Science. 1972 Jan 21;175(4019):313-7. doi: 10.1126/science.175.4019.313.
A preliminary analysis of 15 radio occultation measurements taken on the day side of Mars between 40 degrees S and 33 degrees S has revealed that the temperature in the lower 15 to 20 kilometers of the atmosphere of Mars is essentially isothermal and warmer than expected. This result, which is also confirmed by the increased altitude of the ionization peak of the ionosphere, can possibly be caused by the absorption of solar radiation by fine particles of dust suspended in the lower atmosphere. The measurements also revealed elevation differences of 13 kilometers and a range of surface pressures between 2.9 and 8.3 millibars. The floor of the classical bright area of Hellas was found to be about 6 kilometers below its western rim and 4 kilometers below the mean radius of Mars at that latitude. The region between Mare Sirenum and Solis Lacus was found to be relatively high, lying 5 to 8 kilometers above the mean radius. The maximum electron density in the ionosphere (about 1.5 x 10(5) electrons per cubic centimeter), which was found to be remarkably constant, was somewhat lower than that observed in 1969 but higher than that observed in 1965.
对 15 次在火星南纬 40 度至 33 度之间的白天进行的无线电掩星测量进行的初步分析表明，火星低层大气（15 至 20 公里）的温度基本是等温的，比预期的要温暖。这一结果也得到了电离层电离峰升高的证实，可能是由于悬浮在低层大气中的细尘颗粒吸收了太阳辐射。测量还揭示了 13 公里的海拔差异和 2.9 至 8.3 毫巴之间的表面压力范围。发现赫拉斯古典亮区的底部比其西部边缘低约 6 公里，比该纬度火星的平均半径低 4 公里。发现在水手号海和太阳湖之间的区域相对较高，位于平均半径以上 5 至 8 公里处。在电离层中发现的最大电子密度（约每立方厘米 1.5 x 10(5)个电子）非常稳定，其值略低于 1969 年观测到的值，但高于 1965 年观测到的值。
