Jet stream definition geography

Wind is the movement of air caused by the uneven heating of the Earth by the sun. It does not have much substance—you cannot see it or hold it—but you can feel its force. It can dry your clothes in summer and chill you to the bone in winter. It is strong enough to carry sailing ships across the ocean and rip huge trees from the ground. It is the great equalizer of the atmosphere, transporting heat, moisture, pollutants, and dust great distances around the globe. Landforms, processes, and impacts of wind are called Aeolian landforms, such as sand dunes and Loess deposits, which are deposits of silt. Differences in atmospheric pressure generate winds. At the Equator, the sun warms the water and land more than it does the rest of the globe. Warm equatorial air rises higher into the atmosphere and migrates toward the poles. This is a low-pressure system. At the same time, cooler, denser air moves over Earth’s surface toward the Equator to replace the heated air. This is a high-pressure system. Winds generally blow from high-pressure areas to low-pressure areas. The boundary between these two areas is called a front. The complex relationships between fronts cause different types of wind and weather patterns. Prevailing winds are winds that blow from a single direction over a specific area of the Earth. Areas where prevailing winds meet are called convergence zones. Generally, prevailing winds blow east-west rather than north-south. This happens because Earth’s rotation generate...

The past few months have seen some remarkable weather, from the UK’s Key to this unseasonable weather are persistent high-pressure “blocking” weather systems, which bring clear, dry conditions on the ground below for many days or weeks. Blocking events bat away oncoming low-pressure systems that would bring the prospect of clouds and rain. They are particularly synonymous with heatwaves and drought in summer and bitterly cold conditions in winter. But what are the prospects for blocking events in a warming climate? And could a rapidly warming Arctic also have a role to play? In this Q&A, Carbon Brief takes a closer look at the causes of blocking events and the potential changes in the future. What is ‘blocking’? Around the mid-latitudes of the northern hemisphere, low-pressure weather fronts, which bring cloudy, windy and potentially wet weather, generally move from west to east. These are carried along by the The jet generally keeps a steady stream of weather systems moving across the Earth’s surface. This means that any low-pressure system – or intervening high-pressure system that brings clear, still and sunny conditions – will generally only linger for a matter of days before being shunted on by the next system. However, sometimes weather systems can get stuck in place for an extended period of time. This is known as “blocking”, explains “Blocking is a stationary and persistent weather pattern, most often an anticyclone [high-pressure system], that blocks the oncoming ...

The polar front is the junction between the Ferrell and Polar cells. At this low pressure zone, relatively warm, moist air of the Ferrell Cell runs into relatively cold, dry air of the Polar cell. The weather where these two meet is extremely variable, typical of much of North America and Europe. The polar jet stream is found high up in the atmosphere where the two cells come together. A jet stream is a fast-flowing river of air at the boundary between the troposphere and the stratosphere. Jet streams form where there is a large temperature difference between two air masses. This explains why the polar jet stream is the world’s most powerful. Jet streams move seasonally just as the angle of the Sun in the sky migrates north and south. The polar jet stream, known as “the jet stream,” moves south in the winter and north in the summer.

In 1934, knowledge of the jet stream increased when Wiley Post, an American pilot, attempted to fly solo around the world. To complete this feat, he invented a pressurized suit that would allow him to fly at high altitudes and during his practice runs, Post noticed that his ground and airspeed measurements differed, indicating that he was flying in a current of air. Description and Causes of the Jet Stream Thanks to further research conducted by pilots and meteorologists, it is understood today that there are two main jet streams in the northern hemisphere. While jet streams do exist in the southern hemisphere, they are strongest between latitudes of 30°N and 60°N. The weaker subtropical jet stream is located closer to 30°N. The location of these jet streams shift throughout the year however and they are said to "follow the sun" since they move north with warm weather and south with cold weather. Jet streams are also stronger in the winter because there is a large contrast between the colliding Arctic and Jet streams typically cover long distances and can be thousands of miles long. They can be discontinuous and often meander across the atmosphere but they all flow east at a rapid speed. The meanders in the jet stream flow slower than the rest of the air and are called Rossby Waves. They move slower because they are caused by the Coriolis Effect and turn west in respect to the flow of air they are embedded in. As a result, it slows the eastward movement of the air when the...

Here’s a tabular comparison between a jet stream and a sea breeze in atmospheric circulation: Aspect Jet Stream Sea Breeze Definition High-altitude, fast-flowing air current in the upper atmosphere Localized wind circulation near coastal areas Altitude Found in the upper troposphere and lower stratosphere Occurs near the Earth’s surface, typically up to a few hundred meters Formation Created by large temperature gradients and pressure systems Result of differential heating between land and adjacent water bodies Wind speed Strong winds, often exceeding 100 km/h (62 mph) Moderate winds, typically less than 20 km/h (12 mph) Geographical extent Can span across continents or large portions of the globe Limited to coastal regions and influenced by local geography Orientation Generally follows a meandering eastward or westward path Driven by onshore movement, with wind blowing from sea to land Seasonal variability May vary in strength and position with changing seasons More prominent during warm seasons and weaker in colder seasons Influence on weather Affects weather patterns and plays a role in storm development Provides localized cooling and modifies local weather conditions Examples Polar jet stream, subtropical jet stream Coastal areas experiencing sea breeze circulation It’s important to note that both the jet stream and sea breeze are influenced by complex atmospheric processes and can exhibit variations in their characteristics depending on specific geographical locations...

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • In these videos, Britannica explains a variety of topics and answers frequently asked questions. • Check out these retro videos from Encyclopedia Britannica’s archives. • In Demystified, Britannica has all the answers to your burning questions. • In #WTFact Britannica shares some of the most bizarre facts we can find. • In these videos, find out what happened this month (or any month!) in history. • Britannica is the ultimate student resource for key school subjects like history, government, literature, and more. • While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today. • Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians. • Britannica Presents Earth’s To-Do List for the 21st Century. Learn about the major environmental problems facing our planet and what can be done about them! • Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!

Pacific High High pressure system that develops over the central Pacific Ocean near the Hawaiian Islands. Also called the Hawaiian High. Paleoclimate Climatic conditions in the geological past reconstructed from a direct or indirect data source. Paleoclimatology Scientific study of the Earth's Paleolake An ancient Paleosol A Paleozoic Geologic Palsa A mound of Pan or PAN (1) Collection of chemicals found in PAN). (2) Compact soil horizon that has a high clay content. (3) Large natural basin or depression found in desert climates. Pangaea Hypothetical super continent that existed in the geological past. Its break-up created the current configuration of landmasses found on the Earth. Parallel A line parallel to the Parametric Tests Statistical tests that assume the sample data is Parasite Consumer organism that feeds on a Parasitism Biological Parent Material The Particulate Matter Particles of dust, soot, salt, sulfate compounds, pollen, or other particles suspended in the Parts Per Billion ( ppb) Number of parts of a substance found in one billion parts of a particular gas, liquid, or solid. Parts Per Million ( ppm) Number of parts of a substance found in one million parts of a particular gas, liquid, or solid. ppt) Number of parts of a substance found in one thousand parts of a particular gas, liquid, or solid. Passive Remote Sensing Form of Paternoster Lakes A linear series of mountain valley Pathogen Microscopic Patterned Ground Term used to describe a number of surface...

• • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • In these videos, Britannica explains a variety of topics and answers frequently asked questions. • Check out these retro videos from Encyclopedia Britannica’s archives. • In Demystified, Britannica has all the answers to your burning questions. • In #WTFact Britannica shares some of the most bizarre facts we can find. • In these videos, find out what happened this month (or any month!) in history. • Britannica is the ultimate student resource for key school subjects like history, government, literature, and more. • While this global health crisis continues to evolve, it can be useful to look to past pandemics to better understand how to respond today. • Britannica celebrates the centennial of the Nineteenth Amendment, highlighting suffragists and history-making politicians. • Britannica Presents Earth’s To-Do List for the 21st Century. Learn about the major environmental problems facing our planet and what can be done about them! • Britannica presents SpaceNext50, From the race to the Moon to space stewardship, we explore a wide range of subjects that feed our curiosity about space!

Pacific High High pressure system that develops over the central Pacific Ocean near the Hawaiian Islands. Also called the Hawaiian High. Paleoclimate Climatic conditions in the geological past reconstructed from a direct or indirect data source. Paleoclimatology Scientific study of the Earth's Paleolake An ancient Paleosol A Paleozoic Geologic Palsa A mound of Pan or PAN (1) Collection of chemicals found in PAN). (2) Compact soil horizon that has a high clay content. (3) Large natural basin or depression found in desert climates. Pangaea Hypothetical super continent that existed in the geological past. Its break-up created the current configuration of landmasses found on the Earth. Parallel A line parallel to the Parametric Tests Statistical tests that assume the sample data is Parasite Consumer organism that feeds on a Parasitism Biological Parent Material The Particulate Matter Particles of dust, soot, salt, sulfate compounds, pollen, or other particles suspended in the Parts Per Billion ( ppb) Number of parts of a substance found in one billion parts of a particular gas, liquid, or solid. Parts Per Million ( ppm) Number of parts of a substance found in one million parts of a particular gas, liquid, or solid. ppt) Number of parts of a substance found in one thousand parts of a particular gas, liquid, or solid. Passive Remote Sensing Form of Paternoster Lakes A linear series of mountain valley Pathogen Microscopic Patterned Ground Term used to describe a number of surface...

Wind is the movement of air caused by the uneven heating of the Earth by the sun. It does not have much substance—you cannot see it or hold it—but you can feel its force. It can dry your clothes in summer and chill you to the bone in winter. It is strong enough to carry sailing ships across the ocean and rip huge trees from the ground. It is the great equalizer of the atmosphere, transporting heat, moisture, pollutants, and dust great distances around the globe. Landforms, processes, and impacts of wind are called Aeolian landforms, such as sand dunes and Loess deposits, which are deposits of silt. Differences in atmospheric pressure generate winds. At the Equator, the sun warms the water and land more than it does the rest of the globe. Warm equatorial air rises higher into the atmosphere and migrates toward the poles. This is a low-pressure system. At the same time, cooler, denser air moves over Earth’s surface toward the Equator to replace the heated air. This is a high-pressure system. Winds generally blow from high-pressure areas to low-pressure areas. The boundary between these two areas is called a front. The complex relationships between fronts cause different types of wind and weather patterns. Prevailing winds are winds that blow from a single direction over a specific area of the Earth. Areas where prevailing winds meet are called convergence zones. Generally, prevailing winds blow east-west rather than north-south. This happens because Earth’s rotation generate...