Dynamics Energetics of General Circulation In the previous lecture we discussed the characteristics of the general circulation of the atmosphere In today’s.

Slides:



Advertisements
Similar presentations
Introduction Irina Surface layer and surface fluxes Anton
Advertisements

Section 2: The Planetary Boundary Layer
Chapter Four Fluid Dynamic
Lecture 15: Capillary motion
Dr. R. Nagarajan Professor Dept of Chemical Engineering IIT Madras Advanced Transport Phenomena Module 2 Lecture 5 Conservation Principles: Momentum &
AOSS 321, Winter 2009 Earth System Dynamics Lecture 10 2/10/2008 Christiane Jablonowski Eric Hetland
Vertical structure of the atmosphere. Review of last lecture Earth’s energy balance at the top of the atmosphere and at the surface. What percentage of.
General Circulation and Kinetic Energy
Exergy: A Measure of Work Potential Study Guide in PowerPoint
Chapter 8 Coordinate Systems.
Atms 4320 / 7320 – Lab 5 Using the Kinematic Method in Estimating Vertical Motions.
ES 202 Fluid and Thermal Systems Lecture 7: Mechanical Energy Balance (12/16/2002)
Course Schedule Overview Natural Environments: The Atmosphere GE 101 – Spring 2007 Boston University Myneni Feb (1 of 1) GG101 Overview (L01) Part.
ENAC-SSIE Laboratoire de Pollution de l'Air The Atmospheric Layers.
Climate Change 1020 Lecture Oct 16, 2006 Lis Cohen.
Lecture 1: Energy and Enthalpy Reading: Zumdahl 9.1 and 9.2 Outline –Energy: Kinetic and Potential –System vs. Surroundings –Heat, Work, and Energy –Enthalpy.
Temperature, pressure, and winds. Review of last lecture Earth’s energy balance at the top of the atmosphere and at the surface. What percentage of solar.
Convection Convection: transfer of heat by a flowing liquid or gas
The Atmosphere: Part 5: Large-scale motions Composition / Structure Radiative transfer Vertical and latitudinal heat transport Atmospheric circulation.
Hans Burchard Leibniz Institute for Baltic Sea Research Warnemünde Coastal Ocean Dynamics First course: Hydrodynamics.
Air Pressure. State Variables Describe the “state” of the gas “Variable” means they can change Physicists use P, V, T, N and constant k Chemists use P,
Solar System Physics I Dr Martin Hendry 5 lectures, beginning Autumn 2007 Department of Physics and Astronomy Astronomy 1X Session
Section 5: The Ideal Gas Law The atmospheres of planets (and the Sun too) can be modelled as an Ideal Gas – i.e. consisting of point-like particles (atoms.
Evaporation Slides prepared by Daene C. McKinney and Venkatesh Merwade
Energy Equation. Chapter 2 Lecture 3 2 Mechanical Energy? Forms of energy that can be converted to MECHANICAL WORK completely and directly by mechanical.
General Circulation of the Atmosphere Lisa Goddard 19 September 2006.
Lecture Oct 18. Today’s lecture Quiz returned on Monday –See Lis if you didn’t get yours –Quiz average 7.5 STD 2 Review from Monday –Calculate speed of.
Basic dynamics  The equations of motion and continuity Scaling Hydrostatic relation Boussinesq approximation  Geostrophic balance in ocean’s interior.
Results from kinetic theory, 1 1. Pressure is associated with collisions of gas particles with the walls. Dividing the total average force from all the.
AOSS 401, Fall 2007 Lecture 27 November 28, 2007 Richard B. Rood (Room 2525, SRB) Derek Posselt (Room 2517D, SRB)
2-D Modeling of a Walking Human-clothing System. Motivation When people are active, the air spacing between the fabric layer of a porous clothing system.
METR February Review State variables: p, ρ, T Pressure Temperature Equation of state: p = NkT/V = ρ R d T Virtual temperature T v = T (1.
Conservation of mass If we imagine a volume of fluid in a basin, we can make a statement about the change in mass that might occur if we add or remove.
Thermodynamics They study of energy and its transformations.
EVAT 554 OCEAN-ATMOSPHERE DYNAMICS FILTERING OF EQUATIONS OF MOTION FOR ATMOSPHERE (CONT) LECTURE 7 (Reference: Peixoto & Oort, Chapter 3,7)
Lecture 8 Evapotranspiration (1) Evaporation Processes General Comments Physical Characteristics Free Water Surface (the simplest case) Approaches to Evaporation.
FLUID ROTATION Circulation and Vorticity. Arbitrary blob of fluid rotating in a horizontal plane Circulation: A measure of the rotation within a finite.
AOSS 401, Fall 2007 Lecture 6 September 19, 2007 Richard B. Rood (Room 2525, SRB) Derek Posselt (Room 2517D, SRB)
Thermodynamic systems and concepts—topic 10.1
Three Lectures on Tropical Cyclones Kerry Emanuel Massachusetts Institute of Technology Spring School on Fluid Mechanics of Environmental Hazards.
* Reading Assignments: All Sections. 8. Hydrostatic Stability Describe the states of vertical stratification of atmosphere: * Stable equilibrium * Unstable.
Systems, Energy, & Efficiency
EVAT 554 OCEAN-ATMOSPHERE DYNAMICS EQUATIONS OF MOTION (CONT); ENERGY EQUATION LECTURE 4 (Reference: Peixoto & Oort, Chapter 3)
How Does Air Move Around the Globe?
Ocean Dynamics Previous Lectures So far we have discussed the equations of motion ignoring the role of friction In order to understand ocean circulations.
A particle moving along the x-axis experiences the force shown in the graph. If the particle has 2.0 J of kinetic energy as it passes x = 0 m, what is.
Basic dynamics ●The equations of motion and continuity Scaling Hydrostatic relation Boussinesq approximation ●Geostrophic balance in ocean’s interior.
Basic dynamics The equation of motion Scale Analysis
Thermochemistry. Energy Review Energy – the capacity to do work or transfer heat. Work – the energy used to move an object against a force. Heat – energy.
Details for Today: DATE:13 th January 2005 BY:Mark Cresswell FOLLOWED BY:Practical Dynamical Forecasting 69EG3137 – Impacts & Models of Climate Change.
ATS/ESS 452: Synoptic Meteorology Friday 08 January 2016 Review Material Overview of Maps Equations of Motion Advection Continuity.
Work and energy (a) give examples of energy in different forms, its conversion and conservation, and apply the principle of energy conservation to simple.
Lesson 3 General Circulation. Quick Recap Last lesson we learnt that uneven heating across the earth led to movement of air. Last lesson we learnt that.
OEAS 604: Introduction to Physical Oceanography Conservation of Mass Chapter 4 – Knauss Chapter 5 – Talley et al. 1.
Atms 4320 / 7320 lab 8 The Divergence Equation and Computing Divergence using large data sets.
Meteorological Variables 1. Local right-hand Cartesian coordinate 2. Polar coordinate x y U V W O O East North Up Dynamic variable: Wind.
Thermal Response of Climate System
Chapter 8 Exergy: A Measure of Work Potential Study Guide in PowerPoint to accompany Thermodynamics: An Engineering Approach, 8th edition by Yunus.
Geostrophic adjustment
Lecture 8 Evapotranspiration (1)
EVAT 554 OCEAN-ATMOSPHERE DYNAMICS
Chapter 8 Exergy: A Measure of Work Potential Study Guide in PowerPoint to accompany Thermodynamics: An Engineering Approach, 5th edition by Yunus.
Dynamics Vorticity In the previous lecture, we used “scaling” to simplify the equations of motion and found that, to first order, horizontal winds are.
ATOC 4720 class37 1. The vertically averaged divergence
ATOC 4720 class38 Thermally driven circulation in the absence of rotation Generation of kinetic energy.
The Hadley Cell continued…
Geostrophic adjustment
FLUID MECHANICS - Review
Physics 451/551 Theoretical Mechanics
Atmosphere GEOG 366.
Presentation transcript:

Dynamics Energetics of General Circulation In the previous lecture we discussed the characteristics of the general circulation of the atmosphere In today’s lecture we want to focus on how these characteristics affect the energy balance in different regions of the earth How the general circulation results in the transfer of energy from the equator to the poles How the general circulation affects other climate variable (namely moisture and momentum)

Dynamics Energetics of General Circulation The atmospheric energy balance can be written as: Therefore, we can write the local rate of change as: If we take the vertical average of this equation, we get four terms related to energy in the atmosphere Internal - energy associated with the temperature of the atmosphere Potential - energy associated with vertical “position” of the atmosphere Kinetic - energy associated with large-scale motions Latent - energy associate with phase change of water Hence, we can write the total energy of the atmosphere as: We can estimate the size of the various terms

Dynamics Energetics of General Circulation If we assume a hydrostatic atmosphere, we can write the total internal energy as: Changing the vertical coordinate from z to p gives: Next, we can write the potential energy as: Integrating by parts gives:

Dynamics Energetics of General Circulation So we find that the ratio of the internal energy to the potential energy is fixed: This implies that much of the internal energy of the atmosphere is required simply to maintain the potential energy associated with the structure of the atmosphere (this is implicit in the hydrostatic assumption) We can now calculate the total kinetic energy: If we assume that |u| ~ 15m/s, then the ratio of kinetic to total internal energy (potential and internal) is: Hence, kinetic energy is a very small fraction of the total energy in the atmosphere

Dynamics Energetics of General Circulation It can be shown that of the total energy in the atmosphere, only about 0.5% is available for conversion into kinetic energy (i.e. the generation of motion); the rest is tied up in maintaining the hydrostatic structure of the atmosphere First we can write the change of potential energy as: This implies that potential energy is converted through vertical motions in the atmosphere

Dynamics Energetics of General Circulation Next we can write the change of internal energy as: Here we see that internal energy is created/destroyed via heating and work done via compression/expansion If we use the momentum equation multiplied by u, we can calculate the rate of change of kinetic energy: Hence, kinetic energy is converted via work done against a pressure gradient as well as work done against the force of gravity From our discussion about internal energy, there was a term related to: This suggests a mechanism for converting internal energy to kinetic energy via compression and expansion

Dynamics Energetics of General Circulation In addition, from before, the change in potential energy is related to: This suggests a mechanism for converting potential energy to kinetic energy The final term we need is the one related to latent heat: Here, the evaporation/condensation term is essentially the conversion of latent heat into sensible heat, I.e. it represents a heating/cooling of the atmosphere Hence, this suggests a mechanism for converting latent heat to internal energy

Dynamics Energetics of General Circulation Now we can put all four terms together to get a sense of the flow of energy within the atmospheric system We can also estimate the zonal averages of the different transport terms Transport associated with mean and transient processes

Dynamics Energetics of General Circulation Just as the general circulation of the atmosphere transports energy it also transports moisture This transport results in convergence and divergence of moisture in particular regions of the globeThis transport results in convergence and divergence of moisture in particular regions of the globe In addition, the general circulation also transports momentum

Dynamics Energetics of General Circulation FormDesignationSize% of Total Internal cvTcvT 1800x10 5 J/m 2 70% Potential  gz Latent  Lq Kinetic (1/2)  u

Dynamics Energetics of General Circulation Latent  Lq Kinetic  (1/2u 2 ) Internal  c v T Potential  gz Evap.  Q/  t -u  P Friction -L(e-c) -u  Friction  gw

Dynamics Energetics of General Circulation

Dynamics Energetics of General Circulation

Dynamics Energetics of General Circulation

Dynamics Energetics of General Circulation

Dynamics Energetics of General Circulation