DAILY MISCELLANY

SCIENCE QUESTION Why are some clouds flat on top?

Cumulus clouds form when heat from the Earth (warmed by the sun) causes convection in the lower atmosphere. The development and height of cumulus clouds will partly depend on the amount of convection, which is linked to the amount of heating. Strong convection leads to higher cloud tops.

Very often the atmosphere above the Earth will be layered and this means that winds may be stronger at greater altitudes. If the tops of a cumulus cloud reach a zone where wind speeds are greater than lower down, the tops can be sheared in the direction of the prevailing wind. This is called a castellate texture.

WORD OF THE DAY

arrogate [ar-uh-geyt]

To claim or seize unwarrantably, presumptuously or without sufficient justification From Latin arrogare “to appropriate for oneself”

“Arrogant” comes from the same root, and applies to the sense of superiority one gets from claiming (or arrogating) more consideration than is warranted by one’s position or abilities

“…the Roman pontiffs … in consequence of their claim of supreme power on earth, arrogate the right of dispensing with precepts and duties of every kind.” (William Robertson, The History of the Reign of the Emperor Charles V, 1827)

Today’s word suggested by Sue Fauset and sent in by Jim Buckley of Weybridge in Kent. To suggest a word of the day, please tap don@independent.co.uk