Weather and Climate: A Comprehensive Overview

Weather and Climate

Weather

Weather is the state of the atmosphere at a specific time and place. It's characterized by its variability and is determined through direct observations. Meteorology is the science that studies weather.

Climate

Climate represents the average state of the atmosphere in a particular location. This average is determined by the typical patterns of weather that occur throughout the year. Climate exhibits more stable characteristics over time and is statistically determined by calculating average values over a period of at least thirty years to ensure reliability.

Atmospheric Pressure

Barometer: Measures the weight of air above a unit area, typically in millibars (mb) or hectopascals (hPa).
Isobars: Lines on weather maps connecting points with the same atmospheric pressure, depicting the topography of the air.
Surface Weather Maps: Generally represent isobars at 4 mb intervals.
Normal Pressure: 1013.5 mb (though weather maps often use 1016 mb as a standard).

Solar Radiation and Insolation

Insolation is the amount of solar radiation received by the Earth's surface. Spain, due to its latitude, receives over 2,000 hours of sunshine annually. However, there are significant variations, with the Cantabrian coast receiving less sunshine compared to the southeastern peninsula and islands.

Cloudiness and Haze

Cloudiness: Refers to the extent to which the sky is covered by clouds. The Cantabrian region in Spain experiences the highest cloud cover. The Guadalquivir Valley, the southern Atlantic coast, and parts of the Canary Islands have the most cloudless days.
Haze: A type of atmospheric obscurity that reduces visibility. It's caused by a high concentration of fine dust particles in the lower atmosphere. In Spain, haze often forms during dry, anticyclonic summer conditions when dry soil particles are lifted and suspended by upward air currents due to intense ground heating.

Evapotranspiration

Evapotranspiration: The combined loss of moisture from the Earth's surface through evaporation (due to solar radiation) and transpiration from plants and soil.
Actual Evapotranspiration: The amount of evapotranspiration that actually occurs.
Potential Evapotranspiration (ETP): The amount of evapotranspiration that would occur if there were an unlimited supply of water.