help

Relationship (or Lack Thereof) Between the Earth-Sun Distance and Weather

-- | August 8, 2012

Question: Hey, Guys!
Just to let you know, I was by the VLA last August. Just on the road alone I was impressed with the distances the telescopes are apart. Anyway, here is my question: Being from the midwest, we’ve had a very hot summer. Now the word is out that this is the hottest July since 1936 when the year of the dustbowl took place. I also heard on the news that we are at our furthest from the sun, this year. This is in the neighborhhod of 94+million miles. I would also think that our winter, which was also warmer, means we were closer to the sun also. Between 2012 and 1936 is a span of 76 years, so does this timeline also coincide with sometime around 1974 for a hot year? And does this mean that every 36 years we swing out to a most distant perigee for the summer and closest apogee for the winter?

— Kenneth

Answer: Glad you found the VLA interesting! Now to your question. In fact, the (small) changes in distance between the Earth and the Sun have no bearing whatsoever on the weather here on Earth. It is the Earth’s 23.5 degree tilt that drives our seasonal temperature variations, as this tilt changes the length of time that the Sun is above the horizon and the angle at which the Sun’s rays strike the Earth. This axis tilt is the reason why the number of daylight hours are long and the Sun is high in the sky in the summer, while the number of daylight hours are short and the Sun is low in the sky in the winter.

Jeff Mangum

The National Radio Astronomy Observatory is a facility of the U.S. National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
	Founded in 1956, the NRAO provides state-of-the-art radio telescope facilities for use by the international scientific community. NRAO telescopes are open to all astronomers regardless of institutional or national affiliation. Observing time on NRAO telescopes is available on a competitive basis to qualified scientists after evaluation of research proposals on the basis of scientific merit, the capability of the instruments to do the work, and the availability of the telescope during the requested time. NRAO also provides both formal and informal programs in education and public outreach for teachers, students, the general public, and the media.
	The U.S. National Science Foundation (NSF) is an independent federal agency created by Congress in 1950 "to promote the progress of science; to advance the national health, prosperity, and welfare; to secure the national defense..."
	AUI collaborates with the scientific community and research sponsors to plan, build, and operate cutting-edge facilities. We cultivate excellence, deliver value, enhance education, and engage the public.