The Atacama Cosmology Telescope: Modeling bulk atmospheric motion

Fluctuating atmospheric emission is a dominant source of noise for ground-based millimeter-wave observations the cosmic microwave background (CMB) temperature anisotropy at angular scales $\ensuremath{\gtrsim}0.5\ifmmode^\circ\else\textdegree\fi{}$. We present model atmosphere as discrete set emissive turbulent layers that move with respect to observer horizontal wind velocity. After introducing statistic derived from time-lag dependent correlation function detector pairs in an array, referred pair-lag, we use this estimate aggregate motion time-ordered data Atacama Cosmology Telescope (ACT). find estimates ACT's CMB alone agree those satellite weather additionally include height-dependent velocity and water vapor density. also explore dependence measured spectrum on relative angle between telescope scan direction. In particular, varying changes predictable way. Computing pair-lag opens up new avenues understanding how fluctuations impact measurements anisotropy.