TY - CONF TI - In situ observations of contrail micro-physics and implications for their radiative impact AB - Increasing levels of air traffic have raised concerns about the potential effects of aircraft exhaust on the climate. Current knowledge is expanded by examining in situ data from 21 contrails sampled at altitudes of 9.3 - 12.5 km and temperatures of -47 deg C to -66 deg C. The airborne equipment allowed measurements of particles as small as 2 {mu}m in diameter, which have not previously been reported. The microphysical characteristics of the contrails, which occurred in both clear and cloudy air, are presented and compared with natural cirrus properties. Computations of the wavelength-dependent radiative properties of the sampled particle distributions are also presented and compared with laboratory measurements. Finally, implications of these findings for climatic assessment are discussed. (R.P.) 9 refs. AU - "Poellot, M R [North Dakota Univ., Grand Forks, ND (United States)]" AU - "Arnott, W P" AU - "Hallett, J [Nevada Univ., Reno, NV (United States). Desert Research Inst.]" KW - "54 ENVIRONMENTAL SCIENCES" KW - "AIRCRAFT" KW - "EXHAUST GASES" KW - "CLIMATIC CHANGE" KW - "PARTICLE SIZE" KW - "CONDENSATES" KW - "CLOUDS" KW - "EARTH ATMOSPHERE" KW - "SOLAR RADIATION" DO - https://doi.org/ UR - https://www.osti.gov/etdeweb/servlets/purl/623626 PB - CY - France PY - 1997 DA - 1998-12-31 LA - English J2 - [] VL - C1 - Office National d`Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France) C2 - C3 - ONERA-97-Vol.1; CONF-9610234- C4 - C5 - OSTI as DE98731902 L3 - Conference: International colloquium: Impact of aircraft emissions upon the atmosphere, Paris (France), 15-18 Oct 1996; Other Information: PBD: 1997; Related Information: Is Part Of Proceedings of impact of aircraft emissions upon the atmosphere. V. 1; PB: [381] p. ER -