A correction to the unimodal and bimodal truncated normal distributions for a more accurate representation of extreme and calm wind speeds

2019 ◽  
Author(s):  
Domenico Mazzeo ◽  
Giuseppe Oliveti ◽  
Alberta Marsico
Keyword(s):  
Normal Distributions ◽  
Accurate Representation ◽  
Wind Speeds ◽  
Truncated Normal ◽  
Calm Wind

Truncated Normal Distributions

Nature ◽  
1950 ◽  
Vol 165 (4194) ◽  
pp. 444-445 ◽  
Author(s):  
H. R. THOMPSON
Keyword(s):  
Normal Distributions ◽  
Truncated Normal

scholarly journals Validating CFD Predictions of Flow over an Escarpment Using Ground-Based and Airborne Measurement Devices

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4688 ◽  
Author(s):  
Asmae El Bahlouli ◽  
Daniel Leukauf ◽  
Andreas Platis ◽  
Kjell zum Berge ◽  
Jens Bange ◽  
...  
Keyword(s):  
Mesoscale Model ◽  
Potential Temperature ◽  
Test Site ◽  
Unmanned Aircraft ◽  
Horizontal Wind ◽  
Cfd Validation ◽  
Wind Speeds ◽  
Inclination Angles ◽  
Aircraft System ◽  
Calm Wind

Micrometeorological observations from a tower, an eddy-covariance (EC) station and an unmanned aircraft system (UAS) at the WINSENT test-site are used to validate a computational fluid dynamics (CFD) model, driven by a mesoscale model. The observation site is characterised by a forested escarpment in a complex terrain. A two-day measurement campaign with a flow almost perpendicular to the escarpment is analysed. The first day is dominated by high wind speeds, while, on the second one, calm wind conditions are present. Despite some minor differences, the flow structure, analysed in terms of horizontal wind speeds, wind direction and inclination angles shows similarities for both days. A real-time strategy is used for the CFD validation with the UAS measurement, where the model follows spatially and temporally the aircraft. This strategy has proved to be successful. Stability indices such as the potential temperature and the bulk Richardson number are calculated to diagnose atmospheric boundary layer (ABL) characteristics up to the highest flight level. The calculated bulk Richardson values indicate a dynamically unstable region behind the escarpment and near the ground for both days. At higher altitudes, the ABL is returning to a near neutral state. The same characteristics are found in the model but only for the first day. The second day, where shear instabilities are more dominant, is not well simulated. UAS proves its great value for sensing the flow over complex terrains at high altitudes and we demonstrate the usefulness of UAS for validating and improving models.

Letter to the editor: Fitting truncated normal distributions

2017 ◽  
Vol 27 (12) ◽  
pp. 3835-3838
Author(s):  
Iain L MacDonald
Keyword(s):  
Em Algorithm ◽  
Normal Distributions ◽  
Letter To The Editor ◽  
The Em Algorithm ◽  
Truncated Normal

I comment here on a recent paper in this journal, on the fitting of truncated normal distributions by the EM algorithm. I show that the fitting of such distributions by direct numerical maximization of likelihood (rather than EM) is straightforward, contrary to an assertion made by the authors of that paper.

Mean and Variance of Truncated Normal Distributions

1999 ◽  
Vol 53 (4) ◽  
pp. 357-361 ◽  
Author(s):  
Donald R. Barr ◽  
E. Todd Sherrill
Keyword(s):  
Normal Distributions ◽  
Mean And Variance ◽  
Truncated Normal
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