SGP/RUC/X1 - Subsetting RUC-40

Users who would like access to subsetted RUC-40 data products similar to those products 
currently available for RUC-20 can use NCO utilities to create subsets from the 
"sgpallruc40" data products.  Below is one method that can be used. This is also mentioned in the 
FAQ on the ARM RUC description page at: http://www.arm.gov/xds/static/ruc.stm
--------------------------------------------------------------

Question: How can I create subsetted RUC 40 data similar to the RUC 20 data currently 
available at the Archive?

Currently, the RUC 40 netCDF data available at the archive are the full area, hourly files 
(sgpallruc40isobX1.c1 and sgpallruc40hybrX1.c1). Using the netCDF Operator (NCO) 
utilities, it is easy to produce subsetted, daily files similar to the RUC 20 subsets available 
(sgpruc20hybrX1.c1 and sgpruc20isobX1.c1).

The NCO utilities can be found at http://nco.sourceforge.net/
Using the ncks (NCO "kitchen sink") command, you can subset the ruc data as follows:

ncks -d nx,, -d ny,,  

Note: xmin,xmax,ymin,ymax are index ranges.

For example to subset around the SGP site use the following index values
for latitudes 34.209 to 38.928 and longitudes -99.798 to -95.
xmin = 71
xmax = 82
ymin = 40
ymax = 53


ncks -d nx,71,82 -d ny,40,53 sgpallruc40isobX1.c1.20000314.130000.cdf 
sgpruc40isobX1.c1.subset.cdf

Here is a sample C-Shell script for subsetting the ruc40 and using the NCO command ncrcat 
to concatenate the hourly subsetted files into a ruc 40 subsetted daily file similar to 
the sgpruc20isobX1.c1 files.

#!/bin/csh
# This script subsets the RUC 40 isobaric files
# and then concatenates hourly files into 1 daily file
# usage: subset_ruc40.csh 
#   where yyyymmdd is the date of the files to subset
#   and concatenate. Ex. 20000314 (yyyy=2000,mm=03, dd=14)
# Example: subset_ruc40.csh 20000314
# xmin,xmax,ymin,ymax are indices for
# lat = 34.209, 38.928, lon = -99.798, -95
set xmin = 71
set xmax = 82
set ymin = 40
set ymax = 53
set date = $1
foreach file (sgpallruc40isob*$date*)
  ncks -d nx,${xmin},${xmax} -d ny,${ymin},${ymax} $file $file.sub
end
ncrcat -h sgpallruc40isob*$date*sub sgpruc40isobX1.c1.$date.000000.cdf
rm *.sub
exit

For more information on the NCO commands ncks and ncrcat see:
http://nco.sourceforge.net/nco.html#ncks-netCDF-Kitchen-Sink
http://nco.sourceforge.net/nco.html#ncrcat-netCDF-Record-Concatenator

Also other commands for subsetting and analysis of netCDF data can be found at 
http://www.arm.gov/data/tools.stm

• Number Concentration of Ice Particles (hybrid-b grid)(ndensice)
• Time offset from base_time(time_offset)
• Sub-grid Scale Precipitation at Surface(precipsubgrid)
• Derived pressure(pressure)
• Surface/Sub-surface Heights(heightss)
• base time in epoch(base_time)
• East longitude(longitude)
• altitude(altitude)
• North latitude(latitude)
• Convective Inhibition(cinhib)
• Surface,Sub-surface Soil Temperature(tempsoilsrfsubsrf)
• Pressure Vertical Velocity (hybrid-b grid)(velocityw)
• v-Component of Wind (hybrid-b grid)(windv)
• u-Component of Wind (hybrid-b grid)(windu)
• Net Longwave Irradiance at Surface(fluxlwnetsrf)
• Precipitable water vapor(pwv)
• Relative Humidity (hybrid-b grid)(rh)
• Surface Runoff(runoffsrf)
• u-Component of Wind at Tropopause(windutrop)
• Snow Accumulation over 3-hr(snowaccum)
• Mixing Ratio of Cloud Water (hybrid-b grid)(mxratioliquid)
• Geopotential Height (hybrid-b grid)(heightgp)
• Surface,Sub-surface Soil Volumetric Moisture(moistsoilvolumesrfsubsrf)
• Net Shortwave Irradiance at Surface(fluxswnetsrf)
• Mixing Ratio of Snow (hybrid-b grid)(mxratiosnow)
• Mixing Ratio of Rain Water (hybrid-b grid)(mxratiorain)
• Evapotranspiration Flux near Surface(fluxevaptranssrf)
• Pressure at Tropopause(pressuretrop)
• Precipitation Rate at Surface(preciprate)
• Mixing Ratio of Graupel (hybrid-b grid)(mxratiograupel)
• Potential Temperature at Tropopause(temppottrop)
• Sensible Heat Flux at Surface(fluxsensiblesrf)
• Evaporation of Canopy Water near Surface(evapcanopysrf)
• Sub-surface Runoff(runoffsubsrf)
• Snow Depth(snowdepth)
• Surface,Sub-surface Soil Moisture Content(moistsoilcontentsrfsubsrf)
• v-Component of Wind at Tropopause(windvtrop)
• Snow Temperature at Snow or Top Soil Level(snowtemp)
• Rate of Water Dropping from Canopy to Ground(dropwaterratesrf)
• Resolvable Scale Precipitation at Surface(precipresolved)
• Water Condensation Rate near Surface(condensewaterratesrf)
• MAPS Pressure at Mean Sea Level(pressuremsl)
• Convective available potential energy(cape)
• Latent Heat Flux at Surface(fluxlatentsrf)
• Environmental Temperature (hybrid-b grid)(temp)
• Mixing Ratio of Water Vapor (hybrid-b grid)(mxratiovapor)
• Mixing Ratio of Ice Water (hybrid-b grid)(mxratioice)
• Turbulent Kinetic Energy (hybrid-b grid)(tketurb)
• Evaporation from Bare Soil at Surface(evapsoilsrf)
• Virtual Potential Temperature (hybrid-b grid)(tempvirtpot)
• forecast period(forecast_period)
• Plant Canopy Surface Water(watercanopy)

• altitude(altitude)
• Surface Runoff Accumulated(runoffsrfacc)
• Relative Humidity at Freezing Level(rhfrz)
• Lifted Index(indexlifted)
• v-Component of Wind at Maximum Wind Level(windvwindmax)
• u-Component of Wind at Maximum Wind Level(winduwindmax)
• North latitude(latitude)
• Equilibrium Level Height(heightequillevel)
• Geopotential Height (p grid)(heightgpp)
• Convective Inhibition(cinhib)
• Categorical Rain(catrain)
• Dew Point Temperature (2 m fixed height)(tempdewpt2m)
• Earth Surface Pressure(pressuresrf)
• Gust Wind Speed(windgustspeed)
• Categorical Snow(catsnow)
• Cloud Base Height(heightcldbase)
• Pressure Intervals (30-0,60-30,90-60,120-90,150-120,180-150) of the m grid(pressuremgrid)
• Convective available potential energy(cape)
• Precipitable water vapor(pwv)
• Pressure at Maximum Wind Level(pressurewindmax)
• Environmental Temperature (p grid)(tempp)
• Environmental Temperature (m grid)(tempm)
• forecast period(forecast_period)
• v-Component of Wind (m grid)(windvm)
• v-Component of Wind (p grid)(windvp)
• Pressure at Top Freezing Level(pressurefrztop)
• Snow Depth(snowdepth)
• Planetary Boundary Height(heightpbl)
• Altimeter Setting(altimeter)
• Time offset from base_time(time_offset)
• Earth Surface Height(heightsrf)
• u-Component of Wind (10 m fixed height)(windu10m)
• Geopotential Height at Freezing Level(heightgpfrz)
• Best Lifted Index(indexliftedbest)
• u-Component of Wind at Tropopause(windutrop)
• Soil Moisture Availability(moistsoilavail)
• Visibility(visibility)
• u-Component of Storm Motion(stormmotionu)
• v-Component of Storm Motion(stormmotionv)
• 2 meter temperature(temp2m)
• Cloud Top Height(heightcldtop)
• Specific Humidity (2 m fixed height)(sh2m)
• Dew Point Depression (2 m fixed height)(tempdewptdep2m)
• Snow Accumulation over 3-hr(snowaccum)
• base time in epoch(base_time)
• Precipitation Rate at Surface(preciprate)
• Relative Humidity at Top Freezing Level(rhfrztop)
• MAPS Pressure at Mean Sea Level(pressuremsl)
• Sub-grid Scale Precipitation (3 hr)(precipsubgrid3hr)
• Sub-grid Scale Precipitation (Accumulated)(precipsubgridacc)
• v-Component of Wind at Tropopause(windvtrop)
• Water Equivalent Snow Depth(snowdepthwatereq)
• u-Component of Wind (m grid)(windum)
• Categorical Freezing Rain(catfreezerain)
• u-Component of Wind (p grid)(windup)
• Storm-Relative Helicity 0-3 km(stormrelhelicity)
• Convective Cloud Top Height(heightcldtopconv)
• Resolvable Scale Precipitation (Accumulated)(precipresolvedacc)
• Resolvable Scale Precipitation (3 hr)(precipresolved3hr)
• East longitude(longitude)
• Geopotential Height at Top Freezing Level(heightgpfrztop)
• Sub-surface Runoff(runoffsubsrf)
• v-Component of Wind (10 m fixed height)(windv10m)
• Categorical Ice Pellets(caticepellets)
• Vertical Velocity (m grid)(velocitywm)
• Relative Humidity (p grid)(rhp)
• Vertical Velocity (p grid)(velocitywp)
• Relative Humidity (m grid)(rhm)
• Relative Humidity (2 m fixed height)(rh2m)
• Potential Temperature at Tropopause(temppottrop)
• Potential Temperature (2 m fixed height)(temppot2m)
• Pressures of the p grid(pressurepgrid)
• Pressure at Tropopause(pressuretrop)
• Equivalent Potential temperature(tempeqpot)
• Maximum Equivalent Potential Temperature Pressure(pressuretempeqpotmax)
• Pressure Tendency (3-hr)(pressuretend)
• Pressure at Freezing Level(pressurefrz)