Surface heat budget in the Southern Ocean from 42°S to the Antarctic marginal ice zone: four atmospheric reanalyses versus icebreaker Aurora Australis measurements

• DOI: 10.33265/polar.v38.3349
• Publication Date: 2019-06-28T09:29:22Z
• Authors: Lisan Yu; Xiangze Jin; Eric W. Schulz
• Keywords: Shortwave radiation; Energy budget; Longwave

Surface heat fluxes from four atmospheric reanalyses in the Southern Ocean are evaluated using air–sea measurements obtained the Aurora Australis during off-winter seasons 2010–12. The icebreaker tracked between Hobart, Tasmania (ca. 42°S), and Antarctic continent, providing situ benchmarks for surface energy budget change Subantarctic (58–42°S) eastern marginal ice zone (MIZ, 68–58°S). We find that show a high-level agreement among themselves, but this reflects universal bias, not “truth.” Downward shortwave radiation (SW↓) is overestimated (warm biased) downward longwave (LW↓) underestimated (cold biased), an indication cloud amount all models too low. ocean both regimes shows gain atmosphere when averaged over seven months (October–April). However, by 10–36 W m−2 (80–220%) MIZ 6–20 m−2 (7–25%) Subantarctic. biases SW↓ LW↓ cancel out each other MIZ, causing to be dictated underestimation bias sensible loss. These affect meaningfully affecting timing of seasonal transition net loss at relative strength different summer, length-of-day effect can lead increased high latitudes.