Programming :: Re-direct The Output Within An Awk Script?

I need to re-direct the output within an awk script, but not to already known, fixed filenames. The output file names depend on values of the fields. For example (the actual problem is surely more complicated), if, on a given line, the second field is DATA, the third is 1984, I would like to print some information in a file called output_DATA_1984. This could/would change in the following line of the same input file. Such things are pretty easy in bash, put I cannot do it in awk, as I can only find manual references for redirecting output to fixed filenames between double quotes.