The 27-day solar rotational cycle in the Freie Universität Berlin Climate Middle Atmosphere Model with interactive chemistry (FUB CMAM CHEM)

We simulate twenty, perpetual Januaries each under solar minimum and maximum conditions using the Freie Universität Berlin Climate Middle Atmosphere Model with interactive chemistry (FUB CMAM CHEM), including the 27-day solar rotational cycle. Cross-correlation functions (r) of tropical ozone and ultraviolet (UV) suggest peak values of +0.5 to +0.6 (with % changes in ozone of 0.4–0.6%) in the middle atmosphere. Temperature in the middle atmosphere varies with UV by up to 0.5 K, which appears to be mainly dynamical in origin. We calculate a signal associated with the rotational cycle in the troposphere, although this requires further investigations.