Spurious shear from the atmosphere in ground-based weak-lensing observations

Weak-lensing observations have the potential to be even more powerful than cosmic microwave background observations in constraining cosmological parameters. However, the practical limits to weak-lensing observations are not known. Most theoretical studies of weak-lensing constraints on cosmology assume that the only limits are shot noise on small scales, and cosmic variance on large scales. For future large surveys, shot noise will be so low that other, systematic errors will likely dominate. Here we examine a potential source of additive systematic error for ground-based observations: spurious power induced by the atmosphere. We show that this limit will not be a significant factor even in future massive surveys such as LSST.