Polar Education

The temperature increase due to climate change is much higher in polar regions than for the global average. At the same time, polar regions play an important role in the global climate. Despite their importance, courses related to these remote regions are not generally taught at many colleges. Our project, Polar ENgagement through GUided INquiry (PENGUIN; https://serc.carleton.edu/penguin), seeks to bring polar research into undergraduate classrooms through computational guided inquiry modules, in which the instructor guides the student in working through a computational module. PENGUIN modules are designed to be taught in a wide variety of STEM courses, from Environmental Science to Quantum Mechanics, through hands-on analysis of polar data using disciplinary tools. For example, in an Economics class, students examine the consequences of sea level rise due to polar ice melt on the cost/benefit analysis of building a sea wall. In a Physics class, students investigate heat diffusion through permafrost. Survey results indicate that students and instructors alike feel that students make substantial learning gains through the modules, increase their comfort with the computational tools, and increase their interest in learning more about polar regions. A module was recently developed for an introductory statistics class, in which students use statistics concepts like linear regression to reconstruct temperature records from ice cores and compare them to greenhouse gas records. Survey results for this module demonstrate quantitative learning gains for both statistics and polar literacy that exceed learning gains in control-group statistics classes where the module was not taught. This suggests that PENGUIN modules effectively bring polar research to undergraduate students without sacrificing course learning goals, but rather enhance them.

Southern Ocean Clouds

Clouds over the Southern Ocean (SO) play an important role in the surface energy balance through their interactions with shortwave and longwave radiation. Many climate, weather forecasting, and reanalysis models have biases in surface radiative fluxes over the SO, primarily due to incorrectly modeling clouds. Thus there is a need for in-situ and surface-based cloud measurements over the SO, where low-level clouds are nearly ubiquitous and supercooled liquid is common. Here we characterize cloud properties and downwelling radiative fluxes from 2017 to 2023 using a suite of measurements made from Escudero Station (62.2°S, 58.97°W), situated on King George Island, north of the Antarctic Peninsula in the SO. Measurements include surface-based broadband radiance measurements, radiosoundings, and cloud profiling with a mini micro pulse lidar. Clouds are found to be present over Escudero 96% of the time, with most of the lowest cloud bases within the first kilometer (82%) and with a preponderance of supercooled liquid. Comparing to the European Centre for Medium-Range Weather Forecasts Reanalysis version 5 (ERA5), we find that ERA5 overestimates shortwave downward flux in the summer by about 40 W/m2 and underestimates longwave downward flux by an average of 16 W/m2 over the year. By comparison, for the Polar Weather Research Forecasting (Polar WRF) model, biases were found to be considerably lower. (Polar WRF comparisons were only made during strong atmospheric river events). For the years 2017 to 2023, bias-corrected ERA5 results indicate that the monthly average net cloud forcing varied from -107 W/m2 in January to 65 W/m2 in June.