Climate Change and Weather Patterns Notes

Key Concepts of Climate Change and Weather Phenomena

• Temperature Distribution

  • Visual representation showing warmer regions in red and colder regions in blue.
  • Highlights variability in temperatures across different geographical areas, e.g., warmer Arctic despite winter conditions.

• Heterogeneity of Temperature

  • Variation in temperatures indicates differences across regions such as the Arctic vs. equatorial areas.
  • Arctic regions show less coldness compared to historical averages, impacting ice cover.

• Greenhouse Gases

  • Function like a blanket, trapping outgoing infrared radiation, especially at higher latitudes.
  • Temperature increases are documented predominantly in middle and high latitudes.

• Weather vs. Climate

  • Weather refers to short-term atmospheric conditions, while climate is the long-term average of these conditions.
  • Local weather events (e.g., cold spells) do not negate overall climate trends.

• Global Warming Trends

  • February's global temperature was approximately 1.26 degrees Celsius above the centennial average.
  • Threshold of 1.5 degrees Celsius is recognized as a significant mark for climate change progression.

• Atmospheric Circulation

  • Discusses the Hadley cell, Ferrell cell, and polar cell structures.
  • Hadley Cell: Strongest convection cell located in tropics, responsible for warm humid climates.
  • Equatorial Low: Zone where air converges, rises due to heating, and cools, leading to precipitating clouds.
  • Subtropical Highs: Areas around 30° latitude where air descends, creating dry conditions and deserts.

• The ITCZ (Intertropical Convergence Zone)

  • Seasonally migrates affecting rainfall patterns; significantly impacts monsoon climates.
  • The zone brings precipitation to regions like India during its summer shift northward.
  • Climatic variations are influenced by the migration of the ITCZ, causing differences between wet seasons in various regions.

• Statistics and Measurement

  • Importance of long-term averages to determine climatic thresholds (e.g., 1.5 degrees Celsius) requires extended data observation (> 10 years).

• Regional Winds and Weather Patterns

  • Katabatic Winds: Dense cold air flowing downhill, can cause rapid temperature changes and snow sublimation.
  • Chinook Winds: Warm dry winds descending from mountains, causing temperature increases on the leeward side (e.g., Death Valley).
  • Santa Ana Winds: Result from high-pressure systems bringing dry conditions to Southern California.

• Local Wind Systems

  • Valley Breezes: Rising warm air during the day due to heating of valley surfaces.
  • Mountain Breezes: Cool air flows down mountains at night due to temperature differentials.
  • Sea Breezes: Onshore winds induced by differential heating of land and sea surfaces, prevalent in coastal regions.

• Key Takeaways

  • Temperature and precipitation are critical in defining climate.
  • Atmospheric conditions, geographical features, and solar input influence weather, climate patterns, and local winds.
  • Understanding the distinctions between various climatic and weather phenomena is fundamental in predicting and responding to changes due to climate change and global warming.