Used in this study are monthly mean temperatures at 10 standard levels from surface to 30 hPa, total ozone and 2 800 MHz solar flux over Antarctic 16 stations in 1962～1993 that are treated by a maximum entropy spectrum method with the aim to uncover the linear trend variation in climate and spectral features at all the levels alongside possible causes discussed for January, April, July and October (as mid season months). Evidence shows that stratospheric temperature (total ozone) is becoming lower (smaller) for these months; 100 hPa temperature (total ozone) shows maximum variability in October of -1.8℃ (-14.8%) per 10 years; tropospheric temperature (2 800 MHz solar flux) has a tendency to warm up (enhance) in these months; 500 hPa temperature (solar flux) has the variability of 0.4℃ (22.1×2 800 MHz) per decade in January with the flux displaying salient periods of 3 and 9～10 years for these months; tropospheric 850～500 hPa temperature variation entropy spectrum exhibits corresponding features only in July; no appreciable trend and periods occur to tropopause temperature in the study months; pronounced decrease of ozone in spring and growth of solar flux in summer represent major causes of stratospheric cooling and tropospheric warming; Antarctic ice melting related to the summer tropospheric warming may be a major cause of sea level rise on a global basis.