Which cloud type is found at mid-level and forms a light sheet that allows the sun or moon to appear as a bright spot?

Which cloud type is found at mid-level and forms a light sheet that allows the sun or moon to appear as a bright spot?

• A. Cirrocumulus
• B. Altostratus
• C. Nimbostratus
• D. Fog

Answer: (B)

Mid-level clouds that form a light, uniform sheet can dim the sky but still let the sun or moon show through as a bright spot when the veil is thin. Altostratus fits this description: it forms a gray to blue-gray sheet at mid-altitude, roughly 2,000 to 7,000 meters (6,500 to 23,000 feet). Because the layer can be thin enough, the sun or moon may appear as a bright spot beneath it, even though the sky is still overcast. Cirrocumulus are much higher in the atmosphere and occur in small patches, not a mid-level sheet. Nimbostratus are thick, dark, and bring prolonged precipitation, which typically hides the sun. Fog sits at the ground, not mid-level. So the best match is altostratus.

Mid-level clouds that form a light, uniform sheet can dim the sky but still let the sun or moon show through as a bright spot when the veil is thin. Altostratus fits this description: it forms a gray to blue-gray sheet at mid-altitude, roughly 2,000 to 7,000 meters (6,500 to 23,000 feet). Because the layer can be thin enough, the sun or moon may appear as a bright spot beneath it, even though the sky is still overcast. Cirrocumulus are much higher in the atmosphere and occur in small patches, not a mid-level sheet. Nimbostratus are thick, dark, and bring prolonged precipitation, which typically hides the sun. Fog sits at the ground, not mid-level. So the best match is altostratus.