The Maproom explores historical daily precipitation by calculating simple seasonal statistics.
Many options can be specified to produce yearly time series of a chosen seasonal diagnostic of the daily precipitation data. The user can then choose to map the mean, standard deviation or probability of exceeding a chosen threshold, over years; clicking on the map will then produce a local yearly time series of the chosen diagnostic.
Years and Season: specify the range of years over which to perform the analysis and choose the start
and end dates of the season , over which the diagnostics are to be performed.
Wet/Dry Day/Spell Definitions: define the amount in millimeters (non inclusive) above which a day is considered
to be a wet day (as opposed to dry), and the minimum number (inclusive) of consecutive
wet (dry) days to define a wet (dry) spell.
Seasonal daily statistics: choose the seasonal diagnostic quantity (i.e the statistic of the daily data) to
be computed for each season, from the following choices.
Total Rainfall: total cumulative precipitation (in mm) falling over the season.
Number of Wet Days: the number of wet days (as defined above) during the season.
Number of Dry Days: the number of dry days (as defined above) during the season.
Rainfall Intensity: the average daily precipitation over the season considering only wet days.
Number of Wet (Dry) Spells: the number of wet (dry) spells during the season according to the definitions in
the Options section. For example, if a wet spell is defined as 5 contiguous wet days,
10 contiguous wet days are counted as 1 wet spell. Note that a spell, according to
the definitions above, that is overlapping the start or end of the season will be
counted only if the part of the spell that falls within the season reaches the minimal
length of consecutive days.
Yearly seasonal statistics: a choice of yearly statistics over the chosen season of the selected range of years
to produce the map among: the mean, the standard deviation and the probability of
exceeding a user specified threshold.
Spatial Resolution: the analysis can perform and map at each 0.0375 resolution grid point. Additionally
it is possible to average the results of the analysis over the 0.0375 grid points
falling within administrative boundaries for the time series graph.
ThePlots Range controls define the range of the vertical axis of the time series and the horizontal axis of the probability of exceeding graph. Blanking the boxes will set the range to the extrema of graph in view.
Contact help@iri.columbia.edu with any technical questions or problems with this Maproom.