Sea breeze

About: Sea breeze is a research topic. Over the lifetime, 2544 publications have been published within this topic receiving 55651 citations.

The diel cycle of water vapor in west Greenland

Abstract: We present a study of the dynamics of small-scale (~100 km) atmospheric circulation in west Greenland which is dominated by interactions of marine and continental air masses. Water vapor concentration and isotopic ratios measured continuously over a 25 day period in Kangerlussuaq, Greenland were used to monitor the convergence of easterly katabatic winds and westerly sea breezes that form a front between the dry, isotopically depleted, glacial air mass and the moist, isotopically enriched, marine air mass. During the latter 16 days of the measurement period, an interval with no large-scale synoptic interference, the inland penetration of the sea breeze controlled the largest day-to-day humidity and vapor isotopic variations. Kangerlussuaq experienced sea breezes in the afternoon on 9 days, consistent with the long-term average of such occurrences on 56% of days in July and August. The inland position of the sea breeze front is controlled by the katabatic wind strength, which is stronger during times of reduced cloud coverage and/or higher-pressure gradient between the coast and the Greenland ice sheet. The position and movement of the front will likely respond to changes in the general atmospheric circulation and regional radiation balance resulting from global warming, which will, in turn, impact the local hydrological cycle and ecosystem processes.

A study of nonhydrostatic effects in idealized sea breeze systems

Abstract: Nonhydrostatic effects in two-dimensional mesoscale sea breeze systems are investigated by numerical simulations. It is shown that nonhydrostatic effects are directly contributed by the vertical gradients of the vertical velocity variance as well as by the vertical accelerations. It is also shown that a K-type turbulence closure is not suitable in a nonhydrostatic primitive equation model, and a higher-order closure scheme should therefore be used. Results from hydrostatic and fully-nonhydrostatic models are compared for various surface and atmospheric background conditions, such as scale and strength of surface heating, geostrophic wind, stability, surface roughness contrast, Coriolis effect, etc. It is found that for strongly developed sea breeze cases, vertical gradients of vertical velocity variance contribute most to nonhydrostatic forcing in the lower layers, and that the resultant nonhydrostatic pressure gradient acts against the hydrostatic pressure gradient, so that nonhydrostatic simulations produce weaker systems than hydrostatic ones. For weak sea breeze systems, the difference between the two models tends to be small.

The inland boundary layer at low latitudes: II Sea-breeze influences

Abstract: Two-dimensional mesoscale model results support the claim of evening sea-breeze activity at Daly Waters, 280 km inland from the coast in northern Australia, the site of the Koorin boundary-layer experiment. The sea breeze occurs in conditions of strong onshore and alongshore geostrophic winds, not normally associated with such activity. It manifests itself at Daly Waters and in the model as a cooling in a layer 500–1000 m deep, as an associated surface pressure jump, as strong backing of the wind and, when an offshore low-level wind is present, as a collapse in the inland nocturnal jet.

Analysing wind farm efficiency on complex terrains

Abstract: Actual performances of onshore wind farms are deeply affected both by wake interactions and terrain complexity: therefore monitoring how the efficiency varies with the wind direction is a crucial task. Polar efficiency plot is therefore a useful tool for monitoring wind farm performances. The approach deserves careful discussion for onshore wind farms, where orography and layout commonly affect performance assessment. The present work deals with three modern wind farms, owned by Sorgenia Green, located on hilly terrains with slopes from gentle to rough. Further, onshore wind farm of Nprrekffir Enge has been analysed as a reference case: its layout is similar to offshore wind farms and the efficiency is mainly driven by wakes. It is shown and justified that terrain complexity imposes a novel and more consistent way for defining polar efficiency. Dependency of efficiency on wind direction, farm layout and orography is analysed and discussed. Effects of atmospheric stability have been also investigated through MERRA reanalysis data from NASA satellites. Monin-Obukhov Length has been used to discriminate climate regimes.