Low-level easterly winds blowing through the Tsugaru strait, Japan. Part I: Case study and statistical characteristics based on observations

Teruhisa Shimada, Masahiro Sawada, Weiming Sha, Hiroshi Kawamura

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)

Abstract

This study has investigated structures and diurnal variations of the easterly surface winds blowing throughout the east-west passage comprising the Tsugaru Strait, Mutsu Bay, and circumjacent terrestrial gaps in northern Japan during the summer months. Based on observational and reanalysis data, a representative case study in June 2003 and supplemental statistical analyses are presented. The cool easterly winds accompanied by clouds and fog are blocked by the central mountain range. This condition increases an along-strait sea level pressure (SLP) gradient, which induces strong winds in the west of the strait. The along-strait SLP gradient is enhanced by the developed Okhotsk high and by low pressure systems passing along the southern coast of Japan or over the Japan Sea. Stronger (weaker) and easterly (east-northeasterly) winds are observed during the nighttime (daytime), corresponding to the cool air intrusion from the east (retreat from west). Differences in SLP observed at meteorological observation stations on the east and west can be a good indicator of wind speed in the west of the strait. Meanwhile, the winds over the land also show diurnal variations specific to the times of the prevailing cool easterly winds. The easterly winds over the land are stronger and more divergent across the strait during the daytime than nighttime. This indicates the possibility that the diurnal wind variations are thermally induced. Reduction of diurnal air temperature changes in the east increases east-west thermal contrast. Additionally, the cool air over the strait and the bay can enhance land-sea thermal contrast across the coast.

Original languageEnglish
Pages (from-to)3806-3821
Number of pages16
JournalMonthly Weather Review
Volume138
Issue number10
DOIs
Publication statusPublished - 2010 Oct

ASJC Scopus subject areas

  • Atmospheric Science

Fingerprint Dive into the research topics of 'Low-level easterly winds blowing through the Tsugaru strait, Japan. Part I: Case study and statistical characteristics based on observations'. Together they form a unique fingerprint.

Cite this