平流（Advection）的含义是指（）

温度平流的表达式是：1）请作图分析冷、暖平流时该项的正负号。 2）请说明温度平流的拉普拉斯的含义？

A.平均温度平流

B.冷暖平流

C.厚度平流

D.平均层的气流

Advection fog is most commonly caused by ______.

A.air being warmed above the dew point

B.saturation of cold air by rain

C.a rapid cooling of the air near the surface of the Earth at night

D.warm moist air being blown over a colder surface

A.辐射雾

B.平流雾

C.所有类型的雾

D.蒸发雾

Which of the following is TRUE of advection fog ().

A.It commonly occurs on coastal waters during cold seasons

B.It moves in a bank or dense cloud

C.It is caused by warmer air moving to a cooler location

D.All of the above

A.辐射雾

B. 平流雾

C. 所有类型的雾

D. 蒸发雾

Advection fog may be formed by cold air passing over a ______.

A.colder sea surface

B.warmer sea surface

C.dry coastal plains

D.high mountain or plateau