Colorado Monthly Meteorological Data {fields} | R Documentation

## Monthly surface meterology for Colorado 1895-1997

### Description

Source: These is a group of R data sets for monthly min/max temperatures and precipitation over the period 1895-1997. It is a subset extracted from the more extensive US data record described in at http://www.image.ucar.edu/Data/US.monthly.met. Observed monthly precipitation, min and max temperatures for the conterminous US 1895-1997. See also http://www.image.ucar.edu/Data/US.monthly.met/CO.shtml for an on line document of this Colorado subset. Temperature is in degrees C and precipitation is total monthly accumulation in millimeters. Note that minimum (maximum) monthly tempertuare is the mean of the daily minimum (maximum) temperatures.

Data domain:

A rectagular lon/lat region [-109.5,-101]x [36.5,41.5] larger than the boundary of Colorado comprises approximately 400 stations. Although there are additional stations reported in this domain, stations that only report preicipitation or only report temperatures have been excluded. In addition stations that have mismatches between locations and elevations from the two meta data files have also been excluded. The net result is 367 stations that have colocated temperatures and precipitation.

### Format

This group of data sets is organized with the following objects:

CO.info
  A data frame with columns: station id, elev, lon, lat, station name
CO.elev
  elevation in meters
CO.id
  alphanumeric station id codes
CO.loc
  locations in lon/lat
CO.ppt CO.tmax CO.tmin
  Monthly means as three dimensional arrays ( Year, Month, Station). Temperature is in degrees C and precipitation in total monthly accumulation in millimeters.
CO.MAM.ppt CO.MAM.tmax CO.MAM.tmin
  Spring seasonal means (March, April,May) as two dimensional arrays (Year, Station).
CO.MAM.ppt.climate CO.MAM.tmax.climate CO.MAM.tmin.climate
  Spring seasonal means (March, April,May) means by station for the period 1960-1990. If less than 15 years are present over this period an NA is recorded. No detreding or other adjustments have been made for these mean estimates.

### Creation of data subset

Here is the precise R script used to create this data subset from the larger US monthly data set. This parent data set is available from http://www.image.ucar.edu/public/Data with a general description at http://www.image.ucar.edu/Data/US.monthly.met.

These technical details are not needed for casual use of the data – skip down to examples for some R code that summarizes these data.

    attach("RData.USmonthlyMet.bin")

    #To find a subset that covers Colorado (with a bit extra):

    indt<- UStinfo$lon< -101 &  UStinfo$lon > -109.5
    indt<- indt & UStinfo$lat<41.5 &  UStinfo$lat>36.5

    # check  US(); points( UStinfo[indt,3:4])

    #find common names restricting choices to the temperature names
    tn<-  match(  UStinfo$station.id, USpinfo$station.id)
    indt<- !is.na(tn) & indt

    # compare  metadata locations and elevations.
    # initial matches to precip stations
    CO.id<- UStinfo[indt,1]
    CO.names<- as.character(UStinfo[indt,5])
    pn<-  match(  CO.id, USpinfo$station.id)

    loc1<- cbind( UStinfo$lon[indt], UStinfo$lat[indt], UStinfo$elev[indt])
    loc2<- cbind( USpinfo$lon[pn], USpinfo$lat[pn], USpinfo$elev[pn])

    abs(loc1- loc2) ->  temp
    indbad<- temp[,1] > .02 | temp[,2]> .02 |  temp[,3] > 100

    # tolerance at 100 meters set mainly to include the CLIMAX station
    # a high altitude station.

    data.frame(CO.names[ indbad], loc1[indbad,], loc2[indbad,], temp[indbad,] )

    #  CO.names.indbad.      X1    X2   X3    X1.1  X2.1 X3.1 X1.2 X2.2 X3.2
    #1     ALTENBERN    -108.38 39.50 1734 -108.53 39.58 2074 0.15 0.08  340
    #2     CAMPO 7 S    -102.57 37.02 1311 -102.68 37.08 1312 0.11 0.06    1
    #3     FLAGLER 2 NW -103.08 39.32 1519 -103.07 39.28 1525 0.01 0.04    6
    #4     GATEWAY 1 SE -108.98 38.68 1391 -108.93 38.70 1495 0.05 0.02  104
    #5     IDALIA       -102.27 39.77 1211 -102.28 39.70 1208 0.01 0.07    3
    #6     KARVAL       -103.53 38.73 1549 -103.52 38.80 1559 0.01 0.07   10
    #7     NEW RAYMER   -103.85 40.60 1458 -103.83 40.58 1510 0.02 0.02   52

    # modify the indt list to exclude these mismatches (there are 7 here)

    badones<-  match(  CO.id[indbad], UStinfo$station.id)
    indt[ badones] <- FALSE

    ###### now have working set of CO stations have both temp and precip
    ##### and are reasonably close to each other.

    N<- sum( indt)
    # put data in time series order instead of table of year by month.
    CO.tmax<-  UStmax[,,indt]
    CO.tmin<-  UStmin[,,indt]

    CO.id<- as.character(UStinfo[indt,1])
    CO.elev<- UStinfo[indt,2]
    CO.loc <-  UStinfo[indt,3:4]
    CO.names<- as.character(UStinfo[indt,5])

    CO.years<- 1895:1997

    # now find precip stations that match temp stations
    pn<-  match(  CO.id, USpinfo$station.id)
    # number of orphans
    sum( is.na( pn))

    pn<- pn[ !is.na( pn)]
    CO.ppt<- USppt[,,pn]

    # checks --- all should zero

    ind<- match( CO.id[45], USpinfo$station.id)
    mean( abs( c(USppt[,,ind])   - c(CO.ppt[,,45]) ) , na.rm=TRUE)

    ind<- match( CO.id[45], UStinfo$station.id)
    mean( abs(c((UStmax[,,ind])) - c(CO.tmax[,,45])), na.rm=TRUE)

    mean( abs(c((UStmin[,,ind])) - c(CO.tmin[,,45])), na.rm=TRUE)

    # check order
    ind<- match( CO.id, USpinfo$station.id)
     sum( CO.id != USpinfo$station.id[ind])
    ind<- match( CO.id, UStinfo$station.id)
     sum( CO.id != UStinfo$station.id[ind])

    # (3 4 5) (6 7 8) (9 10 11)  (12 1 2)
    N<- ncol( CO.tmax)

    CO.tmax.MAM<- apply( CO.tmax[,3:5,],c(1,3), "mean")

    CO.tmin.MAM<- apply( CO.tmin[,3:5,],c(1,3), "mean")

    CO.ppt.MAM<- apply( CO.ppt[,3:5,],c(1,3), "sum")

    # Now average over 1961-1990
    ind<-  CO.years>=1960 & CO.years < 1990

     temp<- stats( CO.tmax.MAM[ind,])
     CO.tmax.MAM.climate<- ifelse( temp[1,] >= 15, temp[2,], NA)

     temp<- stats( CO.tmin.MAM[ind,])
     CO.tmin.MAM.climate<- ifelse( temp[1,] >= 15, temp[2,], NA)

     CO.tmean.MAM.climate<- (CO.tmin.MAM.climate + CO.tmin.MAM.climate)/2

     temp<- stats( CO.ppt.MAM[ind,])
     CO.ppt.MAM.climate<- ifelse( temp[1,] >= 15, temp[2,], NA)

    save( list=c( "CO.tmax", "CO.tmin", "CO.ppt",
                  "CO.id", "CO.loc","CO.years",
                  "CO.names","CO.elev",
                  "CO.tmin.MAM", "CO.tmax.MAM", "CO.ppt.MAM",
                  "CO.tmin.MAM.climate", "CO.tmax.MAM.climate",
                  "CO.ppt.MAM.climate", "CO.tmean.MAM.climate"),
                   file="COmonthlyMet.rda")

### Examples

    data(COmonthlyMet)

    #Spatial plot of 1997 Spring average daily maximum temps
     quilt.plot( CO.loc,CO.tmax.MAM[103,]  )
     US( add=TRUE)
     title( "Recorded MAM max temperatures (1997)")

    # min and max temperatures against elevation

    matplot( CO.elev, cbind( CO.tmax.MAM[103,], CO.tmin.MAM[103,]),
      pch="o", type="p",
      col=c("red", "blue"), xlab="Elevation (m)", ylab="Temperature (C)")
    title("Recorded MAM max (red) and min (blue) temperatures 1997")

[Package fields version 6.01 Index]