#http://hadobs.metoffice.com/hadsst2/diagnostics/global/nh+sh/monthly

#
get.hadsst=function(hemi="gl",period="monthly",verbose="default")  { 
# hemi="gl"; period="monthly";verbose="default" 
 	index=c(gl="global/nh+sh",nh="hemispheric/northern",sh="hemispheric/southern",trp="regional/30-30",
	  nh_ext="regional/north_30n", sh_ext="regional/south_30s" )
 if(period=="monthly") {
 	loc=file.path("http://hadobs.metoffice.com/hadsst2/diagnostics",index[paste(hemi)],"monthly" )  
  	download.file(loc,"temp")
	D=read.table("temp") #dim(D) #1928 12 #start 1850
    	names(D)=c("year","anom","u_sample","l_sample","u_coverage","l_coverage","u_bias","l_bias","u_sample_cover","l_sample_cover",
    	   "u_total","l_total")
    	monthly=ts(D[,2],start=c(1850,1),freq=12)	
	return(monthly)  
   } # monthly

if(period=="annual") {
	loc=file.path("http://hadobs.metoffice.com/hadcrut3/diagnostics",index[paste(hemi)],"annual" )  
  	D=read.table(loc) #dim(D) #158 12 #start 1850
    	names(D)=c("year","anom","u_sample","l_sample","u_coverage","l_coverage","u_bias","l_bias","u_sample_cover","l_sample_cover",
    	   "u_total","l_total")
    	annual=ts(D[,2],start=1850	)
	return(annual)
  } #annual
}


#   had=get.hadsst(hemi="gl",period="annual")