Upslope Flows. Prandtl (1942) one-dimensional theory Defant (1949) continued with Prandtl’s model Egger (1981) 2-D model.

Slides:

Advertisements

Similar presentations

AIR POLLUTION AND METEOROLOGY

Advertisements

Chapter 4. Atmospheric Pressure and Wind

Air Earth’s Atmosphere.

The sea/land-breeze circulation Part I: Development w/o Earth rotation.

19.1 Understanding Air Pressure. What is Air Pressure? The force exerted by the weight of a column of air above a given point Exerted in all directions.

Air Pressure and Wind Pressure: the amount of force exerted per unit of surface area Pressure can be increased in 2 ways 1.By increasing density or decreasing.

Session 2, Unit 3 Atmospheric Thermodynamics

Chapter 9 Vertical Motion. (1) Divergence in two and three dimensions. The del “or gradient” operator is a mathematical operation performed on something.

EOSC 112: THE FLUID EARTH ATMOSPHERIC STRUCTURE AND DYNAMICS Atm12 Read: Kump et al. Chap.3, p ; Chap.4, p Objectives: 1.To describe how.

NATS Lecture 13 Curved Flow and Friction Local winds.

Chapter 7 Atmospheric Pressure and Wind

What Makes the Wind Blow? ATS 351 Lecture 8 October 26, 2009.

Thermally-Driven Circulations in Mountain Terrain.

Chapter 9 Meteorology. Section A, Weather Factors §Atmosphere l Comprised of: Oxygen - 21% Nitrogen - 78% Other gases - 1% l 99.9% of Atmosphere is within.

Understanding Local Diurnal Winds Sea Breezes and Land Breezes dependent on the differences in heating and cooling between land and water. Upslope and.

ENAC-SSIE Laboratoire de Pollution de l'Air The Atmospheric Layers.

Temperature, Pressure, Density and Vertical Motion Adapted from Scott Denning’s presentation for CSU CMMAP course Summer 2007 By Jim Barnaby Summer 2008.

MET 61 1 MET 61 Introduction to Meteorology MET 61 Introduction to Meteorology - Lecture 3 Thermodynamics I Dr. Eugene Cordero San Jose State University.

Air Pressure Can you feel it?.

Lecture 6. EPS 5: 23 Sep Review the concept of the barometric law (hydrostatic balance: each layer of atmosphere must support the weight of the.

atmosphere at a given time with respect to heat, pressure,

Warm Up What liquid did you find to have a density of 1.2? Time’s Up!

 What is pressure?  Pressure is accumulative force of gas particles   High Energy gas (HOT) has lots of movement, therefore.

Geographical Influences on Weather. EQ: How do mountains, large bodies of water and wind affect climate and weather?

Thermodynamics, Buoyancy, and Vertical Motion Temperature, Pressure, and Density Buoyancy and Static Stability Adiabatic “Lapse Rates” Convective Motions.

Overview  Basic Meteorological Assumptions  Traditional Wind Model  Condensation Induced Winds Derivation Experimental Evidence  Greater Implications.

WIND Factors Affecting Wind  Wind is the result of horizontal differences in air pressure. Air flows from areas of higher pressure to areas of lower pressure.

The troposphere, except in shallow, narrow, rare locations, is stable to dry processes. For the purpose of synoptic analysis, these areas can be ignored.

Chapter 6 Atmospheric Forces and Wind

Brain Bender  What causes wind?. Winds Goals  1. Describe what causes winds.  2. Name the four types of local winds. 

Movement of Air in Earth’s Atmosphere. What is wind? The movement of air from an area of higher pressure to an area of lower pressure. The movement of.

Winds Professor Jeff Gawrych De Anza College. Principle forces Q: What drives the weather in the atmosphere? The uneven heating of the earth Q: What causes.

Air Pressure and Wind. What is air pressure? The force exerted by air molecules as they collide with a surface The weight of the atmosphere as it pushes.

Sea & land breezes AS Geography.

Fire Weather: Winds.

LAND AND SEA BREEZES. What’s going to heat up faster??? Why???

Understanding Local Diurnal Winds

An example of vertical profiles of temperature, salinity and density.

Weather & Water Investigation 8

Synoptic Scale Balance Equations Using scale analysis (to identify the dominant ‘forces at work’) and manipulating the equations of motion we can arrive.

AOS 100: Weather and Climate Instructor: Nick Bassill Class TA: Courtney Obergfell.

The Wind: PGF Pressure gradient force is what sets air in motion

Buoyancy, Lapse Rate Stability & Convection. Lecture 6. EPS 5: 09 Feb Review the concept of the barometric law (hydrostatic balance: each layer.

Air Pressure and Winds. Air Pressure : The weight of the atmosphere as measured at a point on the earth’s surface.  How do differences in air pressure.

Air. What’s in air? The atmosphere is made up mostly of nitrogen gas. Oxygen makes up a little more than 20% of the atmosphere. Air Composition.

Isobars and wind barbs sea level pressure. factors affecting wind wind is the result of horizontal differences in pressure air flows from higher to lower.

Vocabulary Set #1. Condensation the process of changing from a gas to a liquid.

11.2 Properties of the atmosphere. Temperature A measure of the average kinetic energy of the particles in a material. A measure of the average kinetic.

Unit 4 Weather Lesson 1 How Does Uneven Heating of Earth Affect Weather?

Chapter 10 Fluids Pressure in Fluids Pressure is defined as the force per unit area. Pressure is a scalar; the units of pressure in the SI system.

7 – Group 임지유, 김도형, 방주희. Consider a layer of the atmosphere in which ( Γ

Local Wind Systems and Temperature Structure in Mountainous Terrain

Air Masses and fronts An air mass is a large body of air that has similar temperature and moisture properties throughout. A front is defined as the transition.

Hydrostatics Dp Dz Air Parcel g.

Note: Winds are parallel to the lines of constant pressure height.

Local and Global Wind Systems

The Atmosphere’s Air Pressure Changes

State of the Atmosphere

Sea & land breezes AS Geography.

State of the Atmosphere

State of the Atmosphere

NATS Lecture 12 Curved Flow and Friction Local winds

NATS Lecture 12 Curved Flow and Friction Local winds

Is this daytime or nighttime?

Local and Global Wind Systems

Isobars and wind barbs sea level pressure.

Convection Currents.

Unit 2: “Earth and Space Science”

Presentation transcript:

Upslope Flows

Prandtl (1942) one-dimensional theory Defant (1949) continued with Prandtl’s model Egger (1981) 2-D model

“Slope winds are spontaneous and intermittent in space and time. They are not continuous and stationary, but a succession of thermal bubbles from favorable, rocky, dry spots on the slope.” Slope flows react instantly to insolation. Upslope breezes start a few minutes after sunrise. (Vergeiner and Dreiseitl 1987)

“Slope wind field experiments, rare anyway, give random inconclusive results from which representative values of mass and heat transport in the slope layer cannot be derived.”

 1T11T1 2T22T2 x z T 1 > T 2  1 <  2 warmcold PGF Buoyancy Forces in Idealized Upslope Flow (Adapted from Atkinson 1981)

Air parcel above slopes surface has a higher potential temperature and therefore lower density than air parcel at same height above sea level over the plain (valley). Two forces acting on the parcel above the slope: 1.Pressure Gradient Force: pushing air towards the slope. 2.Buoyancy Force: drives air parcel vertically. Sum of both forces results in upward movement of air over slope, which is replaced by air coming from valley atmosphere. Forces in Idealized Upslope Flow

Banta 1984)

Reuten et al. 2005