Solar Cycle Signal in Air Temperature in North America: Amplitude, Gradient, Phase and Distribution

The 11-yr solar cycle temperature signal in records from North America is further elucidated by single- and two-channel (Morf et al., 1978) high-resolution signal processing. In agreement with earlier analysis (Currie, 1979), the signal T sub(e) is found only at locations east of the Rocky Mts. and north of 35 degrees N. Revised estimates of mean amplitude and latitude gradient are 0.18 degrees C and 0.13 plus or minus 0.03 degrees C/10 super(3) km, respectively. In view of the recently detected 11-yr term in Earth rotation, Delta T = ET - UT (Currie, 1980), cross spectra of temperature records with Delta T were computed. At the solar cycle period, T sub(e) lags Delta T by 3.0 plus or minus 0.7 yr; since Delta T lags the change in length of the day Delta (lod) by 2.7 yr and Delta (lod) is in phase with sun-spot numbers R sub(z) (Currie, 1981b), the result is that T sub(e) lags R sub(z) by 5.7 plus or minus 0.7 yr.