Convective type precipitation

This is associated with towering cumulus (cumulus congestus) and cumulonimbus clouds. Three subcategories may be distinguished according to their degree of spatial organization.

1 Scattered convective cells develop through strong heating of the land surface in summer (Plate 25), especially when low temperatures in the upper troposphere facilitate the release of conditional or convective instability (see B, this chapter). Precipitation, often including hail, is of the thunderstorm type, although thunder and lightning do not necessarily occur. Small areas (20 to 50 km2) are affected by individual heavy downpours, which generally last for about 30 minutes to an hour.

2 Showers of rain, snow or soft hail pellets may form in cold, moist, unstable air passing over a warmer surface. Convective cells moving with the wind can produce a streaky distribution of precipitation parallel to the wind direction. Such cells tend to occur parallel to a surface cold front in the warm sector of a depression (sometimes as a squall line), or parallel to and ahead of the warm front (see Chapter 9D). Hence the precipitation is widespread, although of limited duration at any locality.

3 In tropical cyclones, cumulonimbus cells become organized around the centre in spiralling bands (see Chapter 11B.2). Particularly in the decaying stages of such cyclones, typically over land, the rainfall can be very heavy and prolonged, affecting areas of thousands of square kilometres.

Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

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