# Synoptic Met Test 1

 Absolute Vorticity A measure of the total spin in the atmosphere. It is the sum of the spin due to the Earth’s rotation (the Coriolis force) and the relative vorticity. Adiabatic Process A process in which no heat is added or removed from an air parcel. The temperature change is due solely to expansion or contraction of the air parcel. Advection The horizontal transport of some property of the atmosphere (e.g., temperature, vorticity, moisture) by the wind. Curvature vorticity Rotation due to curvature of the wind flow (curvature in the contour lines or streamlines). Dine’s Compensation Rule The condition in which upper-level convergence (divergence) is approximately balanced by low-level divergence (convergence) Equivalent Potential Temperature (Θe): The temperature of an air parcel if it is lifted pseudo-adiabatically until all moisture is condensed, then lowered dry adiabatically to 1000 MB. Geopotential Height A measure of the height given in geopotential meters rather than true meters (2998m=3000gpm at 45ºN). Geostrophic Wind The “hypothetical” wind generated by the balance between the pressure gradient force and the Coriolis effect. The geostrophic wind flows with high pressure (heights) to the right. The geostrophic wind is a good approximation for the actual wind for straight-line flow without friction. Isentrope A line of constant potential temperature. Positive Vorticity Advection (PVA) The horizontal transport of decreasing vorticity (anticyclonic spin) to some location. Potential Temperature (q) The temperature a parcel of air would have if it were moved dry adibataically to 1000 MB. Relative Vorticity (ζ) A measure of the local spin in the atmosphere. It does not include the vorticity due to the Earth’s rotation (the Coriolis force). Solenoids Boxes formed by the intersection of geopotential height contours and isopleths of some atmospheric property. The size of the solenoids represents the amount of advection (smaller boxes means greater advection). Specific Heat The amount of energy it takes to raise the temperature of 1g of water by 1 ºC. Synoptic Scale The size of migratory high and low pressure systems in the lower troposphere that cover a horizontal area of several hundred miles or more. Thermal Wind A component of the wind generated by temperature differences in the atmosphere. The thermal wind blows with warm air to the right. Also defined as the vector difference of the upper-level geostrophic wind minus the lower-level geostrophic wind. Thickness The difference in geopotential height between two pressure levels (commonly 500 and 1000mb). According to Poisson’s equation, the thickness is directly proportional to the mean virtual temperature of the layer defined by the two pressure levels. Vorticity A measure of “spin” in the atmosphere. Positive vorticity is a cyclonic spin (counterclockwise in the Northern Hemisphere); negative vorticity is an anticyclonic spin (clockwise in the Northern Hemisphere). Warm Air Advection (WAA) The horizontal transport of warm air to some location, associated with increasing temperatures. Planetary Vorticity Temperature measure of internal (thermal) kinetic energy of a system. Heat thermal energy transferred between systems at different temperatures. Heat Capacity Ratio of the amount of energy absorbed by the substance to the temperature rise that occurs in the substance. Diabatic Process Loss or gain of energy or heat from a system Adiabatic process No exchange of heat with the surroundings. – Lifting and lowering of unsaturated air is an adiabatic process.– Temp change due to expansion and contraction without loss or gain of heat Dry adiabat A line of constant potential temperature used in a vertical profile of the atmosphere. Theta surface or isentropic surface A surface of constant potential temperature, as opposed to a constant elevation or constant pressure surface. – Often used on cross sections Ideal Gas Law Pressure = Density * Constant * Temperature pV = ρRT - p = pressure (Pa)- V = volume (m3)- ρ = mass or density (kg)- R = gas constant (J K-1 kg-1)- T = temperature (K) dry-air gas constant R = 287 J K-1 kg-1 If we hold temperature Constant... pV = ρRTPressure ~ DensityAt the same temperature, air at a higher pressure is more dense than air at a lower pressure. If we hold pressure constant... P = ρRT(constant P) * 1/R = T*ρAt a given atmospheric pressure, air that is cold is more dense than air that is warm. Virtual Temperature The temperature dry air would need to attain in order to have the same density as moist air at the same pressure. geopotential Is the amount of work necessary to raise the mass of air to some height (or pressure!) Planetary boundary layer is a viscous sub-layer that has profound consequences for atmospheric flow. Omega Equation for which f is the Coriolis parameter, σ is the static stability, vg is the geostrophic velocity vector, ζg is the geostrophic relative vorticity, φ is the geopotential, ∇H2 is the horizontal Laplacian operator, and ∇H is the horizontal del operator.The right-hand side of the omega equation can also be expressed in terms of the divergence of the Q vector. Authorknoxweather ID39837 Card SetSynoptic Met Test 1 DescriptionSynoptic Test Updated2010-10-05T04:45:33Z Show Answers