Berlin 2014 – scientific programme
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UP: Fachverband Umweltphysik
UP 12: Atmosphäre - Labor
UP 12.4: Talk
Thursday, March 20, 2014, 10:30–10:45, MAG 100
Laboratory experiments on ice nucleation and growth rates on meteoric smoke particles at mesospheric conditions — •Mario Nachbar1, Denis Duft2, Markus Eritt2, and Thomas Leisner1,2 — 1Institute for Environmental Physics, Ruprecht-Karls-University Heidelberg, Germany — 2Institute for Meteorology and Climate Research, Karlsruher Institute of Technology (KIT)
Ice particles have been detected at the polar mesopause region (height of 80-90 km) during summer term by radar measurements as polar mesospheric summer echoes (PMS). If large enough, they can be observed by eye as noctilucent clouds (NLC). Heterogeneous nucleation on nanometer sized (< 2nm) meteoric smoke particles (MSP) is believed to be one of the major nucleation processes taking place. PMSE and NLC could be used as a probe for the extreme physical and thermodynamical conditions of the mesopause region. In addition, long term trends due to the influence of anthropogenic greenhouse gas emissions could be validated. Therefore, the microphysical processes need to be understood in detail. We produce charged nanometer sized particles in a microwave resonator at 60 mb and transfer them into the TRAPS apparatus in order to examine ice nucleation as well as growth rates. Our new quadrupol ion trap allows us to store these particles under controlled mesospheric temperature and water vapor saturation conditions. Ice nucleation and growth processes are examined by analysing the mass distribution of the particles with a time of flight spectrometer as a function of the trapping time. In this talk, first measurements using the new setup will be presented.