Weekly log: environmental studies: earth science
tkrmAJ
week2lab.pptxWeek 2
ES 101 Laboratory
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Week 2 Activities
Earth/sun relations
Solar Angle: meet “Ana”
Insolation (not the stuff in your attic)
Temperature patterns
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Earth/Sun relations
Rotation (Earth rotates once on axis every 24 hrs)
Revolution (Earth orbits around the Sun once in every 365 1/4 days); not a perfect circle
Perihelion (closest)
Aphelion (farthest)
Inclination: tilt of Earth’s axis; about 23.5 degrees but changes over long time
Parallelism: Earth’s axis always pointed same way
Equinox vs. solstice: equinox has 12 hrs of dark & light all latitudes
Rays of the Sun:
Vertical
Tangent
Circle of illumination
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Solar Angle
Figuring out where on Earth the direct rays (vertical rays) of the Sun hit the Earth’s surface; useful for solar energy siting and other considerations
Tropic of Cancer at June Solstice
Equator at Equinoxes
Tropic of Capricorn at December Solstice
Latitude receiving vertical rays is called declination of the Sun; shown graphically with analemma (see above and page 36)
Solar Altitude is apparent elevation of noon Sun in sky
Solar Altitude (SA) = 90o – Arc Distance (AD)
AD is the number of degrees of latitude between latitude of interest and declination of the Sun (pay attention to North and South!)
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Insolation
Read and summarize each bolded major section:
Insolation
Angle of Incidence
Length of day
Atmospheric obstruction
No problems to work
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Temperature patterns
Factors influencing temperature patterns in a given area:
Latitude
Land-water contrasts
Ocean currents (warm or cold)
Wind patterns (where weather comes from)
Altitude (temperature decreases with increasing altitude)
Use global maps of sea-level temperatures for January and June to explain observed temperature patterns
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