dBZ stands for decibels of Z. It is a meteorological measure of equivalent reflectivity (Z) of a radar signal reflected off a remote object.[1] The reference level for Z is 1 mm6 m-3, which is equal to 1 μm3. It is related to the number of drops per unit volume and the sixth power of drop diameter.
Reflectivity of a cloud is dependent on the number and type of hydrometeors, which includes rain, snow, and hail, and the hydrometeors’ size. A large number of small hydrometeors will reflect the same as one large hydrometeor. The signal returned to the radar will be equivalent in both situations, so a group of small hydrometeors is virtually indistinguishable from one large hydrometeor on the resulting radar image.
A meteorologist can determine the difference between one large hydrometeor and a group of small hydrometeors as well as the type of hydrometeor through knowledge of local weather condition contexts.
One dBZ-scale of rain: > 40 heavy, 24-39 moderate and 8-23 light
安哥拉在什么地方?wiki是这样写的:
Angola, officially the Republic of Angola is a country in south-central Africa
这个国家有什么特别的?
Angola’s economy has undergone a period of transformation in recent years, moving from the disarray caused by a quarter century of war to being the second fastest growing economy in Africa and one of the fastest in the world.
为什么我们要飞去那里?
According to an American think tank, oil from Angola has increased so significantly that Angola now is China’s biggest supplier of oil.