How to save all the graphics made with a loop in a folder?

Question

I produce 61 graphs (at 61 different dates) using a loop in R. I would like to know how to automatically save these graphs in a folder on my computer.

Here is my code:

par(mfrow=c(2,2))
for(day in 1:61){
  map <- subset(analCHL,day, drop=TRUE)
  plot(map,zlim=c(0,15),xaxt="n",yaxt="n",col=jet.colors(100),main="Satellite analysed Chl_a (µMol)")
  text(-4.25,48.58,dates[day])
}

Thank you for your help