This is the result with ACR set to Tungsten (or Auto, either yields the same setting). Note that the noise pattern - caused by over-amplification of the red channel is now almost absent. Much the same effect is visible in blue skies; at normal (5200-higher) ACR WB settings, noise is strong and visible even at ISO 100. If a tungsten filter is fitted (85C) for daylight shots and a tungsten setting also used for raw conversion, noise is much lower.