Cryogenic Air Sampling System for Measurements of the Concentrations of Stratospheric Trace Gases and Their Isotopic Ratios over Antarctica.

Abstract

In order to measure the concentrations of trace gases such as C02, CH4, N20 and halocarbons and the isotopic ratios of 513C, 5180 and A14C of CO2 in the stratosphere over Antarctica in January 1998, a balloon-borne cryogenic air sampling system was developed on the basis of the sampler which has used for the collection of stratospheric air over Japan since 1985. The sampler developed in this study is capable of collecting air samples with volumes of 20-30 lsTp at 12 height levels. Special attention was paid to the sampler so that the collection of a large amount of the stratospheric air can be completed in a short time, which is crucial for recovering the sampler near the station using a helicopter. In addition, the samplerwas designed to land on the sea or the ice field safely. W e also simulated the flight trajectories ofthe sampler using the wind data observed at Syowa Station (69'00'S, 39'35'E), Antarctica. The results suggested that the sampler may land within approximately 150 km from the station, if air sampling is made in the summer season. Indeed, the trajectories, thus predicted, were confirmed to be valid by experiments made using a rubber balloon at Syowa Station on January 21 and February 6, 1995.

Long-term observation of mass-independent oxygen isotope anomaly in stratospheric CO<sub>2</sub>

“…Stratospheric whole air samples were collected during six balloon flights over Sanriku, Japan (39 • N, Honda et al, 1996;Aoki et al, 2003;Honda, 2001). Herein, we describe them briefly.…”

“…The air sampling system can collect multiple whole-air samples into pre-evacuated 760 cm 3 stainless steel sample bottles. Chemical and isotopic compositions in the sampled air are only slightly affected by the collection process (Honda et al, 1996;Honda, 2001). Preliminary experimental tests showed that a possible change of δ 18 O CO 2 caused by isotope exchange between CO 2 and water on the inner walls of the sample bottle is comparable to our analytical precision of 0.05‰ (Honda, 2001;Gamo et al, 1995;Aoki et al, 2003).…”

Age and gravitational separation of the stratospheric air over Indonesia

“…In the present study, air sampling was performed during balloon ascent. In the past, we conducted a number of similar air samplings using a cryogenic sampler with liquid helium (Honda et al, 1996) in which we collected samples during the balloon ascent and descent over Japan; they showed that the outgassing from the balloon and payload had a negligibly small impact on the air sample quality even if air sampling was made during the balloon ascent (Morimoto et al, 2009;. One sampler assigned to 21 km leaked after landing due to a defect in electric circuit.…”

NOy‐N2O correlation observed inside the Arctic vortex in February 1997: Dynamical and chemical effects

“…Air samplcs for the N20 and CH 4 analyses were also collected by cryogenic samplers from the University of Frankfurt [Schmidt et al, 1987] and Tohoku University [Honda et al, 1996] on board balloons launched from Kiruna on February 11 and 22, respectivcly. Air samples were collected between 10 and 27 km, mostly during descent, and they were analyzed in the laboratory using gas chromatography.…”