If you place your finger on the Sun’s position during a given frame, each day, the Sun moves to the left.  Since the Sun is increasing in elevation, we are looking at the Sun’s motion during the morning hours, so we are looking in an eastward direction.  North must be to the left, so each day, the Sun’s path is shifting northward.

12 hours.

66.5º above the horizon.

Very warm to hot.

Estimate the time of sunrise and sunset from the hour positions (the orange and gray circles on the declination circle).

Sunrise ~ 4:15 AM

Sunset ~ 7:45 PM

There are 15.5 hours of daylight between the estimates times for sunrise and sunset.

The actual is 15.4 hours.

68.5º above the horizon.

The Sun is higher in the sky than for the Equator at this time of year, and there is more hours of daylight.

Expect it to be very warm to hot.

24 hours.

Technically local noon doesn’t exist at the North Pole since the since stays the same angle above the horizon all day.  Also, all longitudes meet at the poles, so the Sun is continuously crossing a longitude line (another criterion for local noon).

Although not the local noon Sun angle, the Sun is 23.5º above the horizon all day.

The pole has been experiencing three months of daylight up to this point, although it has been relatively low in the sky.  The Sun will remain above the horizon for another three months.

It is surprising to think about six months of daylight. When the Sun is 20%, the beam spread is 2.92, and the intensity of sunlight on a unit square piece is ground is 34% compared to when the Sun is directly overhead, having extended periods of daylight adds up.  The North Pole receives more sunlight during a day compared to the Equator during an equinox!  

But if covered by snow and ice, which reflect most of the incoming sunlight, the Pole stays cool.  But if it melts, the exposed ground will warm considerably.

So this period is cold if snow and ice are present.  Much warmer if the ground is exposed.

• Earth experiences astronomical seasons due to its obliquity.
• How much sunlight and how intense it is during an astronomical season are the primary drivers for creating the region’s season temperature.
• For a given location, latitude and obliquity determine how daylight hours and the local noon Sun angle change throughout the year.

An overview of how the Sun’s energy is generated and how its thermal radiation illuminates and heats Earth.

• Overview: The Sun illuminates the spherical, rotating planets orbiting it.
• Obliquity and Earth’s Illumination: Obliquity is the angle between the planes of the Earth’s equator and its orbit around the Sun.
• Declination, Latitude, & Earth Illumination: Solar declination is the angle between the Sun’s rays and the plane of the Earth’s Equator.  Its value depends on where Earth is in its orbit around the Sun.
• Astronomical Seasons & Illumination: Astronomical seasons are based on the orientation of Earth’s axis of rotation to the Sun, which determines the amount of illumination between the Northern and Southern Hemispheres.

• Overview: Even though an area is illuminated by sunlight, there can be quite a range of energy interacting with the surface.
• Sun Angle and Beam Concentration: If every beam of sunlight reaching Earth has the same amount of energy, why do some areas warm up more than others?
• Diurnal Heating: Diurnal heating is the temperature change over 24 hours.  When sunlight shines on the ground, it warms.  Two critical factors that determine the amount of heating deal with the Sun’s illumination.
• Seasons: Earth experiences astronomical seasons due to its obliquity.
• Climate Regimes: Climate regimes are an extension of diurnal heating and seasons, but the time frame is now years. 

• Overview: Drawings of declination circles contain the visual and numerical information to understand and predict the Sun’s motion across the sky.
• Declination Circles 101: Draw a declination circle with just a ruler and protractor/compass to quickly and accurately know the Sun’s position in the sky at any day and time of the year for any location on Earth.
• Drawing Declination Circles: Declination circles are quite easy to draw by hand.
• Interpreting Time on Declination Circles: Accurately estimate the time of day using the Sun’s location in the sky.
• Sunrise, Sunset, & Twilight: Calculate the timing and duration when the Sun is at or near the horizon.
• Solar Time, Angle, & Position: The sun’s angle and direction to the local horizon define the Sun’s position in the local sky.  Explore how to use declination circles to calculate the Sun’s position at any solar time anywhere in the world on any day of the year.
• Changing Views of Declination Circles: Use the web app View Declination Circles to explore three common views of declination circles to identify their strengths, limitations, and applications.  Then learn how to go from one view to another.
• Using Declination Circles: Humans have been using the apparent motion of the Sun as a compass, clock, and calendar for millennia.
  • Using Sundials: Humans have been using the Sun’s position to navigate and tell the time, day, and season for millennia.  Sundials create shadows that make it easier to do these tasks.