The highly variable thin blue line is a plot of global cloud coverage from this source with the following change: the blue curve has been inverted. (c3headlines.com)
The several thin blue lines are the results of the individual models, while the gray vertical lines represent major cooling events due to volcanic eruptions. (nybooks.com)
Alexander Skarsgård and Michael Peña put the «blue» and «line» in thin blue line in this salty buddy cop comedy. (lwlies.com)