What is/are the reason(s) for pressure differences in the athmosphere?
Solar radiation and heating
Distribution of day and night durations
Rotation in nothern high pressure region.
Clockwise
What are Hadley cell, Ferrel cell and polar cell?
Rational flow, tangential to earth surface an tropopause
Flow between Hadley and Ferrel cell.
Flow is directed towards the earth surface.
What is the Jetstream?
Straight flow, oriented with latitude (Breitengrad)
Right or Wrong?
Basic wind velocity vb.
Assumes a roughness category II.
Occurs within a period of T=50 years theoretically once.
statements concerning the natural boundary
Is generally turbulent in the building relevant regions.
Differs over height with respect to mean velocity and turbulence.
Gumbel Distribution
Maximum yearly wind speeds of several years wind observation.
Weibull Distribution
All wind speeds, measured over a longer time period e.g. 1 year (prevalent wind).
Normal Distribution
All wind speed values within a short time period of 10 min. or 1 hour.
Steps to analyze meteorological data for an analysis of the characteristic wind speed (e.g. the basic velocity)
Grouping the data in yearly partitions.
Determination of the extreme wind speeds.
Calculation of the probabilities which are associated with the extreme wind speeds.
Plotting wind speeds over probability in a Gumbel plot paper (or using the reduced variate)
Linear Interpolation.
Determination of the velocity for the aimed target probability.
Gust velocity formula
vm*(1+g*Iv),
Turbulence Intensity formula
σ/vm,
Gust factor formula
vp/vm
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