Metastable Nitric Acid Trihydrate in Ice Clouds
نویسندگان
چکیده
منابع مشابه
Metastable Nitric Acid Trihydrate in Ice Clouds.
The composition of high-altitude ice clouds is still a matter of intense discussion. The constituents in question are ice and nitric acid hydrates, but the exact phase composition of clouds and its formation mechanisms are still unknown. In this work, conclusive evidence for a long-predicted phase, alpha-nitric acid trihydrate (alpha-NAT), is presented. This phase was characterized by a combina...
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A PSC was detected on 6 February 2003 in the Arctic stratosphere by in-situ measurements onboard the high-altitude research aircraft Geophysica. Low number densities (∼10−4 cm−3) of small nitric acid (HNO3) containing particles (d<6μm) were observed at altitudes between 18 and 20 km. Provided the temperatures remain below the NAT equilibrium temperature TNAT, these NAT particles have the potent...
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Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occur...
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Nitric acid hydrates are important constituents of solid PSC and Cirrus cloud particles. Due to the phase diagram only hexagonal ice and nitric acid trihydrate have a reasonable thermodynamic stability and are commonly observed in the stratosphere. Besides, also a number of metastable modifications might exist: α-NAD, β-NAD, α-NAT, NAP and cubic ice. The existence of these metastable compounds ...
متن کاملQuasi-Lagrangian Measurements of Nitric Acid Trihydrate Formation Over Antarctica
In 2010, the joint French-United States Concordiasi project released 19 long-duration superpressure balloons from McMurdo Station, Antarctica. Four of these balloons carried a gondola with particle counters and temperature sensors to measure polar stratospheric clouds. One gondola spent 5 days at stable temperatures between equilibrium temperatures for nitric acid trihydrate (NAT) and for super...
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ژورنال
عنوان ژورنال: Angewandte Chemie International Edition
سال: 2016
ISSN: 1433-7851
DOI: 10.1002/anie.201510841