This data set from Connelly et al. (2017) measures the Arctic sea ice extent in 10^6 square kilometers. It includes lower bounds and upper bounds on annual averages.
A data frame with 115 observations on the following 4 variables.
the annual Arctic sea ice extent (in 10^6 sq km)
The upper bound of the value, provided by Connelly et al.
The lower bound of the value, provided by Connelly et al.
This is for illustration of climate change for my intro students. Connelly et al. (2017) are in part a methodological paper. The data I present here are from the "rescaled (unadjusted T)" data in the second sheet from their replication files.
Connolly et al. (2017), ''Re-calibration of Arctic sea ice extent datasets using Arctic surface air temperature records''. *Hydrological Sciences Journal* 62(8): 1317--40.