You can download a pdf of Odishaw's article here. The backgrounds on some of the projects it describes have been provided in previous posts. Below I will bullet-point some of the highlights of the Bulletin’s 8-page article, using headings and subheadings from that article.
Physics of the Upper Atmosphere
Solar activity
- The first major solar flare observed as part the IGY program was on 28 June 1957 (just before the official start of the IGY), leading to an Alert concerning the probability of solar disturbances.
- Measurements at the Mount Wilson Observatory in California found that the magnetic field at the sun's surface is about 10,000 times greater than that of the Earth.
- Magnetic observatories confirmed the existence of the equatorial electro-jet, a large but narrow electric current circling the Earth's equator high in the atmosphere.
Aurora and airglow
- The most complete synoptic maps ever of auroral displays were compiled, including the first confirmation that auroral displays at the north and south poles were synchronous.
Cosmic rays
- The "cosmic ray equator," where the cosmic ray intensity is a minimum, was found to deviate from the geomagnetic equator, perhaps due to cosmic ray deflections by extraterrestrial magnetic fields.
- With the first launch of an IGY test rocket on 5 July 1956 from Wallop's Island, Virginia, 83 rockets had been launched so far during the IGY, revealing atmospheric temperature, pressure, density, and ionization profiles.
- The launches of Sputniks 1 and 2 represented an extension of rockets' probing of the high atmosphere.
- The U.S. was developing two types of satellites: test spheres for the testing of the Vanguard rocket system, and instrumented satellites to be later used with Vanguard and Jupiter-C rockets.
Earth's Heat and Water Regimen
Meteorology
- Synoptic meteorological maps of Antarctica were prepared for the first time, and continued on a daily basis.
- The South Pole Station, 10,000 feet above sea level, reported the lowest temperature ever recorded, -102.1 °F.
- Weather balloons were sent to altitudes of as much as 80,000 feet (15 miles) over Antarctica.
- Atmospheric ozone was measured in Antarctica for the first time, the beginning of a database that showed progressively decreasing levels of atmospheric ozone. In the 1980s, this depletion of ozone was attributed to the release of chlorofluorocarbon pollutants, garnering the 1995 Nobel Prize in chemistry for Paul J. Crutzen, Mario J. Molina, and F. Sherwood Rowland.
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| Ozone ground measurements (black circles) starting at the time of the IGY, and later measurements above Antarctica (NASA) |
- Carbon dioxide, "another minor constituent of the atmosphere which may play a role in climatic changes," was also measured in Antarctica. A summary of early analyses of carbon dioxide in Antarctic air collected in glass flasks at the South Pole between 17 May 1957 and 6 February 1976
were reported and tabulated in the publication Antarctic Carbon Dioxide Project, Report No. 5 (July 15, 1976), prepared by Charles D. Keeling, J. Alexander Adams and Carl A. Ekdahl of the Scripps Institution of Oceanography. This level has continued to increase in Antarctica, as it has worldwide. I think we can safely remove the qualifier "may" from the quote above.
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| The earliest carbon dioxide measurements from Antarctica (Keeling et al., 1976) |
Glaciology
- In Greenland, the U.S. Army's Snow, Ice and Permafrost Research Establishment perfected techniques for drilling holes in the ice with hollow drills to obtain ice cores. The first hole drilled in Greenland in 1956 reached a depth of over 1000'. The layers of ice provide a stratigraphy of climate, precipitation, and volcanism
- Seismic studies in Antarctica were used to ascertain thicknesses of the ice sheet. Byrd Station, at an elevation of 5000', sat atop ice almost 10,000' thick.
- Oceanographic expeditions were used among other reasons for studying mean sea level. No mention was made in the Bulletin article about the sea level rise that has been a result of global warming.
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| Rise in sea levels since 1900. Pre-1940, glaciers and Greenland meltwater dominated the rise; dam projects slowed the rise in the 1970s. Recently, ice sheet and glacier melt, plus thermal expansion, dominate the rise. Tide-gauge data shown in blue and satellite data in orange. (NASA/JPL-Caltech) |
- Geophysicists on Drifting Station A in the Arctic Ocean used seismic and gravity measurements to infer the floe had drifted over an underlying oceanic ridge which rose more than 5,000' above the ocean floor.
Earth's Structure and Interior
Seismology
- New earthquake seismographs were developed and deployed around the world, including ten long period seismographs that were especially able to detect surface waves with periods of 400 seconds, generated by only the very largest earthquakes.
- Seismographs installed in the Pacific and Antarctic regions were to yield more complete patterns of global seismicity (which a decade later became critical for the theory of plate tectonics).
- Seismologists probed the thickened continental "roots" beneath the Andes Mountains of South America (a topic of isostasy to be blogged about at some point).
- The first successful gravity measurements were made on the open sea using a new model of gravimeter.
IGY Data
To handle the voluminous amount of data to be collected during the IGY at 2,000 stations by 10,000 scientists from 67 countries, three World Data Centers were to be established in the U.S., Europe, and the Soviet Union.
We can see that a number of strands of IGY research projects have endured, and have implications for critical issues that were barely considered at the time. That's how basic scientific research works, and why we must support it!
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