Climatology of the semidiurnal tide at 52–56°N from ground-based radar wind measurements 1985–1995

1999 ◽  
Vol 61 (13) ◽  
pp. 975-991 ◽  
Author(s):  
Ch. Jacobi ◽  
Yu.I. Portnyagin ◽  
T.V. Solovjova ◽  
P. Hoffmann ◽  
W. Singer ◽  
...  
Keyword(s):  
Semidiurnal Tide ◽  
Wind Measurements

Mesopause region semidiurnal tide over Europe as seen from ground-based wind measurements

1999 ◽  
Vol 24 (11) ◽  
pp. 1545-1548 ◽  
Author(s):  
Ch. Jacobi ◽  
Yu.I. Portnyagin ◽  
T.V. Solovjova ◽  
P. Hoffmann ◽  
W. Singer ◽  
...  
Keyword(s):  
Semidiurnal Tide ◽  
Mesopause Region ◽  
Wind Measurements

Amplitude modulation of the semidiurnal tide based on MLT wind measurements with a European/Siberian meteor radar network in October – December 2017

2020 ◽  
Vol 66 (3) ◽  
pp. 631-645
Author(s):  
E. Merzlyakov ◽  
T. Solovyova ◽  
A. Yudakov ◽  
D. Korotyshkin ◽  
Ch. Jacobi ◽  
...  
Keyword(s):  
Amplitude Modulation ◽  
Semidiurnal Tide ◽  
Meteor Radar ◽  
Radar Network ◽  
Wind Measurements

scholarly journals On the longitudinal structure of the transient day-to-day variation of the semidiurnal tide in the mid-latitude lower thermosphere − I. Winter season

2001 ◽  
Vol 19 (5) ◽  
pp. 545-562 ◽  
Author(s):  
E. G. Merzlyakov ◽  
Yu. I. Portnyagin ◽  
C. Jacobi ◽  
N. J. Mitchell ◽  
H. G. Muller ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Winter Season ◽  
Semidiurnal Tide ◽  
Longitudinal Structure ◽  
Transient Behaviour ◽  
Meteorology And Atmospheric Dynamics ◽  
S Transform ◽  
Wind Measurements ◽  
Waves And Tides

Abstract. The longitudinal structure of the day-to-day variations of semidiurnal tide amplitudes is analysed based on coordinated mesosphere/lower thermosphere wind measurements at several stations during three winter campaigns. Possible excitation sources of these variations are discussed. Special attention is given to a nonlinear interaction between the semidiurnal tide and the day-to-day mean wind variations. Data processing includes the S-transform analysis which takes into account transient behaviour of secondary waves. It is shown that strong tidal modulations appear during a stratospheric warming and may be caused by aperiodic mean wind variations during this event.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides)

scholarly journals Migrating tide climatologies measured by a high-latitude array of SuperDARN HF-radars

2020 ◽  
Author(s):  
Willem E. van Caspel ◽  
Patrick J. Espy ◽  
Robert E. Hibbins ◽  
John P. McCormack
Keyword(s):  
High Latitude ◽  
Lower Thermosphere ◽  
Late Summer ◽  
Meridional Wind ◽  
Semidiurnal Tide ◽  
Planetary Scale ◽  
Global Environmental ◽  
Wind Measurements ◽  
Year 2000 ◽  
Polarization Phase

Abstract. This study uses hourly meteor wind measurements from a longitudinal array of 10 high-latitude SuperDARN HF-radars to isolate the migrating diurnal, semidiurnal and terdiurnal tidal modes at Mesosphere-Lower-Thermosphere (MLT) heights. The planetary-scale array of radars covers 180 degrees of longitude, with eight out of 10 radars being in near-continuous operation since the year 2000. Time series spanning 16 years of tidal amplitudes and phases in both zonal and meridional wind are presented, along with their respective annual climatologies. The method to isolate the migrating tidal modes from SuperDARN meteor winds is validated using two years of winds from NAVGEM-HA (Navy Global Environmental Model – High Altitude). The validation steps demonstrate that, given the geographical spread of the radar stations, the derived tidal modes are most closely representative of the migrating tides at 60° N. Some of the main characteristics of the observed migrating tides are that the semidiurnal tide shows sharp phase jumps around the equinoxes and peak amplitudes during late summer, and that the terdiurnal tide shows a pronounced secondary amplitude peak around DOY 260. In addition, the diurnal tide is found to show a bi-modal circular polarization phase relation between summer and winter.

Hub height optimisation of commercial WTGs based on accurate wind resource analysis

2021 ◽  
pp. 0309524X2110227
Author(s):  
Kyle O Roberts ◽  
Nawaz Mahomed
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Wind Power ◽  
Capacity Factor ◽  
Resource Analysis ◽  
Wind Speeds ◽  
Unique Maximum ◽  
Wind Measurements ◽  
Generation Capacity ◽  
Wind Resource

Wind turbine selection and optimal hub height positioning are crucial elements of wind power projects. However, in higher class wind speeds especially, over-exposure of wind turbines can lead to a reduction in power generation capacity. In this study, wind measurements from a met mast were validated according to specifications issued by IRENA and NREL. As a first step, it is shown that commercial WTGs from a database may be matched to the wind class and turbulence intensity. Secondly, a wind turbine selection algorithm, based on maximisation of capacity factor, was implemented across the range of WTGs. The selected WTGs were further exposed to an iterative algorithm using pointwise air density and wind shear coefficients. It is shown that a unique maximum capacity factor, and hence wind power generation, exists for a wind turbine, premised on its eventual over-exposure to the wind resource above a certain hub height.

scholarly journals Analysis of offshore wind farm located on Baltic Sea

2019 ◽  
Vol 137 ◽  
pp. 01049
Author(s):  
Anna Sobotka ◽  
Kajetan Chmielewski ◽  
Marcin Rowicki ◽  
Justyna Dudzińska ◽  
Przemysław Janiak ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Wind Farm ◽  
Wind Farms ◽  
Offshore Wind ◽  
The European Union ◽  
European Union Policy ◽  
Offshore Wind Farms ◽  
Wind Speeds ◽  
Wind Measurements ◽  
The Baltic

Poland is currently at the beginning of the energy transformation. Nowadays, most of the electricity generated in Poland comes from coal combustion. However, in accordance to the European Union policy of reducing the emission of carbon dioxide to the atmosphere, there are already plans to switch to low-emission energy sources in Poland, one of which are offshore wind farms. The article presents the current regulatory environment of the offshore wind energy in Poland, along with a reference to Polish and European decarbonisation plans. In the further part of the article, the methods of determining the kinetic energy of wind and the power curve of a wind turbine are discussed. Then, on the basis of historical data of wind speeds collected in the area of the Baltic Sea, calculations are carried out leading to obtain statistical distributions of power that could be generated by an exemplary wind farm with a power capacity of 400 MW, located at the place of wind measurements. On their basis, statistical differences in the wind power generation between years, months of the year and hours of the day are analysed.

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