Angular power spectra for each of the constrained realization maps shown in Fig. 1. The ΛCDM cosmological model corresponding to θ is shown as a dashed black line, while the colored curves show (from dark to light) spectra for the fluctuation map, the mean field map, and the full constrained realization. Note that in the fully noise-dominated cases, such as the entire B-mode power spectrum and all high multipoles, the fluctuation term and the CMB estimate a_ℓm have nearly identical power spectra by design.