Lecture 10:Radioactive balance, Coriolis force, and winds

Incoming Energy: Earth receives solar energy from the sun, which is essential for heating the surface.
Outgoing Energy: Earth must radiate energy back into space to maintain a balanced temperature.
Radiative Balance: When the energy coming in equals the energy going out, earth maintains a steady surface temperature, similar to a bank account where income equals expenses.

Global Warming: Current trends indicate an imbalance in energy fluxes, leading to rising global temperatures.

The sun emits energy primarily in the visible spectrum, with temperatures around 5,500 to 6,000 degrees Celsius.
Solar rays reach Earth in parallel beams due to the sun's distance, but due to Earth's curvature, this energy is unevenly distributed across the surface.
Higher latitudes experience less heating compared to lower latitudes (equatorial regions).

Earth radiates energy back into space mainly through infrared radiation, which is not visible to the human eye.
Different geographical regions exhibit varying fluxes of outgoing radiation, with warm regions (indicated in red) emitting more energy than cooler regions (indicated in blue).

Differences in radiation patterns between January and July:
- January: Cooler regions, less energy emitted.
- July: Warmer regions, more energy emitted.
Temperature dictates the amount of radiation, with higher temperatures resulting in increased flux of infrared energy.

Conventional Heat Transfer: Theoretically, a single large convection cell could move heat efficiently from equator to pole, but real-world scenarios are complex.
Fluid Dynamics: Earth experiences many complex swirls in atmospheric and oceanic currents, influenced by the Coriolis force.

The Coriolis force results from Earth’s rotation; it influences the motion of winds and currents.
Observation from Nansen's Expedition:
- Nansen's observations indicated that the drifting ice observed a deviation (to the right in the Northern Hemisphere) due to the Coriolis effect.

In an inertial frame (stationary relative to the stars), motion appears straight; in a rotating frame (Earth), motion appears deflected.
- Example: Merry-Go-Round Analogy: If one throws a ball from a rotating merry-go-round, it appears to bend due to the rotation.
Coriolis force is a 'real' force in a rotating frame and appears as an apparent force elsewhere (e.g., inertial frame).

Foucault Pendulum: Demonstrates Earth's rotation; swinging paths change relative to Earth’s surface, illuminating the Coriolis effect.
Velocity Differences: Greater velocity at the equator results in greater deflection of objects moving towards poles.

Effects observed with motion:
- Northern Hemisphere: Deflection to the right.
- Southern Hemisphere: Deflection to the left.

Understanding the formation of distinct wind patterns, like Easterlies and Westerlies:
- Easterlies: Winds from the east towards the west.
- Westerlies: Winds from the west towards the east.
Local examples include seasonal weather systems driven by the general circulation patterns, emphasizing the critical role of Coriolis forces.

Variations in land and ocean temperatures lead to the formation of high and low pressure areas, affecting wind movements:
- Summer: Low pressure over warmer land; High pressure over cooler oceans.
- Winter: Conversely, land cools down causing high pressure, and relatively warmer water creates a low-pressure region.

The interaction between oceans and atmosphere illustrates dynamical coupling, driving temperature variations and impacting weather patterns.
Monsoon Systems: The South Asian monsoon exemplifies how seasonal variations in pressure lead to wet and dry periods based on wind patterns and temperature gradients.

The importance of energy balance in climate stability and the role of Coriolis forces in atmospheric dynamics.
The interplay between oceanic temperature and atmospheric pressure patterns significantly influences global and regional weather systems.
Students should be prepared to analyze temperature, radiation, and pressure systems in understanding weather phenomena.
The ability to grasp these concepts is vital for comprehending climate patterns, including seasonal changes, storm formations, and winds across latitudes.