Winter duration

In the UK, security of supply standards are defined to meet " 1 in 20 years" peak day demand and "1 in 50 years" winter duration. Similar standards are applied in The Netherlands and France and other Member States. 

Fig. 9 hiterannual variability of ice event dates (a) ice formation, (b) ice break-up, and (c) winter duration (difference between the two dates) (after [7])... 

If it is variable, set the outside air intake quantity to the winter value. Set the desired temperature up to a maximum, leaving the humidity setting alone. It will be appreciated that as the room temperature rises during the heating test the rh tends to fall. However, since the humidity setting remains unaltered the humidifying system will be called upon to operate until at one condition it is working at peak winter rate. Due to the faster characteristic of heaters, the rh will be found to fall but absolute moisture should be found to steadily rise. The duration of the test is normally about 3 h and final conditions should be held for half an hour to prove the moisture source. 

The predictions for almost all communities in Canada include more violent winter storms, very high intensity rainfalls of short-duration, and extended heat waves with the accompanying increased risk of smog, wildfires, tree parasites, severe thunderstorms and tornadoes. Current structural design, farming,... 

A field operator exposure study was designed to accommodate the chemical properties and the use pattern involved in the treatment of potato crops for protection against the Colorado potato beetle. Fifteen farmworkers experienced in the use of tractor-drawn sprayers for application of crop protection materials to crops were selected. All were adult males. To avoid production of a large quantity of treated potato crop prior to registration of the product for sale, the trials were performed on stubble fields after harvest of winter wheat crops in a potato-growing area of southern Ontario. This allowed the use of typical farm spray equipment and a typical duration of exposure for a complete shift of work. 

To gain a better understanding of the annual and seasonal effects of the two future climate scenarios considered in the present analysis, three types of monthly flow duration curves are computed one with all the monthly streamflows (left column), another only with the winter (DJF) monthly streamflows (centre column), and final one with the summer (JJA) streamflows only (right column). 

WINTER (DJF) Flow Duration Curve on Q063, Subb=79... 

WINTER (DJF) Flow Duration Curve on Q093, Subb=115 SUMMER (JJA) Flow Duration Curve on Q093, Subb=115... 

Fig. 14 Monthly flow duration curves for the subcatchments 057, 079, 090 and 115. Black lines refer to the flow duration curves obtained by considering the observed values during the control period 1961-1990, while the blue and red lines refer to the streamflows derived from the two RCMs HIRHAM H and RCAO E, respectively. The left column represent the flow duration curves computed with all the monthly values during the period 2071-2100 the central column was computed with the monthly values belonging to the winter season (DJF) and the right column represent the flow duration curve computed with the monthly values belonging to the summer season (JJA). Note that vertical scales are different...

We do know, however, that some motile cells persist at temperatures as low as 0-2°C in laboratory cultures (26, 27), but the duration of this survival has not been determined. Winter temperatures in coastal waters can be highly variable, but they often drop to this same 0-2°C range (5, 28). Summer survival would not be a problem in most areas since tamarensis growth has been reported at temperatures as high as 24°C (25, 26), a temperature above the maximum for most coastal waters. There is thus the potential for small, motile cell populations to persist in certain temperature regions throughout the year. 

A pronounced seasonal variation is observed in the coarse and fine fractions of both mass and soils, as illustrated in Figures 3 and 4. Shown are the mean values for each time period for the northern and southern halves of the network. One significant trend is the sharp decrease in coarse and fine soil and coarse mass during the winter months. The duration of this minimum is, however, different for the fine soil the fine soil drops sharply in mid-October, while the coarse soil does not drop until January. The coarse soil concentration Increases during mid-December, yet there is no corresponding fine soil increase. Also, the minimum for fine soil is more pronounced in the north than in the south, perhaps due to increased snow cover at the northern sites. Finally, these plots show the strong correlation between coarse soil and coarse mass and the considerably weaker correlation between fine soil and fine mass. It is obvious that most of the winter episodes of fine mass are not associated with fine soil. 

The temporal variation of airborne soil is shown in even greater detail in the dally concentrations of coarse silicon (3.6 to 15pm) at three multiday sites for 1978 (Figure 5). The concentrations are much lower in winter (mid-September to mid-March) than in summer. Also, the concentrations are dominated by episodes of A to 5 days duration. These episodes are somewhat more frequent in summer than in winter (A per month vs. 2 per month). 

In mild winters, the release from ice occurs during March first in the southern regions and in river mouths, then in the north, and, finally, in Taganrog Bay (Fig. 1). The average duration of the ice period is 4.5 months. In anomalously warm or severe winters, the times of ice formation and thawing may be shifted by 1-2 months or even greater. 

Usually, the ice formation in the sea starts in mid-December while the maximum ice extension is observed in February. The sea is released from ice in March (early release at the beginning of March and late release at the beginning of April). The duration of the ice period ranges from 130 days in extremely severe winters to 40 days in mild winters. 

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