Cirrus

Definition

Cirrus clouds are high-altitude clouds characterized by their thin, wispy appearance, often resembling feathers or hair. These clouds typically form at altitudes above 20,000 feet and are composed of ice crystals, making them distinct from other cloud types that contain water droplets. Cirrus clouds indicate fair weather but can also signal a change in weather as they often precede a warm front.

5 Must Know Facts For Your Next Test

1. Cirrus clouds are formed from ice crystals due to their high altitude and low temperatures in the atmosphere.
2. These clouds typically appear white and can sometimes create halo effects around the sun or moon.
3. Cirrus clouds can indicate an approaching warm front, suggesting that a change in weather may occur within the next 24 hours.
4. They are often seen on clear days but can also appear during transitions from fair to stormy weather.
5. Cirrus clouds play a role in regulating the Earth's temperature by trapping heat, contributing to the greenhouse effect.

Review Questions

• How do cirrus clouds form and what conditions lead to their development?
  • Cirrus clouds form at high altitudes where temperatures are extremely low, causing water vapor to freeze into ice crystals. These conditions typically occur above 20,000 feet in the atmosphere. The presence of moisture and upward air movement can lead to their development, resulting in their thin, wispy appearance. Because of their formation conditions, cirrus clouds can signify changes in weather patterns, particularly indicating an approaching warm front.
• Discuss the role of cirrus clouds in weather prediction and what they might indicate about future weather conditions.
  • Cirrus clouds serve as important indicators in weather prediction. Their presence in the sky often signifies fair weather but can also suggest an impending change as they typically precede warm fronts. When observed alongside other cloud types or atmospheric conditions, cirrus clouds can provide valuable information for forecasting potential precipitation or storms within the next day. Meteorologists pay attention to these formations to help predict transitions in weather.
• Evaluate the environmental impact of cirrus clouds on Earth's climate and energy balance.
  • Cirrus clouds have a significant impact on Earth's climate due to their ability to influence energy balance. By trapping outgoing longwave radiation through the greenhouse effect, these clouds can contribute to warming of the atmosphere. This dual role of cooling during daytime by reflecting sunlight and warming at night raises important questions about their net effect on climate change. Understanding this balance is crucial for climate models and predicting future environmental changes.

Related terms

Cumulus:

Cumulus clouds are fluffy, white clouds that often have a flat base and typically indicate fair weather.

Stratus: Stratus clouds are low, uniform gray clouds that can cover the entire sky like a blanket, often bringing light rain or drizzle.

Nimbostratus: Nimbostratus clouds are thick, dark clouds that cover the sky and produce continuous, steady precipitation.