Joint International Conference on Long-term Experiments ...

the frosty nights begin in November and last until March. The maximum number of
frosty nights is recorded in January: 4.7 and 4.9 days in Săcueni and Oradea, 6.4 days in
Borod and 14.9 days in Stâna de Vale (fig.1).
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25
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15
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Figure no.1: Variation of the number of days with
minimum temperature ≤10ºC (frosty nights)
I II III IV V VI VII VIII IX X XI XII An
Borod
Oradea
Sacueni
Stâna de Vale
2. The average frequency of freezing days (minimum temperature≤0ºC)
The freezing days have a higher share from October up to April, but low values (0.1
days) are recorded too from September to May in plain areas and depression, with
freezing days all year long in mountain areas.
The frequency of freezing days increases with the rise of altitude, reaching the
maximum value at Stâna de Vale (1108m) with 182 freezing days per year, while
lower, at Borod (333m) the value is 107.8 days per year, dropping to 91.4 days of
freezing days per year at Săcueni (fig.2).
In the studied area, over a 36 years period, under the influence of the
atmosfere’s general circulation and the local conditions, during the year the highest
number of freezing days appear in January 23-24 days in the plain areas, 25.4 days at
Borod, while at Stâna de Vale the maximum value of 29.6 days of freezing are
recorded. At Stâna de Vale station, freezing days are found all year long, but with a
lower frequency of 0.3 days in August and only 0.1 days in July.
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