The aim of this work is the study of the vertical turbulent structure and the spectral characteristics of the marine Low Level Jet (LLJ). The analyzed data are based on SODAR and in-situ instrumentation measurements, performed during summer 2003, in the frame of the Coupled Boundary Layers Air-Sea Transfer Experiment in Low Winds (CBLAST-Low), at Nantucket Island, MA, USA. The study of vertical profiles of the wind speed and temperature reveal the frequent development of marine LLJs, a modification of thermal stratification of the vertical structure of the marine Atmospheric Boundary Layer (MABL) and strengthening of LLJs depending on the meteorological conditions. In order to reveal the distribution of the intensity of wind variations in time scales corresponding to different physical processes, the Hilbert-Huang Transform (HHT) was applied to time series of the wind data from ground observations and SODAR data at different levels. Results are presented and discussed for a case study where the observed LLJ was formed on the top of the temperature inversion. It was persistent for several hours and the analysis of the wind speed data showed high amplitudes corresponding to contributions from the inertial motions but also from processes with a variety of time-scales.
Intrinsic Mode Function Inertial Motion Inertial Oscillation Marine Atmospheric Boundary Layer Intrinsic Mode Function Component
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Banta RM, Newsom RK, Lundquist JK, Pichugina YL, Coulter RL, Mahrt L (2002) Nocturnal low-level jet characteristics over Kansas during CASES-99. Bound-Lay Meteorol 105:221–252. doi:10.1023/A:1019992330866CrossRefGoogle Scholar
Blumen W (1997) A model of inertial oscillations with deformation frontogenesis. J Atmos Sci 54:2681–2692. doi:10.1175/1520-0469(1997) 054<2681:AMOIOW>2.0.CO;2CrossRefGoogle Scholar
Edson J et al (2007) The coupled boundary layers and air-sea transfer experiment in low winds (CBLAST-LOW). B Am Meteorol Soc 88:341–356CrossRefGoogle Scholar
Gerber H, Chanf S, Holt T (1989) Evolution of a marine boundary layer jet. J Atmos Sci 46:1312–1326. doi:10.1175/1520-0469(1989) 046<1312:EOAMBL>2.0.CO;2CrossRefGoogle Scholar
Lundquist JK (2003) Intermittent and elliptical inertial oscillations in the atmospheric boundary layer. J Atmos Sci 60:2661–2673. doi:10.1175/1520-0469(2003) 060<2661:IAEIOI>2.0.CO;2CrossRefGoogle Scholar
Smedman AS, Bergstrom H, Horstrom U (1995) Spectra, variances and length scales in a marine stable boundary layer dominated by a low level jet. Bound-Lay Meteorol 76:211–232. doi:10.1007/BF00709352CrossRefGoogle Scholar