Weather vs. climate
Weather and climate are fundamental concepts in meteorology that describe different aspects of the Earth's atmospheric conditions. Weather refers to the specific meteorological phenomena occurring at a particular time and place, including temperature, humidity, precipitation, and wind. It is characterized by its variability and can change rapidly from day to day. In contrast, climate is the long-term average of weather patterns over an extended period, typically 30 years, and encompasses the general trends and characteristics of a region's atmospheric conditions.
Understanding the distinction between weather and climate is crucial, as climate provides a broader context for interpreting weather events, including seasonal patterns and potential future changes. Various factors influence a location's climate, such as latitude, altitude, and proximity to bodies of water, leading to diverse climate types across different regions. For instance, areas near the equator experience tropical climates, while regions at higher elevations may exhibit cooler temperatures.
While weather can be directly experienced, climate is more abstract and is often analyzed through historical data and scientific observations. The study of past climates, known as paleoclimatology, relies on geological and archaeological evidence to understand changes over time. This distinction highlights the interplay between immediate weather events and the overarching climate trends that shape our environment.
Weather vs. climate
Weather is the set of temporally or spatially local meteorological phenomena: It is the concrete set of events that actually occur over time. Climate is an abstraction from weather: It is the set of the averages of meteorological measurements taken in a given place over a given time period. Changes in climate may be used as predictors of future weather patterns.
Background
The weather is one of the most obvious and tangible aspects of Earth’s atmospheric environment. One can see, feel, hear, smell, and even taste weather. It consists of the measurable meteorological conditions of the atmosphere at any given time. In contrast, climate is a concept that is constructed by the averages of the component elements of the weather: temperature, wind, pressure, precipitation, clouds, and visibility. Complicating the understanding of climate is the fact that the Earth’s atmosphere reflects many kinds of climates over many different areas at any given time.
Weather
The term meteorology, the study of the weather, originates from the work Aristotelous peri geneseōs kai phthoras (n.d.; Meteorologica, 1812), by the Greek philosopher Aristotle (384-322 BCE). Much of what Aristotle wrote was based around his assumptions about how the weather worked; he provided a model that was accepted without question for nearly two thousand years. However, with the advent of weather instruments (1600-1850s) such as the thermometer, barometer, and hydrometer, a science of meteorology slowly emerged. The invention of the telegraph in 1844 allowed for the rapid distribution of weather observations accumulated from a large geographical area. It was the telegraph that assisted meteorologists in constructing the first weather maps and charts.
Modern Observations
Today, meteorologists depend on a wide range of instruments and communication systems to measure and distribute information about the weather. Weather observations at the surface of the Earth include measurements of wind direction and velocity, air temperature, visibility, types of observed clouds, atmospheric pressure, precipitation amount and type, and humidity. Usually, weather stations record surface conditions. However, some stations take observations of the upper atmosphere with the aid of a balloon (radiosonde). Many stations use Doppler radar. Hourly weather observations are logged at these stations. These observations are then sent to forecasters, who use them to develop long-term forecasts.
Climate is defined as the average amount of precipitation and average temperature at a given location within a given season. A location’s climate is determined by its latitude, altitude, and locational characteristics. The latitude of a station determines the amount of the station will receive at any given time during the year. Higher latitudes experience less insolation than do stations located within the tropics. Altitude is the elevation of a station. Given the environmental lapse rate, or the general decline in temperature with altitude (4° Celsius per 1,000 meters), stations found at higher elevations exhibit generally cooler climates. A station’s climate is also controlled by its location with respect to land and water.
Seattle, Washington, although somewhat high in latitude, is also climatically influenced by its orientation with respect to Puget Sound. Its maritime location keeps Seattle’s climate from exhibiting extreme temperatures. In contrast, locations such as Wenatchee, Washington, less than 160 kilometers to the east but on the leeward side of the Cascades, is located in a more continental position. Temperatures there are considerably colder in the winter and warmer in the summer. Additionally, the Cascades act as an barrier to precipitation, making Wenatchee’s climate a desert.
Climate
To understand climate, scientists must have access to weather data over long periods of time. Relatively accurate weather observations have only been available for a short time. However, past climatic conditions can also be studied by indirectly interpreting the signature left by the movement of animals and plants, as well as the of human activity. For example, seven thousand-year-old cave drawings in the Sahara Desert suggest that in the past this desert region retained a climate that was conducive to habitation. From 400 to 1200 CE, historic records suggest, the Vikings exploited the warm, ice-free conditions on their coastlines and ventured out in ships in exploratory enterprises, settling Greenland and Iceland during this time. However, historic records are subject to problems of precision and human interpretation. It would not be until the late 1800s that weather records would be scientifically collected in the United States. It is the reliability of these meteorological data that dictates how accurate scientists’ understanding of climate can become.
Climate Classification
Climates on the Earth can be classified and defined by their characteristics and their environmental qualities. However, classification systems are limited by the number of variables they utilize. One way to classify climate is to look at the distribution of different types of animals or plants that live within that climate. For example, the Köppen classification system uses temperature and moisture levels related to plants to define the patterns of climate types. On the other hand, humans are found in every climate type on Earth.
Present Climate Distributions
The general categories of climates include climates of the tropics; equatorial climates; climates in areas such as the African region of the Sudan and Sahel; and tropical semiarid climates. Additionally, desert climates can be found anywhere the geographical conditions are right for moisture to be depleted from the air. Monsoonal climates are found in India, Northern Australia, and regions within Southeast Asia. Mediterranean climates are located around the Mediterranean Sea, but they can also be found in Central Chile, California, and South Africa. Humid subtropical climates are found on the eastern margins of continents, in regions such as the southeastern United States, Uruguay, Brazil, Argentina, southern Japan, the Natal of South Africa, Taiwan, and parts of Eastern China.
West coast marine cool temperature climates are found along the west coasts of continents and in the middle latitudes. Seattle is a good example of this climate, which is also found on the Atlantic coasts of France and the United Kingdom. The warm summer continental climates are found in areas such as the central United States, northeastern China, and Korea. Cool summer continental climates are found in the northeastern United States, northern Japan, and Eastern Europe. Steppe climates are found in continental areas of North America, Argentina, and Patagonia. Sub-Arctic climates are known as the Taiga, a Russian term for the coniferous forests found in the areas of Siberia and Canada. Tundra is a cold climate just below the Arctic region. climates are found at the North and South Poles. Vegetation does not grow, and precipitation is sparse.
Context
In contrast to weather, climate is an abstract concept made up of the measured averages and extremes of weather. Climate, then, cannot be experienced firsthand. Over the course of a year, one can experience the change of seasons, but only on the basis of what one might expect the weather for those seasons to bring. Complicating this further is the variation in the types of climate that exist and the limitations to the models by which they are defined. The evidence for changes in climate is clearly found in the fossil record, as well as in geologic structures showing the advance and retreat of ice over the land. Additionally, the archaeological record indicates climate change through shifts in cultural activity. Core samples from glaciers can be analyzed to reveal the oxygen content and thermal conditions of past atmospheres. Ice from these past periods continues its hold on parts of the globe.
Key Concepts
- archaeological record: the human-made objects and residues of the past that are used by archaeologists to reconstruct history
- desert climate: a hot climate characterized by extremely low and sometimes deficit amounts of precipitation
- insolation: the amount of solar energy received at a given point on the Earth
- orographic barrier: a mountain or a hilly area that acts as a control on the climate on either side
- semiarid climate: a climate of low annual precipitation (250-500 millimeters)
- tropical climate: a climate generally found in equatorial or tropical regions that exhibit high temperatures and precipitation year-round
- west coast marine climate: a mild, annually moist climate found along the western coasts of continents
Bibliography
Aguado, Edward, and James E. Burt. Understanding Weather and Climate. 4th ed. Upper Saddle River, N.J.: Pearson Prentice Hall, 2007.
Critchfield, Howard J. General Climatology. Englewood Cliffs, N.J.: Prentice-Hall, 1998. Deals with all aspects of the establishment of climate.
Miller, George R. Lewis and Clark’s Northwest Journey: Weather Disagreeable. Portland, Oreg.: Frank Amato, 2004.
"What Is the Difference Between Weather and Climate?" National Ocean Service, 16 June 2024, oceanservice.noaa.gov/facts/weather‗climate.html. Accessed 12 Dec. 2024.