HR: 09:30h
AN: A31D-07    [Abstracts]
TI: Cirrus Observations in the Tropical Tropopause Layer Over the Western Pacific
AU: * Fujiwara, M
EM: fuji@ees.hokudai.ac.jp
AF: Hokkaido University, N10 W5, Sapporo, 060-0810, Japan
AU: Iwasaki, S
EM: iwasaki@nda.ac.jp
AF: National Defense Academy, Hashirimizu 1-10-20, Yokosuka, 239-8686, Japan
AU: Shimizu, A
EM: shimizua@nies.go.jp
AF: National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, 305-8506, Japan
AU: Shiotani, M
EM: shiotani@rish.kyoto-u.ac.jp
AF: RISH, Kyoto University, Gokasho, Uji, 611-0011, Japan
AU: Matsuura, H
EM: matu@rish.kyoto-u.ac.jp
AF: RISH, Kyoto University, Gokasho, Uji, 611-0011, Japan
AU: Inai, Y
EM: wwyoww@ees.hokudai.ac.jp
AF: Hokkaido University, N10 W5, Sapporo, 060-0810, Japan
AU: Hasebe, F
EM: f-hasebe@ees.hokudai.ac.jp
AF: Hokkaido University, N10 W5, Sapporo, 060-0810, Japan
AU: Matsui, I
EM: i-matsui@nies.go.jp
AF: National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, 305-8506, Japan
AU: Sugimoto, N
EM: nsugimot@nies.go.jp
AF: National Institute for Environmental Studies, Onogawa 16-2, Tsukuba, 305-8506, Japan
AU: Okamoto, H
EM: okamoto@caos-a.geophys.tohoku.ac.jp
AF: Tohoku University, Aoba 6-3, Sendai, 980-8578, Japan
AU: Yoneyama, K
EM: yoneyamak@jamstec.go.jp
AF: JAMSTEC, Natsushima 2-15, Yokosuka, 237-0061, Japan
AU: Hamada, A
EM: hamada@kugi.kyoto-u.ac.jp
AF: Graduate School of Science, Kyoto University, Kitashirakawa Oiwaketyou, Kyoto, 606-8502, Japan
AU: Nishi, N
EM: nishi@kugi.kyoto-u.ac.jp
AF: Graduate School of Science, Kyoto University, Kitashirakawa Oiwaketyou, Kyoto, 606-8502, Japan
AU: Immler, F
EM: Franz.Immler@awi.de
AF: Alfred Wegener Institute Potsdam, Telegrafenberg A43, Potsdam, D-14473, Germany
AB: Cirrus clouds in the tropical tropopause layer (TTL), between 14 and 17 km, are keys for the dehydration of the air entering the stratosphere and for the Earth's radiation budget. In this presentation, we will discuss three-campaign results of ship-borne lidar measurements over the western Pacific, in relation to large-scale dynamics and transport. A polarization lidar was continuously operated on the Japanese research vessel MIRAI in three one-month campaigns. The locations and time periods are: 2.0N, 138.0E, 9 Nov. to 9 Dec. 2001 (MR01); 2.0N, 138.5E, 15 Nov. to 14 Dec. 2002 (MR02); and 7.5N, 134.0E, close to Palau, 14 Dec. 2004 to 11 Jan. 2005 (MR04). Three hourly intensive radiosonde soundings were also made on the vessel during all these campaigns. In the MR01 campaign, the tropopause region was cold, but the TTL was often clear with some Sub-Visual Cirrus (SVC). Potential vorticity data (with RDF method) and trajectories show that the TTL in this period was strongly affected by dry air transport from the northern mid-latitude lower stratosphere. In the MR02 campaign, a packet of large-amplitude Kelvin waves primarily controlled the generation and disappearance of cirrus in the TTL. In the MR04 campaign, a cold phase of Kelvin waves resulted in cirrus generation in the TTL, and outflow from the SPCZ also caused optically very thick TTL cirrus in early January 2005. A clear diurnal variation of TTL cirrus, an apparent descending motion at night, was also observed in early January 2005.
DE: 0320 Cloud physics and chemistry
DE: 0340 Middle atmosphere: composition and chemistry
DE: 0341 Middle atmosphere: constituent transport and chemistry (3334)
DE: 0368 Troposphere: constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting