Latent heat polynyas form in areas where prevailing winds or oceanic currents create divergence in the ice cover, leading to openings either surrounded by extensive pack ice or bounded by land on one side and pack ice on the other (coastal polynyas) (Armstrong, 1972; Park et al., 2018). The open water of polynyas is critical for air–sea heat exchange, since ice-covered waters are better insulated and reduce the net heat flux to the atmosphere (Fusco et al., 2009; Talley et al., 2011). A key feature of coastal or latent heat polynyas are katabatic winds (Fig. 1), which form as cold, dense air masses over the ice sheets of Antarctica. These air masses flow as gravity currents, descending off the glacier, sometimes funneled by topography, as in the Terra Nova Bay polynya whose katabatic winds form in the Transantarctic Mountains. This episodic offshore wind creates and maintains latent heat polynyas. This study focuses on in situ measurements taken from two coastal latent heat polynyas in the Ross Sea, the Terra Nova Bay and the Ross Sea polynyas.