The Spectral Signature of Surface Turbulent Fluxes during Arctic Warmings: Combining MPLNET Lidar and Surface Turbulence Observations

The similarity approximation of Surface Turbulent fluxes of momentum and sensible heat is examined during winter warmings in high latitudes Interior of Alaska. In this analysis we combine MPLNET Lidar vertical profiling and surface turbulence observations by eddy-covariance towers in the University of Alaska Fairbanks Experimental Farm during the Fall /Winter transition of 2018. During winter warming events (i.e., northward migration of the polar front) the calculated turbulent fluxes spectra is observed to shift towards lower frequencies as well as changes in the dissipation rate in response to the changes in the stability of the atmospheric surface layer. Based on the combined experimental datasets we identified several cases that combined with a suite of synoptic meteorological analysis to provide a clear description of the spectral changes during the northward migration of stratocumulus clouding.