Wind Climatology for Alaska: Historical and Future

When making radar-based precipitation products, a radar measurement is commonly taken to represent the geographical location vertically below the contributing volume of the measurement sample. However, when wind is present during the fall of the hydrometeors, precipitation will be displaced horizontally from the geographical location of the radar measurement. Horizontal advection will introduce discrepancies between the radar-measured and ground level precipitation fields. The significance of the adjustment depends on a variety of factors related to the characteristics of the observed precipitation as well as those of the desired end product. In this paper the authors present an advection adjustment scheme for radar precipitation observations using estimated hydrometeor trajectories obtained from the High-Resolution Limited-Area Model (HIRLAM) MB71 NWP model data. They use the method to correct the operational Finnish radar composite and evaluate the significance of precipitation advection in typical Finnish conditions. The results show that advection distances on the order of tens of kilometers are consistently observed near the edge of the composite at ranges of 100–250 km from the nearest radar, even when using a low elevation angle of 0.3°. The Finnish wind climatology suggests that approximately 15% of single radar measurement areas are lost on average when estimating ground level rainfall if no advection adjustment is applied. For the Finnish composite, area reductions of approximately 10% have been observed, while the measuring area is extended downstream by a similar amount. Advection becomes increasingly important at all ranges in snowfall with maximum distances exceeding 100 km.

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A model-based wind climatology of the eastern Adriatic coast

Meteorologische Zeitschrift ◽

10.1127/0941-2948/2001/0010-0005 ◽

2001 ◽

Vol 10 (1) ◽

pp. 5-16 ◽

Cited By ~ 23

Author(s):

Dietrich Heimann

Keyword(s):

Model Based ◽

Wind Climatology ◽

Adriatic Coast

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The semiannual oscillation (SAO) in the tropical middle atmosphere and its gravity wave driving in reanalyses and satellite observations

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-13763-2021 ◽

2021 ◽

Vol 21 (18) ◽

pp. 13763-13795

Author(s):

Manfred Ern ◽

Mohamadou Diallo ◽

Peter Preusse ◽

Martin G. Mlynczak ◽

Michael J. Schwartz ◽

...

Keyword(s):

Gravity Wave ◽

Gravity Waves ◽

Wave Drag ◽

Satellite Observations ◽

Absolute Gravity ◽

Data Sets ◽

Background Wind ◽

Wind Climatology ◽

Basic Features ◽

Semiannual Oscillation

Abstract. Gravity waves play a significant role in driving the semiannual oscillation (SAO) of the zonal wind in the tropics. However, detailed knowledge of this forcing is missing, and direct estimates from global observations of gravity waves are sparse. For the period 2002–2018, we investigate the SAO in four different reanalyses: ERA-Interim, JRA-55, ERA-5, and MERRA-2. Comparison with the SPARC zonal wind climatology and quasi-geostrophic winds derived from Microwave Limb Sounder (MLS) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite observations show that the reanalyses reproduce some basic features of the SAO. However, there are also large differences, depending on the model setup. Particularly, MERRA-2 seems to benefit from dedicated tuning of the gravity wave drag parameterization and assimilation of MLS observations. To study the interaction of gravity waves with the background wind, absolute values of gravity wave momentum fluxes and a proxy for absolute gravity wave drag derived from SABER satellite observations are compared with different wind data sets: the SPARC wind climatology; data sets combining ERA-Interim at low altitudes and MLS or SABER quasi-geostrophic winds at high altitudes; and data sets that combine ERA-Interim, SABER quasi-geostrophic winds, and direct wind observations by the TIMED Doppler Interferometer (TIDI). In the lower and middle mesosphere the SABER absolute gravity wave drag proxy correlates well with positive vertical gradients of the background wind, indicating that gravity waves contribute mainly to the driving of the SAO eastward wind phases and their downward propagation with time. At altitudes 75–85 km, the SABER absolute gravity wave drag proxy correlates better with absolute values of the background wind, suggesting a more direct forcing of the SAO winds by gravity wave amplitude saturation. Above about 80 km SABER gravity wave drag is mainly governed by tides rather than by the SAO. The reanalyses reproduce some basic features of the SAO gravity wave driving: all reanalyses show stronger gravity wave driving of the SAO eastward phase in the stratopause region. For the higher-top models ERA-5 and MERRA-2, this is also the case in the lower mesosphere. However, all reanalyses are limited by model-inherent damping in the upper model levels, leading to unrealistic features near the model top. Our analysis of the SABER and reanalysis gravity wave drag suggests that the magnitude of SAO gravity wave forcing is often too weak in the free-running general circulation models; therefore, a more realistic representation is needed.

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Wind Resources 1: The European Wind Climatology

Renewable Energy ◽

10.4324/9781315793245-19 ◽

2018 ◽

pp. 236-245

Author(s):

Erik L. Petersen

Keyword(s):

Wind Climatology ◽

Wind Resources

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The Role of Weather during the Greek–Persian “Naval Battle of Salamis” in 480 B.C.

Atmosphere ◽

10.3390/atmos11080838 ◽

2020 ◽

Vol 11 (8) ◽

pp. 838 ◽

Cited By ~ 1

Author(s):

Christos Zerefos ◽

Stavros Solomos ◽

Dimitris Melas ◽

John Kapsomenakis ◽

Christos Repapis

Keyword(s):

Sea Breeze ◽

Weather Conditions ◽

Early Morning ◽

Area Of Interest ◽

Open Sea ◽

Early Afternoon ◽

Wind Climatology ◽

South Sea ◽

Diurnal Wind

The Battle of Salamis in 480 B.C. is one of the most important naval battles of all times. This work examines in detail the climatically prevailing weather conditions during the Persian invasion in Greece. We perform a climatological analysis of the wind regime in the narrow straits of Salamis, where this historic battle took place, based on available station measurements, reanalysis and modeling simulations (ERA5, WRF) spanning through the period of 1960–2019. Our results are compared to ancient sources before and during the course of the conflict and can be summarized as follows: (i) Our climatological station measurements and model runs describing the prevailing winds in the area of interest are consistent with the eyewitness descriptions reported by ancient historians and (ii) The ancient Greeks and particularly Themistocles must have been aware of the local wind climatology since their strategic plan was carefully designed and implemented to take advantage of the diurnal wind variation. The combination of northwest wind during the night and early morning, converging with a south sea breeze after 10:00 A.M., formed a “pincer” that aided the Greeks at the beginning of the clash in the morning, while it brought turmoil to the Persian fleet and prevented them to escape to the open sea in the early afternoon hours.

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Development and performance testing of a small, multi-bladed wind turbine

Wind Engineering ◽

10.1177/0309524x19849845 ◽

2019 ◽

Vol 44 (1) ◽

pp. 3-20 ◽

Cited By ~ 1

Author(s):

Tonio Sant ◽

Robert N Farrugia ◽

Martin Muscat ◽

Cedric Caruana ◽

Redeemer Axisa ◽

...

Keyword(s):

Wind Turbine ◽

Development Process ◽

Field Tests ◽

Performance Testing ◽

Rural Landscape ◽

Rotor Design ◽

Wind Climatology ◽

And Performance ◽

Water Pumps ◽

Satisfactory Manner

This article presents selected results from the development process of a small, prototype multi-bladed wind turbine designed to replace the American western-style, wind-driven water pumps still encountered in the Maltese rural landscape. The main focus of this article is on the rotor design, fabrication and system assembly, as well as on the results of the first open field tests. While the new design proves that the new machine is capable of aesthetically representing the windmills of old, preliminary findings indicate that it is also capable of meeting its predicted performance characteristics in a satisfactory manner, albeit subject to the installation site’s specific wind climatology.

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