Effects of environmental factors on the LHAASO-ED array

Abstract

KM2A is a sub-array of the Large High Altitude Air Shower Observatory (LHAASO) which comprising 5195 electromagnetic detectors (EDs) and 1188 muon detectors (MDs). The array is affected by various environmental factors, such as temperature, atmospheric pressure, and precipitation, particularly for the EDs which are installed in an open-air configuration. In this study, we analyse and compare the KM2A data of the full array with meteorological records to investigate the variations in the trigger rate array. The temperature and pressure coefficients are found to be stable over a year and half. After applying temperature and atmospheric pressure corrections, sudden changes in trigger related to atmospheric electric fields during thunderstorms are examined.