Three-dimensional Atmospheric River Frequency and precipitation over Southern Hemisphere

Monthly atmospheric river (AR) frequency and AR-related precipitation derived using a three-dimensional AR detection algorithm that extends the conventional method of Takahashi and Sakazaki (2025). European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis version 5 (ERA5) is used to compute ARs. The file "AR_ground_frequency_ALL_{yyyy}.nc" contains the monthly count of AR occurrences at each grid point based on the 3D AR mask. The file "AR_ground_frequency_iwv_weighted_ALL_{yyyy}.nc" provides the monthly integrated fraction of water vapor contained within ARs relative to the total integrated water vapor (IWV) from the surface to 300 hPa. The file "pr24_{yyyy}.nc" contains AR-related precipitation diagnosed using the three-dimensional algorithm. AR-related precipitation is defined as the accumulated precipitation from AR onset to 24 hours after the final time step of the AR footprint.