BIOL 201 Natural History of Grenada Lecture 3: Climate & Weather

Weather is the specific atmospheric conditions at a particular location for a certain point in time. It can change quickly, from hour to hour or even minute to minute.

Climate is the long-term average patterns of weather in a specific region. It is calculated over a prolonged period, like 30 years, and reflects the overall weather trends.

The Intertropical Convergence Zone (ITCZ) is a belt of low pressure near the equator. It is a region of frequent thunderstorms and heavy rainfall.

Northeast Tradewinds are steady winds blowing from the northeast. They are a characteristic feature of the tropics, bringing relatively dry conditions and little seasonal variation in weather.

Microclimates are localized variations in weather patterns within a larger climate region. They are influenced by factors like elevation, vegetation, and proximity to water.

Elevation, which is the height above sea level, plays a crucial role in shaping habitats. Higher elevations generally experience cooler temperatures, increased rainfall, and different vegetation compared to lower elevations.

Latitude, a measure of distance north or south of the equator, strongly influences climate. Areas closer to the equator receive more direct sunlight and experience warmer temperatures than regions farther away.

Ocean currents, moving bodies of water, have a significant impact on climate. Warm currents bring warmer temperatures and increased moisture to coastal regions, while cold currents have a cooling effect.

Topography refers to the shape and features of the Earth's surface. Mountain ranges can block winds and create rain shadows, leading to dry areas on the leeward side.

Island size plays a crucial role in species richness. Larger islands tend to support a greater diversity of species due to their larger area, which provides more habitats and resources.

Island distance from the mainland affects species richness by influencing colonization rates. Islands closer to the mainland have a higher chance of being colonized by new species, leading to greater biodiversity.

Transportation by sea, like floating vegetation rafts, can play a significant role in the dispersal of reptiles to islands. The rafts can carry reptiles across vast distances, allowing them to colonize new islands.

Ocean currents can act as pathways for ocean waif dispersal, which involves the spread of organisms across oceans. These currents can carry marine life to new locations, allowing them to colonize distant islands.

Weather components encompass various aspects of the atmosphere, including temperature, humidity, precipitation, cloudiness, wind, atmospheric pressure, sunshine, snow, sleet, thunderstorms, and heat waves.

Weather is measured at a specific point in time, whereas climate is measured over an extended period, often 30 years or more. Weather is fleeting, while climate represents a long-term trend.

Physical factors like latitude, elevation, and topography play a significant role in island evolution. These factors determine the island's climate, habitats, and overall environmental conditions, influencing which species can thrive.

Biodiversity, or the variety of life in a particular area, is not considered a component of weather. Weather primarily focuses on the physical atmospheric conditions, not biological diversity.