THE COMMUNITY

**NOAH LAND-SURFACE MODEL (LSM)**

> **N**: **N**ational Centers for Environmental Prediction (NCEP)
>
> **O**: **O**regon State University (Dept of Atmospheric Sciences)
>
> **A**: **A**ir Force (both AFWA and AFRL - formerly AFGL, PL)
>
> **H**: **H**ydrologic Research Lab - NWS (now Office of Hydrologic Dev
> \-- OHD)

## User's Guide

### **Public Release Version 2.2**

#### [Last Updated 25 June 2001]{.underline}

This document is filename README_2.2.doc at

ftp://ftp.ncep.noaa.gov/pub/gcp/ldas/noahlsm/ver_2.2

# Author / Point of Contact: Kenneth.Mitchell@noaa.gov (NCEP/EMC), phone 301-763-8000

Collaborators: Mike Ek, Dag Lohmann, Fei Chen, George Gayno, Brian
Moore, Hua-Lu Pan, John Schaake, Victor Koren, Qingyun Duan, Ying Lin,
Pablo Grunmann, Dan Tarpley, Tilden Meyers, Curtis Marshall, Larry
Mahrt, Jinwon Kim, Paul Rusher

##### PROGRAM HISTORY LOG 

###### 01 Mar 99: Ver_1.0

08 Mar 99: Ver_1.1

27 Jul 99: Ver_2.0

23 Oct 00: Ver_2.1

25 Mar 01: Ver_2.2

##### TABLE OF CONTENTS

1.  Introduction

2.  Model Heritage

3.  Directory Contents and Quick-Start Guide to Execution

4.  Subroutine Summary and Calling Tree

5.  Control File Contents and Function

6.  Input Atmospheric Forcing File

7.  LSM Initial Conditions

8.  Specifying Model Parameters

9.  Execution Output Files

10. Issues to be Addressed in Future Releases

11. Technical References

12. Revisions History (pending)

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1.  **INTRODUCTION**

This User's Guide provides execution guidance for and physical
description of the public version of the community NOAH LSM. This
version of the NOAH LSM is a stand-alone, uncoupled, 1-D column version
used to execute single-site land-surface simulations. In this
traditional 1-D uncoupled mode, near-surface atmospheric forcing data is
required as input forcing (see Sec 6.0). This LSM simulates soil
moisture (both liquid and frozen), soil temperature, skin temperature,
snowpack depth, snowpack water equivalent (and hence snowpack density),
canopy water content, and the energy flux and water flux terms of the
surface energy balance and surface water balance. See Sec 11 for the
lineage of key technical references.

The public server directory in which this User's Guide resides also
contains the complete, self-contained NOAH LSM source code file, input
control file, input atmospheric forcing file, and example execution-time
LSM output files for a full one-year 1998 simulation. This simulation is
valid at the Champaign, Illinois surface-flux site (40.01 N, 88.37 W) of
NOAA/ARL investigator Tilden Meyers. See Sec 3 for a "Quick-Start" guide
to executing the NOAH LSM code in this directory to duplicate the cited
1998 simulation at this site. To execute NOAH LSM simulations at other
sites for other initial times, study Secs 5 through 8.

This Version 2.2 of the NOAH LSM is the most current public-release
version at the time of posting of this User's Guide (see date cited at
top). It is the version currently executing in the NCEP realtime Land
Data Assimilation System - LDAS (Mitchell et al., 2000). Related
ancestors of the NOAH LSM are used in a) the NCEP-OH submissions to
PILPS-2a, 2c, 2d, 2e, b) the operational coupled NCEP mesoscale Eta
model (Chen et al., 1997) and its companion Eta Data Assimilation System
(EDAS) (Rogers et al., 1996), and c) the coupled NCEP global
Medium-Range Forecast model (MRF) and its companion Global Data
Assimilation System (GDAS). The operational coupled Eta/EDAS suite is
the source of the multi-year Eta/EDAS GCIP archive at NCAR, going back
to April 01, 1995 (http://www.emc.ncep.noaa.gov
/mmb/gcp/access.perm.html).

[(Reminder: See Sec 3 for a "Quick-Start" guide to executing the NOAH
LSM.)]{.underline}

**2.0 MODEL HERITAGE**

Beginning in 1990, and accelerating after 1993 under sponsorship from
the GEWEX/GCIP Program Office of NOAA/OGP via collaboration with
numerous GCIP Principal Investigators (PIs), the Environmental Modeling
Center (EMC) of the National Centers for Environmental Prediction (NCEP)
joined with the NWS Office of Hydrology (OH) and the NESDIS Office of
Research and Applications (ORA) to pursue and refine a modern-era LSM
suitable for use in NCEP operational weather and climate prediction
models. Early in this effort, NCEP carried out an intercomparison of
four LSMs, including 1) a simple bucket model, 2) the OSU LSM (known as
the CAPS model in some PILPS studies), 3) the SSiB model, and 4) the
Simple Water Balance model (SWB) of OH. The results of this
intercomparison were reported in Chen et al. (1996, see references
therein for the four cited LSMs). As a result of the good performance of
the OSU LSM in this study and pre-existing hands-on experience with this
LSM by various EMC staff members, including Hua-Lu Pan and Ken Mitchell,
EMC chose the OSU LSM for further refinement and implementation in NCEP
regional and global coupled weather and climate models (and their
companion data assimilation systems). The results of the cited LSM
intercomparison and the initial EMC refinements to the OSU LSM were
reported in Chen et al. (1996).

At the beginning of the EMC LSM effort in 1990, the OSU LSM already had
a 10-year history. Its initial development was carried out by OSU in a
series of three papers (Mahrt and Ek, 1984; Mahrt and Pan, 1984; and Pan
and Mahrt, 1987). As the EMC LSM effort unfolded during the 1990\'s, a
series of NCEP extensions to the OSU LSM were a) added by EMC and its
GCIP collaborators and b) tested and validated in both uncoupled and
coupled studies (see review of these in Mitchell et al, 1999, 2000). At
NCEP, the LSM was first coupled to the operational NCEP mesoscale Eta
model on 31 Jan 96, with significant Eta LSM refinements subsequently
implemented on 18 Feb 97, 09 Feb 98, and 03 Jun 98. Recently in 1999,
with a) the new addition and testing of frozen soil and patchy snow
cover physics in the uncoupled LSM used for the NCEP-OH submission to
PILPS-2d (Valdai, Russia), and b) the growing number of external user
requests for access to and use of the NCEP LSM (e.g. GCIP PIs), we
decided the NCEP LSM had advanced to a stage appropriate for formal
public release (first in March 99).

Most recently in 2000, given a) the advent of the \"New Millenium\", b)
a strong desire by EMC to better recognize its LSM collaborators, and c)
a new NCEP goal to more strongly pursue and offer \"Community Models\",
EMC decided to coin the new name \"NOAH\" for the LSM that had emerged
at NCEP during the 1990s. With our choice of the \"NOAH\" acronym,
already defined at the top of this User\'s Guide, we in EMC strive to
explicitly acknowledge both the multi-group heritage and informal
\"community\" useage of this LSM, going back to the early 1980's. Since
its beginning then at Oregon State University, the evolution of the
present NOAH LSM herein has spanned significant ongoing development
efforts by the following groups:

NCEP/EMC: NCEP Environmental Modeling Center (EMC)

(Mitchell, Chen, Ek, Lin, Marshall, Janjic, Manikin, Lohmann, Grunmann,
Pan)

OSU: Oregon State University

(Mahrt, Pan, Ek, Kim, Rusher)

HL: NWS Hydrology Lab - formerly Office of Hydrology

(Schaake, Koren, Duan)

AFWA: Air Force Weather Agency - formerly AFGWC

(Moore, Mitchell, Gayno)

AFRL: Air Force Research Lab - formerly AFGL and PL

(Mitchell, Hahn, Chang, Yang)

In addition to "in-house" NOAH LSM development and validation by the
above organizations, the following external PIs (primarily GCIP), have
also performed valuable validations of the NOAH LSM and its immediate
NCEP 1990\'s predecessors:

E.H. Berbery and Rasmusson: U. Maryland (ARM/CART)

C. Marshall and Crawford U. Oklahoma (OU Mesonet)

I. Yucel and Shuttleworth: U. Arizona (ARM/CART, AZNET)

A.K. Betts: Atmospheric Res Inc (ISLSCP/FIFE)

C.D. Peters-Lidard, Wood Princeton U. (TOPLATS extensions)

L. Hinkelman and Ackerman: Penn State U. (ARM/CART)

T.H. Chen, W. Qu, Henderson-Sellers, et al. RMIT (PILPS-2a)

E. Wood, Lettenmaier, Liang, Lohmann: Princeton U. (PILPS-2c)

A. Schlosser, A.G. Slater, Robock, et al. U. Maryland (PILPS-2d)

R. Angevine NOAA/AL (Flatland Exp)

See Sec 11 for technical references on the above external validations.

Lastly, one crucial collaborator deserves special mention, namely the
[NESDIS Office of Research and Applications (Tarpley, Gutman,
Ramsay)]{.underline}, which has been the source of critical global
surface fields of a) vegetation greenness and its seasonality and b)
realtime snow cover, plus important GOES, satellite-based, hourly
surface validation fields of c) land surface skin temperature and d)
solar insolation, both on a 0.50-degree lat/lon CONUS grid.

3.  **DIRECTORY CONTENTS AND QUICK-START GUIDE TO EXECUTION**

The directory /pub/gcp/ldas/noahlsm/ver_2.2 on anonymous server
[ftp.ncep.noaa.gov](ftp://ftp.ncep.noaa.gov/) contains fifteen files as
follows: 1) this User's Guide (file README_2.2.doc), 2) a complete
self-contained NOAH-LSM source code file, 3-4) the latter file split for
the User\'s convenience into two mutually exclusive files representing
a) \"driver\" routines and b) \"physics\" routines, 5) an input control
file that defines model configuration and provides initial conditions,
6) an input atmospheric forcing file, 7) a doc file describing the
source and valid period/location of this forcing file, 8-10) an input
\"namelist\" file triad that allows input of non-default physical
parameters, 11-15) five execution-time output files, resulting from an
entire one-year 1998 simulation valid near the Champaign, Illinois
surface-flux site of Tilden Meyers of NOAA/ARL. This site is located at
the lat/lon coordinates of (40.01 N, 88.37 W). The15 filenames are:

**[Filename]{.underline}** **[Contents]{.underline}**

1 \-- README_2.2.doc This User\'s Guide

2 \-- NOAHLSM_SRC_VER_2.2.f Self-contained NOAH LSM source code

3 \-- DRIVER_SRC_VER_2.2.f \"DRIVER\" family of routines from file 2
above

4 \-- SFLXALL_SRC_VER_2.2.f \"PHYSICS\" family of routines from file 2
above

5 \-- controlfile_ver_2.2 Input control file

6 \-- obs98.dat.Z Input near-surface atmospheric forcing file

7 \-- CHAMP_IL.doc Observing site description

8 \-- namelist_filename.txt 1-line 50-char name of namelist-read input
file

9 \-- soil_veg_namelist_ver_2.2 namelist-read input file

10- namelist_chg_example alternate namelist-read input file

11- PRTSCREEN.TXT.Z Execution "print \* " screen output

12- DAILY.TXT.Z Execution Output File 1

13- HYDRO.TXT.Z Execution Output File 2

14- THERMO.TXT.Z Execution Output File 3

15- OBS_DATA.TXT.Z Execution Output Data File 4

All files are text files, except files README_2.2 and CHAMP_IL, which
are MS Word files. Download all 15 files to your workstation. Proceed
with a NOAH LSM execution test as described below.

Compile/load file NOAHLSM_SRC_VER_2.2.f . This file is the complete NOAH
LSM source code. It is Fortran 90 compatible and compiles free of
warning and error messages using "f90" on SGI Origin 2000 Workstations.
The Unix command "f90 NOAHLSM_SRC_VER_2.2.f" will create the executable
"a.out". Lets assume here that we rename "a.out" to "lsm.x".

To prepare to execute lsm.x, first uncompress the ".Z" files with the
Unix uncompress command.

The uncompress yields file "obs98.dat" and five upper-case "\*.TXT"
files. **These TXT files are lsm.x execution-time output files. Move
these "TXT\* files to a separate sister directory for later comparison
to the equivalent output files from your own local lsm.x execution.**

The four lower-case files given by filenames

controlfile_ver_2.2

obs98.dat

namelist_filename.txt

soil_veg_namelist_ver_2.2

are the four input files required during the execution of lsm.x. The
"controlfile" (see Sec 5) contains model configuration variables such as
number and thickness of soil layers, number and length of time steps,
initial date/time of the simulation, lat/lon location of the simulation
site, initial conditions for all state variables, and site-specific land
classifications (integer indexes for vegetation-type, soil-type, and
surface-slope category).

The file obs98.dat (see Sec 6) contains one year's worth (1998) of
30-min observed atmospheric forcing data and independent observed
verification data (e.g. surface energy fluxes and soil temperature)
valid at the Champaing, Illinois surface-flux site operated and
maintained by Tilden Meyers of NOAA/ARL. The site is located at the
lat/lon coordinates of (40.01 N, 88.37 W).

Now invoking "lsm.x \>PRTSCREEN.TXT" will launch and complete the 1998
one-year LSM simulation for the aforementioned Illinois site, producing
the same 5 "\*.TXT" output files that you obtained originally from the
NCEP server. Normal termination of the execution is marked by the
termination message "STOP: 0". Since all the "\*.TXT" files are ascii
files, one can and should confirm that the 5 output files from the local
simulation agree very closely with the originally downloaded output
files from NCEP.

The output file PRTSCREEN.TXT contains the output from "Print \*" write
statements in the

MAIN program. In this Version 2.2, these are the block of three "Print
\*" statements located within the time-step loop in the PROGRAM MAIN
source shortly after the return from CALL SFLX . These three Print \*
statements output the time step counter and the small surface energy
balance residual during each of the first 50 time steps and then every
50 time steps thereafter.

The other four output files are the execution output data files of
greater interest and their contents are described in Sec 9.

One important degree of freedom regarding these remaining four output
files must be cited here. The unit numbers for these output files are
43, 45, 47, and 49, which are explicitly assigned in PROGRAM MAIN (via
variable names NOUT1, NOUT3, NOUT5, and NDAILY). The sign of these
assigned unit numbers controls whether the output is ascii or binary.
The sign of all four unit numbers is determined by a signed parameter
(IBINOUT) read-in from the control file (see Sec 5). When the sign of
IBINOUT is positive (negative), the format of these four output files is
binary (ascii). When the output format is ascii (binary) then the
extension \*.TXT (\*.GRS, meaning GrADS-readable) appears on the
generated filename. The ascii choice (negative unit number sign) was
invoked in the default control run you obtain from the server.

**4.0 SUBROUTINE SUMMARY AND CALLING TREE**

Below, we split up the subroutine calling tree into that portion
associated with PROGRAM MAIN in the \"Driver family\" of subroutines
(file DRIVER_SRC_VER_2.2.f) and that portion associated with the
\"Physics family\" of subroutines (file SFLXALL_SRC_VER_2.2.f),
comprised of physics \"sub-driver\" routine SFLX and all subordinate
subroutines.

> **4.1 The Driver Routines**

Briefly the ten main steps of the MAIN program are:

1)  read in control file ( model configuration, site characteristics,
    and initial conditions)

2)  open output file unit numbers

3)  invoke time-step loop (including optional spin-up loop if indicated
    by control file)

4)  read atmospheric forcing data and change its sign and units as
    expected by SFLX

5)  interpolate monthly-mean surface greenness and albedo to julian day
    of time step

6)  assign downward solar and longwave radiation from input forcing

7)  calculate actual and saturated specific humidity from input
    atmospheric forcing

8)  assign wind speed from input forcing

9)  invoke LSM physics (CALL SFLX) to update state variables / sfc
    fluxes over one time step

10\) write simulation output data each time step to four output files

The section in driver PROGRAM MAIN associated with each of the above ten
steps is clearly delineated with comment line \"DRIVER STEP n\".

NOTE: The section of PROGRAM MAIN for Step 6 includes optional code
(presently commented out) for calculating the downward radiation from
the input air temperature and humidity if the input forcing file does
not provide it.

NOTE: The section of PROGRAM MAIN for Step 8 includes optional code
(presently commented out) for invoking a User-provided routine to
calculate the surface exchange coefficient for heat (Ch) in place of the
default scheme.

##### PROGRAM MAIN Calling Tree

-   READCNTL: read control file (including LSM initial conditions and
    site characteristics)

-   \-\-\-\-\-\-\-\-\-\-- Begin optional Multi-year Spin-Up Loop: if
    invoked by control file \-\-\-\-\-\-\-\-\-\-\-\--

-   \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--
    Begin: Time Step Loop
    \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

-   READBND : read atmospheric forcing data (and observed validation
    variables)

-   MONTH-D: interpolate monthly albedo and veg greenness to current
    julian day

> \-- JULDATE: determine julian day for current time

-   QDATAP: calculate actual and saturated specific humidity

> \-- E (function) calculate vapor pressure

-   DQSDT (function): slope of sat specific humidity wrt air temp
    (needed in PENMAN)

> \-- DQS (function) intermediate value for routine dqsdt

-   **SFLX**: call to family of physics routines (see Sec 4.2) \*\*\*\*
    key call \*\*\*\*

-   PRTDAILY: write daily total values to output file 1 (once a day
    only)

-   PRTHYDF: write LSM water related variables to output file 2 (every
    time step)

-   PRTHMF: write LSM energy related variables to output file 3 (every
    time step)

-   PRTBND: write out input atmospheric forcing to output file 4 (every
    time step)

-   \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-- End:
    Time Step Loop
    \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

-   \-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--End: Optional
    Multi-year Spin-Up
    Loop\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

-   STOP 0

> **4.2 The SFLX Family of Subroutines**

The SFLX family of subroutines contain the physics of the LSM and is
rather self-contained. Each user should become familiar with the
argument list of SFLX. This argument list is thoroughly documented at
the top of subroutine SFLX. Once becoming familiar with the argument
list, users could if they so choose create their own MAIN driver program
with reasonably little effort. Calling SFLX each time step updates and
returns all the LSM state variables and all the surface energy balance
and surface water balance terms. In using SFLX in a coupled atmospheric
model, the output arguments needed from SFLX are:

ETA - latent heat flux

H - sensible heat flux

T1 - skin temperature (from which to calculate upward longwave
radiation)

ALBEDO - (including snowpack effects) for calculating upward solar
radiation

##### SUBROUTINE SFLX Calling Tree

REDPRM \-- set land-surface parameters

\-- set soil-type dependent parameters

\-- set veg-type dependent parameters

\-- set other land-surface parameters

SFCDIF \-- calculate surface exchange coefficient for heat/moisture

CSNOW -- (function): compute thermal conductivity of snow

SNO_NEW -- update snow depth and snow density to account for new
snowfall

TDFCND -- compute soil thermal diffusivity

###### PENMAN -- compute potential evaporation

CANRES -- compute canopy resistance

**NOPAC** -- this path invoked if ZERO snowpack on ground and zero
snowfall (frozen precip)

\-- surface skin temperature updated via surface energy balance

**SMFLX** -- compute a) surface water fluxes and b) layer soil moisture
update

DEVAP- compute direct evaporation from top soil layer

TRANSP -- compute transpiration from vegetation canopy

SRT -- compute time-rate-of-change of soil moisture

WDFCND -- compute hydraulic conductivity and diffusivity

SSTEP -- forward time-step integration of soil moisture rate-of-change

ROSR12 -- tri-diagonal matrix solver

######  TDFCND -- compute soil thermal diffusivity

**SHFLX** -- compute a) ground heat flux and b) layer soil temperature
update

HRT -- compute time-rate-of-change of soil temperature

TDFCND -- compute soil thermal diffusivity (dependent on soil moist.)

TBND -- determine soil layer interface temperature

SNKSRC --(function) compute heat sink/source from soil ice phase change

TDFCND -- compute soil thermal diffusivity

FRH2O -- (function) calculate subzero unfrozen soil water

HSTEP -- forward time step integration of soil temperature
rate-of-change

ROSR12 -- tri-diagonal matrix solver

##### SNOPAC -- this path invoked if NONZERO snowpack on ground and/or NONZERO snowfall

-   surface skin temperature updated via surface energy balance

-   new patchy snow cover treatment in above

-   snowmelt computed if thermal and available energy conditions warrant

CSNOW -- see above

#####  SMFLX -- see above

######  DEVAP -- see above

TRANSP -- see above

SRT -- see above

WDFCND -- see above

SSTEP -- see above

ROSR12 -- see above

TDFCND -- see above

SNOWPACK -- update snow depth and snow density owing to snow compaction

**SHFLX --** see above

HRT -- see above

TDFCND -- see above

TBND -- see above

SNKSRC -- see above

TDFCND -- see above

FRH2O -- see above

HSTEP -- see above

######  ROSR12 -- see above

**NOTES on SFLX Calling Tree:**

1 -- Both the NOPAC and SNOPAC branches treat freezing processes within
soil

2 -- Calling sequences **under** NOPAC and SNOPAC via SMFLX and SHFLX
are very similar

3.  -- Snowpack physics in SNOPAC are treated mainly "in-line", before
    calls to SMFLX/SHFL

4.  -- SHFLX and subordinates do heat fluxes and soil temperature update

5.  -- SMFLX and subordinates do water fluxes and soil moisture update

> \-- SMFLX operates independently of the soil thermodynamics (SHFLX)
> and can stand
>
> alone, requiring only inputs of precipitation and potential
> evaporation
>
> \-- SHFLX cannot operate independently of soil hydraulics, unless
> thermal conductivity
>
> dependence on soil moisture dependence is removed (in routine TDFCND)

0.  **CONTROL FILE CONTENTS AND FUNCTION**

The filename of the control file is "controlfile_ver_2.2". The user may
want to have a printout of the control file handy (about one page) when
reviewing the comments below.

The control file is read-in early in the MAIN program and provides
inputs of the following types of information: a) valid location and
start date/time of simulation, b) model configuration,

c\) name of input forcing file, d) integer indexes for land-sfc classes
for the site, e ) initial values of all the model state variables.

**NOTE**: The control file does not provide model physical parameters,
except for the lower boundary condition on the soil temperature (which
should be assigned the value of the annual mean sfc air temperature for
the simulation location). Physical parameters are set in subroutine
REDPRM and many of these parameters are dependent in REDPRM on the
veg-type index and soil-type index read from the control file.

**The control file consists of 30 data lines that contain the
following:**

Line 01: [LAT]{.underline} - simulation site latitude (positive N from
equator, hundredths of a degree)

Line 02: [LON]{.underline} - simulation site longitude (positive W from
Greenwich, hundredths of a degree)

Note: The above serve only to document the valid site of the input
forcing data.

The physics do not use the above, since forcing data provides downward
solar radiation.

Above would be needed by a MAIN driver that had to calculate downward
solar radiation

Line 03: [IBINOUT]{.underline} - either positive interge \"1\", or
negative integer \"-1\".

Negative sign invokes ascii text output files with extension \*.TXT

Postive sign invokes binary output files with extension \*.GRS -denoting
GrADS readable

Line 04: [JDAY]{.underline} - Integer Julian Day (1-366) of start of
forcing data (start of simulation)

Line 05: [TIME]{.underline} - 4-digit \"hhmm\" integer time of day
(local) at start of forcing data,

hh is 2-digit hour (0-23) and mm is 2-digit minute (0-59).

Note: Except for use of JDAY to to temporal interpolation of monthly
greenness and albedo read-in later below, the above JDAY and TIME serve
only to document the valid start date/time of the input forcing data.
The physics do not use the above, since forcing data provides downward
solar radiation. Above would be needed by a MAIN driver that had to
calculate downward solar radiation

Line 06: [NCYCLES]{.underline} -- number of times the integration will
cycle through the input forcing data

(useful for multi-year spin-up runs, wherein input forcing file spans
one complete year)

Line 07: [SYDAYS]{.underline} - number of days in spin-up year (either
365 or 366)

(relevant only if NCYCLE is 2 or greater)

Line 08: [L2nd_data]{.underline}: logical variable: value of .true. or
.false.

**if TRUE**: then NCYCLES must be set to 2 or greater, and thus invokes
spin-up runs of

NCYCLE-1 spin-up years with first forcing file given below, followed by
1 final cycle

(not necessarily full year)executed from second forcing file below and
representing the

final production run period. Will write output only during final cycle,
unless two forcing

files have the same name, then will write output from each cycle

**if FALSE**: then only first named forcing file is used, still for the
number of cycles given

by NCYCLE, and will write output from every cycle

Note: The true option for L2nd_data is useful for multi-year
\"PILPS-type\" spin-up runs

For forcing files spanning only a partial year, L2nd_data should be
false and NCYCLE=1

Line 09: [NRUN]{.underline} is the total number of simulation time steps
[per cycle.]{.underline}

Line 10: [DT]{.underline} -- floating point length of time step (secs)
used in physical integration

Note: DT should NOT be larger than one hour (3600 secs)

Note: There must be one forcing data record in forcing file for each
time step

Line 11: [NSOIL]{.underline} - integer number of soil layers

Note: **NSOIL must be 2 or greater, NOT to exceed 20, strongly recommend
at least 4**

Line 12: [Z]{.underline} -- height in meters above ground of atmospheric
forcing data

Note: In observed forcing data, the height of the temperature/humidity
observation (e.g. 2 m) is often different from the height of the wind
observation (e.g. 10 m ). When that is the case, we recommend using the
height of the wind observation for Z.

Line 13: [SLDPTH]{.underline} - thickness values for the NSOIL soil
layers in meters (chosen by user), starting with the uppermost layer and
proceeding downward

Note: We recommend that each succeeding soil layer downward not exceed 3
times the thickness of the soil layer above it. For the common 4-layer
configuration, we recommend

Layer 1: 10 cm (.10 m)

Layer 2: 30 cm (.30 m)

> Layer 3: 60 cm (.60 m)
>
> Layer 4:100 cm (1.0 m)

Note: The physical equations in the LSM predict the soil
moisture/temperature state variables at the midpoint of each model soil
layer.

**NOTE:!! Sum total of all soil layer thicknesses should not exceed
about 2/3 of depth parameter ZBOT.** The lower boundary condition TBOT
of soil temperature is applied at the depth specified by parameter ZBOT,
whose current default value of -3.0 meters is set in routine REDPRM
(ZBOT follows negative sign convention for soil depth), but this default
can be changed via the optional NAMELIST I/O in REDPRM. (A more
appropriate value of the default value for ZBOT would probably by -8.0,
likely to be adopted in future versions.)

Line 14: - filename of the first input forcing file (up to 72
characters)

Line 15: - filename of the second input forcing file (up to 72
characters)

Note: see above discussion of logical variable \"L2nd_data

Note: the two forcing files may be the same name (used for both spin-up
and production years)

NOTE !! : User should contact NCEP Point of Contact given at top of Page
1 for recommended values for Lines 12-18

Line 16: [SOILTP]{.underline} - soil type integer index (range 1-9), see
definitions in routine REDPRM

Line 17: [VEGTYP]{.underline} veg type integer index (range 1-13), see
definitions in routine REDPRM

Line 18: [SLOPTYP]{.underline} sfc slope integer index (range 1-9), see
definitions in routine REDPRM

Note: SLOPTYP is a sfc slope category (flat, steep, mixed, etc) used in
the bottom drainage

Line 19: [ALBEDO]{.underline} -- 12 monthly values of surface albedo
fraction (snow-free) for simulation site

Note: LSM physics will internally add snow cover effects to ALBEDO

Line 20: [SHDFAC]{.underline} - 12 monthly values of green vegetation
fraction for simulation site

**NOTE !!** See contact point at top of this User\'s Guide to get
monthly vegetation greenness values for your simulation site of
interest.

NCEP now sets monthly SHDFAC using the global database and publication
of

Gutman, G. and A. Ignatov, 1998: The derivation of the green vegetation
fraction from

NOAA/AVHRR for use in numerical weather prediction models. International
Journal

of Remote Sensing, 19, 1533-1543.

This latter work provides a 5-year, monthly mean, global database of
green vegetation fraction at 0.144 degree resolution, obtained from
NDVI. The authors forcefully argue that the two AVHRR channels that are
used to derive NDVI do NOT provide sufficient degrees of freedom to
derive BOTH vegetation greenness and LAI independently. They instead
argue for embracing all the seasonality of vegetation in the greenness
fraction and holding the LAI at a fixed constant annual value in the
range of 1-5 (thus LAI becomes a tuning parameter). NCEP has obtained
reasonable behavior with LAI=3.

Line 21: [SNOALB]{.underline} -- maximum albedo expected over deep snow

###### Note: NCEP takes the above from the 1-degree, N. Hemisphere, digital database of 

Robinson, D.A., and G. Kukla, 1985: Maximum surface albedo of seasonally
snow-

Covered Lands in the Northern Hemisphere. J. Climate Appl. Meteor., 23,
1626-1634

(See Fig. 4 therein for depiction from digital database).

Line 22: [ICE]{.underline} -- Flag to invoke sea-ice physics (always set
to 0 for land-mass simulations)

Note: The integer flag "ICE" forces branch to sea-ice physics in LSM.

Be aware that this ICE flag has no bearing on soil ice physics in NCEP
LSM.

Line 23**:** [TBOT]{.underline} -- set to the climo annual mean sfc air
temperature (K) for the modeled site

.

Note: TBOT serves as the annually fixed, soil-temperature
bottom-boundary condition at a soil depth of ZBOT. ZBOT is currently set
at a default 3-meter depth (-3.0) in routine REDPRM. ZBOT is the assumed
nominal soil depth where the amplitude of the soil-temperature annual
cycle is near zero (e.g. about double the e-folding depth in the soil of
the annual cycle of surface air temperature).

**Initial conditions for all state variables follows**:

Line 24: [T1]{.underline} -- initial skin temperature (K). Can be set to
initial air temperature. Model physics

rapidly spins this up in first few 2-3 time steps.

Line 25: [STC]{.underline} (1-NSOIL): initial soil temperature (K), in
each soil layer

Line 26: [SMC]{.underline} (1-NSOIL): initial volumetric total soil
moisture (liquid and frozen) in each layer

(usually in the range .1-.43)

Note: Initial SMC should not exceed soil saturation (porosity), as set
in routine REDPRM for given soil class.

Line 27: [SH2O]{.underline} (1-NSOIL): initial volumetric liquid soil
moisture (unfrozen) in each layer

Note: initial SH2O must not exceed porosity, nor exceed initial SMC

NOTE: During conditions of no soil freezing, SH2O=SMC in each layer.

NOTE: Initializing soil ice (case of SH2O less than SMC) is very
difficult. Recommend starting the model run in the warm season and
letting the physics spin-up soil ice, or running multi-year spin-up
cycles.

Line 28: [CMC]{.underline} -- initial canopy water content (m). Set to
zero as physics rapidly spins this up.

Line 29: [SNOWH]{.underline} -- initial snow depth (m)

Line 30: [SNEQV]{.underline} -- initial water equivalent (m) of above
snowdepth. If not observed, dividing

SNOWH by 5 gives a nominal initial value.

**6.0 ATMOSPHERIC FORCING FILE**

As is typical with many off-line, uncoupled LSMs, the NCEP LSM requires
the following near-surface atmospheric forcing data, preferably at
30-minute time intervals (or interpolated to

30-minute time intervals [or smaller]{.underline} from say 1-6 hour
interval observations \-- Aside note: for observation intervals longer
than 1-hour, the incoming surface solar insolation needs to be
interpolated with a solar zenith angle weighting, in order to capture
the full amplitude of the diurnal solar insolation).

> Air temperature at height Z above ground
>
> Air humidity at height Z above ground
>
> Surface pressure at height Z above ground
>
> Wind speed at height Z above ground
>
> Surface downward longwave radiation
>
> Surface downward solar radiation
>
> Precipitation

For the example one-year LSM simulation provided with this User's Guide,
we were extremely fortunate to benefit from the collaboration of
GCIP-sponsored PI Tilden Meyers of NOAA/ARL, who operates a flux site
located just south of Champaign, IL (40.01 N lat, 88.37 W lon).

The site characteristics and observing instrumentation are described in
the MS Word document

CHAMP_IL, provided by courtesy of Tilden Meyers, and available in same
directory as this User's Guide.

The 1998 forcing file from the above flux site is available as filename
"obs98.dat" in the same directory as this User's Guide. This file
contains one record for each 30-minute observation time and the file
spans the entire calendar year of 1998 (hence 2 X 24 X 365 = 17520
records). Each 30-min record provides the following 33 observed
variables (including the 7 required LSM forcing variables, marked by
"\*\*"), listed in the order they appear in each record of the file:

> jday Julian Day
>
> time LST, half hour ending
>
> w_speed propeller anemometer (10 meters, Bondville ISIS)
>
> w_dir wind direction (10 meters, Bondville ISIS)

\*\* Ta air temperature (C), at 3 m

\*\* RH relative humidity at 3 m (list continued)

\*\* Pres surface pressure in mb

\*\* Rg incoming solar radiation (W/m2)

> Par_in incoming visible radiation (0.4‑0.7 um) in uE/m2/s
>
> Par_out outgoing or reflected visible light
>
> Rnet net radiation (W/m2)
>
> GHF soil or ground heat flux (W/m2)

\*\* rain total rain for half hour (inches)

> wet wetness sensor (in voltage with higher values indicating wetness)
>
> IRT surface or skin temp (C)
>
> 2_cm soil temp at 2 cm (C)
>
> 4_cm soil temp at 4 cm
>
> 8_cm soil temp at 8 cm
>
> 16_cm soil temp at 16 cm
>
> 32_cm soil temp at 32 cm
>
> 64_cm soil temp at 64 cm

\*\* u_bar average wind vector speed at 6-meters (m/s)

> u'w' kinematic shear stress (m2/s2)
>
> u'2 streamwise velocity variance (m2/s2)
>
> v'2 crosswind velocity variance (m2/s2)
>
> w'2 vertical velocity variance(m2/s2)
>
> H sensible heat flux (W/m2)
>
> LE latent energy flux (W/m2)
>
> CO2 CO2 flux (mg CO2/m2/s)

\*\* LW_in downwelling longwave from sky (W/m2)

> sm_5 soil volumetric water content at 5 cm zone (after November 19
> 1997)
>
> sm_20 soil volumetric water content at 20 cm zone (after November 19
> 1997)
>
> sm_60 soil volumetric water content at 60 cm zone (after November 19
> 1997)

In the LSM, program MAIN reads in all 33 of the above variables at each
time step via the call to subroutine READBND, which also fills in
occasional missing observations. Missing obs are very sparse and
virtually always involve missing values of the wind speed (u_bar at 6
m), for which the READBND software substitutes (w_speed at 10 m).
Finally, the last section of routine READBND performs unit conversions
on "rain", "Ta", and "Pres" to convert them to the units expected in the
call to SFLX .

In addition to the LSM-required atmospheric forcing variables in the
above list, the other variables in the list represent either a)
independent validation data or b) useful initial conditions for the LSM
state variables. LSM initial conditions are discussed in the next
section.

At each time step in the MAIN program, after the return from the physics
update in CALL SFLX, useful LSM validation data from the above
observation file is written out to validation output file OBS_DATA.TXT
via call to routine PRTBND (e.g. LE, H, GHF, RNET, IRT, and the layer by
layer soil moisture and temperature).

**7.0 LSM INITIAL CONDITIONS**

###### The LSM requires input values (read-in from control file in routine READCNTL, see Sec 5 for details on units) of the following state variable initial conditions :

###### 1 -- SMC: total volumetric soil moisture (liquid and frozen) in each soil layer

2 -- SH2O: liquid volumetric soil moisture in each soil layer

3 -- STC: temperature in each soil layer

4 -- T1: skin temperature

5 -- CMC: canopy water content

6-- SNOWH: snow depth

7 - SNEQV: water-equivalent snow depth

Typically, a number of these state variables are not observed at a given
validating observation site. The following initial variables were not
available in the site observation file (obs98.dat):

SNEQV, SNOWH, CMC, nor SMC (and SH2O) below 60 cm

Since January 1998 was mild (El'Nino) at the given site, we assumed a)
zero snow cover (SNOWH=0.0, SNEQV=0.0) and b) zero soil ice (SMC=SH2O),
plus we set CMC=0.

While we in general found the physical behavior of the observed data in
file obs98.dat to be very good, inspection of the **observed** soil
moisture at the 20 and 60 cm levels showed them to be virtually time
invariant over the entire year, despite substantial wetting and drying
periods. Hence their accuracy is very suspect.

####### It is typical for LSM simulations at a particular observation site to be hampered by non-observed

(e.g. snowdepth, frozen soil moisture, deep soil moisture ) or
ill-observed initial state variables (.e.g. soil moisture). Facing this
dilemma, the Project for Intercomparison of Land-Surface Process Schemes
(PILPS) has come to urge modelers to use a one-year spin-up protocol,
whereby the simulation for a desired period (1998 here) is preceded by a
spin-up year (say 1997 in this case) where the spin-up year forcing is
repeated several years to allow the LSM to essentially achieve
equilibrium.

Tilden Meyers provided us with the 1997 forcing data for his site, and
we proceeded to execute the PILPS-recommended spin-up protocol to
provide all initial soil states for the one-year 1998 production run
provided in this directory.

Specifically, in a prior run using the same model configuration as in
the control file given here and using L2nd_data = .false., NCYCLES= 10,
and the aforementioned 1997 forcing file we call \"obs97.dat\", we
executed a 10-year spin-up run over the 1997 annual cycle in order to
derive initial conditions of soil state and snow state (turned out zero
snowpack, because of warm fall and early winter in 1997) for the 1998
production run provided here in the directory with this User\'s Guide.
In practice, a full 10-years of spin-up is not needed. We generally
recommend 3-5 years of spin-up.

**8.0 SPECIFYING MODEL PARAMETERS**

The vast majority of the NOAH LSM land-surface parameters are set in
subroutine REDPRM. However, the assignment of some land-surface
parameters have not yet been "collected" into the REDPRM setting and
remain buried deep in the LSM code. We feel these exceptions are
primarily parameters of secondary or tertiary importance. A few
exceptions may be some parameters used in the snowpack physics, such as
the parameter that controls the amount of supercooled water allowed in
the soil over a range of sub-freezing temperatures. We are working to
identify such parameters and bring them into the REDPRM setting in a
future release.

In a broader sense, one should also consider the number (NSOIL) and
thickness (SLDPTH) of the soil layers (especially thickness of top soil
layer) specified in the control file to be adjustable parameters.

Before proceeding further in this section, the reader should have on
hand a copy of the subroutine REDPRM.

In REDPRM, we define the NAMELIST named \"/SOIL_VEG/\", which includes
**ALL** the parameters defined in REDPRM, including parameter arrays
whose elements depend on soil type, vegetation type, or slope type.
Moreover, this namelist includes three variables that respectively
define the number of classes (up to a maximum of 30) that we carry for
soil type, vegetation type, and slope type. With the powerful and robust
flexibility of the namelist construct, we can even make wholesale
changes to the soil and vegetation classification scheme used and the
soil and vegetation parameters associated with the change in
classification. Thus via the namelist read, we can change as little as
one single universal parameter, or multiple- element parameter arrays
associated with a classification, or the number of classification
categories themselves, or a combination of these, all without any
recompiling of source code.

One exercises the above flexibility through the input filename called
\"namelist_filename.txt\", which is read-in by routine REDPRM. This
1-line 50-char text file provides the name of the namelist file, which
the routine REDPRM then reads in as well. By this mechanism, one can
carry multiple namelist files (providing different parameter sets) in
the same execution directory. The contents of the 1-line file
\"namelist_filename.txt\" thus acts as a pointer to the namelist file
you wish to read-in during a given execution.

Every namelist file so pointed to must begin with the following syntax:

\$SOIL_VEG LPARAM = .FALSE.\$

or

\$SOIL_VEG LPARAM = .TRUE.\$

with the latter followed by at least one or more defined parameter
values.

We recall that the beginning of Sec 3 listed all the filenames in the
directory /ver_2.2with this User\'s Guide (README_2.2.doc). Inspecting
the contents of filename \"namelist_filename.txt\" therein, we find that
this file points to the filename \"\"soil_veg_namelist_ver_2.2\". On
inspection we find the contents of this file to be

\$SOIL_VEG LPARAM = .FALSE.\$ ,

hence ALL the default values of the parameters defined in REDPRM will be
retained unchanged.

If the contents of \"namelist_filename.txt\" instead pointed to filename
\"namelist_chg_example\", then we find on inspection that the contents
of the latter file are

\$SOIL_VEG LPARAM = .TRUE.\$

\$SOIL_VEG NROOT_DATA =
3,3,3,3,3,3,2,2,2,2,0,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 \$

\$SOIL_VEG Z0_DATA(7) = 0.15 \$

\$SOIL_VEG REFKDT_DATA = 1.0 \$

In the above example, our execution will utilize 1) new values for all
the elements of array NROOT, 2) a new value for the 7-th element of the
array of roughness lengths (this element corresponding to veg class #7,
or perennial grassland), and 3) a new value for the scalar surface
runoff parameter REFKDT.

Below, we will review ALL the parameters defined in REDPRM. All these
parameters are included in the NAMELIST /SOIL_VEG/, which is specified
in routine REDPRM as

NAMELIST /SOIL_VEG/ SLOPE_DATA, RSMTBL, RGLTBL, HSTBL, SNUPX,

& BB, DRYSMC, F11, MAXSMC, REFSMC, SATPSI, SATDK, SATDW,

& WLTSMC, QTZ, LPARAM, ZBOT_DATA, SALP_DATA, CFACTR_DATA,

& CMCMAX_DATA, SBETA_DATA, RSMAX_DATA, TOPT_DATA,

& REFDK_DATA, FRZK_DATA, BARE, DEFINED_VEG, DEFINED_SOIL,

& DEFINED_SLOPE, FXEXP_DATA, NROOT_DATA, REFKDT_DATA, Z0_DATA,

& CZIL_DATA, LAI_DATA, CSOIL_DATA

In the above list, there are five kinds of land-surface parameters,
reviewed in order below.

a)  single universal values

b)  values dependent on the soil class index (default categories are 1-
    9)

> c\) values dependent on the vegetation class index (default categories
> are 1-13)
>
> d\) values dependent on the surface slope index (default categories
> are 1-7)
>
> e\) parameters specifying the numbers of vegetation, soil, and slope
> classes

A)  **Universal values (14)** (current default value in this release
    listed)

**CZIL** = 0.20: Zilintikevich parameter (range 0.0 - 1.0), recommended
range 0.2 - 0.4

Note: CZIL is a tuneable parameter, which controls the ratio of the
roughness length for heat to the roughness length for momentum, and is
known as the Zilintikevich coefficient. This parameter effectively
allows tuning of the aerodynamic resistance of the atmospheric surface
layer. **Increasing CZIL increases aerodynamic resistance**. For a full
description and example impacts of this primary parameter, see the
article by

Chen, F, Z. Janjic, and K. Mitchell, 1997: Impact of the atmospheric
surface-layer

parameterizations in the new land-surface scheme of the NCEP mesoscale
Eta model.

Boundary-Layer Meteor., 85, 391-421

**REFDK**=2.0E-6: a parameter used with REFKDT below to compute sfc
runoff parameter KDT

**REFKDT** = 3.0: surface runoff parameter (nominal range of 0.5 -- 5.0)

NOTE: REFKDT is a tuneable parameter that significantly impacts surface
infiltration and hence the partitioning of total runoff into surface and
subsurface runoff. **Increasing** REFKDT **decreases** surface runoff.
See next publication:

Schaake, J., V. Koren, Q.-Y. Duan, K. Mitchell, and F. Chen, 1996:
Simple water

balance model for estimating runoff at different spatial and temporal
scales.

J. Geophysical Res., 101, No. D3.

NOTE: REFDK corresponds to the saturation hydraulic conductivity Ksat
for silty clay loam. If the latter parameter value is changed, then
REFDK must be equated to that new value.

**ZBOT** = -3.0 m: nominal depth of TBOT: lower boundary condition on
soil temp (range 3-20m)

(see discussion of ZBOT in discussion of TBOT in notes below Lines 13
and 23 of Control File in Section 5.0)

**FXEXP** = 2.0: bare soil evaporation exponent

**SBETA**= -2.0:used to compute veg canopy effect on ground heat flux as
a function of greenness

**CSOIL** = 1.26E+6: soil heat capacity (J/m\*\*3/K)

**SALP** = 2.6:shape parameter used in function to infer percent area
snow cover from snow depth

**CFACTOR** = 0.5: exponent used in function for canopy water
evaporation

**CMCMAX** =0.0005 (m): maximum canopy water capacity used in canopy
water evaporation

**FRZK**=0.15 a base reference value (for light clay soil type) of
parameter for the frozen-soil freeze factor representing the ice content
threshold above which frozen soil is impermeable

**RSMAX**=5000 (s/m) maximum stomatal resistance used in canopy
resistance routine CANRES

**TOPT**= 298(K) optimum air temperature for transpiration in canopy
resistance routine CANRES

**RTDIS**: array specifying vertical root distribution, i.e. the
fraction of total root mass present

in each soil layer

Note: RSMAX and TOPT are not yet functions of vegetation class.

Note: Presently, RTDIS is set universally (not dependent on vegetation
class) and assumes a

uniform root distribution throughout the specified number of root layers
for the given

vegetation class.

B\) Soil-class dependent parameter arrays (10)

Routine REDPRM applies 9 soil texture classes. These classes are defined
near the top of routine REDPRM. The parameters dependent on soil class
are:

SMCMAX: maximum volumetric soil moisture (porosity)

SMCREF: soil moisture threshold for onset of some transpiration stress

SMCWLT: soil moisture wilting point at which transpiration ceases

SMCDRY: top layer soil moisture threshold at which direct evaporation
from soil ceases

DKSAT: saturated soil hydraulic conductivity

PSISAT: saturated soil matric potential

B: the "b" parameter in hydraulic functions

DWSAT: saturated soil water diffusivity

QUARTZ: quartz content, used to compute soil thermal diffusivity

FRZFACT: a parameter used with FRZK to compute the value of parameter
FRZX

Note: if soil parameters such as SMCMAX and SMCREF or soil
classification scheme are

changed, then parameters FRZK and FRZFACT must be changed

**C) Vegetation-class dependent parameters arrays (7)**

Routine PRMVEG applies the 13 "SiB" vegetation classes. These classes
are described in the comment block at the top of routine PRMVEG. The
seven veg-class dependent parameters are:

**Z0:** (m) roughness length

**RCMIN** (s/m) : minimal stomatal resistance used in canopy resistance
of routine CANRES

**RGL**: radiation stress parameter used in F1 term in canopy resistance
of routine CANRES

**HS**: coefficient used in vapor pressure deficit term F2 in canopy
resistance of routine CANRES

**LAI**: presently set to universal value of 3.0 across all vegetation
classes

Note: seasonality of vegetation greenness carried by fraction of green
vegetation (SHDFAC)

**NROOT**: number of soil layers from top down reached by roots

**SNUP**: the water-equivalent snowdepth upper threshold at which

1)  100 percent snow cover is achieved for given veg class

2\) maximum snow albedo is achieved for given veg class

**D) Surface-slope dependent parameter arrays (1)**

Routine REDPRM embodies 7 categories of surface slope. These categories
are described in a comment block near the top of routine REDPRM. The
parameter dependent on slope class is:

**SLOPE** -- a coefficient between 0.1-1.0 that modifies the drainage
out the bottom of the last

soil layer. A larger surface slope implies larger drainage

**E) Classification dimension parameters (3)**

Vegetation Types (\"SiB-1\") after Dorman and Sellers (1989; JAM)

**DEFINED_VEG** = 13: the number of SiB-1vegetation class categories,
assigned as follows:

1: BROADLEAF-EVERGREEN TREES (TROPICAL FOREST)

2: BROADLEAF-DECIDUOUS TREES

3: BROADLEAF AND NEEDLELEAF TREES (MIXED FOREST)

4: NEEDLELEAF-EVERGREEN TREES

5: NEEDLELEAF-DECIDUOUS TREES (LARCH)

6: BROADLEAF TREES WITH GROUNDCOVER (SAVANNA)

7: GROUNDCOVER ONLY (PERENNIAL)

8: BROADLEAF SHRUBS WITH PERENNIAL GROUNDCOVER

9: BROADLEAF SHRUBS WITH BARE SOIL

10: DWARF TREES AND SHRUBS WITH GROUNDCOVER (TUNDRA)

11: BARE SOIL

12: CULTIVATIONS (THE SAME PARAMETERS AS FOR TYPE 7)

13: GLACIAL (THE SAME PARAMETERS AS FOR TYPE 11)

Soil Types after Zobler (1986), except for quartz after Cosby et al
(1984)

**DEFINED_SOIL** = 9: the number of Zobler soil class categories,
assigned as follows:

[TEXTURE]{.underline} [DESCRIPTION]{.underline} [QUARTZ
CONTENT]{.underline}

1 COARSE LOAMY SAND (0.82)

2 MEDIUM SILTY CLAY LOAM (0.10)

3 FINE LIGHT CLAY (0.25)

4 COARSE-MEDIUM SANDY LOAM (0.60)

5 COARSE-FINE SANDY CLAY (0.52)

6 MEDIUM-FINE CLAY LOAM (0.35)

7 COARSE-MED-FINE SANDY CLAY LOAM (0.60)

8 ORGANIC (0.40)

9 GLACIAL LAND ICE LOAMY SAND (0.82)

Slope Types after Zobler (1986)

**DEFINED_SLOPE** = 9: the number of Zobler defined slope categories,
assigned as follows:

SLOPE CLASS PERCENT SLOPE

1 0-8

2 8-30

3 \> 30

4 0-30

5 0-8 & \> 30

6 8-30 & \> 30

7 0-8, 8-30, \> 30

8 GLACIAL ICE

9 OCEAN/SEA

**9.0 EXECUTION OUTPUT FILES**

There are five execution-time output files:

PRTSCREEN.TXT: holds results from "Print \* " output via execution
command line syntax of "lsm.x \>PRTSCREEN.TXT" (i.e. capture of "screen"
print). Presently file contains the surface energy balance residual and
time-step value for first 50 time steps, then every 50 steps thereafter.

a)  DAILY.TXT: contains daily-defined output values once-per-day, from
    routine PRTDAILY,

such as daily total evaporation and precipitation.

b)  HYDRO.TXT: contains water related outputs at every \"time step\",
    from routine PRTHYDF,

such as actual and potential evaporation, soil moisture, snowdepth,
snowmelt, runoff.

c)  THERMO.TXT: contains energy related outputs at every \"time
    step\",from routine PRTHMF,

such as skin temperature, soil temperature, and all surface energy
fluxes

d\) OBS_DATA.TXT: output of observed input forcing/validation data, from
routine PRTBND,

such as incoming radiation, skin temperature, soil temperature, precip,
net radiation, latent,

sensible, and ground heat fluxes (i.e. this file echoes the input
observation file "obs98.dat",

but with some units conversion for compatibility with other model
outputs)

**10.0 ISSUES TO BE ADDRESSED IN FUTURE RELEASES**

**10.1 Technical**

\-- continue to seek and move tuneable parameter values not yet embraced
in the central

parameter-definition routine of REDPRM (e.g., the parameters BLIM and CK
in routine

FRH2O that control the amount of super-cooled soil water permitted when
sub-freezing).

\-- in documentation of model parameters in Sec 8, add a superscript
notation of say 1-5 to

identify parameters of a certain physical influence (Ed, canopy
resistance, surface runoff, soil

water or heat transfer, frozen soil, snow pack, aerodynamic resistance,
soil heat transfer).

Also, update the Sec 8 discussion to clarify the differences in number
and name of parameters

in the REDPRM subroutine argument list and the REDPRM NAMELIST list.

\-- given improvements in Ver 2.0, 2.1, and 2.2 in treatment and
compactness of logic for ground

heat flux under snowpack, seek to reunify the now separate routines of
NOPAC and SNOPAC

\-- before first call to SFLX, check that all initial input arguments
are within expected range (e.g.

that vegetation greenness fraction is not negative, which causes
extremely spurious behavior)

**10.2 Physical**

**a) sooner**

\-- despite Ver 2.2 increase in both a) root depth (from 1 m to 2 m) for
forest vegetation

classes and b) LAI parameter, somewhat low transpiration is still
realized in summer in mid-

latitudes over relatively dense vegetated areas with little soil
moisture stress. Canopy

resistance is apparently somewhat high. Revisit both the values of
certain canopy resistance

parameters such as RSMIN, as well as the formulation of the vapor
pressure deficit stress

\-- the aerodynamic resistance embodied in the surface exchange
coefficient CH (computed in

routine SFCDIF) appears to be a bit low (e.g. potential evaporation is
somewhat too high

compared to NOAA pan measurements), so try increase in default CZIL
value in REDPRM

from .2 to .3 (or .4, TBD by testing)

\-- test explicit schemes for CH, (recent descendants of Louis (1982)),
in place of the Paulson

scheme, to allow application of OSU/Mahrt sub-grid variability treatment
for the stable

surface layer, as a way to retard the decrease of Ch for increasing
moderate stable conditions.

\-- revisit the value of the lower bound on unfrozen water content in
freezing soil conditions via

the BLIM and CK parameters in routine FRH2O

\-- use explicit soil layer state temperature, STC(k), instead of TAVG,
to compute the soil ice,

thereby eliminating the need to calculate TSURF at top of soil column
under snowpack

\-- remove the equating of SMCDRY to SMCWLT in REDPRM on the first call
to REDPRM.

Rather let the separate DATA statements in REDPRM for SMCDRY and SMCWLT

determine whether they are specified to be equal or not

\-- in the initial calculation of parameters REFSMC and WLTSMC on the
first call to REDPRM,

replace the hardwired parameters of 3.0 and 0.5, respectively with
flexible parameter values

that can be altered via the NAMELIST I/O in REDPRM. Eliminate the DATA
statements for

REFSMC and WLTSMC in REDPRM

**b) later**

\-- allow non-uniform root density profile and rooting depths that
varying with vegetation class

\-- allow horizontally varying total depth of soil column (e.g. vary
thickness of deepest soil layer)

\-- allow vertically varying soil texture

\-- add a TOPMODEL-like approach to baseflow runoff

\-- allow simultaneous infiltration excess and saturation excess surface
runoff

(present version allows only for latter)

\-- reformulate canopy transpiration to include CO~2~ flux

\-- consider adding a veg-class \"tile approach\" in Driver surrounding
calls to SFLX

\-- consider adding a 2-layer canopy, i.e. for treatment of melting snow
under shading canopy

\-- consider adding a multi-layer snowpack model

**11.0 TECHNICAL REFERENCES**

**11.1 [Model Physics Lineage]{.underline} (OSU, AFGL/PL/AFRL,
AFGWC/AFWA, NCEP, OH/OHD)**

*Original soil hydrodynamic physics*:

Marht and Pan, 1984, Boundary Layer Meteorol, 29, 1-20.

*Stability-dependent Penman potential evaporation:*

Mahrt and Ek, 1984, J. Clim. Appl. Meteorol, 23, 222-234.

*Original soil thermodynamic physics*:

Pan and Mahrt, 1987, Boundary Layer Meteorol, 38, 185-202.

*Time-integration scheme advancements*:

Kalnay and Kanamitsu, 1988: Mon. Wea. Rev., 116, 1945-1958

*Canopy resistance advancements*:

Chen, F., K. Mitchell, et al, 1996: J. Geophys. Res., 101, No. D3,
7251-7268 (Secs. 3.1.1-3.1.2)

*Surface infiltration advancements*:

Schaake, J., et al., 1996: J. Geophys. Res., 101, 7461-7475.

*Surface-layer turbulence advancements*:

Chen, F., Z. Janjic, and K. Mitchell, 1997, Boundary-Layer Meteorol, 85,
391-421.

*Bare soil evaporation and vegetation greenness advancements*:

Betts, A., F. Chen, K. Mitchell, and Z. Janjic, 1997: Mon. Wea. Rev.,
125, 2896-2916.

Gutman, G., and A. Ignatov, 1998: Int. J. Remote Sensing, 19, 1533-1543.

*Snowpack and frozen ground physics advancements*:

Koren, V., et al., 1999: J. Geophys. Res., 101, No. D3, 7251-7268.

*For subsurface heat flux advancements*:

Peters-Lidard, C., M. Zion, and E. Wood, 1997: JGR, 102, No. D4,
4303-4324 (Sec. 2.1.2)

Peters-Lidard, C., 1998: J. Atmos. Sci., 55, 1209-1224. (Sec. 2.b)

Lunardini,V.,1981:Heat Transfer in Cold Climates. Van Nostrand
Reinhold,1-731 (Sec. 4.12.1.1)

Chang, S.,D.Hahn, C.-H.Yang, D.Norquist, and M.Ek, 1999: J. Appl.
Meteorology, 38, 405-422.

**11.1 [OSU Heritage: 1981-1998]{.underline} (OSU)**

[Uncoupled]{.underline}

Marht and Pan, 1984, Boundary Layer Meteorol, 29, 1-20.

Mahrt and Ek, 1984, J. Clim. Appl. Meteorol, 23, 222-234.

Pan and Mahrt, 1987, Boundary Layer Meteorol, 38, 185-202.

OSU 1-D PBL Model User's Guide, Version 1.0.0,1988.

OSU 1-D PBL Model User's Guide, Version 1.0.4, 1991.

Ek, M., and R. Cuenca, 1994, Boundary-Layer Meteorology, 70, 369-383.

**11.2 [Air Force Lineage: 1985-present]{.underline}** **(AFGWC,
AFGL/PL/AFRL)**

[Uncoupled]{.underline}

Mitchell, 1985 (AFGWC Tech Report)

Moore, B., K. Mitchell, et al., 1990: 20th AMS Conf. Ag and Forest
Meteorology, 7-11.

Chang, S.,D.Hahn, C.-H.Yang, D.Norquist, and M.Ek, 1999: J. Appl.
Meteorology, 38, 405-422.

[Coupled]{.underline}

Yang, C.-H., et al., 1989, AFGL Tech Report, GL-TR-89-0158, 262 pp.

**11.3 [NCEP Lineage: 1990-present]{.underline} (NMC, NCEP)**

[Uncoupled]{.underline}

Chen, F., K. Mitchell, et al., 1996: J. Geophys. Res., 101, No. D3,
7251-7268 (Secs. 3.1.1, 3.1.2)

Chen, F., and K. Mitchell, 1999: J. Meteorol. Soc. of Japan, 77,
167-182. (GSWP Special Issue)

Mitchell, K., et al., 2000: 15th AMS Conf. on Hydrology, 1-4.

[Coupled]{.underline}

Mitchell, K., 1994: 5th AMS Symposium on Global Change Studies, 192-198.

Chen, F., Z. Janjic, and K. Mitchell, 1997, Boundary-Layer Meteorol, 85,
391-421.

Betts, A., F. Chen, K. Mitchell, and Z. Janjic, 1997: Mon. Wea. Rev.,
125, 2896-2916.

Mitchell, K., et al., 1999: 14th AMS Conf. on Hydrology, 261-264.

Marshall, C., et al., 1999: 14th AMS Conf. on Hydrology, 265-268.

Mitchell, K., et al., 2000: 15th AMS Conf. on Hydrology, 180-183.

Ek, M., K. Mitchell, et al., 2001: 9th AMS Conf. on Mesoscale Processes,
Paper P1.10

**11.4 [OHD Heritage: 1995-present]{.underline} (OH, HRL, OHD)**

Schaake et al., 1996: J. Geophys. Res., 101, 7461-7475.

Koren, V., et al.,1999: J.Geophys.Res.,101,7251-7268

**11.5 [External Validators of NCEP NOAH Model]{.underline}**

[Uncoupled]{.underline}

> PILPS-2a (two papers)
>
> PILPS-2c (three papers)
>
> PILPS-2d (two papers)
>
> GSWP (several papers)

[Coupled]{.underline}

Berbery, Rasmusson, Mitchell, 1996, JGR, 101, 7305-7319.

Yarosh, Ropelewski, Mitchell, 1996, JGR, 101, 23289-23298.

Betts, Chen, Mitchell, Janjic, 1997, Mon. Wea. Rev., 125, 2896-2916.

Yucel, Shuttleworth, Washburne, Chen, 1998, Mon. Wea. Rev., 126,
1977-1991.

Berbery, Mitchell, Benjamin, Smirnova, Ritchie, et al., 1999, JGR, 104,
19329-19348.

Berbery and Rasmusson, 1999, Mon. Wea. Rev., 127, 2654-2673.

Yarosh, Ropelewski, Berbery, 1999, JGR, 104, 19349-19360.

Hinkelman, Ackerman, Marchand, 1999, JGR, 104, 19535-19549.

Berbery and Collini, 2000, Mon. Wea. Rev., 128, 1328-1346.

Fennessy and Shukla, 2000, J. Climate, 13, 2605-2627.

Angevine and Mitchell, 2001, Mon. Wea. Rev., in press.

Marshall, Crawford, Mitchell, Stensrud, 2001, J. Hydrometeor.,
Submitted.

Berbery, 2001, J. Climate, 14, 121-137.

**11.6 [NESDIS/ORA Land Surface Fields for NCEP Operational
Use]{.underline}**

Daily N.H. 23-km snow cover:

Ramsay, B., 1998, Hydrological Processes, 12, 1537-1546.

Annual cycle of monthly global vegetation greenness:

Gutman, G., and A. Ignatov, 1998, Int. J. Remote Sensing, 19, 1533-1543.

Annual cycle of monthly snow-free surface albedo:

Csiszar, I., and G. Gutman, 1999, J. Geophys. Res., 104, 6215-6228.