Antarctic Precipitation System – In situ Measurement of Precipitation in Antarctica: The Antarctic Precipitation System project is focused on improving the measurement of precipitation in Antarctica, advancing our understanding of Antarctic precipitation processes, and using this knowledge to evaluate weather and climate models. The basic measurement of precipitation in Antarctica is exceedingly difficult due to the separation of falling snow from blowing snow and due to the relatively small amount of annual precipitation. An accurate measurement of precipitation is critical for calculating Antarctica’s mass balance and contributions to global sea level rise, interpreting ice core records, and providing benchmarks for promising model− and satellite−based precipitation estimates. The APS project deployed a suite of four low−power, autonomous, polar−grade instruments, referred to as an Antarctic Precipitation System (APS), from November 2017 to November 2019. The APSs are designed with an integrated sensor approach to provide multiple, simultaneous, and different types of observations of snow accumulation at a given site. The project is currently analyzing and preparing publications on the observations from the 2017-2019 deployments. Ongoing efforts focus on additional science applications for potential future deployments in Antarctica, and the possibility for Arctic-focused research involving in situ measurement of precipitation. Source of support: National Science Foundation

HiLAT-RASM: High-Latitude Application and Testing of Earth System Models (HiLAT) Science Focus Area, in Collaboration with the Regional Arctic System Model (RASM): The HiLAT-RASM project is a collaborative project across the Naval Postgraduate School, University of Washington, and the Department of Energy’s Pacific Northwest National Lab (PNNL) and Los Alamos National Lab (LANL). The goal of the project is to develop and evaluate current and next-generation climate models with a focus on the Arctic and the Antarctic. Additionally, the project advances polar-focused climate science through Earth system model simulations, including those in the sixth Coupled Model Intercomparison Project (CMIP6). One such study, being led by Seefeldt, is looking at the changes in atmospheric circulation of the Arctic from the beginning to the end of the twenty-first century. The study is using the method of self-organizing maps (SOMs) and the data from eight CMIP6 ESMs produced by modeling centers from around the world. The CU Boulder HiLAT-RASM team is also responsible for the atmospheric model in the Regional Arctic System Model (RASM). The atmospheric model in RASM is the Weather Research and Forecasting (WRF) model. The WRF model is used in research and operational meteorology applications for studies ranging from large-eddy to regional climate simulations. Much of the work with WRF in RASM is in evaluating the configuration and parameterizations in WRF that produce the most realistic results in the Arctic. The efforts by Seefeldt are also spent in maintaining and upgrading the WRF software in RASM to capitalize on the latest improvements and benefits in the ongoing efforts to improve WRF by the larger modeling community. Source of support: Department of Energy

Modifications to the ott pluvio2 precipitation gauge for year-round measurement of precipitation at remote locations in Antarctica