Lecture

Mountain Meteorology: Atmospheric Flow and Local Weather

Graph Chat

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

Description

This lecture explores the impact of mountains on atmospheric flow, local weather, and climate. Topics covered include stability of the atmosphere, thermally driven circulation, flow interaction with topography, orographic precipitation, downslope winds, and frontal passage. The lecture delves into concepts such as Brunt-Väisälä frequency, flow interactions with topography, orographic precipitation mechanisms, downslope winds like Föhn and Bora, mountain waves, and local winds like Joran.

This video is available exclusively on Mediaspace for a restricted audience. Please log in to MediaSpace to access it if you have the necessary permissions.

Watch on Mediaspace

Official source

Ontological neighbourhood

Earth science

Atmospheric science: Meteorology

Related concepts (32)

Orographic lift

Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions, precipitation. Orographic lifting can have a number of effects, including precipitation, rain shadowing, leeward winds, and associated clouds. Precipitation induced by orographic lift occurs in many places throughout the world.

Precipitation types

In meteorology, the different types of precipitation often include the character, formation, or phase of the precipitation which is falling to ground level. There are three distinct ways that precipitation can occur. Convective precipitation is generally more intense, and of shorter duration, than stratiform precipitation. Orographic precipitation occurs when moist air is forced upwards over rising terrain and condenses on the slope, such as a mountain.

Foehn wind

A Foehn or Föhn (UKfɜːn, USfeɪn, fʌn,_fɜːrn), is a type of dry, relatively warm, downslope wind that occurs in the lee (downwind side) of a mountain range. It is a rain shadow wind that results from the subsequent adiabatic warming of air that has dropped most of its moisture on windward slopes (see orographic lift). As a consequence of the different adiabatic lapse rates of moist and dry air, the air on the leeward slopes becomes warmer than equivalent elevations on the windward slopes.

Orography

Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as oreography, orology, or oreology) falls within the broader discipline of geomorphology. The term orography comes from the Greek: όρος, hill, γραφία, to write. Mountain ranges and elevated land masses have a major impact on global climate. For instance, the elevated areas of East Africa substantially determine the strength of the Indian monsoon.

Internal wave

Internal waves are gravity waves that oscillate within a fluid medium, rather than on its surface. To exist, the fluid must be stratified: the density must change (continuously or discontinuously) with depth/height due to changes, for example, in temperature and/or salinity. If the density changes over a small vertical distance (as in the case of the thermocline in lakes and oceans or an atmospheric inversion), the waves propagate horizontally like surface waves, but do so at slower speeds as determined by the density difference of the fluid below and above the interface.

Related lectures (64)

Snowfall Records and Crystal Formation

Explores snowfall records, crystal formation, atmosphere composition, vapor pressure, cloud formation, and precipitation mechanisms.

Katabatic Winds in Antarctica: A Fascinating Phenomenon

Delves into the captivating katabatic winds in Antarctica and their impact on precipitation, exploring historical context, wind behavior, and coastal interactions.

Air Pollution and Wind Analysis

Focuses on analyzing wind directions to understand air pollutant origins, covering loading libraries, reading wind data, and visualizing wind roses.

Lake Geneva: Hydrodynamics and Environmental Impact

Delves into Lake Geneva's hydrodynamics, focusing on wind effects, internal waves, and basin exchange.

Aerosol-Cloud Interactions: Insights from the East Mediterranean