Grade 8 Science: Pressure, Winds, Storms, and Cyclones

Vocabulary practice flashcards covering fundamental definitions, scientific concepts, units of measurement, and meteorological phenomena from Chapter 6: Pressure, Winds, Storms, and Cyclones.

Pressure

The physical quantity defined as the force acting perpendicularly per unit area on a surface, calculated as $\text{Pressure} = \frac{\text{Force}}{\text{Area}}$.

Pascal

The SI unit of pressure, denoted by $\text{Pa}$, which is equal to one newton per square metre ($1\,\text{N/m}^2$).

Millibar

A practical unit of air pressure, abbreviated as $\text{mb}$, which is equal to $100\,\text{Pa}$.

Hectopascal

A unit used to express air pressure, abbreviated as $\text{hPa}$, which is equal to $100\,\text{Pa}$.

Atmosphere

The gaseous envelope of air surrounding the Earth extending up to many kilometres above the surface, consisting primarily of nitrogen, oxygen, argon, and carbon dioxide.

Atmospheric Pressure

The pressure exerted by the weight of the column of atmospheric air on all objects around us.

Rubber Sucker

A suction device that adheres to a smooth, flat surface when pressed, because internal air is expelled and the higher external atmospheric pressure holds it firmly in place.

Wind

Air in motion that naturally flows from a region of higher air pressure to a region of lower air pressure.

Sea Breeze

The daytime movement of cooler, higher-pressure air blowing from the sea toward the lower-pressure area that develops over warmer land.

Land Breeze

The nighttime movement of wind blowing from the higher-pressure region over cooler land toward the lower-pressure region over warmer sea water.

Storm

A weather condition characterized by strong winds accompanied by heavy precipitation in the form of rain, hail, or snow.

Thunder

The loud booming sound produced when lightning rapidly heats the surrounding air, causing it to quickly expand.

Lightning

A bright flash of light caused by a sudden flow and discharge of static electric charges between clouds, within a cloud, or between a cloud and the ground.

Thunderstorm

A weather disturbance characterized by strong winds accompanied simultaneously by lightning, thunder, and heavy rainfall.

Kalboishakhi

Localized pre-monsoon thunderstorms occurring in West Bengal, Bihar, and Jharkhand that aid in the cultivation of kharif crops.

Bordoisila

The local name in Assam for pre-monsoon thunderstorms that assist in the growth of kharif crops.

Mango Showers

Pre-monsoon thunderstorms occurring in Kerala, Karnataka, and Tamil Nadu that assist in the ripening of mangoes.

Lightning Conductor

A metallic rod installed along the exterior walls of a building with a pointed end extending above the roof and the lower end buried deep in the ground to provide a safe passage for electric charges into the earth.

Cyclone

A large, revolving storm system that forms over warm ocean waters, characterized by a central area of very low pressure surrounded by high-speed spiraling winds, clouds, and heavy rain.

Eye of the Cyclone

The calm, low-wind central region of lowest atmospheric pressure within a tropical cyclone.

India Meteorological Department (IMD)

The national scientific agency in India responsible for monitoring weather phenomena, tracking cyclones and thunderstorms, and issuing forecasts, alerts, and warnings.