|
Yagi-Uda antenna(Often called yagi antenna.) A type of directional antenna comprising an elevated linear array of horizontal dipoles with different lengths and spacings, typically arranged as a driven element, reflector element, and several director elements. The dipoles are organized to maximize the radiation in the forward direction. Radar systems requiring large antennas often use arrays of Yagi-Uda antennas (e.g., some wind profiler radars).
|
|
yalcaA local name for a severe snowstorm with a strong squally wind that occurs in the Andes Mountain passes of northern Peru.
|
|
yamaseA cool, onshore, easterly wind in the Senriku district of Japan in summer. It originates in the Okhotsk anticyclone and blows over the cold sea, bringing periods of three to seven days of clouds, rain, and fog.
|
|
year1. The period during which the earth completes one revolution around the sun. This has several interpretations, as follows. 1) Sidereal year: time of true revolution around the sun, that is, the time it takes the earth (as seen from the sun) to reappear at the same fixed star, equal to 365.2564 mean solar days or 365 days, 6 hours, 9 minutes, 10 seconds; 2) Tropical year (also called mean solar year, ordinary year): the time measured from one vernal equinox to the next, that is, the apparent revolution of the sun through the zodiac, equal to 365.2422 mean solar days or 365 days, 5 hours, 48 minutes, 46 seconds (this is not constant but decreases by about 5 seconds in one thousand years.); and 3) Calendar year: fixed by the Gregorian calendar of 365 days in ordinary years and 366 days in leap years. See day. 2. Any arbitrary 12-month period selected for a special purpose, such as the water year. See also climatological year, farmer's year, grower's year.
|
|
Yellow Sea Warm CurrentA surface current flowing northward along the central axis of the Yellow Sea. The current is very shallow but strong, with speeds of 0.2 m s−1. It is effectively an offshoot from the Kuroshio sandwiched between southward flowing coastal currents on the Chinese and Korean side. Advection of the warm Kuroshio water increases the temperature of the central Yellow Sea several degrees over the temperatures of the coastal regions.
|
|
yellow snowSnow given a golden or yellow appearance by the presence of pine or cypress pollen.
|
|
yellow windA strong, cold, dry, west wind of eastern Asia, especially northern China, that sweeps across the plains in winter carrying a fine yellow dust from the deserts. The deposition of this dust over thousands of years has formed the loess deposits of China.
|
|
