In this paper we attempted to relate the relative abundance measurements of the solar wind at the earth's orbit to conditions in the solar corona. We followed the distribution of ionization stages of oxygen and helium by integrating the coupled rate equations outward from the corona to the earth's orbit. We concluded that the material observed in the solar wind at the earth's orbit must be a superposition of contributions from hotter and cooler regions of the corona.
Solar wind measurements made on the earth-orbiting Vela 3A and 3B satellites revealed the presence of high ionization stages of oxygen (BAME et al., 1968). It was found that the o+S/O +6 ratio at the earth's orbit was always about 0.1, while the ratio 0+7/0 +6 varies from the value of 3 to the value of 0.3. But most of the time 0 +6 was found to be more abundant than 0 +7 . Concurrent measurements of solar wind helium gave the value He+/He + + < 10-3.
Recently, KOZLOVSKY and ZIRIN (1968) andALLEN andDUPREE (1967) have calculated the ionization structure of oxygen in the solar corona. They found that at a typical value of the temperature of the corona, 1.5 x 106 K, O+5/O+6~0.002, and O+7/O+6~0.2. The purpose of this note is to attempt to relate relative abundance measurements at the earth's orbit to conditions in the corona. In order to follow the distribution of ionization stages of oxygen and helium in the solar wind we solved the following coupled equations: