Description Usage Arguments Value Note Author(s) References See Also
The function creates 24 values of hourly temperature from
minimum and maximum daily values. This function applies
to single series and to single day couples of minimum and
maximum temperature. It is called by functions
Th_int_series
and shape_calibration
. The
function uses four different curves: from time 00 to the
minimum time: a horizontalaxis parabola (a line, if this
choice is enabled and according to the daily thermal
range of the day); from minimum to maximum time: an
increasing sinusoidal curve; from maximum time to sunset:
a decreasing sinusoidal curve; from sunset to time = 23:
a horizontalaxis parabola (a line, if this choice is
enabled and according to the daily thermal range of the
day). Calibration parameters are series and
monthlyspecific. This function is operationally called
by Th_int_series
, which requires the daily series
and the calibration table as input (plus other
parameters). A general user will conveniently use the
latter function.
1 2 3 
Tmin 
a daily table of 4 named columns, the first 3 being year, month, day, the 4th minimum temperature. The column names "month" and "T" are mandatory 
Tmax 
same for Tmax 
Tsuns 
temperature at sunset time 
Th_24_before 
temperature at time 24 of the previous day (time 00 of the present day) 
day 
progressive number of the day (row of both

tab_calibr 
"hour" parameter calibration table for
the specific series. See 
dtr_month 
monthly daily thermal range table (see
function 
ratio_dtr 
parameter for the choice of the night
curve shape; it is 
late_min 
logical; allows to shift the time of
occurrence of minima to the late hours of the day
(assumes the value of 
A vector containing the values from hour = 0 (element 1) to hour = 23 (element 24)
The function is called by Th_int_series
.
If the series ID coincides with one with nonnull results
of the par_calibration
function (enough data for
calibration) its table is passed to the interpolation
function, otherwise the average (cal_table
) is
used.
A nonNULL value for ratio_dtr
enables the
function to interpolate night values with a line, if the
conditions on Daily Thermal Range occur. This may give
rise to a sharp change for the hours following the min.
Tmin of the day before the first is set = to Tmin of the first day and Tmin of the day after the last = Tmin of the last day.
If T from sunset falls below the minimum of the day
(temptatively attributed to time_min
), an
adjustement is done: the early hours assume a constant T
= T[00] and the minimum is shifted so that T[23] =
Tmin
for that day
Since the very first value of T series at sunset (of the
day before) is NULL
, the first hourly values
produced till time_min
are = Tmin
of the
day.
Emanuele Eccel, Emanuele Cordano emanuele.eccel@iasma.it
Eccel, E., 2010: What we can ask to hourly temperature recording. Part II: hourly interpolation of temperatures for climatology and modelling. Italian Journal of Agrometeorology XV(2):4550 http://www.agrometeorologia.it/documenti/Rivista2010_2/AIAM%2022010_pag45.pdf,www.agrometeorologia.it
Original algorithm from: Cesaraccio, C., Spano, D., Duce, P., Snyder, R.L., 2001. An improved model for determining degreeday values from daily temperature data. Int. J. Biometeorol. 45: 161169. http://www.springerlink.com/content/qwctkmlq3tebthek/
See also: Eccel, E., 2010: What we can ask to hourly temperature recording. Part I: statistical vs. meteorological meaning of minimum temperature. Italian Journal of Agrometeorology XV(2):4143. http://www.agrometeorologia.it/documenti/Rivista2010_2/AIAM%2022010_pag41.pdf,www.agrometeorologia.it
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