Sky & Telescope - April 2023 - 33

outside the eclipse path but gets a very deep partial of 99.8%.
The path width across New Brunswick is 170 km, and the
Sun's altitude is 34°.
Western Prince Edward Island lies within the zone of
totality, but Charlottetown misses; observers there will have
to settle for a 99.2% partial. Quebec's Magdalen Islands
straddle the central line, and the shadow track also clips the
northeastern tip of Nova Scotia's Cape Breton Island.
The final landfall for the umbral shadow is on the island
of Newfoundland. There, the late-afternoon Sun is only
24° above the horizon, the eclipse duration at the central
line is 2m 54s, and the path width is 162 km. St. John's, the
capital, is 42 km south of the umbral path. The city will
get a deep partial eclipse, with 98.8% of the Sun's diameter
covered by the Moon.
Mother Nature dealt New Hampshire, Vermont, Maine,
and New Brunswick a lousy hand when it comes to weather
prospects for this eclipse. The Moon's shadow crosses a series
of terrain landmarks that spell out cloudiness: the Green
Mountains of Vermont, the White Mountains of New Hampshire
and Maine, the Longfellow Mountains of Maine, and
the Miramachi Highlands in New Brunswick. Cloud cover is
least on the New York-Vermont border, where the track passes
the Champlain Valley and the St. Lawrence Lowlands.
Monthly cloud cover rises from around 68% at Montreal,
Quebec, and Plattsburgh, New York, to nearly 90% at Jackman,
Maine, before settling back to 80% for the rest of the
passage to the Gulf of St. Lawrence. Cloudiness has little
30%
40%
50%
60%
70%
80%
90%
100%
20%
10%
0%
THE VIEW FROM ABOVE This photograph, acquired from NASA's
NOAA-20 satellite, shows the cloud cover along the eclipse track on April
8, 2022. At the time of this image, the eclipse shadow would lie over the
Great Lakes. The discontinuity in the scene that stretches over Lake Ontario
is caused by incorporating an earlier satellite passage into the view.
variation across the track, and terrain influences are muted
because of the high natural cloudiness of the region arising
from its position astride the season's main storm tracks.
The bright light in this gloomy scenario comes along New
Brunswick's shoreline, where the track reaches the Gulf of
St. Lawrence. As with the Great Lakes, water suppresses the
formation of convective clouds - an effect that extends for
a short distance inland when winds come from the north.
CLEARINGS AND CLOUDS This map
of average April cloud cover along the
eclipse path is derived from 21 years of daily
satellite imagery. Amounts are expressed
in fractional sky cover and represent the
amount of time the sky was cloudy in the
two-decade interval.
ECLIPSE UPS AND DOWNS The April
fractional cloud amount along the central
line of the eclipse is displayed graphically at
left. It was derived from the same 21-year
dataset as the map at far left. In many locations,
the cloud statistics away from the
central axis are quite different.
Location
sk yand tele scope .o r g * APRIL 2023 33
SATELLITE IMAGE: JAY ANDERSON; GRAPH: JAY ANDERSON,
DATA SOURCE: NASA
Cloud fraction
Pacific Ocean
Mazatlán
Mexico
Texas
Oklahoma
Arkansas
Missouri
Illinois
Indiana
Ohio
Pennsylvania
New York
Vermont
Maine
Plattsburgh
New Brunswick
Quebec
Quebec / Gulf of
St. Lawrence
Newfoundland
Gander
Atlantic Ocean
Tignish
Stephenville
Miramichi
Houlton
Iles de la
Madeleine
Little Rock
Poplar Bluff
Carbondale
Indianapolis
Lima
Cleveland
Rochester
Buffalo
Watertown
Durango
Torreón
Zaragoza
Uvalde
Dallas
https://skyandtelescope.org/
Sky & Telescope - April 2023

Table of Contents for the Digital Edition of Sky & Telescope - April 2023
