make_ccsbt_sa <- function(dat,latvar,lonvar) {
  dat$sarea <- NA
  dat[latvar < -10 & latvar > -20 & lonvar > 100 & lonvar < 130,"sarea"] <- 1
  dat[latvar < -20 & latvar > -35 & lonvar > 80  & lonvar < 120,"sarea"] <- 2
  dat[latvar < -20 & latvar > -35 & lonvar > 120 & lonvar < 140,"sarea"] <- 3
  dat[latvar < -30 & latvar > -40 & lonvar > 140 & lonvar < 170,"sarea"] <- 4
  dat[latvar < -30 & latvar > -40 & lonvar > 170 & lonvar < 190,"sarea"] <- 5
  dat[latvar < -40 & latvar > -60 & lonvar > 160 & lonvar < 190,"sarea"] <- 6
  dat[latvar < -40 & latvar > -60 & lonvar > 120 & lonvar < 160,"sarea"] <- 7
  dat[latvar < -35 & latvar > -40 & lonvar > 120 & lonvar < 140,"sarea"] <- 7
  dat[latvar < -35 & latvar > -60 & lonvar >  60 & lonvar < 120,"sarea"] <- 8
  dat[latvar < -35 & latvar > -60 & lonvar >   0 & lonvar <  60,"sarea"] <- 9
  dat[latvar < -35 & latvar > -60 & lonvar > 340 & lonvar < 360,"sarea"] <- 9
  dat[latvar < -35 & latvar > -60 & lonvar > 290 & lonvar < 340,"sarea"] <- 10
  dat[latvar < 100 & latvar > -35 & lonvar > 300 & lonvar < 340,"sarea"] <- 11
  dat[latvar < 100 & latvar > -20 & lonvar > 340 & lonvar < 360,"sarea"] <- 11
  dat[latvar < 100 & latvar > -20 & lonvar >   0 & lonvar <  20,"sarea"] <- 11
  dat[latvar < 100 & latvar > -30 & lonvar > 140 & lonvar < 190,"sarea"] <- 12
  dat[latvar < 100 & latvar > -60 & lonvar > 190 & lonvar < 290,"sarea"] <- 12
  dat[latvar < 100 & latvar > -20 & lonvar >  30 & lonvar < 100,"sarea"] <- 13
  dat[latvar < 100 & latvar > -10 & lonvar > 100 & lonvar < 130,"sarea"] <- 13
  dat[latvar < -20 & latvar > -35 & lonvar >  20 & lonvar <  80,"sarea"] <- 14
  dat[latvar < -20 & latvar > -35 & lonvar > 340 & lonvar < 360,"sarea"] <- 15
  dat[latvar < -20 & latvar > -35 & lonvar >   0 & lonvar <  20,"sarea"] <- 15
  return(dat)
  }