the tropical western Pacific region, - Warm pool convection - Release of latent heat drive the global circulation Precipitation mechanisms relate to - Upward transportation of water vapor - Vertical heat budget 3
Motivation 2 - Liu & Fu (21), Takayabu (22) TRMM data different precipitation system over ocean and land - The difference originates from - - - Specific heat properties of land and sea? Large-scale circulation pattern? Cloud microphysics? - Importance of in situ microphysical observation of clouds developed over the tropical ocean - Goal: to investigate the precipitation particle distribution over the ocean using Videosonde 4
Videosonde 1 Takahashi (199) 5
Videosonde 1 Takahashi (199) 6
Videosonde 1 Takahashi et al. (1995) at Manus Island, Papua New Guinea, TOGA-COARE 7
Videosonde 2 8
Videosonde 2 9
Videosonde 3 Suzuki et al. (26) 1
Specification Total observation time 6 minutes approximately Particle size resolution.1mm (.1 mm for videosonde 2) Video picture Black and white Transmission power.5 W Carrier frequency 168 MHz Video band width 1 Hz to 1 MHz Modulation FM Band width less than 4 MHz Battery Lithium/Alkaline battery Dimensions 57mm*18mm*34mm (videosonde 1) 8mm*24mm*4mm (videosonde 2) 45mm*16mm*22mm (videosonde 3) Weight 4. kg (videosonde 1) 4.5 kg (videosonde 2) 1.8 kg (videosonde 3) * present 1.2kg Cost 11
Videosonde Observations Pingliang (China) 1992 Shanghai (China) 1998 Joetsu, Niigata (Japan) 1993 Tsunekami, Fukui (Japan) 1994 Kagoshima (Japan) 1994, 1995 Tanegashima, Kagoshima (Japan) 1996 Chang Rai (Thailand) 1997 Surat Thani (Thailand) 1994 Songkhla (Thailand) 1993 R/V Mirai MR4-8 (Palau) 24 Phuket (Thailand) 1996 Ponape (Micronesia) 1988 Bandar Seri Begawan (Brunei) 1996 Manus (Papua New Guinea) 1991, 1992 Melville Is. (Australia) 1995 12
Pingliang (China) 1992 Shanghai (China) 1998 Chang Rai (Thailand) 1997 Joetsu, 7 Niigata (Japan) 1993 Tsunekami, Fukui (Japan) 1994 4 Kagoshima (Japan) 1994, 1995 3 Tanegashima, Kagoshima (Japan) 1996 7 Surat Thani (Thailand) 1994 ICE CRYSTAL GRAUPEL R/V Mirai MR4-8 (Palau) 24 1 Songkhla (Thailand) 1993 6 Phuket (Thailand) 1996 Ponape (Micronesia) 1988 5 Bandar Seri Begawan (Brunei) 1996 HEIGHT(km) 8 4 3 2 1 Maritime Region 17 16 ICE CRYSTAL 15 14 RAINDROP FROZEN DROP 2 1 2 TEMPERATURE ( ) HEIGHT(km) 13 12 11 1 Melville Is. (Australia) 1995 9 8 6 5 2 1.1.4.5.6.7.8.91 4 5 6 7 8 91 DIAMETER(mm) 836(LCT) OCT.4 1988 GRAUPEL SNOWFLAKE FROZEN DROP RAINDROP Manus (Papua New Guinea) 1991, 1992 8 7 6 5 4 3 2 1 1 2 TEMPERATURE ( ).1.4.5.6.7.8.91 4 5 6 7 8 91 DIAMETER(mm) 952(LCT) NOV.24 1992 13
Continental Region 13 12 Pingliang (China) 1992 Shanghai (China) 1998 Chang Rai (Thailand) 1997 HEIGHT(km) 11 1 9 8 7 6 5 4 3 ICE CRYSTAL 5 Joetsu, Niigata (Japan) 1993 4 Tsunekami, Fukui (Japan) 1994 SNOWFLAKE Kagoshima (Japan) 1994, 1995 2 Tanegashima, Kagoshima (Japan) 1996 3 1 GRAUPEL TEMPERATURE ( ) Phuket (Thailand) 1996 Surat Thani (Thailand) 1994 Songkhla (Thailand) 1993 2 1 R/V Mirai MR4-8 (Palau) 24.1.4.5.6.7.8.91 4 5 6 7 8 91 DIAMETER(mm) 72(LCT) JUL.14 1992 Bandar Seri Begawan (Brunei) 1996 RAINDROP 1 Ponape (Micronesia) 1988 Manus (Papua New Guinea) 1991, 1992 Melville Is. (Australia) 1995 14
HEIGHT(km) 13 12 11 1 9 8 7 6 5 4 3 2 1 Pingliang (China) 1992.1.4.5.6.7.8.91 4 5 6 7 DIAMETER(mm) 13(LCT) NOV.11 1993 6 Monsoon Region 5 ICE CRYSTAL 4 15 GRAUPEL 3 14 13 2 FROZEN DROP 12 ICE CRYSTAL SNOWFLAKE 1 11 1 RAINDROP Phuket (Thailand) 1996 TEMPERATURE ( ) Shanghai (China) 1998 Chang Rai (Thailand) 1997 2 Surat Thani (Thailand) 1994 Songkhla (Thailand) 1993 Bandar Seri Begawan (Brunei) 1996 HEIGHT(km) 1 9 Joetsu, Niigata 8 (Japan) 1993 Tsunekami, Fukui 7 (Japan) 1994 Kagoshima (Japan) 5 1994, 1995 Tanegashima, Kagoshima (Japan) 1996 18 R/V Mirai MR4-8 (Palau) 24 17 Melville Is. (Australia) 1995 6 4 GRAUPEL FROZEN DROP 3 1 2 1 RAINDROP 2.1.4.5.6.7.8.91 4 5 6 7 DIAMETER(mm) 746(LST) Jun.25 1995 Ponape (Micronesia) 1988 HEIGHT(km) 11 Manus (Papua New Guinea) 1991, 1992 16 15 7 6 5 4 3 2 1 TEMPERATURE ( C) ICECRYSTAL 14 SNOWFLAKE 13 12 GRAUPEL 4 1 3 9 8 2 7 FROZEN DROP 1 6 5 4 RAINDROP 3 2 1 1 2.1.4.5.6.7.8.91 4 5 6 7 DIAMETER(mm) 1515(LCT) NOV.17 1995 15 8 7 6 5 TEMPERATURE ( C)
Mass Contribution Ice (Graupel and Ice Crystal) 1 1 MASS CONTRIBUTION C 4 C 2 Continent Maritime-Continent Maritime SO 3 C 3 ST 5 ST 13 K 5 MC 3 C 5 K 4 P 6 SO 12 ST 4 SO 15 SO 9 K 3 P 4 PK 11 SO 13 ST 2 M 7 M 3 K 13 MR 2 PK 15 K 1 MC 13 P 1 M 11 M 9 M 1 ST 16 P 2M 5 MR 4 1 1 1 MR 61 Or Less Liquid (Raindrop) P: Ponape, Micronesia C: Pingliang, China M: Manus, Papua New Guinea MC: Melville Is., Australia MR: MR4 8 SO: Songkhla, Thailand ST: Surat Thani, Thailand K: Kagoshima, Japan PK: Puket, Thailand Mass contribution (%) of liquid / ice phase against total precipitation in climatologically different areas. (Takahashi and Kuhara, 1988; Takahashi et al., 1995a, b; Takahashi et al., 21; Takahashi and Keenan, 16 24)
R/V Mirai MR4-8 Cruise Dec.15 24 Jan.9 25 off the Palau Islands first time to launch videosondes from vessel Pingliang (China) 1992 Shanghai (China) 1998 Joetsu, Niigata (Japan) 1993 Tsunekami, Fukui (Japan) 1994 Kagoshima (Japan) 1994, 1995 Tanegashima, Kagoshima (Japan) 1996 Chang Rai (Thailand) 1997 Surat Thani (Thailand) 1994 R/V Mirai MR4-8 (Palau) 24 Songkhla (Thailand) 1993 Phuket (Thailand) 1996 Ponape (Micronesia) 1988 Bandar Seri Begawan (Brunei) 1996 Manus (Papua New Guinea) 1991, 1992 Melville Is. (Australia) 1995 17
R/V Mirai MR4-8 Cruise Sonde# Date Time (LST) Remarks 4 Dec.28, 24 1531 Developing cumulus Large raindrops, ice particles 2 Dec.3, 24 2328 Developing cumulus with strong gust Raindrops, ice particles 6 Dec.31, 24 122 Mature cumulus, no gust Raindrops, many ice particles 1 Dec.31, 24 1816 Dissipating stratiform cloud Aggregates near freezing level 5 Jan.9, 25 73 Thick stratiform cloud, Bright band Many ice particles above freezing level 18
R/V Mirai MR4-8 Cruise 19
Convective Cloud on Dec.31, 24 9 no data 2 8 GRAUPEL AGGREGATE HEIGHT(km) 7 6 5 4 3 ICE CRYSTAL FROZEN DROP 1 1 TEMPERATURE ( ) 2 1 2 RAINDROP.1.4.5.6.7.8.91 4 5 6 7 8 9 1 DIAMETER(mm) 122(LST) DEC.31 24 2
Convective Cloud on Dec.31, 24 9 No.6 2 9 No.6 2 8 Graupel 8 7 Aggregate Ice Crystal 1 7 Aggregate Ice Crystal Graupel 1 HEIGHT (km) 6 5 4 3 Frozen Particle 1 TEMPERATURE (deg C) HEIGHT (km) 6 5 4 3 Frozen Particle 1 TEMPERATURE (deg C) 2 Raindrop 2 Raindrop 1 2 1 2 1 1 2 MASS DENSITY (mg/m 3 ) 1 1 2 1 4 NUMBER DENSITY (/m 3 ) Mass density (left) and number density (right) of convective cloud on Dec.31, 24. 21
Ice (Graupel and Ice Crystal) 1 1 MASS CONTRIBUTION C 4 C 2 Continent Maritime-Continent Maritime SO 3 C 3 ST 5 ST 13 K 5 MC 3 C 5 K 4 P 6 SO 12 ST 4 SO 15 SO 9 K 3 P 4 PK 11 SO 13 ST 2 M 7 M 3 K 13 MR 2 PK 15 K 1 MC 13 P 1 M 11 R/V Mirai MR4-8 Cruise M 9 M 1 ST 16 P 2M 5 MR 4 1 1 1 MR 61 Or Less Liquid (Raindrop) P: Ponape, Micronesia C: Pingliang, China M: Manus, Papua New Guinea MC: Melville Is., Australia MR: MR4 8 SO: Songkhla, Thailand ST: Surat Thani, Thailand K: Kagoshima, Japan PK: Puket, Thailand Mass contribution (%) of liquid / ice phase against total precipitation in climatologically different areas. (Takahashi and Kuhara, 1988; Takahashi et al., 1995a, b; Takahashi et al., 21; Takahashi and Keenan, 24) 22
Thick Stratiform Cloud on Jan.9, 25 ICE CRYSTAL 9 GRAUPEL 2 8 7:36 (9km) 7:12 (3km) 7:18 (5km) 7:28 (7km) HEIGHT(km) 7 6 5 4 AGGREGATE 1 TEMPERATURE ( ) 3 RAINDROP 1 2.1.4.5.6.7.8.91 4 5 6 7 8 9 1 DIAMETER(mm) 73(LST) JAN.9 25 23
Aggregate Graupel and Aggregate Particle observed in a thick stratiform cloud in TOGA-COARE. (Takahashi et al., 1995) Particle images obtained from Videosonde#5. Aggregate? observed at 4.9km (-.3C) in the other stratiform cloud (captured by a cloud videosonde). 24
Summary 1. This study was the first to launch videosondes from an ocean-going vessel. 2. Within convective clouds, the vertical distribution of precipitation particles is characterized by raindrops, frozen drops, and nearly round graupel. This is similar to the results in the TOGA-COARE project and at Ponape, where the warm-rain-freezing process was observed to be dominant. 3. Within the thick stratiform clouds, aggregates were observed of small frozen drops or nearly round graupel. 25
Future plan and challenge 1. Additional videosonde observations are required to understand the general features of precipitation over oceanic area Indian Ocean R/V Mirai Cruise in 26 2. Further improvement of videosonde low-cost, light-weight, easy analysis 3. Development of new digital videosonde This challenge has been started with Fujiwara-san. Goal : Digitalization of image transmission Application to Snow White, Drop-videosonde Easy observation for everyone 26