Publication Date:
2023-09-15
Description:
〈jats:p〉Abstract. The important roles that the atmospheric boundary layer (ABL) plays in the central Arctic climate system have been recognized, but the atmospheric
boundary layer height (ABLH), defined as the layer of continuous turbulence adjacent to the surface, has rarely been investigated. Using a
year-round radiosonde dataset during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, we improve a
Richardson-number-based algorithm that takes cloud effects into consideration and subsequently analyze the characteristics and variability of the ABLH over the
Arctic Ocean. The results reveal that the annual cycle is clearly characterized by a distinct peak in May and two respective minima in January and July. This
annual variation in the ABLH is primarily controlled by the evolution of the ABL thermal structure. Temperature inversions in the winter and summer are
intensified by seasonal radiative cooling and warm-air advection with the surface temperature constrained by melting, respectively, leading to the low
ABLH at these times. Meteorological and turbulence variables also play a significant role in ABLH variation, including the near-surface potential
temperature gradient, friction velocity, and turbulent kinetic energy (TKE) dissipation rate. In addition, the MOSAiC ABLH is more suppressed than the ABLH during the Surface
Heat Budget of the Arctic Ocean (SHEBA) experiment in the summer, which indicates that there is large variability in the Arctic ABL structure during the
summer melting season.
〈/jats:p〉
Repository Name:
EPIC Alfred Wegener Institut
Type:
Article
,
peerRev
Format:
application/pdf
Permalink
