Ignore:
Timestamp:
2019-12-10T17:11:51+01:00 (12 months ago)
Message:

Catching up with "dev_r12072_MERGE_OPTION2_2019"

Location:
Files:
2 edited

### Legend:

Unmodified
Removed

 r12051 author = "E. B. Kraus and J. A. Businger", title = "Atmosphere-ocean interaction.", journal="Quarterly Journal of the Royal Meteorological Society",, journal="Quarterly Journal of the Royal Meteorological Society", year = "1996", volume = "122", } @techreport{fairall.blomquist_rpt18, title         = "The {TOGA-COARE} bulk air-sea flux algorithm", pages         = "16", author        = "C. W. Fairall and B. Blomquist and L. Bariteau and J. B. Edson", institution   = "(NOAA/ERSL/PSD, Boulder, USA", year          = "2018", month         = "aug", url           = "ftp://ftp.etl.noaa.gov/BLO/Air-Sea/bulkalg/cor3_6/coare36_readme_1.doc" }
 r12051 \documentclass[../main/NEMO_manual]{subfiles} \usepackage{fontspec} \usepackage{fontawesome} \begin{document} Note: all the NEMO Fortran routines involved in the present section have been initially developed (and are still developped in parallel) in initially developed (and are still developed in parallel) in the \href{https://brodeau.github.io/aerobulk/}{\texttt{AeroBulk}} open-source project \citep{brodeau.barnier.ea_JPO17}. % \begin{subequations}\label{eq_bulk} \label{eq:SBC_bulk_form} \begin{eqnarray} \mathbf{\tau} &=& \rho~ C_D ~ \mathbf{U}_z  ~ U_B \label{eq_b_t} \\ Q_H           &=& \rho~C_H~C_P~\big[ \theta_z - T_s \big] ~ U_B \label{eq_b_qh} \\ E             &=& \rho~C_E    ~\big[    q_s   - q_z \big] ~ U_B \label{eq_b_e}  \\ Q_L           &=& -L_v \, E  \label{eq_b_qe} \\ \mathbf{\tau} &=& \rho~ C_D ~ \mathbf{U}_z  ~ U_B \\ Q_H           &=& \rho~C_H~C_P~\big[ \theta_z - T_s \big] ~ U_B \\ E             &=& \rho~C_E    ~\big[    q_s   - q_z \big] ~ U_B \\ Q_L           &=& -L_v \, E \\ % Q_{sr}        &=& (1 - a) Q_{sw\downarrow} \\ and longwave radiative fluxes, respectively. % Note: a positive sign of $\mathbf{\tau}$, the various fluxes of heat implies a gain of the relevant quantity for the ocean, while a positive $E$ implies a freshwater loss for the ocean. Note: a positive sign for $\mathbf{\tau}$, $Q_H$, $Q_L$, $Q_{sr}$ or $Q_{ir}$ implies a gain of the relevant quantity for the ocean, while a positive $E$ implies a freshwater loss for the ocean. % $\rho$ is the density of air. $C_D$, $C_H$ and $C_E$ are the bulk transfer coefficients for momentum, sensible heat, and moisture, respectively (hereafter referred to as BTCs). coefficients for momentum, sensible heat, and moisture, respectively. % $C_P$ is the heat capacity of moist air, and $L_v$ is the latent heat of % The bulk scalar wind speed, namely $U_B$, is the scalar wind speed, $|\mathbf{U}_z|$, with the potential inclusion of a gustiness contribution . $|\mathbf{U}_z|$, with the potential inclusion of a gustiness contribution. % $a$ and $\delta$ are the albedo and emissivity of the sea surface, respectively.\\ % $T_s$ is the sea surface temperature. $q_s$ is the saturation specific humidity of air at temperature $T_s$ and includes a 2\% reduction to account for the of air at temperature $T_s$; it includes a 2\% reduction to account for the presence of salt in seawater \citep{sverdrup.johnson.ea_1942,kraus.businger_QJRMS96}. Depending on the bulk parametrization used, $T_s$ can either be the temperature (\np[=.true.]{ln_NCAR}{ln\_NCAR}) for which $T_s$ is the bulk SST (\ie~temperature at first T-point level). For more details on all these aspects the reader is invited to refer For the open ocean, four bulk parametrization algorithms are available: For the open ocean, four bulk parametrization algorithms are available in NEMO: \begin{itemize} \item NCAR, formerly known as CORE, \citep{large.yeager_rpt04,large.yeager_CD09} \item COARE 3.0 \citep{fairall.bradley.ea_JC03} \item COARE 3.6 \citep{edson.jampana.ea_JPO13} \item COARE 3.6 \citep{edson.jampana.ea_JPO13,fairall.blomquist_rpt18} \item ECMWF (IFS documentation, cy45) \end{itemize} Differences between versions 3.0 and 3.6 of the COARE algorithm mainly ... wind stress BLABLA \citep{edson.jampana.ea_JPO13,brodeau.barnier.ea_JPO17}. Therefore it is recommanded to use version 3.6 of the COARE algorithms rather than version 3. With respect to version 3, the principal advances in version 3.6 of the COARE bulk parametrization are built around improvements in the representation of the effects of waves on fluxes \citep{edson.jampana.ea_JPO13,brodeau.barnier.ea_JPO17}. This includes improved relationships of surface roughness, and whitecap fraction on wave parameters. It is therefore recommended to chose version 3.6 over 3. For the cool-skin scheme parametrization COARE and ECMWF algorithms share the same basis: \citet{fairall.bradley.ea_JGR96}. With some minor updates based on \citet{zeng.beljaars_GRL05} for ECMWF, and \citet{fairall.ea_19} for COARE on \citet{zeng.beljaars_GRL05} for ECMWF, and \citet{fairall.blomquist_rpt18} for COARE 3.6. turbulence input from Langmuir circulation). Importantly, COARE warm-layer scheme \citep{fairall.ea_19} includes a prognostic Importantly, COARE warm-layer scheme \citep{fairall.blomquist_rpt18} includes a prognostic equation for the thickness of the warm-layer, while it is considered as constant in the ECWMF algorithm. \begin{figure}[!t] \centering \includegraphics[width=0.96\textwidth]{SBC_dT_skin-SST} \caption[Skin temperature]{Hourly difference between skin temperature and bulk SST (1\,m deep) simulated by the NEMO \texttt{STATION\_ASF} test-case, based on in-situ data from PAPA station (50.1\deg N, 144.9\deg W) in 2018; for two different sets of bulk algorithm + cool-skin/warm-layer parametrizations'': COARE 3.6 and ECMWF.} \label{fig:SBC_dT_skin-SST} \end{figure} % \subsection{Appropriate use of each bulk parametrization} \subsubsection{NCAR} NCAR bulk parametrizations (formerly know as CORE) is meant to be used with the CORE II atmospheric forcing \citep{large.yeager_CD09}. Hence the following namelist parameters must be set: NCAR bulk parametrizations (formerly known as CORE) is meant to be used with the CORE II atmospheric forcing \citep{large.yeager_CD09}. The expected sea surface temperature is the bulk SST. Hence the following namelist parameters must be set: % \begin{verbatim} \subsubsection{ECMWF} % With a DFS* or any ECMWF-based type of atmospheric forcing, we strongly recommend to use the ECMWF bulk parametrizations with the cool-skin and warm-layer parametrizations turned on. In ECMWF reanalyzes, since air temperature and humidity are provided at the 2\,m height, and given that the humidity is provided as the dew-point temperature, the namelist must be tuned as follows: With an atmospheric forcing based on a reanalysis of the ECMWF, such as the Drakkar Forcing Set \citep{brodeau.barnier.ea_OM10}, we strongly recommend to use the ECMWF bulk parametrizations with the cool-skin and warm-layer parametrizations activated. In ECMWF reanalyzes, since air temperature and humidity are provided at the 2\,m height, and given that the humidity is distributed as the dew-point temperature, the namelist must be tuned as follows: % \begin{verbatim} % Since the ECMWF parametrization is largely based on the COARE* parametrization, the two algorithms are very similar in terms of structure and closure approach (see \citet{brodeau.barnier.ea_JPO17} for the differences). As such, the namelist tuning for COARE 3.x is identical to that of ECMWF: the two algorithms are very similar in terms of structure and closure approach. As such, the namelist tuning for COARE 3.x is identical to that of ECMWF: % \begin{verbatim} ~ %lulu \np{cn_dir}{cn\_dir} is the directory of location of bulk files \np{ln_taudif}{ln\_taudif} is the flag to specify if we use Hight Frequency (HF) tau information (.true.) or not (.false.) %\np{ln_taudif}{ln\_taudif} is the flag to specify if we use High Frequency (HF) tau information (.true.) or not (.false.) \np{rn_zqt}{rn\_zqt}: is the height of humidity and temperature measurements (m) \np{rn_zu}{rn\_zu}: is the height of wind measurements (m) Its range must be between zero and one, and it is recommended to set it to 0 at low-resolution (ORCA2 configuration). As for the flux parameterization, information about the input data required by the model is provided in As for the flux parametrization, information about the input data required by the model is provided in the namsbc\_blk namelist (see \autoref{subsec:SBC_fldread}).