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Directions on US station data plotting and analysis Pages
Plots of Distributions
This page will plot histograms of the station data for user supplied seasons, years, and time-averaging period.
- Maximum temperature, minimum temperature and (liquid) precipitation. For time averages longer than a day, the temperatures are averaged and the precipitation is totaled.
- Stations available
- Stations included in the list have a fairly complete time coverage from 1950-1999 and have both precipitation and temperature available. Climate Division values are calculated by averaging all the stations within a climate division. No attempt was made to area weight within a division. Latitude, longitude and elevation will available for each station from the data description web page.
- Time Range
- Enter season from which values will be drawn. For full year, use 1 to 365 (entry form will change to use months/days). Note that Feb 29 is ignored in the distribution page. You use a season that extends over Dec 31 (say, Dec-Feb). Years will refer to 2nd year of seasons that extend over Dec 31.
- Time Average
- Daily values will be averaged over the time interval selected. The starting date will be the first date entered for time range. Monthly values refer to Jan, Feb etc and not 30 day averages.
- Bin Size
- The code will select a bin size based on the range of the data. It may not be optimal. Please feel free to change it. Note that daily data is integer and non-integer bins may not work well. When there are many values (daily distributions for a month or season) using a bin size of 1 may work quite well. For precipitation data, you may want to set the lower bound to 1 as 0's can be quite frequent for some stations and seasons, especially for daily data. You must set the bin size and the range. I may change this.
- Y range
- The code will automatically select a y range. Changing it depending on the results may make it easier to see some bins. You can also compare different cities or seasons more easily.
Year entry format for composites of a subset of years.
Output If you don't select the years, you will get back the default climatology (1950-1999) for the plot. The distributions will consist of bars representing the number of values in the bin. Bin limits are listed below the plots. The x axis represents the values of the data.
- Year range
- You can select a range from anywhere between 1950 and 1999. For seasons that extend over Dec 31, year will refer the the part of the season after Dec 31.
- Enter Years
- You can enter the years directly. This overrides year range.
- Time Series to get years for composites
- You can use the following monthly time series to obtain years for composites. Most time series extend between 1950 and 1999 (at least). Please read documentation on time series so you know how the time series is defined and created. You may misunderstand your results if you do not. Also, please reference any time-series you use in publications.
- Enter value of the time series you wish to set as a cutoff. Value in the time series above (or below) the cutoff will be used. You can enter the actual value, the anomaly , the standardized anomalies or the percentile.
- Enter less than or equal or greater than or equal the value entered.
- The season chosen is the one that is used to check the time series values. The season you wish to plot in the distributions does NOT have to match this season.
Below the plot is a table of statistics for the values and a table of the bin size and the number in each category. If you select a subset of years, you will get two plots. The first is the distribution for the years you selected. The 2nd is climatology plotted using the same axis values so they can be compared.
You will also get back a table comparing various statistics of the two sets of data. Sample Plot