North Pole at Solstice
June 21, 2004
With little fanfare, the imaginary line defined by Earth’s axis of rotation crossed the imaginary line that passes through the sun perpendicular to the plane of Earth’s orbit at 57 minutes past midnight Universal Time on June 21st, marking the summer solstice, the official beginning of summer in the northern hemisphere. In practical terms, this marks the day of the year with the longest time between sunrise and sunset in the northern hemisphere, the day when the sun reaches its highest elevation in the sky (if you live north of the Tropic of Cancer). Conversely, today marks the beginning of the southern hemisphere winter, the day with the longest period of darkness south of the equator.
Indeed the North Pole was illuminated, through cloud cover, as NOAA's Pacific Marine Environmental Laboratory webcam image above attests, acquired within a few minutes of solstice. The images from the cameras track the North Pole snow cover, weather conditions and the status of PMEL's North Pole instrumentation, which includes meteorological and ice sensors (seen in the camera images).