[chasjohn (OP)]

In just the same way that a core soil sample is taken of the Earth and archived for later analysis, how could the scientific community make use of 'test tube' atmospheric samples that are taken at altitude and physically returned to Earth.
Would this be a viable support to current methods of remote sensing from the ground or satellite?
Would this provide a valid archive of our upper atmosphere for historical analysis of ozone, volcanic ash, bacteria etc;

[CliffordK]

Weather balloons are launched all the time, and can get up to 20,000 or 30,000 feet.  Presumably they could be used to retrieve samples, if not already being done.

Keeping archival samples might be difficult, as the quantities are small, and they might not store indefinitely.  While concentration may be fixed, taking a portion of the sample will alter the overall pressure/quantity in the sample.  It might be best to permanently seal glass vials in space, but that would mean adding heat which could affect the sample.

For bacteria, there is always a risk of contamination, and they may in fact break down over time if kept n a sealed sample.