Wind drift

Clays composed of attapulgite, montmorillonite, and kaoHnite are used for pesticides in finely pulverized or granular form. Granular formulations are reportedly less expensive, more easily handled, reduce loss caused by wind drift, and produce a more effective coverage. 

Fig. 1. Major oceanographic features 1. Canary Current, 2. Gulf Stream, 3. North Atlantic Current, 4. Sargasso Sea, 5. North Atlantic Gyre, 6. Labrador Current, 7. Loop Current, 8. North Pacific Gyre, 9. South Equatorial Current, 10. Benguela Current, 11. Humboldt Current, 12. Antilles Current, 13. Florida Current, 14. Brazil Current, 15. Kuroshio, 16. Antarctic West Wind Drift.

In the Cape Basin region of the South Atlantic, polyethylene and polypropylene pellets were observed at concentrations of 1333-3600 pellets km (48). Since this area is far from any major shipping lane and is dominated oceanographically by the Antarctic West-Wind Drift with possibly some input from the Brazil Current, the source of the floating plastic was thought to be ships transporting the raw material in the South Atlantic (48). The weathered appearance of the pellets indicated that they had been adrift for an extended period and, therefore, carried long distances by the ocean currents. 

Mobility and leachability of diflubenzuron in soils is low, and residues are usually not detectable after 7 days. In water, half-time persistence (Tb 1/2) is usually less than 8 days and lowest at elevated temperatures, alkaline pH, and high sediment loadings (Fischer and Hall 1992) (Table 17.2). Increased concentrations of diflubenzuron in soils and waters are associated with increased application frequency, flooding of treated supratidal areas, wind drift, and excessive rainfall (Cunningham 1986). 

Smoke Flares Orange 160 and Orange 80, used as wind drift indicators, are described on pp 79-80 of Ref 1... 

Spray Residues. As a general rule, little or no toxic material is used on vineyards after early summer. Finding a spray residue on grapes at the winery is highly unlikely, although many analyses are still made to detect this. Residues are usually traceable to wind drift from an adjacent field with another crop. Nevertheless, the prudent winery monitors this... 

The cultivable soil systems, water bodies, and free air are our most precious natural assets and must not be contaminated further. Soil seepage, wind drift, runoff surface and groundwaters, microbial activity, and interaction have further aggravated the problem. 

In hot weather, evaporation pans lose up to one-half inch of water per day. Vineyards with cover crops lose up to 75 percent of evaporation pan losses. Up to 25 percent of the irrigation water can be lost through wind drift and evaporation. This results in a situation that is within 4 percent of a theoretical break-even input and output. To accomplish this break-even situation requires constant, twenty-four hour a day irrigation. While this concern is yet to be tested, past history with other crops has proved eminently successful. In 1978, 500 acres of V. vinifera grapes were planted under center-pivot irrigation. Since that time, an additional 1500 acres have been planted under center-pivot systems, so that today 2000 of the state s estimated 4500 acres of V. vinifera are utilizing center-pivot irrigation. 

In the vertical distribution of the modules of mean current vectors (Fig. 3a), the highest vertical gradient (shear) is observed between 10 and 25 m (total mean values of 0.215 and 0.165 m s-1, respectively). This is probably related to the effect of the wind drift. In the layer 25-50 m, mean velocities are homogeneous and the main shear in their values takes place deeper down... 

Figure 2-6 a shows the simplest pattern of water movement in a lake, caused by wind exerting a force on the water at the lake surface. The downwind surface current is called wind drift and typically moves at a rate of 2 to 3% of the average wind speed. Clearly, the water moving downwind cannot pile up indefinitely at the end of the lake instead, it flows back upwind, typically at... 

Although positions (Ion, lat) can be determined now within a few meters by differential GPS (Global Positioning System, Leva et al., 1996 NIMA, 2000), this accuracy was not always available in the past. Reissmann (1999) estimated the GPS position uncertainty as 37 m. Additionally, when desired monitoring positions could not exactly be met by the research vessel due to fishery or other obstacles, sometimes the actual positions, sometunes the standard positions were reported with the cast. Depending on the vessel s equipment, wind drift may have displaced the vessel during the station work. BALTIC uses the initial station position for aU samples of the particular cast. We estimate the position uncertainty to about 100 m. 

The output part of the salt balance included wind salt drift (mechanical evaporation), filtration of sea water into the shores and bottom, and sedimentation of low-solubility salts (carbonates). Apart from the wind drift (its share is not large, in fact) the most significant path for the loss of sea salts was via continuous filtration of saline waters in the eastern shallow areas into the shores and bottom of the sea. 

At the short end of the scale (of the order of 10 cm) the motion may be due to convective instability in a shallow surface layer as explained by Gem-merich and Hasse (1992). They made field observations of the surface motion by spraying powdered corkwood on the surface, watching how it collected on a time scale of 10 seconds or less, into various structures depending on the condition. Lines were by far the most common structure observed. They may, for example, be caused by convective rolls along the wind drift direction. 

Fig. 3. Frequency spectra (a) and phase velocities (b) of wind waves at two fetches (1 - small fetch, 2 - large fetch). Clean water, wind velocity 2.5 m/s. Solid line in Fig. 3b - phase velocity for linear gravity-capillary waves (surface tension 72 rnN/m) accounting for wind drift...

Estimates of average current velocity and wind drift... 

In addition, the contractor was never told that arsenicals were tested in open air bursts, which was readily apparent from the records. Hence, there was no effort to establish a wind drift plume of arsenic. Thus, even... 

Nonetheless, PDV has evaluated the characteristics of a sea spill, both in the laboratory and in field tests (64, 66). It has been found that, as soon as the product contacts the water, it disperses to form a 2 to 3 m deep floating plume located a few centimeters below the surface. Consequently, the extension of the spill is smaller than the one produced by conventional oils, and prevailing wind drift has almost no effect on emulsion spill in contrast to oil spill. 

For smaller rivers, which are often tortuous and sheltered, the wind drift term in Eq. (20.2) is dropped. The velocities of the leading and trailing edges of the slick are ... 

Once in the ocean, the tides and currents driven by wind control the circulation of shallow water. Seven major currents, shown in Figure 2.1 [27], move water around the globe the West Wind Drift (or the Antarctic Circumpolar Current), East Wind Drift, the North and South Equatorial currents, the Peru Current, the Kuroshio Current, and the Gulf Stream. These currents can move quickly. The Gulf Stream, for example, usually travels at a speed of 3 or 4 knots, which is equivalent to 5.6 to 7.4 kilometers per hour [27]. As these currents spiral through the ocean they form five major gyres the North Atlantic, South Atlantic, North Pacific, South Pacific, and Indian Ocean gyres. 

Sanmartin, L, Wanntorp, L., and Winkworth, R.C. (20(f ) West wind drift revisited Testing for directional dispersal in the southern hemisphere using event-based tree fitting. Journal of Biogeography, 34 398-416. 

Like steel, but unlike some advertised soft tungsten loads, Hevi-Shot does not deform in its passage out the barrel, and consequently results in excellent patterns with few flyers. Thus, many experienced reloaders like to drop down a single size from the lead load - still the standard for performance and price - and perhaps a couple sizes smaller than steel. This is appropriate because the extra density being shot compensates for wind drift and friction. 

---