Atmospheric Forcing and its Spatial Variability over the Japan/East Sea


Robert Beardsley (WHOI),
Clive Dorman (SDSU),
Richard Limeburner (WHOI),
Alberto Scotti (UNC),

Award Number


Project Overview

The overall goal of this project is to improve our understanding of the marine atmospheric boundary layer (MABL), its spatial structure and variability, and the resultant ocean surface forcing over the Japan/East Sea (JES).

Winter circulation and water mass formation in the Japan/East Sea are thought to be strongly driven by surface wind stress and heat fluxes. Strong winds off Siberia during cold-air outbreaks and local topographic effects associated with the Sikhote-Alin mountain range that boarder the western rim of the Japan/East Sea may give rise to large spatially-concentrated surface stresses and associated heat and moisture fluxes, which have direct and possibly large effects on the ocean.

Our primary objectives are 1) to determine the structure and variability of the MABL over the JES on synoptic and seasonal time scales, 2) to estimate surface wind stress and heat flux time series during summer and winter conditions, and 3) to examine the role of the coastal mountain ranges along the western perimeter of the JES on the low-level air flow and surface forcing during winter, with special emphasis on cold-air outbreak events that cause the maximum surface wind stresses and air-sea heat flux losses.

This project is part of the ONR Japan/East Sea Directed Research Initiative to examine frontal processes, circulation, and water property evolution in the Japan/East Sea during 1999-2000. The meteorological data collected in this project and modeling directly complements two other components of the ONR JES program. C. Friehe and D. Khelif (UCI) used an instrumented ONR Twin Otter aircraft to map the surface meteorological fields and study the MABL structure over the central JES during late January-February 2000 (one flight overflew the Revelle). Flight patterns included low-level (~ 30m) transects, with soundings to map the vertical structure of the boundary layer. Some flights were timed to sample cold-air outbreaks. S. Chen (UMiami) has collected both land-based and satellite weather data in the JES region for 1999-2000 and used this data with global weather model data to force a regional weather model and produce more highly resolved surface weather fields for the study period.