CliMate:

What Trend?

Explore trends in meteorological data over different periods in recent history (1900 onwards)..

rainfall, temperature, solar radiation

What Trend? Is designed to allows you to visually explore trends in selected weather variables.

A line of best fit (least sum of squares) is shown, along with an estimate of whether the slope of the line is statistically different from zero (i.e. no trend).

Note: This is a simple, visual analysis. The data length is relatively short, and most weather parameters are typically highly variable, making trend analysis difficult.

It allows decision-makers to answer questions such as:

What Trend? Allows you to explore a number of questions such as:

Is the weather changing here?
Am I getting more or less rain compared to the long term?
Is there a trend in rainfall or temperature?

Inputs

What Trend? asks the user for:

The variable of interest
Annual rainfall (mm)
Annual average maximum temperature
Annual average minimum temperature (0C)
Accumulated solar radiation
Incidences of: rainfall, maximum temperature, minimum temperature and solar radiation

When Incidences is selected, choose “greater than” or “less than” , value of parameter and duration of “incidence”

Outputs

What Trend? plots time series of selected variables: rainfall, temperature, radiation and incidences of specified occurrences. A simple line of best fit (least sum of squares) is provided along with an estimate of whether the slope of the line is significantly different from zero (i.e. no trend).

A graph of annual differences from the mean and cumulative differences (residual mass curves) provide another view of departures from the mean over the duration of available (or selected) data.

History

What Trend? Is a new analysis for Australian CliMate and is provided to allow you to explore whether there are visually observable trends in a specified variable (your judgment)?