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Weather radar in Norman, Oklahoma with rainshaft Weather (WF44) radar dish University of Oklahoma OU-PRIME C-band, polarimetric, weather radar during construction. Weather radar, also called weather surveillance radar (WSR) and Doppler weather radar, is a type of radar used to locate precipitation, calculate its motion, and estimate its type (rain, snow, hail etc.).
A tornadic debris signature (TDS), often colloquially referred to as a debris ball, [1] is an area of high reflectivity on weather radar caused by debris lofting into the air, usually associated with a tornado. [1] [2] A TDS may also be indicated by dual-polarization radar products, designated as a polarimetric tornado debris signature (PTDS).
In radar satellites, microwave signals are reflected off a persistent scatter in a target area, and their two-way travel time is measured by satellites. [1] Water vapor in the troposphere and free electrons in the ionosphere affect the propagation of microwave signals through the atmosphere because the different refractive index in these layers affects the speed of propagation.
Radar cross-section (RCS), denoted σ, also called radar signature, is a measure of how detectable an object is by radar. A larger RCS indicates that an object is more easily detected. [1] An object reflects a limited amount of radar energy back to the source. The factors that influence this include: [1] the material with which the target is made;
Even with the increasing power of supercomputers, the forecast skill of numerical weather models only extends to about two weeks into the future, since the density and quality of observations—together with the chaotic nature of the partial differential equations used to calculate the forecast—introduce errors which double every five days ...
Two minutes later, at 11:17 p.m., a correlation coefficient scan from the KLOT weather radar site at Lewis University Airport indicated debris lofted up to 20,000 ft (3.8 mi; 6.1 km) into the air. [5] At this time, the tornado had weakened to EF1 intensity as it impacted Burr Ridge in Cook County, Illinois. [9]
The standard deviation of the observed field () is side a, the standard deviation of the test field () is side b, the centered RMS difference (centered RMS difference is the mean-removed RMS difference, and is equivalent to the standard deviation of the model errors [17]) between the two fields (E′) is side c, and the cosine of the angle ...
The eddy covariance (also known as eddy correlation and eddy flux) is a key atmospheric measurement technique to measure and calculate vertical turbulent fluxes within atmospheric boundary layers. The method analyses high-frequency wind and scalar atmospheric data series, gas, energy, and momentum, [ 1 ] which yields values of fluxes of these ...