Horizontal Distribution of Temperature
The average temperature of Earth is approximately 15°C, but it is not uniformly distributed. Various geographical and atmospheric factors influence how temperature varies across different latitudes.
Key Observations
- Northern Hemisphere is Warmer than the Southern Hemisphere
- Northern Hemisphere: 15.2°C
- Southern Hemisphere: 13.3°C
- Reason: More landmass in the Northern Hemisphere, which heats up and cools down faster than the ocean-dominated Southern Hemisphere.
- Temperature Decreases from the Equator Towards the Poles
- Solar energy received (insolation) is highest at the equator and reduces poleward.
- Polar regions remain cold due to a high angle of sunlight incidence and longer winters.
- Highest Recorded Temperatures are Not at the Equator
- Instead, they are found near the Tropics (Cancer & Capricorn).
- Why?
- Equator has more cloud cover, reflecting a large portion of solar radiation.
- More energy is used for evaporation over equatorial oceans, reducing surface heating.
Temperature Mapping and Terminology
- Isotherms
- Lines on maps that connect places of equal temperature (adjusted to sea level).
- They help in visualizing global temperature patterns.
- Thermal Anomaly (Isanomalous Temperature)
- The difference between the actual temperature of a place and the average temperature of its latitude.
- Example: If a place at 30° latitude has a temperature warmer or colder than the global mean for 30°, it shows a thermal anomaly.
- Isanomals
- Lines on maps that connect places with equal thermal anomalies (similar to isotherms but for deviations).
Conclusion
Temperature is not evenly spread across the globe due to land-ocean contrast, cloud cover, and atmospheric processes. Understanding isotherms and isanomals helps in climate studies, weather forecasting, and agricultural planning. 🌍🔥❄️
