open, read, and re-open a file

[Boyin Huang]

I can read a ascii file using "read(filename)".

As document indicated, the file is "open" when first call is made,
and "close" when script is terminated.

My question is, can I "re-open" a file before termination?

e.g. The file contains SST and SAT in two columns, and I want to plot SST
and SAT in two different plots. I want to open the file, read SST and plot
it, I want to re-open the same file and read SAT and plot.

Can we do this?