Increase In Cosmic Ray Intensity Research Articles

Cosmic-Ray Increase observed at High Southern Latitudes on February 23, 1956

THE large, sudden increase in cosmic-ray intensity between the hours 0300 and 0400 G.M.T. on February 23 was observed at Hobart, Tasmania, Australia, and also at the Australian National Antarctic Research Expedition's bases at Macquarie Island and Mawson, Antarctica. At the same time radio fade-outs, ionospheric and magnetic disturbances were recorded. The cosmic-ray increase resembles those observed in other places on four previous occasions in association with solar flare activity, namely, on February 28 and March 7, 1942, July 25, 1946, and November 19, 19491.

Increase of cosmic ray intensity associated with the solar flare of February 23, 1956

Increase of cosmic ray intensity associated with the solar flare of February 23, 1956

Large increase of cosmic-ray intensity following solar flare on February 23, 1956

Large increase of cosmic-ray intensity following solar flare on February 23, 1956

The cosmic ray intensity and radio fade-outs

The behaviour of the cosmic ray intensity during radio fade-outs has been investigated by superimposing the data for 35 fade-outs occurring between 0900 and 1600 hrs G.M.T. It is found that there is, on the average, an increase of ~ 0.3% in the intensity at the time of such a fade-out. The effect appears to depend on local time since fade-outs are not accompanied by any corresponding increase in cosmic ray intensity on the dark side of the earth.

The Extraordinary Increase of Cosmic-Ray Intensity on November 19, 1949

The Extraordinary Increase of Cosmic-Ray Intensity on November 19, 1949

On the Sudden Increase in Cosmic-Ray Intensity on November 19, 1949

On the Sudden Increase in Cosmic-Ray Intensity on November 19, 1949

Latitude Effect and Meson Decay

IT has been pointed out recently1 that the height of the atmospheric layer (100 mb.) in which most mesons are supposed to be produced decreases from the equator towards the poles. The decay of the mesons causes a corresponding increase in cosmic ray intensity.

An Observed Abnormal Increase in Cosmic-Ray Intensity at Lahore

DURING the course of an experimental study at Lahore on the directional total intensity of the cosmic radiation, with a triple coincidence counter system, we observed over a short period a very large increase (nearly 200 per cent) in the intensity.

Temperature of the Atmosphere

A FURTHER colloquium in the series arranged by the Manchester University Branch of the Association of Scientific Workers was addressed by Dr. T. G. Cowling on December 2, the title being “The Temperature of the Atmosphere”. Dr. Cowling began by describing how the temperature of the lower part of the atmosphere is determined by radiation, convection, and advection (horizontal currents of air and water). The distribution of temperature over the earth's surface varies with the season, and in consequence sudden large fluctuations in temperature due to the passage of air masses are in the British Isles more probable during winter than summer. Turning to the variation of temperature with altitude, Dr. Cowling suggested a possible explanation for the fact that the temperature ceases to decrease at a height known as the tropopause. According to this theory, solar energy is absorbed by ozone in the stratosphere, and in the absence of any gas with strong emission bands in the infra-red, the temperature is increased. Water vapour has broad intense bands in the infra-red, and when it is present tends to keep the temperature low. In considering variations of the temperature in the stratosphere with season and latitude, account must be taken of any variations of the concentrations of gases such as ozone and water vapour, as well as of the intensities of the radiations coming from the sun and earth. During the discussion which followed, Dr. L. Janossy pointed out that the tropopause falls rapidly at the same latitude that shows a marked increase in cosmic ray intensity. Cosmic rays might conceivably produce some ozone, and so account for the higher temperatures over the poles.