Understanding Orographic Effects on Surface Observations at Macquarie Island

Research on Macquarie Island reveals that the island's modest elevation (410 m) has limited orographic effects on precipitation, except for enhancing drizzle during southwesterly winds. Using high-resolution numerical simulations with and without terrain, the study analyzed four common synoptic patterns: cold fronts, warm fronts, postfrontal drizzle, and midlatitude cyclones. The findings indicate that while the island can perturb clouds and precipitation, its shallow height (nondimensional mountain height < 1 in 93.5% of cases) often allows boundary layer flow to pass over it, with greater impact observed in the lee. The weather station's location on the island's north end further limits significant orographic effects, except during specific wind conditions.

Wang, Z., Belusic, D., Huang, Y., Siems, S. T., & Manton, M. J. (2016). Understanding Orographic Effects on Surface Observations at Macquarie Island. Journal of Applied Meteorology and Climatology, 55(11), 2377–2395. https://doi.org/10.1175/jamc-d-15-0305.1