Global View of the Origin of Tropical Disturbance and Storms 報告：陳心穎 William M. Gray 1968: Monthly Weather Review, 96, 669-700

Introduction Global climatology of storm development Location and frequency of initially observed disturbances and storms

The average distance from the point of initial location of disturbance to hurricane intensity : NE Pacific ~7° lat NW Pacific~11° lat North Indian Ocean~ 7° lat The western of Caribbean~8° lat The South Indian Ocean~ 7° lat NW Atlantic ~10~70° long (from the west African coast)

disturbance storm

Climatology of Equatorial Trough

Association of Equatorial trough with initial disturbance location

Climatology of potential buoyancy in lower half of the troposphere

Climatology of tropospheric vertical wind shear

Variability from climatology 3.Statistics of individual storm develop Disturbance intensification Equatorward of 20° latitude NW Pacific

NW Pacific

Western Indian Ocean North Indian Ocean

South Pacific

Disturbance intensification poleward of 20° latitude

Three types of disturbance intensification 4.Statistical characterisitic of Ekman or friction veering of wind over the tropical oceans

10~13 2-3

Importance of vertical momentum transport by the cumulus up- and downdrafts

6. Idealized portrayal of conditions associated with tropical-type disturbance intensification