Year: 2026
Type: preprint
Abstract: The South Pole is among the driest sites on Earth, and the resulting high atmospheric transparency makes it an excellent site for millimeter-wave astronomical observations. Nevertheless, for bolometric surveys of the cosmic microwave background (CMB), fluctuations in line-of-sight water vapor drive variable atmospheric emission, which has a significant impact on survey sensitivity. We have deployed a water vapor radiometer (WVR) to characterize these fluctuations in space and time and to compare atmospheric and CMB signals with other sites. This WVR has been monitoring conditions from the South Pole over the past nine years, co-located and co-observing with the BICEP series of telescopes. In this work, we analyze the performance of the WVR and the characteristics of the South Pole atmosphere and demonstrate coherent wind-driven transport of water vapor structures across the site. We show that fluctuations in CMB detector timestreams are well correlated with fluctuations in atmospheric water vapor, providing independent justification for baseline filtering procedures used to remove these fluctuations and providing a new pathway to detect and mitigate the temperature-to-polarization leakage that currently limits the precision of ground-based CMB polarization measurements.
Source: arXiv (Cornell University)
Authors: Ade, P. A. R., Ahmed, Z., Amiri, M., Barkats, D., Barron, D., Thakur, R. Basu, Birdwell, I., Bischoff, C. A., Beck, D., Bock, J. J., Buza, V., Cantrall, B., Cheshire, J. R., IV, Connors, J., Cornelison, J., Crumrine, M., Cukierman, A. J., Denison, E., Duband, L., Echter, M. A., Eiben, M., Elwood, B. D., Fatigoni, S., Filippini, J. P., Fortes, A., Gao, M., Giannakopoulos, C., Goeckner-Wald, N., Goldfinger, D. C., Gratton, S., Grayson, J. A., Greathouse, A., Grimes, P. K., Halal, G., Halpern, M., Hand, E., Harrison, S. A., Henderson, S., Hoang, T. D., Hubmayr, J., Hui, H., Irwin, K. D., Kang, J. H., Karkare, K. S., Kefeli, S., Kovac, J. M., Kuo, C., Lasko, K., Lau, K., Lautzenhiser, M., Liu, T., Mackey, S. C., Maher, N., Megerian, K. G., Minutolo, L., Moncelsi, L., Nakato, Y., Nguyen, H. T., O'Brien, R., Paine, S. N., Papen, A., Patel, A., Petroff, M. A., Polish, A. R., Precup, N., Prouve, T., Pryke, C., Reintsema, C. D., Romand, T., Salatino, M., Schillaci, A., Schmitt, B., Sheehy, C. D., Singari, B., Soliman, A., Germaine, T. St., Steiger, A., Steinbach, B., Sudiwala, R., Teply, G., Thompson, K. L., Tucker, C., Turner, A. D., Verges, C., Vieregg, A. G., Wandui, A., Weber, A. C., Willmert, J., Wong, C. L., Wu, W. L. K., Yang, H., Yu, C., Zeng, L., Zhang, C., Zhang, S.
Institutions: Cardiff University, SLAC National Accelerator Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, University of British Columbia, Center for Astrophysics Harvard & Smithsonian, University of New Mexico, California Institute of Technology, University of Cincinnati, Jet Propulsion Laboratory, University of Chicago, National Institute of Standards and Technology, Argonne National Laboratory, University of Minnesota, Commissariat à l'Énergie Atomique et aux Énergies Alternatives, University of Iceland, Harvard University, University of Illinois Urbana-Champaign, University of Cambridge, Boston University, Lawrence Berkeley National Laboratory
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
SDG: Climate action
Open Access status: green
Funders: National Science Foundation, Smithsonian Institution, U.S. Department of Energy, National Aeronautics and Space Administration, Gordon and Betty Moore Foundation, California Institute of Technology, Harvard University, University of Chicago, Jet Propulsion Laboratory, Smithsonian Astrophysical Observatory, FAS Division of Science, Harvard University, SLAC National Accelerator Laboratory
Awards: G2048821276, Collaborative Research: Imaging the Beginning of Time from the South Pole: Completing the BICEP Array Survey, G2676722403, G3648211085, Collaborative Research: Imaging the Beginning of Time from the South Pole: Completing the BICEP Array Survey, Research Infrastructure: MRI: Development of a Small Aperture Telescope Pathfinder to Advance Studies of the Polarized Cosmic Microwave Background, MSIP: Innovation to Achieve the Full Science Reach of the BICEP Array Stage 3 CMB Polarization Experiment, MRI: Development of a 150 GHz Receiver for the BICEP Array CMB Polarimeter, G830101876
OpenAlex ID: W7207801064