Dipole Structure of Interannual Variations in Summertime Tropical Cyclone Activity over East Asia
Open Access
- 15 December 2005
- journal article
- research article
- Published by American Meteorological Society in Journal of Climate
- Vol. 18 (24), 5344-5356
- https://doi.org/10.1175/jcli3601.1
Abstract
The present study examines variations in summertime (July–September) tropical cyclone (TC) activity over East Asia during the period 1951–2003. To represent TC activity, a total of 853 TC best tracks for the period were converted to TC passage frequencies (TPFs) within 5° × 5° latitude–longitude grids; TPFs are defined as the percentage values obtained by dividing the number of TC appearances in each grid box by the total number of TCs each year. Empirical orthogonal function analysis of the TPF showed three leading modes: two tropical modes that represent the long-term trend and the relationship with ENSO and one midlatitude mode that oscillates between south of Korea and southeast of Japan with an interannual time scale. The latter proved to be the most remarkable climatic fluctuation of summertime TC activity in the midlatitudes and is referred to as the East Asian dipole pattern (EADP) in this paper. Anomalous atmospheric flows directly connected to the EADP are an enhanced anticyclonic (cyclonic) circulation centering around Japan when the TPF is high south of Korea (southeast of Japan), thereby showing an equivalent barotropic structure in the entire troposphere. This regional circulation anomaly varies in conjunction with the zonally oriented quasi-stationary Rossby wave train in the upper troposphere. This wave train is meridionally trapped in the vicinity of the summer-mean jet stream; therefore, the mean jet stream alters its internal meandering structure according to the phase of the wave train.This publication has 31 references indexed in Scilit:
- The Interannual Variability in the Genesis Location of Tropical Cyclones in the Northwest PacificJournal of Climate, 2002
- Circumglobal Teleconnections, the Jet Stream Waveguide, and the North Atlantic OscillationJournal of Climate, 2002
- Improvements in the Seasonal Forecasting of Tropical Cyclone Activity over the Western North PacificWeather and Forecasting, 2001
- Interannual and Interdecadal Variations of the East Asian Summer Monsoon and Tropical Pacific SSTs. Part I: Roles of the Subtropical RidgeJournal of Climate, 2000
- Tropical Cyclone Activity over the Western North Pacific Associated with El Niño and La Niña EventsJournal of Climate, 2000
- Seasonal Forecasting of Tropical Cyclone Activity over theWestern North Pacific and the South China SeaWeather and Forecasting, 1998
- Interannual Variation in the Tropical Cyclone Formation over the Western North PacificMonthly Weather Review, 1998
- Tropical Cyclone Activity in the Western North Pacific in Relation to the Stratospheric Quasi-Biennial OscillationMonthly Weather Review, 1995
- Tropical Cyclone Activity in the Northwest Pacific in Relation to the El Niño/Southern Oscillation PhenomenonMonthly Weather Review, 1985
- Tropical Cyclone Movement and Surrounding Flow RelationshipsMonthly Weather Review, 1982