Denis and John (2019-01-23)
Updated by Ben Racine for bath temperature T0 = 100 mK results (2019-02-25), and modified some plots.
Since we actually have the time series of the MERRA2 profiles at their full time-resolution (3hours) for these (SouthPole, and ChajnantorPlateau and more), we can actually do better than just take the 10yr MERRA2 median profile, we can compute all the relevant parameters as a time series every 3 hours: pwv, Tsky, Tx, tau, instrument and external loading (cmb+atmosphere), and of course NET. We can then display those results in time series or histograms and get more information than just from the median. This is all done using the exact same framework as that described in the 20170221 posting.
We then pass the atmospheric spectra into the NET calculator given the default instrument. One of the intermediate data product of the NET calculator is the photon loading both internal (from the instrument starting at the window down to the detector) and external (from cmb and sky). I plot the tods of the total loading (Qtot) in pW as well as their distributions per band. In the histograms of the total loading, the solid lines show the fixed instrument loading contribution and the dashed lines show the Qtot obtained from the 10yr median MERRA2 profile. Note the changing scales of the histograms for the different bands.
Note that the coordinated used to compute the Chile atmospheric conditions are from the Chajnantor plateau, i.e. the ALMA site (lon=-67.76175°,lat=-23.0285°,alt=5060m), which is lower in altitude than the ACT site (lon=-67.788°, lat=-22.959°, alt=5190m).
See the 3D map here.