sunspotarea: Annual average sunspot area (1875-2011)

In fpp: Data for "Forecasting: principles and practice"

Description

Annual averages of the daily sunspot areas (in units of millionths of a hemisphere) for the full sun. Sunspots are magnetic regions that appear as dark spots on the surface of the sun. The Royal Greenwich Observatory compiled daily sunspot observations from May 1874 to 1976. Later data are from the US Air Force and the US National Oceanic and Atmospheric Administration. The data have been callibrated to be consistent across the whole history of observations. More information is available at http://solarscience.msfc.nasa.gov/greenwch.shtml.

Usage

data(sunspotarea)

Format

Annual time series of class ts.

Source

NASA. http://solarscience.msfc.nasa.gov/greenwch/sunspot_area.txt

Examples

plot(sunspotarea)

Example output

Loading required package: forecast
Loading required package: fma
Loading required package: tseries
Loading required package: expsmooth
Loading required package: lmtest
Loading required package: zoo

Attaching package: 'zoo'

The following objects are masked from 'package:base':

    as.Date, as.Date.numeric

fpp documentation built on May 2, 2019, 6:34 a.m.