Japan Geoscience Union Meeting 2014

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International Session (Oral)

Symbol P (Space and Planetary Sciences) » P-EM Solar-Terrestrial Sciences, Space Electromagnetism & Space Environment

[P-EM08_2AM2] Space Weather and Space Climate

Fri. May 2, 2014 10:55 AM - 12:45 PM 411 (4F)

Convener:*Ryuho Kataoka(National Institute of Polar Research), Yusuke Ebihara(Research Institute for Sustainable Humanosphere, Kyoto University), Kanya Kusano(Solar-Terrestrial Environment Laboratory, Nagoya University), Toshifumi Shimizu(Institute of Space and Astronautical Science, JAXA), Yoshizumi Miyoshi(Solar-Terrestrial Environement Laboratory, Nagoya University), Ayumi Asai(Unit for Synergetic Studies of Space, Kyoto University), Tatsuhiko Sato(Japan Atomic Energy Agency), Hidekatsu Jin(National Institude of Information and Communications Technology), Kiminori Itoh(Graduate School of Engineering, Yokohama National University), Hiroko Miyahara(College of Art and Design, Musashino Art University), Chair:Hidekatsu Jin(National Institude of Information and Communications Technology)

12:15 PM - 12:30 PM

[PEM08-20] Laboratory experiment with various radiation sources for verification of cloud condensation nucleation by cosmic rays

*Asami SUZUKI1, Kimiaki MASUDA1, Yuya TAKEUCHI1, Yoshitaka ITOW1, Takashi SAKO1, Yutaka MATSUMI1, Tomoki NAKAYAMA1, Sayako UEDA1, Kazuhiko MIURA2, Kanya KUSANO1 (1.Solar-Terrestrial Environment Laboratory,Nagoya University, 2.Tokyo university of science)

Keywords:cosmic rays, cloud, cosmoclimatology, cloud condensation nuclei

It is considered that the solar activity may affect the global climate,but the correlation mechanism is still not understood.One of the possible mechanisms for the correlation is the cloud formation by the galactic cosmic rays, which are modulated by the variation of solar activity. This relation was clearly indicated by the good correlation observed for the galactic cosmic-ray intensity and the global low-cloud amount.This hypothesis includes the ion-induced nucleation model, in which new particles in the atmosphere are created efficiently through atmospheric ions produced by cosmic rays, and finally these particles grow up to the size ofcloud condensation nuclei.In this study, a laboratory experiment for verification of the hypothesis has been conducted with a reaction chamber. A flow of clean air, water vapor, ozone and sulfuric dioxide was introduced to a metallic chamber, where we irradiated UV light for solar irradiance and beta-rays or accelerator beam for cosmic rays. The beam of the heavy ion accelerator HIMAC at National Institute of Radiological Sciences was used in the present experiment.As a result, ions produced by the ionizing radiation and increased particle density were observed for beta rays.Some results with the accelerator beam are the following.Ion density in the chamber increased as the beam intensity and particle density increased with ion density.Particle size distribution was measured and the peak particle size and the particle density became to larger with time after start irradiation, but the density stopped to increase or decreased after irradiation stopped although the peak size continued to increase.It is shown that our system is ready for more detailed measurements.