March Equinox
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March Equinox. March Equinox (around March 21. Noon sun is directly over head on the equator. Days and night are both 12 hrs long (except at the poles). Astronomical end of Northern Hemisphere (NH) winter. Days are getting longer in the NH very fast. June Solstice. - PowerPoint PPT Presentation
Transcript of March Equinox
March Equinox
March Equinox (around March 21. Noon sun is directly over head on the equator. Days and night are both 12 hrs long (except at the poles). Astronomical end of Northern Hemisphere (NH) winter. Days are getting longer in the NH very fast.
June Solstice
June Solstice: Astronomical beginning of NH summer and SH winter. Sun is directly overhead on the tropic of cancer. Longest day of the year for NH latitudes and shortest day of the year for SH latitudes. 24 hours of sunlight North of the Arctic circle and 24 hours of darkness south of the Antarctic circle.
Sept Equinox
September Equinox (around September 22). Noon sun is directly over head on the equator. Days and night are both 12 hrs long (except at the poles). Astronomical end of Northern Hemisphere (NH) summer. Days are getting shorter in the northern hemisphere (NH) very fast.
December Solstice
December Solstice: Astronomical beginning of NH winter and SH summer. Sun is directly overhead on the tropic of Capricorn. Shortest day of the year for NH latitudes and longest day of the year for SH latitudes. 24 hours of darkness North of the Arctic circle and 24 hours of daylight south of the Antarctic circle.
Mon Day Length (hr min)Jan 9 05Feb 10 24Mar 11 55Apr 13 34May 14 56Jun 15 40 longest dayJul 15 22Aug 14 06Sep 12 31Oct 10 56Nov 9 28Dec 8 42 shortest day
Vancouver Washington Length of time between Sunrise & Sunset for the 15th of each month
Length of time between Sunrise & Sunset for different latitudes and different months
Latitude 21-Dec 21-Mar 21-Jun 21-Sep0 12 12 12 12
10 11.4 12 12.6 1220 10.8 12 13.2 1230 10.1 12 13.9 1240 9.1 12 14.9 1250 7.7 12 16.3 1260 5.6 12 18.4 1270 0 12 2 months 1280 0 12 4 months 1290 0 12 6 months 12
The direct sun is more intense because 1. it is concentrated on a smaller area on Earth’s surface 2. it does not go through as much atmosphere.
In both cases the amount of energy provided by the flash light is the same. When the flashlight beam is coming down at an angle the light is spread out over a larger area so the surface does not get as hot. The same is true for sunlight.
Annual Mean temperatures: warm near the equator and cooler toward the poles.
Northern Hemisphere winter has a very large difference between the temperatures at the equator compare to those near the north pole. That is, there is a large temperature gradient in the northern hemisphere during NH winter. SH summer gradient is small.
Northern Hemisphere summer has a fairly small difference between the temperatures at the equator compare to those near the north pole. That is, there is a small temperature gradient in the northern hemisphere during NH summer. SH winter gradient is large.
Rain follows the sunlight: Annual rainfall is greatest near the equator.
Rain follows the sunlight: July rainfall is greatest North of the the equator.
Rain follows the sunlight: January rainfall is greatest South of the equator.
