Details Title: Dynamics of the Atmosphere Description: Test 1 Total Flash Cards: 44 Created: 01/29/2009 08:52:31		New Users: To study from this flashcard set, or to create your own your own study flash cards, REGISTER HERE. Existing Users: CLICK HERE. Additional Meteorology Flashcards
Cards in this set: Term Atmospheric dynamics Definition relationship between forces and winds Term Newtons 2nd Law Definition f=ma Term Acceleration Definition change of wind velocity per time increment Term Momentum Definition p=mv Term Budget Definition comparing what goes into a system vs. what comes out Term Lagrangian Momentum Budget Definition budget of momentum following a parcel of air Term Eularian Momentum Budget Definition budget of momentum at a fixed location in space (like weather station); can be used to formulate forecast equations for wind etc. Term Momentum Advection Definition winds of differing speeds at adifferent locations can themselves be blown by the wind into a different location causing a local wind change or acceleration Term Pressure gradient force Definition force acting along pressure gradient from high to low pressure Term Centrifugal Force Definition apparent force on a parcel of air moving in a curved path involving the square of the velocity and the radius of curvature Term Coriolis Force Definition apparent force due to the rotaion of the earth proportional to the latitude and the wind speed Term Turbulent Drag Force Definition air experiences drag from the ground in a direction opposite to wind direction and increases with wind speed. Only occurs in boundary layer. Term Transport Velocity Definition rate of upward transport of effects from the surface within the boundary layer, related to wind speed and drag coefficient in neutral stability, and buoyancy in an unstable atmosphere Term Drag coefficient Definition function of surface roughness (ranges from 2x10^-3 for smooth surface to sx10^-2 over a rough or forested surface Term Buoyancy Velocity Scale Definition effectivness of thermals in producing vertical heat transport Term Equations of motion Definition The tendency of U and V wind components as a sum of all the forces acting on a parcel in the X and Y directions, respectively, including advection, PGF, coriolis, and turbulent drag Term Pressure coordinates Definition an alternative to geometric coordinates that uses pressure as the vertical coordinate Term Monotonic Definition changes in only one direction (pressure only decreases with height) Term Isobaric Surface Definition surface connecting points of equal pressure Term Feedback process Definition (in equations of motion) winds accelerate, changing forces that depend on wind speed, which in turn changes the acceleration Term Steady State Winds Definition no net force or acceleration, so time derivatives equal zero; winds are constant but not necessarily zero, only acceleration is zero Term Geostrophic Wind Definition wind due to steady state balance between PGF and Coriolis Force Term Gradient Wind Definition wind due to steady-state three way balance between PGF, Coriolis force, and centrifugal force super anticyclonic around highs sub cyclonic around lows Term Rossby Number Definition (Roc) ratio of geostrophic wind speed to coriolis parameter times radius of curvature; small values indicate flow is in geostrophic balance Term Boundary layer wind (straigh isobars) Definition steady state balance between PGF, coriolis force and turbulent drag force Term boundary layer gradient wind Definition winds for a steady state balance of forces between the PGF , coriolis, turbulent drag force, and centrifugal force Term Damped inertial oscillation Definition fluctuations of wind speed as winds accelerate toward the steady state BLG wind solution Term Cyclostrophic wind Definition wind due to steady state two way balance between PGF and centrifugal force Term ageostrophic wind Definition difference between components of actual and corresponding geostrophic component Term Continuity Equation Definition equations for mass budget based on assumption that air mass is neither created nor destroyed during normal atmospheric processes Term incompressible Definition density is constant Term Incompressible continuity eqation Definition time dependent density term vanishes Term Divergence Definition more air going out then coming into a volume (net outflow) Term Convergence Definition more air coming in than going out of a volume of air (net inflow) Term Boundary layer pumping, Eckmann pumping Definition horizontal convergence at the surface due to friction causes air to flow out the top of the boundary layer ie upward vertical air motion Term Streamlines Definition lines that are everywhere parallel to the flow at an instant in time Term Streaklines Definition lines deposited in the flow during a time interval by continuous emission of a tracer from a fixed point, plume of smoke Term Trajectories Definition lines tracing the actual path followed by a parcel moving by the wind Term Dynamic pressure Definition pressure within changed airflow around an obstacle Term Static pressure Definition pressure measured in air flow well away from an obstacle Term Gap wind Definition wind of constant depth (due to strong inversion) flowing through a gap speeds up. Decrease of dynamic pressure in the accelerated flow is called the venturi effect Term Foehn Definition warm wind forced downslope after flowing over a mountain Term Bora Definition cold wind dynamically forced downslope according to Venturi effect after flowing over mountain Term Hydraulic Jump Definition wave or density current propagating upstream toward mountain range against a flow that becomes stationary as its speed exactly counterbalences the Bora flow in the lee of the mountain range , creating a turbulent standing wave