Today is the official day on my calendar marking the winter solstice for the earth’s northern hemisphere. Today is the single day in the year when the entire earth and its north pole are the farthest away from the sun in its orbit. For sun intolerant lupus patients, today is technically the single day all year with the least danger for UV sun exposure. So, today a lupus patient could safely linger a few moments longer outside in the sun.
This morning, I did just that! Standing outside in the cool morning air, I lingered just a bit longer, sipping my hot coffee with the sun’s warmth bathing my shoulders and back. Watching my amusing dog play on the grass just a few minutes longer than normal, I was smiling and thoroughly enjoying his cheerful exuberance. Today, I enjoyed a few more rare moments of sun-drenched simple joy.
The winter solstice usually falls between December 21 to 23 in the Northern Hemisphere, and June 20 to 23 in the Southern Hemisphere. Today’s cooler winter weather is caused by a combination of changing physical conditions coinciding during the winter solstice, but is primarily due to sunlight striking the earth’s surface from the lowest angle in the sky. Today, the earth travels in its oblong orbit at its farthest distance from the sun. Today is this year’s shortest day, and tonight will be its longest night.
Today the North Pole will be completely dark all day and night as it falls completely into the shadowed half of the earth facing away from the sun. Six months from now, a noon sunbeam will strike from high in the sky, but not today. Today, because the earth’s north pole tilts away from the sun, the same sunbeam travels farther through the earth’s atmosphere and enters it from a lower point in the sky. Also, today’s same sunbeam covers a larger area of the ground, warming a larger space less efficiently while spreading its total energy more thinly. Today all the winter cooling factors have their greatest effect.
What does all this mean for a lupus patient or any person with sun sensitivity? Today is probably the safest day all year for lupus patients to be exposed to the sun’s light, including its UV rays. But still, we need to wear our sunscreen and remember to be careful out there!