scholarly journals Wind Speed and Sea State Dependencies of Air‐Sea Gas Transfer: Results From the High Wind Speed Gas Exchange Study (HiWinGS)

2017 ◽  
Vol 122 (10) ◽  
pp. 8034-8062 ◽  
Author(s):  
B. W. Blomquist ◽  
S. E. Brumer ◽  
C. W. Fairall ◽  
B. J. Huebert ◽  
C. J. Zappa ◽  
...  
Keyword(s):  
Wind Speed ◽  
Gas Exchange ◽  
Gas Transfer ◽  
High Wind ◽  
Sea State ◽  
High Wind Speed ◽  
Exchange Study

scholarly journals Air/sea DMS gas transfer in the North Atlantic: evidence for limited interfacial gas exchange at high wind speed

2013 ◽  
Vol 13 (5) ◽  
pp. 13285-13322 ◽  
Author(s):  
T. G. Bell ◽  
W. De Bruyn ◽  
S. D. Miller ◽  
B. Ward ◽  
K. Christensen ◽  
...  
Keyword(s):  
Wind Speed ◽  
North Atlantic ◽  
Interfacial Stress ◽  
Horizontal Wind ◽  
Gas Transfer ◽  
High Wind ◽  
High Wind Speed ◽  
Wind Speeds ◽  
The North ◽  
The North Atlantic

Abstract. Shipboard measurements of eddy covariance DMS air/sea fluxes and seawater concentration were carried out in the North Atlantic bloom region in June/July 2011. Gas transfer coefficients (k660) show a linear dependence on mean horizontal wind speed at wind speeds up to 11 m s−1. At higher wind speeds the relationship between k660 and wind speed weakens. At high winds, measured DMS fluxes were lower than predicted based on the linear relationship between wind speed and interfacial stress extrapolated from low to intermediate wind speeds. In contrast, the transfer coefficient for sensible heat did not exhibit this effect. The apparent suppression of air/sea gas flux at higher wind speeds appears to be related to sea state, as determined from shipboard wave measurements. These observations are consistent with the idea that long waves suppress near surface water side turbulence, and decrease interfacial gas transfer. This effect may be more easily observed for DMS than for less soluble gases, such as CO2, because the air/sea exchange of DMS is controlled by interfacial rather than bubble-mediated gas transfer under high wind speed conditions.

scholarly journals Air–sea dimethylsulfide (DMS) gas transfer in the North Atlantic: evidence for limited interfacial gas exchange at high wind speed

2013 ◽  
Vol 13 (21) ◽  
pp. 11073-11087 ◽  
Author(s):  
T. G. Bell ◽  
W. De Bruyn ◽  
S. D. Miller ◽  
B. Ward ◽  
K. H. Christensen ◽  
...  
Keyword(s):  
Wind Speed ◽  
North Atlantic ◽  
Interfacial Stress ◽  
Horizontal Wind ◽  
Gas Transfer ◽  
High Wind ◽  
High Wind Speed ◽  
Wind Speeds ◽  
The North ◽  
The North Atlantic

Abstract. Shipboard measurements of eddy covariance dimethylsulfide (DMS) air–sea fluxes and seawater concentration were carried out in the North Atlantic bloom region in June/July 2011. Gas transfer coefficients (k660) show a linear dependence on mean horizontal wind speed at wind speeds up to 11 m s−1. At higher wind speeds the relationship between k660 and wind speed weakens. At high winds, measured DMS fluxes were lower than predicted based on the linear relationship between wind speed and interfacial stress extrapolated from low to intermediate wind speeds. In contrast, the transfer coefficient for sensible heat did not exhibit this effect. The apparent suppression of air–sea gas flux at higher wind speeds appears to be related to sea state, as determined from shipboard wave measurements. These observations are consistent with the idea that long waves suppress near-surface water-side turbulence, and decrease interfacial gas transfer. This effect may be more easily observed for DMS than for less soluble gases, such as CO2, because the air–sea exchange of DMS is controlled by interfacial rather than bubble-mediated gas transfer under high wind speed conditions.

scholarly journals Whitecap Coverage Dependence on Wind and Wave Statistics as Observed during SO GasEx and HiWinGS

2017 ◽  
Vol 47 (9) ◽  
pp. 2211-2235 ◽  
Author(s):  
Sophia E. Brumer ◽  
Christopher J. Zappa ◽  
Ian M. Brooks ◽  
Hitoshi Tamura ◽  
Scott M. Brown ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Wind Speed ◽  
Gas Exchange ◽  
Wind Wave ◽  
Reynolds Numbers ◽  
Wave Age ◽  
High Wind ◽  
High Wind Speed ◽  
Wave Statistics ◽  
Whitecap Coverage

AbstractConcurrent wavefield and turbulent flux measurements acquired during the Southern Ocean (SO) Gas Exchange (GasEx) and the High Wind Speed Gas Exchange Study (HiWinGS) projects permit evaluation of the dependence of the whitecap coverage W on wind speed, wave age, wave steepness, mean square slope, and wind-wave and breaking Reynolds numbers. The W was determined from over 600 high-frequency visible imagery recordings of 20 min each. Wave statistics were computed from in situ and remotely sensed data as well as from a WAVEWATCH III hindcast. The first shipborne estimates of W under sustained 10-m neutral wind speeds U10N of 25 m s−1 were obtained during HiWinGS. These measurements suggest that W levels off at high wind speed, not exceeding 10% when averaged over 20 min. Combining wind speed and wave height in the form of the wind-wave Reynolds number resulted in closely agreeing models for both datasets, individually and combined. These are also in good agreement with two previous studies. When expressing W in terms of wavefield statistics only or wave age, larger scatter is observed and/or there is little agreement between SO GasEx, HiWinGS, and previously published data. The wind speed–only parameterizations deduced from the SO GasEx and HiWinGS datasets agree closely and capture more of the observed W variability than Reynolds number parameterizations. However, these wind speed–only models do not agree as well with previous studies than the wind-wave Reynolds numbers.

scholarly journals Estimation of bubbled-mediated air/sea gas exchange from concurrent DMS and CO<sub>2</sub> transfer velocities at intermediate-high wind speeds

2017 ◽  
Author(s):  
Thomas G. Bell ◽  
Sebastian Landwehr ◽  
Scott D. Miller ◽  
Warren J. de Bruyn ◽  
Adrian Callaghan ◽  
...  
Keyword(s):  
Wind Speed ◽  
Gas Exchange ◽  
North Atlantic ◽  
Gas Transfer ◽  
High Wind ◽  
Wind Speeds ◽  
Wide Range ◽  
Carbon Dioxide Co2 ◽  
The Impact

Abstract. Simultaneous air/sea fluxes and concentration differences of dimethylsulfide (DMS) and carbon dioxide (CO2) were measured during a summertime North Atlantic cruise in 2011. This dataset reveals significant differences between the gas transfer velocities of these two gases (Δkw) over a range of wind speeds up to 21 m  s−1. These differences occur at and above the approximate wind speed threshold when waves begin breaking. Whitecap fraction (a proxy for bubbles) was also measured and has a positive relationship with Δkw, consistent with enhanced bubble-mediated transfer of the less soluble CO2 relative to that of the more soluble DMS. However, the correlation of Δkw with whitecap fraction is no stronger than with wind speed. Models used to estimate bubble-mediated transfer from in situ whitecap fraction under-predict the observations, particularly at intermediate wind speeds. Examining the differences between gas transfer velocities of gases with different solubilities is a useful way to detect the impact of bubble-mediated exchange. More simultaneous gas transfer measurements of different solubility gases across a wide range of oceanic conditions are needed to understand the factors controlling the magnitude and scaling of bubble-mediated gas exchange.

BEHAVIOR OF MECHANICALLY ANCHORED WATERPROOFING MEMBRANE EXPOSED IN HIGH WIND SPEED OF ACTUAL WIND

2006 ◽  
Vol 71 (610) ◽  
pp. 29-34 ◽  
Author(s):  
Hiroyuki MIYAUCHI ◽  
Nobuo KATO ◽  
Hirokazu ICHIKAWA ◽  
Takanori SASAKI ◽  
Kyoji TANAKA
Keyword(s):  
Wind Speed ◽  
High Wind ◽  
High Wind Speed ◽  
Waterproofing Membrane

Haul-out behaviour and densities of ringed seals (Phoca hispida) in the Barrow Strait area, N.W.T.

1979 ◽  
Vol 57 (10) ◽  
pp. 1985-1997 ◽  
Author(s):  
Kerwin J. Finley
Keyword(s):  
Wind Speed ◽  
Early Morning ◽  
Maximum Density ◽  
Stable Population ◽  
The Sun ◽  
High Wind ◽  
Phoca Hispida ◽  
High Wind Speed ◽  
Ringed Seals ◽  
Calm Weather

Numbers of ringed seals hauled out on the ice began to increase in early June. Numbers on the ice were highest from 0900 to 1500 hours Central Standard Time and lowest (average 40–50% of peak) in early morning. Seals commonly remained on the ice for several hours, and occasionally (during calm weather) for > 48 h. Numbers on the ice were reduced on windy days and possibly also on unusually warm, bright and calm days. Seals tended to face away from the wind (particularly with high wind speed) and oriented broadside to the sun. Seals usually occurred singly (60–70% of all groups) at their holes.Numbers of seals hauled out at Freemans Cove remained relatively constant during June (maximum density 4.86/km2), whereas at Aston Bay numbers increased dramatically to a maximum density of 10.44/km2 in late June. The increase was thought to be due to an influx of seals abandoning unstable ice. The density of seal holes at Freemans Cove (5.92/km2) was much higher than at Aston Bay (2.73/km2). The ratio of holes to the maximum numbers of seals (1.12:1) at Freemans Cove represents a first estimate of this relationship in an apparently stable population.

scholarly journals Evaluation of the AMPS Boundary Layer Simulations on the Ross Ice Shelf, Antarctica, with Unmanned Aircraft Observations

2017 ◽  
Vol 56 (8) ◽  
pp. 2239-2258 ◽  
Author(s):  
Jonathan D. Wille ◽  
David H. Bromwich ◽  
John J. Cassano ◽  
Melissa A. Nigro ◽  
Marian E. Mateling ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Relative Humidity ◽  
High Wind ◽  
Ice Shelf ◽  
High Wind Speed ◽  
Near Surface ◽  
Ross Ice Shelf ◽  
Low Cloud ◽  
The Antarctic

AbstractAccurately predicting moisture and stability in the Antarctic planetary boundary layer (PBL) is essential for low-cloud forecasts, especially when Antarctic forecasters often use relative humidity as a proxy for cloud cover. These forecasters typically rely on the Antarctic Mesoscale Prediction System (AMPS) Polar Weather Research and Forecasting (Polar WRF) Model for high-resolution forecasts. To complement the PBL observations from the 30-m Alexander Tall Tower! (ATT) on the Ross Ice Shelf as discussed in a recent paper by Wille and coworkers, a field campaign was conducted at the ATT site from 13 to 26 January 2014 using Small Unmanned Meteorological Observer (SUMO) aerial systems to collect PBL data. The 3-km-resolution AMPS forecast output is combined with the global European Centre for Medium-Range Weather Forecasts interim reanalysis (ERAI), SUMO flights, and ATT data to describe atmospheric conditions on the Ross Ice Shelf. The SUMO comparison showed that AMPS had an average 2–3 m s−1 high wind speed bias from the near surface to 600 m, which led to excessive mechanical mixing and reduced stability in the PBL. As discussed in previous Polar WRF studies, the Mellor–Yamada–Janjić PBL scheme is likely responsible for the high wind speed bias. The SUMO comparison also showed a near-surface 10–15-percentage-point dry relative humidity bias in AMPS that increased to a 25–30-percentage-point deficit from 200 to 400 m above the surface. A large dry bias at these critical heights for aircraft operations implies poor AMPS low-cloud forecasts. The ERAI showed that the katabatic flow from the Transantarctic Mountains is unrealistically dry in AMPS.

Research on Low-Wind-Speed Wind Power

2013 ◽  
Vol 448-453 ◽  
pp. 1811-1814
Author(s):  
Hai Hui Song ◽  
Jian Jun Wang ◽  
Zhi Hua Hu ◽  
Jin Zhou
Keyword(s):  
Wind Speed ◽  
Wind Power ◽  
Research Development ◽  
High Wind ◽  
Power Development ◽  
High Wind Speed ◽  
Low Wind Speed ◽  
Key Technologies ◽  
Wind Power Development

For high-wind-speed wind power development and problems, propose development and application of low-wind-speed wind power (LWSP). Analysis of the characteristics of LWSP , advantages and necessity of development and application of it. Research the key technologies of LWSP development. It ultimately lay the foundation for research, development and application of LWSP technologies.

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