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In situ measurements of ice saturation in young contrails
Author(s) -
Kaufmann Stefan,
Voigt Christiane,
Jeßberger Philipp,
Jurkat Tina,
Schlager Hans,
Schwarzenboeck Alfons,
Klingebiel Marcus,
Thornberry Troy
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2013gl058276
Subject(s) - cirrus , water vapor , atmospheric sciences , ice nucleus , ice cloud , environmental science , ice crystals , relative humidity , saturation (graph theory) , stratosphere , meteorology , geology , physics , radiative transfer , optics , mathematics , combinatorics , nucleation , thermodynamics
Relative humidity with respect to ice (RHi) is a major factor controlling the evolution of aircraft contrails. High‐resolution airborne H 2 O measurements in and near contrails were made at a rate of 4.2 Hz using the novel water vapor mass spectrometer AIMS‐H 2 O with in‐flight calibration during the CONtrail, volcano, and Cirrus ExpeRimenT (CONCERT) 2011. Three 2 min old contrails were sampled near 11 km altitude. Independent of the ambient supersaturation or subsaturation over ice, the mean of the RHi frequency distribution within each contrail is shifted toward ice saturation. This shift can be explained by the high ice surface area densities with corresponding RHi relaxation times on the order of 20 s, which lead to the fast equilibration of H 2 O between the vapor and ice phase. Understanding the interaction of water vapor with ice particles is essential to investigate the life cycle of contrails and cirrus.