What is already known:
What this study adds:
The complex structure of the nighttime Arctic stable boundary layer (SBL) has long impeded the development of a comprehensive SBL depth parametrization, consequently leading to poor representation in many climate models. This study attempts to quantify the depth of the SBL in the Arctic region of Finland using high-resolution vertical profile data of temperatures, horizontal wind speeds, and directions extrapolated from in-situ rotary-wing unmanned aircraft systems (rwUAS) flown during the 2018 Innovative Strategies for Observations in the Arctic Atmospheric Boundary Layer (ISOBAR) field campaign. Two SBL depth parametrizations are investigated — 1) the height of the maximum potential temperature gradient and 2) the height of the maximum horizontal wind speed magnitude, or lowest low-level jet height. Initial attempts at calculating a single consistent maximum temperature gradient proved difficult, and averaging and filtering methods were employed to improve chances of observing reasonable heights. The addition of horizontal wind directions as wind vectors to temperature profiles helped offer insights into the behavior of the inversions and confirm or invalidate the maximum gradient heights. Investigating maximum wind speed heights revealed they consistently formed around 80 m – 100 m above the maximum temperature gradient heights. Analyses of the three SBL profiles altogether — temperature, wind speed, and direction — propounded the possibility of their usage in creating a more explicit SBL depth parametrization. The results also demonstrated the capabilities of rwUAS as a promising tool for improving understandings of the SBL structure.