TY - JOUR
AB - A Spot Cause d b y Snowflakes in the Bea m of a Ceiling Projector* R . C. GRAHAM, M.A . Meteorological Service of Canada, Malton, Airport, Ontario CCASIONALL Y at Malton Airport, jector beam by the under side of the Ontario, when snow is falling flakes. at night, there will appear in From this hypothesis, it would fol- the beam of the ceiling projector a low that the spot would only be visible spot which is difficult to explain. It from points in the plane of the pro- always occurs at about 1200 feet, as jector beam and base line; if the ob- indicated by the alidade, even though server walks away from the line join- no cloud as low as this might be ex- ing the alidade and projector, the spot pected, and when aircraft land under should disappear and the beam appear this condition the pilots report no only as a uniform shaft of light due cloud at that level. It only occurs to diffuse reflection. If he walks when light, dry snow is falling, along this line, the spot should main- with light winds. The spot is some- tain a constant angular elevation of times 
TI - Shorter Contributions
JF - Bulletin of the American Meteorological Society
DO - 10.1175/1520-0477-24.10.378
DA - 1943-12-01
UR - https://www.deepdyve.com/lp/american-meteorological-society/shorter-contributions-WVdGeD4bRW
SP - 378
EP - 379
VL - 24
IS - 10
DP - DeepDyve
ER -