Simulating the night-time astronomical seeing at Dome A using Polar WRF

Abstract

ABSTRACT In Antarctica, excellent astronomical observing conditions have been measured at Dome A during night-time (or polar winter). This study investigates the performance of the Polar-optimized version of the Weather Research and Forecasting (Polar WRF, PWRF hereafter) for simulating the night-time astronomical seeing at Dome A. The seeing values were estimated by a seeing model, which used the PWRF-simulated wind speed and temperature as inputs. Furthermore, three methods to obtain the boundary layer height in the seeing model have been examined. The estimated seeing agrees well with 50-d measurements from the KunLun Differential Image Motion Monitor at Dome A during the night-time of 2019; the correlation coefficients range from 0.62 to 0.71. The PWRF-simulated meteorological parameters indicate that low wind speed and strong temperature inversion (when a large gradient Richardson number always occurs) near the ground can lead to good seeing condition. The results suggest that the PWRF model could be a reliable tool for scheduling observational astronomy at Dome A during night-time.