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Data Set ID:
NSIDC-0211

CLPX-Model: Rapid Update Cycle 40km (RUC-40) Model Output Reduced Data, Version 1

The Rapid Update Cycle, version 2 at 40km (RUC-2, known to the Cold Land Processes community as RUC40) model is a Mesoscale Analysis and Prediction System (MAPS) data set that uses the Model Output Reduced Data Set (MORDS) version. This data set has been subsetted for use in the Cold Land Processes Field Experiment (CLPX).

Geographic Coverage

Parameter(s):
  • Precipitation > Snow > Accumulated Snow
  • Atmospheric Temperature > Air Temperature
  • Surface Radiative Properties > Albedo
  • Snow/Ice > Albedo
  • Precipitation > Precipitation Amount > Convective Precipitation
  • Atmospheric Radiation > Longwave Radiation > Downward Longwave Flux
  • Atmospheric Radiation > Shortwave Radiation > Downward Shortwave Flux
  • Altitude > Geopotential Height
  • Clouds > Cloud Height > High Level Cloud Cover
  • Atmospheric Radiation > Heat Flux > Latent Heat Flux
  • Clouds > Cloud Height > Low Level Cloud Cover
Spatial Coverage:
  • N: 42.568, S: 38.394, E: -103.971, W: -108.615

Spatial Resolution: Not Specified
Temporal Coverage:
  • 1 October 2002 to 30 June 2003
Temporal Resolution: Not specified
Data Format(s):
  • ASCII Text
Platform(s) Not specified
Sensor(s): Not specified
Version: V1
Data Contributor(s): Kristi Arsenault
Data Citation

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Arsenault, K. 2004. CLPX-Model: Rapid Update Cycle 40km (RUC-40) Model Output Reduced Data, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: http://dx.doi.org/10.5067/J2K5LZWPH0F3. [Date Accessed].

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Detailed Data Description

Format

The RUC40 forecast model is an updated version of the generalized vertical coordinate model described by Bleck and Benjamin (1993). Modifications to improve the RUC40 included use of the code structure of the NCAR/Penn State Mesoscale Model version 5 (MM5, Grell et al. 1994). This allowed relatively easy transfer of MM5 parameterizations (cloud microphysics, radiation) into the RUC40 model.

The RUC40 model contains 42 model fields produced by the Mesoscale Analysis and Prediction System (MAPS) coupled modeling system at the NOAA Forecast Systems Laboratory (FSL).

The MAPS MORDS data set used here was obtained from NCAR's GCIP Model Output Archive Summary (http://rda.ucar.edu/datasets/ds609.1/). The files were untarred and collected together into monthly directories, but there are known gaps in the times in the archive from NCAR. These gaps are documented more below in the File Naming Convention section.

Some the basic numerical characteristics of the RUC40 mode include:

  • Arakawa-C staggered horizontal grid (Arakawa and Lamb, 1977); u and v horizontal wind points are offset from mass points to improve numerical accuracy.
  • No vertical staggering.
  • Time step is 60 seconds at 40-km resolution.
  • Positive definite advection schemes are used for the continuity equation (advection of pressure thickness between levels) and for horizontal advection (Smolarkiewicz 1983) of virtual potential temperature, and all vapor and hydrometer moisture variables.

RUC40 data are stored in individual ASCII data files, with one file per hour. Within each hourly file, 42 data variables are stored in row-major order, starting at the lower-left coordinate. Because the analysis runs at a 00Z initial time do not contain the full set of the 42 fields (described in the table below), the 00Z forecast run at time of 01Z was selected as the nearest time value to the 00Z analysis output.

Record #

Variable (:”level”)

Name Description [Unit]

1

MSL

1hr fcst:"Mean sea level pressure (MAPS) [Pa]

2

PRES:sfc

1hr fcst:"Pressure [Pa]

3

HGT:sfc

1hr fcst:"Geopotential height [gpm]

4

TSOIL:sfc

1hr fcst:"Soil temp. [K]

5

SOILM:44-0 cm down

1hr fcst:"Soil moisture content [kg/m2]

6

SOILM:0 cm down

1hr fcst:"Soil moisture content [kg/m2]

7

WEASD:sfc

1hr fcst:"Accum. snow [kg/m2]

8

TMP:2 m above gnd

1hr fcst:"Temp. [K]

9

SPFH:2 m above gnd

1hr fcst:"Specific humidity [kg/kg]

10

UGRD:10 m above gnd

1hr fcst:"u wind [m/s]

11

VGRD:10 m above gnd

1hr fcst:"v wind [m/s]

12

APCP

0-1hr acc:"Total precipitation [kg/m2]

13

ACPCP:sfc

0-1hr acc:"Convective precipitation [kg/m2]

14

WEASD:sfc

0-1hr acc:"Accum. snow [kg/m2]

15

SNOM:sfc

0-1hr acc:"Snow melt [kg/m2]

16

SSRUN:sfc

0-1hr acc:"Storm surface runoff [kg/m2]

17

LHTFL:sfc

0-1hr ave:"Latent heat flux [W/m2]

18

SHTFL:sfc

0-1hr ave:"Sensible heat flux [W/m2]

19

SHTFL

0 cm down 0-1hr ave:"Sensible heat flux [W/m2]

20

SNOHF:sfc

0-1hr ave:"Snow phase-change heat flux [W/m2]

21

CD:sfc

1hr fcst:"Drag coefficient [non-dim]

22

SHTFL:sfc

1hr fcst:"Sensible heat flux [W/m2]

23

LHTFL:sfc

1hr fcst:"Latent heat flux [W/m2]

24

CAPE:sfc

1hr fcst:"Convective Avail. Pot. Energy [J/kg]

25

PWAT:atmos col

1hr fcst:"Precipitable water [kg/m2]

26

LCDC

1hr fcst:"Low level cloud cover [%]

27

MCDC

1hr fcst:"Mid level cloud cover [%]

28

HCDC

1hr fcst:"High level cloud cover [%]

29

DSWRF:sfc

0-1hr ave:"Downward short wave flux [W/m2]

30

DLWRF:sfc

0-1hr ave:"Downward long wave flux [W/m2]

31

USWRF:sfc

0-1hr ave:"Upward short wave flux [W/m2]

32

ULWRF:sfc

0-1hr ave:"Upward long wave flux [W/m2]

33

ALBDO:sfc

1hr fcst:"Albedo [%]

34

TSOIL:5 cm down

1hr fcst:"Soil temp. [K]

35

TSOIL:20 cm down

1hr fcst:"Soil temp. [K]

36

TSOIL:40 cm down

1hr fcst:"Soil temp. [K]

37

TSOIL:160 cm down

1hr fcst:"Soil temp. [K]

38

SOILW:sfc

1hr fcst:"Volumetric soil moisture [fraction]

39

SOILW:5 cm down

1hr fcst:"Volumetric soil moisture [fraction]

40

SOILW:20 cm down

1hr fcst:"Volumetric soil moisture [fraction]

41

SOILW:40 cm down

1hr fcst:"Volumetric soil moisture [fraction]

42

SOILW:160 cm down

1hr fcst:"Volumetric soil moisture [fraction]

There are several places in the time span of the data in which gaps are found, and these gaps are documented in two files: (1) in an Excel spreadsheet file calledruc40-list.xls, and (2) a text file called RUC-all.out. These two files provide a list by month of all the files that are contained in the untarred/unzipped monthly directories.

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File and Directory Structure

RUC40 data are stored in individual ASCII data files, with one file per hour. For easier access, these hourly files have been tarred/gzipped by month (e.g., 200210.tar.gz for October 2002 data). Fortran programs are provided in a directory named programs.

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File Naming Convention

RUC40 data are stored in individual ASCII data files, with one file per hour. Within each hourly file, 42 data variables are stored in row-major order, starting at the lower-left coordinate. For easier access, the hourly ASCII files have been tarred/gzipped by month (e.g., 200210.tar.gz for October 2002 data). After the files are gunzipped and untarred by month, RUC40 ASCII data files have file names in the following form: <year><month><day>.<time>. ruc40-mords.asc

example: 2002100204.ruc40-mords.asc, where

year is the four-digit year the data were acquired, e.g., "2002"
month is the two-digit month of year the data were acquired, e.g., "10" is October
day is the two-digit day of the month the data were acquired, e.g., “02” for the 2nd day of October
hour is the two-digit UTC hour of the data, e.g., hour is 04Z in the example.

There are several places in the time span of the data in which gaps are found, and these gaps are documented in two files: (1) in an Excel spreadsheet file called ruc40-list.xls, and (2) a text file called RUC-all.out. These two files provide a list by month of all the files that are contained in the untarred/unzipped monthly directories.

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File Size

Each hourly ASCII file is approximately 80 KB. For easier access, the hourly files have been tarred/gzipped by month (monthly file size is approximately 8 MB each).

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Spatial Coverage

The RUC40 model covers the 40 km (approximate) Lambertian latitude/longitude grid over the Large-Regional Study Area (LRSA) in Colorado and Wyoming, USA.

Southern Latitude: 38.3940 N 
Northern Latitude: 42.5680 N 
Western Longitude: 108.6150 W 
Eastern Longitude: 103.9710 W

Spatial Coverage Map

The following map provides an overview of the observation site:

LRSA and MAPS MORDS (RUC40) Grid Description

The following figure shows the RUC40 domain, which is placed on a Lambert conformal projection and matches what is used for the AWIPS 212 National Weather Service (NWS) distribution grid. The mesh is rectangular on this projection, and its size is 151 by 113 grid points. The grid length is 40.635 km at 35°N. Due to the varying map-scale factor from the projection, the actual grid length in RUC40 varies from about 40.6 km at 35°N to 33 km at the north boundary.

RUC40 grids

A fortran program ("read-asc40.F90") is provided with this data set that reads the latitude/longitude descriptive ASCII file, 40kmlatlon.asc.txt. These files are provided so that users can see the original domain of the RUC40.

The lower left corner point is (1,1), and the upper right corner point is (151,113), as shown in the following table.

RUC-2 point

AWIPS-212 point

Latitude

Longitude

(1,1)

(23,7)

16.2810 N

126.1378 W

(1,113)

(23,119)

54.1731 N

139.8563 W

(151,1)

(173,7)

17.3400 N

69.0371 W

(151,113)

(173,119)

55.4818 N

57.3794 W

In the vertical dimension, there are four subsurface levels in the ground and one surface level, each corresponding to a depth of:

Layer 1: Ground surface level
Layer 2: 5 cm
Layer 3: 20 cm
Layer 4: 40 cm
Layer 5: 160 cm

RUC 40 data, originally in GRIB format and covering a central North American domain, were converted to ASCII format and subsetted to the LRSA domain. Outer bounds of this MAPS-LRSA domain are:

Lower Left : 38.3940°N, 108.6150°W
Lower Right : 38.3940°N, 103.9710°W
Upper Left : 42.5680°N, 108.6150°W
Upper Right : 42.5680°N, 103.9710°W

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Temporal Coverage

The duration of the data set spans the period from 1 October 2002 through 30 June 2003, with a time step of 60 seconds.

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Parameter or Variable

Parameters presented in this data set are relative humidity, sfc temperature, dew point, sea-level pressure, precipitation, snow accumulation, snow depth, categorical precipitation types, freezing levels, 3-h pressure change, CAPE/CIN, lifted index, helicity, precipitable water, soil moisture, tropopause pressure, vertical velocity, PBL depth, gust wind speed, cloud base height, cloud top height, cloud fraction, visibility, pressure of maximum equivalent potential temperature in column, convective cloud top height, and equilibrium level height.

The atmospheric prognostic variables of the RUC40 forecast model are:

  • pressure thickness between levels
  • virtual potential temperature
  • horizontal wind components
  • water vapor mixing ratio
  • cloud water mixing ratio
  • rain water mixing ratio
  • ice mixing ratio
  • snow mixing ratio
  • graupel (rimed snow) mixing ratio
  • number concentration for ice particles
  • turbulence kinetic energy
  • turbulent variance of potential temperature
  • turbulent variance of water vapor mixing ratio
  • turbulent covariance of potential temperature perturbations with water vapor mixing ratio perturbations

The soil prognostic variables (at six model levels) of the RUC40 forecast model are:

  • soil temperature
  • soil volumetric moisture content
  • Other surface-related prognostic variables are snow water equivalent moisture and snow temperature.
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Software and Tools

Software and Tools

For the CLPX project, the RUC40 data have been converted from GRIB to ASCII format. Three sample fortran programs are provided for reading CLPX MAPS-MORDS ASCII gridded data:

"read-asc40.F90" is a fortran program for reading the file "40kmlatlon.asc.txt," which is the original, full North American grid metafile for the RUC40.  This file is useful for reference on how the data were downsized, and for anyone needing the arrays of points surrounding the CLPX domain.  

read-latlon.F90” is a fortran program for reading the actual latitude and longitude points that fit the (12,12) area. This program is in a table-format with the following structure:

Table Headers: lrsa-lon, lrsa-lat, maps-lon, maps-lat, lonval, latvar

lrsa-lon : Values of 1,12 corresponding with longitude elements of the LRSA
lrsa-lat : Values of 1,12 corresponding with latitude elements of the LRSA
maps-lon : MAPS element values of 53,64 (of original 1,151) corresponding with longitude elements of the LRSA
maps-lat : MAPS element values of 54,65 (of original 1,113) corresponding with latitude elements of the LRSA
lonval : MAPS longitude values that correspond to each of the lrsa-lon (and maps-lon ) elements
latvar : MAPS latitude values that correspond to each of the lrsa-lat (and maps-lat ) elements

read-maps.F90” is a fortran program for reading the 3-D array data: (VAR,X,Y)=(42,12,12), described as the total number of variables (42) by the total columns (12) and rows (12). This program is able to read all the ASCII-formatted files, accounting for all gaps in the times of the files.

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Data Acquisition and Processing

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References and Related Publications

Contacts and Acknowledgments

Kristi Arsenault 
NASA Goddard Space Flight Center
Hydrological Sciences Branch (Code 974.1)
Greenbelt, MD 20771

Document Information

DOCUMENT CREATION DATE

18 February 2004

No technical references available for this data set.
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