Impacts of boundary layer turbulence and land surface process parameterizations on simulated sea breeze characteristics

摘要

This paper investigates the sensitivity of sea breeze(SB) simulations to combinations of boundary-layer turbulence andland-surface process parameterizations implemented in the MM5 mesoscalemeteorological mode for an observed SB case over the Swedish west coast.Various combinations from four different planetary boundary layer (PBL)schemes [Blackadar, Gayno-Seaman (GS), Eta, MRF], and two land surface model(LSM) schemes (SLAB, Noah) with different complexity are designed tosimulate a typical SB case over the Swedish west coast. The simulations areconducted using two-way interactively nested grids. Simulated 10-m winds arecompared against observed near-surface wind data from the G?TE2001campaign to examine the diurnal cycle of wind direction and speed for SBtiming. The SB (vertical) circulation is also compared in the differentexperiments. The results show that the different combinations of PBL and LSMparameterization schemes result in different SB timing and verticalcirculation characteristics. All experiments predict a delayed SB. Thevertical component of the SB circulation varies in the experiments, amongwhich the GS PBL scheme produces the strongest SB circulation. Evidentdifferences between the SLAB and Noah LSMs are also found, especially inmaximum of updraft and downdraft velocities of the SB vertical circulation.The results have significant implications for convective initiation, airquality studies and other environmental problems in coastal areas.