Seasons in the Southern Hemisphere

Study Notes

Seasons in the Southern Hemisphere

Spring and summer are about a week shorter in the Southern Hemisphere compared to the Northern Hemisphere due to Earth's elliptical orbit.
The Southern Hemisphere receives more solar energy when closer to the sun, influencing seasonal patterns.

Climate of the Philippines

Tropical maritime climate characterized by high temperatures, humidity, and abundant rainfall.
Mean annual temperature is 26.6°C; lowest in January (25.5°C), highest in May (28.3°C).
Temperature variation is mainly affected by altitude rather than latitude.

Humidity in the Philippines

High relative humidity due to warm temperatures and proximity to water bodies.
Average relative humidity ranges from 71% in March (lowest) to 85% in September (highest).

Rainfall in the Philippines

Key climatic element, with annual rainfall varying between 965 mm to 4,064 mm across regions.
Influences include moisture-bearing winds and mountain locations.
Highest rainfall recorded in Baguio City, Eastern Samar, and Eastern Surigao; lowest in Southern Cotabato and General Santos City.

Seasons in the Northern Hemisphere

The Northern Hemisphere experiences winter solstice on December 21, resulting in the shortest day of the year.
The sun is directly overhead at the Tropic of Capricorn (23.5° S) during the Southern Hemisphere summer solstice on December 21.

Seasonal Variation in the Southern Hemisphere

During winter solstice (June 21), days are shorter, evenings longer with cooler temperatures.
The Southern Hemisphere experiences summer from December 21, opposite the Northern Hemisphere, which is in winter.

Climate Types in the Philippines

Four distinct climate types based on rainfall:
- Type I: Distinct dry and wet seasons.
- Type II: No distinct dry season; evenly distributed rainfall.
- Type III: More or less evenly distributed rainfall with a dry period.
- Type IV: Evenly distributed rainfall with no significant dry season.

Daily Warming and Cooling of Air

Ground heating occurs through conduction from sunlight, warming the air in contact; convection redistributes heat.
Windy conditions enhance heat distribution through mechanical stirring, known as forced convection.

Daily Temperature Variations

Maximum temperature (Tmax) occurs around 3-5 PM on clear days, slightly later in cloudy conditions.
Surface type and cover, such as vegetation, influence Tmax.

Nighttime Cooling

Infrared radiation leads to ground and air cooling after sunset, with colder air frequently settling in valleys.
Radiational cooling increases air density, trapping pollutants in valleys.

Protecting Crops from Cold Night Air

Covering plants with materials like straw can prevent heat loss during cold nights.
Orchard heaters and wind machines can increase near-ground temperature to safeguard crops.

Daily Temperature Range

Greatest temperature variation occurs at the earth’s surface, decreasing with altitude.
High deserts experience the largest diurnal range; infrared sensors can estimate temperatures based on radiant energy emissions.

Summary of Temperature Variations

Daily air temperature is influenced by solar energy input and surface heat output.
Coldest temperatures are typically found at the surface at night due to rapid cooling.
The greatest daily temperature variation occurs at the surface level.

Description

Explore the unique seasonal variations in the Southern Hemisphere caused by Earth's elliptical orbit. Understand how these differences impact the duration of spring and summer, compared to the Northern Hemisphere. Test your knowledge and learn fascinating facts about regional climate changes.