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revision 1.9 by molod, Mon Jul 18 20:45:27 2005 UTC revision 1.10 by molod, Tue Aug 2 15:43:59 2005 UTC
# Line 21  Moist Convective Processes: Line 21  Moist Convective Processes:
21  \label{sec:fizhi:mc}  \label{sec:fizhi:mc}
22    
23  Sub-grid scale cumulus convection is parameterized using the Relaxed Arakawa  Sub-grid scale cumulus convection is parameterized using the Relaxed Arakawa
24  Schubert (RAS) scheme of Moorthi and Suarez (1992), which is a linearized Arakawa Schubert  Schubert (RAS) scheme of \cite{moorsz:92}, which is a linearized Arakawa Schubert
25  type scheme.  RAS predicts the mass flux from an ensemble of clouds.  Each subensemble is identified  type scheme.  RAS predicts the mass flux from an ensemble of clouds.  Each subensemble is identified
26  by its entrainment rate and level of neutral bouyancy which are determined by the grid-scale properties.  by its entrainment rate and level of neutral bouyancy which are determined by the grid-scale properties.
27    
# Line 43  where we have used the hydrostatic equat Line 43  where we have used the hydrostatic equat
43  The entrainment parameter, $\lambda$, characterizes a particular subensemble based on its  The entrainment parameter, $\lambda$, characterizes a particular subensemble based on its
44  detrainment level, and is obtained by assuming that the level of detrainment is the level of neutral  detrainment level, and is obtained by assuming that the level of detrainment is the level of neutral
45  buoyancy, ie., the level at which the moist static energy of the cloud, $h_c$, is equal  buoyancy, ie., the level at which the moist static energy of the cloud, $h_c$, is equal
46  to the saturation moist static energy of the environment, $h^*$.  Following Moorthi and Suarez (1992),  to the saturation moist static energy of the environment, $h^*$.  Following \cite{moorsz:92},
47  $\lambda$ may be written as  $\lambda$ may be written as
48  \[  \[
49  \lambda = { {h_B - h^*_D} \over { {c_p \over g} {\int_{P_D}^{P_B}\theta(h^*_D-h)dP^{\kappa}}} } ,  \lambda = { {h_B - h^*_D} \over { {c_p \over g} {\int_{P_D}^{P_B}\theta(h^*_D-h)dP^{\kappa}}} } ,
# Line 101  $\alpha$ of the total adjustment. The pa Line 101  $\alpha$ of the total adjustment. The pa
101  towards equillibrium.    towards equillibrium.  
102    
103  In addition to the RAS cumulus convection scheme, the fizhi package employs a  In addition to the RAS cumulus convection scheme, the fizhi package employs a
104  Kessler-type scheme for the re-evaporation of falling rain (Sud and Molod, 1988), which  Kessler-type scheme for the re-evaporation of falling rain (\cite{sudm:88}), which
105  correspondingly adjusts the temperature assuming $h$ is conserved. RAS in its current  correspondingly adjusts the temperature assuming $h$ is conserved. RAS in its current
106  formulation assumes that all cloud water is deposited into the detrainment level as rain.  formulation assumes that all cloud water is deposited into the detrainment level as rain.
107  All of the rain is available for re-evaporation, which begins in the level below detrainment.  All of the rain is available for re-evaporation, which begins in the level below detrainment.
# Line 221  The solar constant value used in the pac Line 221  The solar constant value used in the pac
221  and a $CO_2$ mixing ratio of 330 ppm.  and a $CO_2$ mixing ratio of 330 ppm.
222  For the ozone mixing ratio, monthly mean zonally averaged  For the ozone mixing ratio, monthly mean zonally averaged
223  climatological values specified as a function  climatological values specified as a function
224  of latitude and height (Rosenfield, et al., 1987) are linearly interpolated to the current time.  of latitude and height (\cite{rosen:87}) are linearly interpolated to the current time.
225    
226    
227  \paragraph{Shortwave Radiation}  \paragraph{Shortwave Radiation}
# Line 231  heating due to the absoption by water va Line 231  heating due to the absoption by water va
231  clouds, and aerosols and due to the  clouds, and aerosols and due to the
232  scattering by clouds, aerosols, and gases.  scattering by clouds, aerosols, and gases.
233  The shortwave radiative processes are described by  The shortwave radiative processes are described by
234  Chou (1990,1992). This shortwave package  \cite{chou:90,chou:92}. This shortwave package
235  uses the Delta-Eddington approximation to compute the  uses the Delta-Eddington approximation to compute the
236  bulk scattering properties of a single layer following King and Harshvardhan (JAS, 1986).  bulk scattering properties of a single layer following King and Harshvardhan (JAS, 1986).
237  The transmittance and reflectance of diffuse radiation  The transmittance and reflectance of diffuse radiation
238  follow the procedures of Sagan and Pollock (JGR, 1967) and Lacis and Hansen (JAS, 1974).  follow the procedures of Sagan and Pollock (JGR, 1967) and \cite{lhans:74}.
239    
240  Highly accurate heating rate calculations are obtained through the use  Highly accurate heating rate calculations are obtained through the use
241  of an optimal grouping strategy of spectral bands.  By grouping the UV and visible regions  of an optimal grouping strategy of spectral bands.  By grouping the UV and visible regions
# Line 321  low/middle/high classification, and appr Line 321  low/middle/high classification, and appr
321    
322  \paragraph{Longwave Radiation}  \paragraph{Longwave Radiation}
323    
324  The longwave radiation package used in the fizhi package is thoroughly described by Chou and Suarez (1994).  The longwave radiation package used in the fizhi package is thoroughly described by \cite{chsz:94}.
325  As described in that document, IR fluxes are computed due to absorption by water vapor, carbon  As described in that document, IR fluxes are computed due to absorption by water vapor, carbon
326  dioxide, and ozone.  The spectral bands together with their absorbers and parameterization methods,  dioxide, and ozone.  The spectral bands together with their absorbers and parameterization methods,
327  configured for the fizhi package, are shown in Table \ref{tab:fizhi:longwave}.  configured for the fizhi package, are shown in Table \ref{tab:fizhi:longwave}.
# Line 357  Band & Spectral Range (cm$^{-1}$) & Abso Line 357  Band & Spectral Range (cm$^{-1}$) & Abso
357  \end{tabular}  \end{tabular}
358  \end{center}  \end{center}
359  \vspace{0.1in}  \vspace{0.1in}
360  \caption{IR Spectral Bands, Absorbers, and Parameterization Method (from Chou and Suarez, 1994)}  \caption{IR Spectral Bands, Absorbers, and Parameterization Method (from \cite{chzs:94})}
361  \label{tab:fizhi:longwave}  \label{tab:fizhi:longwave}
362  \end{table}  \end{table}
363    
# Line 459  Within the atmosphere, the time evolutio Line 459  Within the atmosphere, the time evolutio
459  of second turbulent moments is explicitly modeled by representing the third moments in terms of  of second turbulent moments is explicitly modeled by representing the third moments in terms of
460  the first and second moments.  This approach is known as a second-order closure modeling.  the first and second moments.  This approach is known as a second-order closure modeling.
461  To simplify and streamline the computation of the second moments, the level 2.5 assumption  To simplify and streamline the computation of the second moments, the level 2.5 assumption
462  of Mellor and Yamada (1974) and Yamada (1977) is employed, in which only the turbulent  of Mellor and Yamada (1974) and \cite{yam:77} is employed, in which only the turbulent
463  kinetic energy (TKE),  kinetic energy (TKE),
464    
465  \[ {\h}{q^2}={\overline{{u^{\prime}}^2}}+{\overline{{v^{\prime}}^2}}+{\overline{{w^{\prime}}^2}}, \]  \[ {\h}{q^2}={\overline{{u^{\prime}}^2}}+{\overline{{v^{\prime}}^2}}+{\overline{{w^{\prime}}^2}}, \]
# Line 493  of TKE. Line 493  of TKE.
493    
494  In the level 2.5 approach, the vertical fluxes of the scalars $\theta_v$ and $q$ and the  In the level 2.5 approach, the vertical fluxes of the scalars $\theta_v$ and $q$ and the
495  wind components $u$ and $v$ are expressed in terms of the diffusion coefficients $K_h$ and  wind components $u$ and $v$ are expressed in terms of the diffusion coefficients $K_h$ and
496  $K_m$, respectively.  In the statisically realizable level 2.5 turbulence scheme of Helfand  $K_m$, respectively.  In the statisically realizable level 2.5 turbulence scheme of
497  and Labraga (1988), these diffusion coefficients are expressed as  \cite{helflab:88}, these diffusion coefficients are expressed as
498    
499  \[  \[
500  K_h  K_h
# Line 569  where $\psi_h$ is the surface layer non- Line 569  where $\psi_h$ is the surface layer non-
569  \]  \]
570  Here $\phi_h$ is the similarity function of $\zeta$, which expresses the stability dependance of  Here $\phi_h$ is the similarity function of $\zeta$, which expresses the stability dependance of
571  the temperature and moisture gradients, and is specified differently for stable and unstable  the temperature and moisture gradients, and is specified differently for stable and unstable
572  layers according to Helfand and Schubert, 1995.  layers according to \cite{helfschu:95}.
573    
574  $\psi_g$ is the non-dimensional temperature or moisture gradient in the viscous sublayer,  $\psi_g$ is the non-dimensional temperature or moisture gradient in the viscous sublayer,
575  which is the mosstly laminar region between the surface and the tops of the roughness  which is the mosstly laminar region between the surface and the tops of the roughness
576  elements, in which temperature and moisture gradients can be quite large.  elements, in which temperature and moisture gradients can be quite large.
577  Based on Yaglom and Kader (1974):  Based on \cite{yagkad:74}:
578  \[  \[
579  \psi_{g} = { 0.55 (Pr^{2/3} - 0.2) \over \nu^{1/2} }  \psi_{g} = { 0.55 (Pr^{2/3} - 0.2) \over \nu^{1/2} }
580  (h_{0}u_{*} - h_{0_{ref}}u_{*_{ref}})^{1/2}  (h_{0}u_{*} - h_{0_{ref}}u_{*_{ref}})^{1/2}
# Line 588  The surface roughness length over oceans Line 588  The surface roughness length over oceans
588  {z_0} = c_1u^3_* + c_2u^2_* + c_3u_* + c_4 + {c_5 \over {u_*}}  {z_0} = c_1u^3_* + c_2u^2_* + c_3u_* + c_4 + {c_5 \over {u_*}}
589  \]  \]
590  where the constants are chosen to interpolate between the reciprocal relation of  where the constants are chosen to interpolate between the reciprocal relation of
591  Kondo(1975) for weak winds, and the piecewise linear relation of Large and Pond(1981)  \cite{kondo:75} for weak winds, and the piecewise linear relation of \cite{larpond:81}
592  for moderate to large winds.  Roughness lengths over land are specified  for moderate to large winds.  Roughness lengths over land are specified
593  from the climatology of Dorman and Sellers (1989).  from the climatology of \cite{dorsell:89}.
594    
595  For an unstable surface layer, the stability functions, chosen to interpolate between the  For an unstable surface layer, the stability functions, chosen to interpolate between the
596  condition of small values of $\beta$ and the convective limit, are the KEYPS function  condition of small values of $\beta$ and the convective limit, are the KEYPS function
597  (Panofsky, 1973) for momentum, and its generalization for heat and moisture:    (\cite{pano:73}) for momentum, and its generalization for heat and moisture:  
598  \[  \[
599  {\phi_m}^4 - 18 \zeta {\phi_m}^3 = 1 \hspace{1cm} ; \hspace{1cm}  {\phi_m}^4 - 18 \zeta {\phi_m}^3 = 1 \hspace{1cm} ; \hspace{1cm}
600  {\phi_h}^2 - 18 \zeta {\phi_h}^3 = 1 \hspace{1cm} .  {\phi_h}^2 - 18 \zeta {\phi_h}^3 = 1 \hspace{1cm} .
# Line 603  The function for heat and moisture assur Line 603  The function for heat and moisture assur
603  speed approaches zero.  speed approaches zero.
604    
605  For a stable surface layer, the stability functions are the observationally  For a stable surface layer, the stability functions are the observationally
606  based functions of Clarke (1970),  slightly modified for  based functions of \cite{clarke:70},  slightly modified for
607  the momemtum flux:    the momemtum flux:  
608  \[  \[
609  {\phi_m} = { { 1 + 5 {{\zeta}_1} } \over { 1 + 0.00794 {{\zeta}_1}  {\phi_m} = { { 1 + 5 {{\zeta}_1} } \over { 1 + 0.00794 {{\zeta}_1}
# Line 661  be $3 \hspace{.1cm} m$ where sea ice is Line 661  be $3 \hspace{.1cm} m$ where sea ice is
661  surface temperature of the ice.  surface temperature of the ice.
662    
663  $C_g$ is the total heat capacity of the ground, obtained by solving a heat diffusion equation  $C_g$ is the total heat capacity of the ground, obtained by solving a heat diffusion equation
664  for the penetration of the diurnal cycle into the ground (Blackadar, 1977), and is given by:  for the penetration of the diurnal cycle into the ground (\cite{black:77}), and is given by:
665  \[  \[
666  C_g = \sqrt{ {\lambda C_s \over 2\omega} } = \sqrt{(0.386 + 0.536W + 0.15W^2)2\times10^{-3}  C_g = \sqrt{ {\lambda C_s \over 2\omega} } = \sqrt{(0.386 + 0.536W + 0.15W^2)2\times10^{-3}
667  {86400 \over 2 \pi} } \, \, .  {86400 \over 2 \pi} } \, \, .
# Line 676  is a function of the ground wetness, $W$ Line 676  is a function of the ground wetness, $W$
676  Land Surface Processes:  Land Surface Processes:
677    
678  \paragraph{Surface Type}  \paragraph{Surface Type}
679  The fizhi package surface Types are designated using the Koster-Suarez (1992) mosaic  The fizhi package surface Types are designated using the Koster-Suarez (\cite{ks:91,ks:92})
680  philosophy which allows multiple ``tiles'', or multiple surface types, in any one  Land Surface Model (LSM) mosaic philosophy which allows multiple ``tiles'', or multiple surface
681  grid cell. The Koster-Suarez Land Surface Model (LSM) surface type classifications  types, in any one grid cell. The Koster-Suarez LSM surface type classifications
682  are shown in Table \ref{tab:fizhi:surftype}. The surface types and the percent of the grid  are shown in Table \ref{tab:fizhi:surftype}. The surface types and the percent of the grid
683  cell occupied by any surface type were derived from the surface classification of  cell occupied by any surface type were derived from the surface classification of
684  Defries and Townshend (1994), and information about the location of permanent  \cite{deftow:94}, and information about the location of permanent
685  ice was obtained from the classifications of Dorman and Sellers (1989).  ice was obtained from the classifications of \cite{dorsell:89}.
686  The surface type for the \txt GCM grid is shown in Figure \ref{fig:fizhi:surftype}.  The surface type for the \txt GCM grid is shown in Figure \ref{fig:fizhi:surftype}.
687  The determination of the land or sea category of surface type was made from NCAR's  The determination of the land or sea category of surface type was made from NCAR's
688  10 minute by 10 minute Navy topography  10 minute by 10 minute Navy topography
# Line 736  and surface albedo.} Line 736  and surface albedo.}
736    
737  \paragraph{Surface Roughness}  \paragraph{Surface Roughness}
738  The surface roughness length over oceans is computed iteratively with the wind  The surface roughness length over oceans is computed iteratively with the wind
739  stress by the surface layer parameterization (Helfand and Schubert, 1991).  stress by the surface layer parameterization (\cite{helfschu:95}).
740  It employs an interpolation between the functions of Large and Pond (1981)  It employs an interpolation between the functions of \cite{larpond:81}
741  for high winds and of Kondo (1975) for weak winds.  for high winds and of \cite{kondo:75} for weak winds.
742    
743    
744  \paragraph{Albedo}  \paragraph{Albedo}
745  The surface albedo computation, described in Koster and Suarez (1991),  The surface albedo computation, described in \cite{ks:91},
746  employs the ``two stream'' approximation used in Sellers' (1987) Simple Biosphere (SiB)  employs the ``two stream'' approximation used in Sellers' (1987) Simple Biosphere (SiB)
747  Model which distinguishes between the direct and diffuse albedos in the visible  Model which distinguishes between the direct and diffuse albedos in the visible
748  and in the near infra-red spectral ranges. The albedos are functions of the observed  and in the near infra-red spectral ranges. The albedos are functions of the observed
# Line 753  to the height of the vegetation elements Line 753  to the height of the vegetation elements
753    
754  Gravity Wave Drag:  Gravity Wave Drag:
755    
756  The fizhi package employs the gravity wave drag scheme of Zhou et al. (1996).  The fizhi package employs the gravity wave drag scheme of \cite{zhouetal:96}).
757  This scheme is a modified version of Vernekar et al. (1992),  This scheme is a modified version of Vernekar et al. (1992),
758  which was based on Alpert et al. (1988) and Helfand et al. (1987).    which was based on Alpert et al. (1988) and Helfand et al. (1987).  
759  In this version, the gravity wave stress at the surface is  In this version, the gravity wave stress at the surface is
# Line 770  A modification introduced by Zhou et al. Line 770  A modification introduced by Zhou et al.
770  escape through the top of the model, although this effect is small for the current 70-level model.    escape through the top of the model, although this effect is small for the current 70-level model.  
771  The subgrid scale standard deviation is defined by $h$, and is not allowed to exceed 400 m.  The subgrid scale standard deviation is defined by $h$, and is not allowed to exceed 400 m.
772    
773  The effects of using this scheme within a GCM are shown in Takacs and Suarez (1996).  The effects of using this scheme within a GCM are shown in \cite{taksz:96}.
774  Experiments using the gravity wave drag parameterization yielded significant and  Experiments using the gravity wave drag parameterization yielded significant and
775  beneficial impacts on both the time-mean flow and the transient statistics of the  beneficial impacts on both the time-mean flow and the transient statistics of the
776  a GCM climatology, and have eliminated most of the worst dynamically driven biases  a GCM climatology, and have eliminated most of the worst dynamically driven biases
# Line 827  current years and frequencies available. Line 827  current years and frequencies available.
827  Surface geopotential heights are provided from an averaging of the Navy 10 minute  Surface geopotential heights are provided from an averaging of the Navy 10 minute
828  by 10 minute dataset supplied by the National Center for Atmospheric Research (NCAR) to the  by 10 minute dataset supplied by the National Center for Atmospheric Research (NCAR) to the
829  model's grid resolution. The original topography is first rotated to the proper grid-orientation  model's grid resolution. The original topography is first rotated to the proper grid-orientation
830  which is being run, and then    which is being run, and then  averages the data to the model resolution.  
 averages the data to the model resolution.    
 The averaged topography is then passed through a Lanczos (1966) filter in both dimensions  
 which removes the smallest  
 scales while inhibiting Gibbs phenomena.    
   
 In one dimension, we may define a cyclic function in $x$ as:  
 \begin{equation}  
 f(x) = {a_0 \over 2} + \sum_{k=1}^N \left( a_k \cos(kx) + b_k \sin(kx) \right)  
 \label{eq:fizhi:filt}  
 \end{equation}  
 where $N = { {\rm IM} \over 2 }$ and ${\rm IM}$ is the total number of points in the $x$ direction.  
 Defining $\Delta x = { 2 \pi \over {\rm IM}}$, we may define the average of $f(x)$ over a  
 $2 \Delta x$ region as:  
   
 \begin{equation}  
 \overline {f(x)} = {1 \over {2 \Delta x}} \int_{x-\Delta x}^{x+\Delta x} f(x^{\prime}) dx^{\prime}  
 \label{eq:fizhi:fave1}  
 \end{equation}  
   
 Using equation (\ref{eq:fizhi:filt}) in equation (\ref{eq:fizhi:fave1}) and integrating, we may write:  
   
 \begin{equation}  
 \overline {f(x)} = {a_0 \over 2} + {1 \over {2 \Delta x}}  
 \sum_{k=1}^N \left [  
 \left. a_k { \sin(kx^{\prime}) \over k } \right /_{x-\Delta x}^{x+\Delta x} -  
 \left. b_k { \cos(kx^{\prime}) \over k } \right /_{x-\Delta x}^{x+\Delta x}  
 \right]  
 \end{equation}  
 or  
   
 \begin{equation}  
 \overline {f(x)} = {a_0 \over 2} + \sum_{k=1}^N {\sin(k \Delta x) \over {k \Delta x}}  
 \left( a_k \cos(kx) + b_k \sin(kx) \right)  
 \label{eq:fizhi:fave2}  
 \end{equation}  
   
 Thus, the Fourier wave amplitudes are simply modified by the Lanczos filter response  
 function ${\sin(k\Delta x) \over {k \Delta x}}$.  This may be compared with an $mth$-order  
 Shapiro (1970) filter response function, defined as $1-\sin^m({k \Delta x \over 2})$,  
 shown in Figure \ref{fig:fizhi:lanczos}.  
 It should be noted that negative values in the topography resulting from  
 the filtering procedure are {\em not} filled.  
   
 \begin{figure*}[htbp]  
   \centerline{  \epsfysize=7.0in  \epsfbox{part6/lanczos.ps}}  
   \caption{ \label{fig:fizhi:lanczos} Comparison between the Lanczos and $mth$-order Shapiro filter  
   response functions for $m$ = 2, 4, and 8. }  
 \end{figure*}  
831    
832  The standard deviation of the subgrid-scale topography  The standard deviation of the subgrid-scale topography is computed by interpolating the 10 minute
833  is computed from a modified version of the the Navy 10 minute by 10 minute dataset.  data to the model's resolution and re-interpolating back to the 10 minute by 10 minute resolution.
 The 10 minute by 10 minute topography is passed through a wavelet  
 filter in both dimensions which removes the scale smaller than 20 minutes.  
 The topography is then averaged to $1^\circ x 1^\circ$ grid resolution, and then  
 re-interpolated back to the 10 minute by 10 minute resolution.  
834  The sub-grid scale variance is constructed based on this smoothed dataset.  The sub-grid scale variance is constructed based on this smoothed dataset.
835    
836    
# Line 1588  $h_{0} = 30z_{0}$ with a maximum value o Line 1536  $h_{0} = 30z_{0}$ with a maximum value o
1536  \noindent  \noindent
1537  $\phi_h$ is the similarity function of $\zeta$, which expresses the stability dependance of  $\phi_h$ is the similarity function of $\zeta$, which expresses the stability dependance of
1538  the temperature and moisture gradients, specified differently for stable and unstable  the temperature and moisture gradients, specified differently for stable and unstable
1539  layers according to Helfand and Schubert, 1993. k is the Von Karman constant, $\zeta$ is the  layers according to \cite{helfschu:95}. k is the Von Karman constant, $\zeta$ is the
1540  non-dimensional stability parameter, Pr is the Prandtl number for air, $\nu$ is the molecular  non-dimensional stability parameter, Pr is the Prandtl number for air, $\nu$ is the molecular
1541  viscosity, $z_{0}$ is the surface roughness length, $u_*$ is the surface stress velocity  viscosity, $z_{0}$ is the surface roughness length, $u_*$ is the surface stress velocity
1542  (see diagnostic number 67), and the subscript ref refers to a reference value.  (see diagnostic number 67), and the subscript ref refers to a reference value.
# Line 1610  where $\psi_m$ is the surface layer non- Line 1558  where $\psi_m$ is the surface layer non-
1558  \noindent  \noindent
1559  $\phi_m$ is the similarity function of $\zeta$, which expresses the stability dependance of  $\phi_m$ is the similarity function of $\zeta$, which expresses the stability dependance of
1560  the temperature and moisture gradients, specified differently for stable and unstable layers  the temperature and moisture gradients, specified differently for stable and unstable layers
1561  according to Helfand and Schubert, 1993. k is the Von Karman constant, $\zeta$ is the  according to \cite{helfschu:95}. k is the Von Karman constant, $\zeta$ is the
1562  non-dimensional stability parameter, $u_*$ is the surface stress velocity  non-dimensional stability parameter, $u_*$ is the surface stress velocity
1563  (see diagnostic number 67), and $W_s$ is the magnitude of the surface layer wind.  (see diagnostic number 67), and $W_s$ is the magnitude of the surface layer wind.
1564  \\  \\
# Line 1622  non-dimensional stability parameter, $u_ Line 1570  non-dimensional stability parameter, $u_
1570  In the level 2.5 version of the Mellor-Yamada (1974) hierarchy, the turbulent heat or  In the level 2.5 version of the Mellor-Yamada (1974) hierarchy, the turbulent heat or
1571  moisture flux for the atmosphere above the surface layer can be expressed as a turbulent  moisture flux for the atmosphere above the surface layer can be expressed as a turbulent
1572  diffusion coefficient $K_h$ times the negative of the gradient of potential temperature  diffusion coefficient $K_h$ times the negative of the gradient of potential temperature
1573  or moisture. In the Helfand and Labraga (1988) adaptation of this closure, $K_h$  or moisture. In the \cite{helflab:88} adaptation of this closure, $K_h$
1574  takes the form:  takes the form:
1575  \[  \[
1576  {\bf ET} = K_h = -{( {\overline{w^{\prime}\theta_v^{\prime}}}) \over {\pp{\theta_v}{z}} }  {\bf ET} = K_h = -{( {\overline{w^{\prime}\theta_v^{\prime}}}) \over {\pp{\theta_v}{z}} }
# Line 1641  are functions of the Richardson number. Line 1589  are functions of the Richardson number.
1589    
1590  \noindent  \noindent
1591  For the detailed equations and derivations of the modified level 2.5 closure scheme,  For the detailed equations and derivations of the modified level 2.5 closure scheme,
1592  see Helfand and Labraga, 1988.  see \cite{helflab:88}.
1593    
1594  \noindent  \noindent
1595  In the surface layer, ${\bf {ET}}$ is the exchange coefficient for heat and moisture,  In the surface layer, ${\bf {ET}}$ is the exchange coefficient for heat and moisture,
# Line 1663  and $W_s$ is the magnitude of the surfac Line 1611  and $W_s$ is the magnitude of the surfac
1611  In the level 2.5 version of the Mellor-Yamada (1974) hierarchy, the turbulent heat  In the level 2.5 version of the Mellor-Yamada (1974) hierarchy, the turbulent heat
1612  momentum flux for the atmosphere above the surface layer can be expressed as a turbulent  momentum flux for the atmosphere above the surface layer can be expressed as a turbulent
1613  diffusion coefficient $K_m$ times the negative of the gradient of the u-wind.  diffusion coefficient $K_m$ times the negative of the gradient of the u-wind.
1614  In the Helfand and Labraga (1988) adaptation of this closure, $K_m$  In the \cite{helflab:88} adaptation of this closure, $K_m$
1615  takes the form:  takes the form:
1616  \[  \[
1617  {\bf EU} = K_m = -{( {\overline{u^{\prime}w^{\prime}}}) \over {\pp{U}{z}} }  {\bf EU} = K_m = -{( {\overline{u^{\prime}w^{\prime}}}) \over {\pp{U}{z}} }
# Line 1683  are functions of the Richardson number. Line 1631  are functions of the Richardson number.
1631    
1632  \noindent  \noindent
1633  For the detailed equations and derivations of the modified level 2.5 closure scheme,  For the detailed equations and derivations of the modified level 2.5 closure scheme,
1634  see Helfand and Labraga, 1988.  see \cite{helflab:88}.
1635    
1636  \noindent  \noindent
1637  In the surface layer, ${\bf {EU}}$ is the exchange coefficient for momentum,  In the surface layer, ${\bf {EU}}$ is the exchange coefficient for momentum,
# Line 2073  net surface upward longwave radiative fl Line 2021  net surface upward longwave radiative fl
2021  sea ice, $H$ is the upward sensible heat flux, $LE$ is the upward latent heat  sea ice, $H$ is the upward sensible heat flux, $LE$ is the upward latent heat
2022  flux, and $C_g$ is the total heat capacity of the ground.  flux, and $C_g$ is the total heat capacity of the ground.
2023  $C_g$ is obtained by solving a heat diffusion equation  $C_g$ is obtained by solving a heat diffusion equation
2024  for the penetration of the diurnal cycle into the ground (Blackadar, 1977), and is given by:  for the penetration of the diurnal cycle into the ground (\cite{black:77}), and is given by:
2025  \[  \[
2026  C_g = \sqrt{ {\lambda C_s \over {2 \omega} } } = \sqrt{(0.386 + 0.536W + 0.15W^2)2x10^{-3}  C_g = \sqrt{ {\lambda C_s \over {2 \omega} } } = \sqrt{(0.386 + 0.536W + 0.15W^2)2x10^{-3}
2027  { 86400. \over {2 \pi} } } \, \, .  { 86400. \over {2 \pi} } } \, \, .
# Line 2428  number 10), and $W_s$ is the surface win Line 2376  number 10), and $W_s$ is the surface win
2376    
2377  \noindent  \noindent
2378  Over the land surface, the surface roughness length is interpolated to the local  Over the land surface, the surface roughness length is interpolated to the local
2379  time from the monthly mean data of Dorman and Sellers (1989). Over the ocean,  time from the monthly mean data of \cite{dorsell:89}. Over the ocean,
2380  the roughness length is a function of the surface-stress velocity, $u_*$.  the roughness length is a function of the surface-stress velocity, $u_*$.
2381  \[  \[
2382  {\bf Z0} = c_1u^3_* + c_2u^2_* + c_3u_* + c_4 + {c_5 \over {u_*}}  {\bf Z0} = c_1u^3_* + c_2u^2_* + c_3u_* + c_4 + {c_5 \over {u_*}}
# Line 2436  the roughness length is a function of th Line 2384  the roughness length is a function of th
2384    
2385  \noindent  \noindent
2386  where the constants are chosen to interpolate between the reciprocal relation of  where the constants are chosen to interpolate between the reciprocal relation of
2387  Kondo(1975) for weak winds, and the piecewise linear relation of Large and Pond(1981)  \cite{kondo:75} for weak winds, and the piecewise linear relation of \cite{larpond:81}
2388  for moderate to large winds.  for moderate to large winds.
2389  \\  \\
2390    

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