Aurora Polaris [pp. 531-534]

532 - V /A UleI
temperature of the air and water increases; the evaporation which in summer appears as fog or mist, pervading
the entire lower atmosphere, now takes
the form of local patches, called in
whaler parlance, "frost smoke"-that
is, wherever a space of water appears,
and the temperature of the air is colder than the water, the vapor of the
water in rising from the surface becomes visible as a dense mist, and is
termed "frost smoke" or " water blink."
At the south of Greenland, where the
ice of Davis Strait edges upon the
waters of the Atlantic, and in the neighborhood of the Aleutian Islands, where
the Pacific comes in contact with the
ice of Behrings Strait, the greatest
quantity of this "frost smoke" appears;
here the air is always loaded with extremely minute spicule of snow, and
here auroras are seen in greatest frequency and with most brilliant displays.
As the cold increases, the number and
intensity of auroras seen at any place
on the Greenland coast are proportioned
to the proximity of the edge of the
ice to that place. Dr. Rink, in his
remarks on the auroras of Greenland,
states, "that undoubtedly the aurora
is seen more frequently and in a more
intense degree in South Greenland
than in North Greenland," and he
can " decidedly affirm that the auroras
at Julianshaab, sixty-one degrees north
latitude, are seen from three to four
times longer than at Omenak, seventyone degrees north latitude;" almost
every night in the winter auroras were
seen at "'Julianshaab." During Dr.
Kane's winter at Rensselaer Harbor,
auroras were scarcely ever seen, the
first being noticed fifteen months after
his arrival there; no water-space or
"frost smoke" were found in this neighborhood.
Passing along the coast of Greenland
'from south to north, the general direction of the auroras will be where these
water spaces obtain, until a point is
ULA4 RIS.
[DEC.
reached where the polar light, instead
of being found in the northern part of
the heavens, will be observed in the
southern. During one winter of the
writer's experience, many df the auroras
noticed were in the direction of the open
water spaces seen during the day, such
spaces being, as usual, marked by the
"frost smoke." A similar remark will
obtain in reference to the general direction of the auroras seen during the
winter at Port Kennedy, the open water
space in Bellot Strait having a persistent
aurora hanging over it. From these
data it is evident that this "frost smoke"
and the auroral light are connected in
some way with each other. It is well
known that the evaporation of the water
of the ocean furnishes a large amount of
electricity, and that the condensation of
vapor is another source of the same;
also that, in the act of freezing of water,
electricity is evolved. The theory, then,
seems to be, that the auroras seen were
caused by the condensation and subsequent freezing of the particles of vapor,
these particles evolving positive electricity, and when approaching particles
of the neighboring atmosphere act by
induction upon the latter, producing a
light transmitted from particle to particle, these rendering the entire mass of
vapor luminous, the lower edge of the
arch of the aurora being the place where
this condensation and freezing first occur. Whenever a cloud charged with
particles of vapor has its temperature
lowered, either by change of position or
by the access of a colder atmosphere,
and its particles become frozen, evolving
positive electricity, and by induction
causing a luminosity, such clouds, meeting with others charged with opposite
electricity, would communicate by bands;
these also would be luminous-in other
words, streamers. These appearances
will present themselves wherever there
are clouds composed of frozen particles
acted upon by the surrounding atmosphere or neighboring clouds; so that