IGY Bulletin, Number 3, September 1957 - Status Report: The Upper Atmosphere Program

Finally moving on to the September 1957 (64 years ago, almost senior citizen status) issue of the IGY Bulletin. I have posted this Bulletin as a pdf downloaded from the AGU archive of the Transactions, American Geophysical Union, vol. 38, #5, October, 1957.

This issue is 16 pages, comprising seven articles. The articles in this issue are listed below. The numbers in parentheses refer to the sub-disciplines covered by the IGY, as discussed in a previous post.

1. Status Report: The Upper Atmosphere Program (an introduction to the following articles)

2. Solar Activity Program (#6)

3. Cosmic Ray Program (#7)

4. Geomagnetism Program (#2)

5. Ionospheric Physics Program (#5)

6. Aurora and Airglow Program (#4)

7. Rocket Program (#11)

The short Status Report article, the topic of this post, explains that the next six articles deal with the various US-IGY programs in each of the atmosphere disciplines, with the final related section on the rocketry program.

The sun is of central importance in the high atmosphere. Its radiation causes ionization and chemical processes in the upper atmosphere. Disturbed solar conditions affect the ionosphere and radio communications, and often cause auroral, geomagnetic, and cosmic ray activity.

In a previous post, I included a diagram showing the stratification of the Earth's atmosphere. The atmosphere refers specifically to the layers of gas surrounding any planet, and their properties. The ionosphere is the ionized part of Earth's upper atmosphere, stretching from a height of about 50 km (30 mi) to more than 1,000 km (600 mi). It includes the atmospheric layers of the entire thermosphere and parts of the mesosphere and exosphere. Ionized by solar radiation, the ionosphere plays an important role in atmospheric electricity and forms the inner edge of the magnetosphere, the envelope containing the Earth's magnetic field. Airglow occurs when atoms and molecules in the upper atmosphere, excited by sunlight, emit light. This phenomenon is somewhat similar to auroras, which are driven by high-energy particles originating from the solar wind.

Atmosphere layers on left; ionosphere layers on right; phenomena and means of measurement in the center (NASA). Click on image to enlarge.