Data:

Here, you are provided with the observational data for temperature at a weather station in Charlottetown, PEI $($Lat: $46\mathrm{.}28$ and Long: $-63\mathrm{.}13).$ This data set is derived from the Homogenized Temperature Datasets for Canada released by Environment Canada $($Vincent et al$.,2012).$ The data set is stored in $"$mm$8300300.$cs$"$ and covers yearly, seasonal, and monthly averages of temperature from $1872$ to $2012.$ There are some missing data in the cs file and the missing flag is $"-9999\mathrm{.}9".$ The units for temperature in this data set is $\backslash$deg C$.$

Reference:

$$ Vincent, L$.$ A$.,$ X$.$ L$.$ Wang, E$.$ J$.$ Milewska, H$.$ Wan, F$.$ Yang, and V$.$ Swail $(2012).$ A second generation of homogenized Canadian monthly surface air temperature for climate trend analysis, J$.$ Geophys. Res., $117,$ D$18110,$ doi:$10\mathrm{.}1029/2012/$D$017859.$

Tasks:

$1)$ Draw some plots showing the timeseries of annual and seasonal temperatures at Charlottetown, PEl from $1872$ to $2012.$ Briefly describes the trends you have seen from the plots. $(5$ points$)$

$2)$

What are the average annual and seasonal temperatures at Charlottetown for these four separate periods: $1900-1929,1930-1959,1960-1989,1990-2012?$ Do you see any changes as we move forward from the first period to the fourth period? $(5$ points$)$

Tips for MS Excel:

$$

To deal with missing values with MS Excel, you should first replace all missing flags $($i$.$e$.,$

$"-9999\mathrm{.}9")$ with $*$#N$/$A$"$

$2)$

To calculate average without missing values, you should use this function:

AGGREGATE$(1,6,$V$2$:V$6).$ You only need to change the third parameter $($i$.$e$.,$ V$2$:V$6)$ to indicate the cells for which you will calculate the average.