Instructions for the WRIT Monthly Timeseries webpage
Page will plot time series of selected pressure level variables from different reanalysis datasets. Select desired options and hit "create plot". Most options have a default setting so a selection is not required. If you have problems, please email with ALL the options you chose. You will get a plot as well as the data used to create the final plot (in netCDF), a post script image and information on the dataset.
Access is provided to various global reanalyses. Currently, just pressure level data is available at the following common levels: 1000., 850.,700.,600.,500.,400.,300.,250.,200.,150.,100. mb. for reanalyses. Note that the MERRA dataset is not defined for values below the surface. There is a new option for users to choose a climate time-series such as a PNA index or else upload their own timeseries. Choose Pre-generated Time Series and then either choose a time-series or select User Uploaded and enter the pathname and a title. See the use your own timeseries directions.
The following monthly variables are available for each of the reanalyses for the time period of each reanalysis: Geopotential Height, Zonal Wind, Meridional Wind, Air Temperature, Specific Humidity and Relative Humidity. There are also single level variables. If you select "Pre-generated Time Series" you will not see the variable list. All variables are converted to use a common unit.
You can select a second datasets/variable similarly to Dataset 1 above.If you choose a second variable, you can plot the difference between the two datasets, plot them on the same time plot, plot a scatter plot or plot a cross-correlation. The correlation and RMS difference will be returned as well as individual statistics on the processed dataset. You cannot plot two distributions.
The following monthly variables are available for each of the reanalyses for the time period of each reanalysis: Geopotential Height, Zonal Wind, Meridional Wind, Air Temperature, Specific Humidity and Relative Humidity. here are also single level variables. If you select "Pre-generated Time Series" you will not see the variable list. All variables are converted to use a common unit.
Enter a year range. This will be the timeseries that is plotted/analyzed (e.g. for correlations). You can change the x-axis below to change the dates displayed but that will just affect the plot; not the analysis.
You can choose to use the original monthly averages or you can create your own season. If you choose season, enter your starting and ending month for the season. The year of a season that extends over December is the year of the second month. Seasonal values are created by averaging monthly means or monthly anomalies. You cannot yet create seasons that don't average the months together (except for using all 12 months).
You can plot means, anomalies, or long term mean (climatology). Anomalies are calculated relative to the climatology range that is input. Monthly anomalies are calculated first and then averaged to create seasonal values.
Enter the years to use for the climatology when selecting anomaly or climatology. You can choose a different time range for each dataset if you desire.
Foe time-series created from gridded datasets, enter the latitude and longitude ranges (S to N and W to E) for each dataset. You can do a single point or an area average. Note that area averages are area weighted by the cosine of the latitude. NCL obtains the closest grid from a dataset and does not interpolate. To get timeseries averaged over 0E, use a negative longitude for longitude 1.
There are 5 types:
Plots one or two timeseries. The same Y axis is used for each plot, if there are two. The same statistic and running mean option are also shown. You can plot different grids, variables, levels or datasets. To use a different Y axis, select that later in the options. Timeseries Difference Plot
Plots the timeseries of the difference between the two selected timeseries.