- Timestamp:
- 2019-12-04T11:51:54+01:00 (4 years ago)
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- NEMO/branches/2019/dev_r11085_ASINTER-05_Brodeau_Advanced_Bulk/doc/latex/NEMO
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NEMO/branches/2019/dev_r11085_ASINTER-05_Brodeau_Advanced_Bulk/doc/latex/NEMO/main/bibliography.bib
r11831 r12046 400 400 } 401 401 402 @article{ brodeau.barnier.ea_JPO1 6,403 title = "Climatologically Significant Effects of Some Approximations in the Bulk Parameterizations of Turbulent Air –Sea Fluxes",402 @article{ brodeau.barnier.ea_JPO17, 403 title = "Climatologically Significant Effects of Some Approximations in the Bulk Parameterizations of Turbulent Air{\textendash}Sea Fluxes", 404 404 pages = "5--28", 405 405 journal = "Journal of Physical Oceanography", … … 407 407 number = "1", 408 408 author = "Brodeau, Laurent and Barnier, Bernard and Gulev, Sergey K. and Woods, Cian", 409 year = "201 6",409 year = "2017", 410 410 month = "jan", 411 411 publisher = "American Meteorological Society", … … 3134 3134 doi = "10.1029/92jc00911" 3135 3135 } 3136 3137 @article{large.yeager_CD09, 3138 author="Large, W. G. and Yeager, S. G.", 3139 title="The Global Climatology of an Interannually Varying Air-Sea Flux Data Set", 3140 pages = "341--364", 3141 journal="Climate Dynamics", 3142 volume = "33", 3143 number = "2-3", 3144 year="2009", 3145 month = "aug", 3146 publisher = "Springer Science and Business Media LLC", 3147 doi="10.1007/s00382-008-0441-3" 3148 } 3149 -
NEMO/branches/2019/dev_r11085_ASINTER-05_Brodeau_Advanced_Bulk/doc/latex/NEMO/subfiles/chap_SBC.tex
r12031 r12046 47 47 48 48 \begin{itemize} 49 \item a bulk formulation (\np[=.true.]{ln_blk}{ln\_blk} with four possible bulk algorithms),49 \item a bulk formulation (\np[=.true.]{ln_blk}{ln\_blk}), featuring a selection of four bulk parameterization algorithms, 50 50 \item a flux formulation (\np[=.true.]{ln_flx}{ln\_flx}), 51 51 \item a coupled or mixed forced/coupled formulation (exchanges with a atmospheric model via the OASIS coupler), … … 537 537 \label{sec:SBC_blk} 538 538 539 % L. Brodeau, December 2019... 540 539 541 \begin{listing} 540 542 \nlst{namsbc_blk} … … 543 545 \end{listing} 544 546 545 In the bulk formulation, the surface boundary condition fields are computed with 546 bulk formulae using prescribed atmospheric fields and prognostic ocean (and 547 sea-ice) surface variables averaged over \np{nn_fsbc}{nn\_fsbc} time-step. 547 If the bulk formulation is selected (\np[=.true.]{ln_blk}{ln\_blk}), the air-sea 548 fluxes associated with surface boundary conditions are estimated by means of the 549 traditional \emph{bulk formulae}. As input, bulk formulae rely on a prescribed 550 near-surface atmosphere state (typically extracted from a weather reanalysis) 551 and the prognostic sea (-ice) surface state averaged over \np{nn_fsbc}{nn\_fsbc} 552 time-step(s). 548 553 549 554 % Turbulent air-sea fluxes are computed using the sea surface properties and … … 555 560 \subsection{Bulk formulae} 556 561 % 557 In NEMO, when the bulk formulation is selected, surface fluxes are computed by means of the traditional bulk formulae: 562 In NEMO, the set of equations that relate each component of the surface fluxes 563 to the near-surface atmosphere and sea surface states writes 558 564 % 559 565 \begin{subequations}\label{eq_bulk} … … 568 574 \end{eqnarray} 569 575 \end{subequations} 570 %lulu 571 % 572 From which, the the non-solar heat flux is \[ Q_{ns} = Q_L + Q_H + Q_{ir} \] 573 % 576 % 577 with 574 578 \[ \theta_z \simeq T_z+\gamma z \] 575 579 \[ q_s \simeq 0.98\,q_{sat}(T_s,p_a ) \] 576 577 578 580 % 581 from which, the the non-solar heat flux is \[ Q_{ns} = Q_L + Q_H + Q_{ir} \] 582 % 579 583 where $\mathbf{\tau}$ is the wind stress vector, $Q_H$ the sensible heat flux, 580 584 $E$ the evaporation, $Q_L$ the latent heat flux, and $Q_{ir}$ the net longwave … … 584 588 and longwave radiative fluxes, respectively. 585 589 % 586 Note: a positive sign of $\mathbf{\tau}$, $Q_H$, and $Q_L$ means a gain of the 587 relevant quantity for the ocean, while a positive $E$ implies a freshwater loss 588 for the ocean. 589 % 590 $\rho$ is the density of air. $C_D$, $C_H$ and $C_E$ are the BTCs for momentum, 591 sensible heat, and moisture, respectively. $C_P$ is the heat capacity of moist 592 air, and $L_v$ is the latent heat of vaporization of water. $\theta_z$, $T_z$ 593 and $q_z$ are the potential temperature, temperature, and specific humidity of 594 air at height $z$, respectively. $\gamma z$ is a temperature correction term 595 which accounts for the adiabatic lapse rate and approximates the potential 596 temperature at height $z$ \citep{Josey_al_2013}. $\mathbf{U}_z$ is the wind 597 speed vector at height $z$ (possibly referenced to the surface current 598 $\mathbf{u_0}$, section \ref{s_res1}.\ref{ss_current}). The bulk scalar wind 599 speed, $U_B$, is the scalar wind speed, $|\mathbf{U}_z|$, with the potential 600 inclusion of a gustiness contribution (section 601 \ref{s_res2}.\ref{ss_calm}). 602 $P_0$ is the mean sea-level pressure (SLP). 590 Note: a positive sign of $\mathbf{\tau}$, the various fluxes of heat implies a 591 gain of the relevant quantity for the ocean, while a positive $E$ implies a 592 freshwater loss for the ocean. 593 % 594 $\rho$ is the density of air. $C_D$, $C_H$ and $C_E$ are the bulk transfer 595 coefficients for momentum, sensible heat, and moisture, respectively (hereafter 596 referd to as BTCs). 597 % 598 $C_P$ is the heat capacity of moist air, and $L_v$ is the latent heat of 599 vaporization of water. 600 % 601 $\theta_z$, $T_z$ and $q_z$ are the potential temperature, absolute temperature, 602 and specific humidity of air at height $z$ above the sea surface, 603 respectively. $\gamma z$ is a temperature correction term which accounts for the 604 adiabatic lapse rate and approximates the potential temperature at height 605 $z$ \citep{Josey_al_2013}. 606 % 607 $\mathbf{U}_z$ is the wind speed vector at height $z$ above the sea surface 608 (possibly referenced to the surface current $\mathbf{u_0}$, 609 section \ref{s_res1}.\ref{ss_current}). 610 % 611 The bulk scalar wind speed, namely $U_B$, is the scalar wind speed, 612 $|\mathbf{U}_z|$, with the potential inclusion of a gustiness contribution 613 (section \ref{s_res2}.\ref{ss_calm}). 614 % 615 $a$ and $\delta$ are the albedo and emissivity of the sea surface, respectively.\\ 616 % 617 %$p_a$ is the mean sea-level pressure (SLP). 618 % 603 619 $T_s$ is the sea surface temperature. $q_s$ is the saturation specific humidity 604 620 of air at temperature $T_s$ and includes a 2\% reduction to account for the 605 621 presence of salt in seawater \citep{Sverdrup_al_1942,Kraus_Businger_1996}. 606 Depending on the bulk parameterization used, $T_s$ can be the temperature at the 607 air-sea interface (skin temperature, hereafter SSST) or at a few tens of 608 centimeters below the surface (bulk sea surface temperature, hereafter SST). 622 Depending on the bulk parameterization used, $T_s$ can either be the temperature 623 at the air-sea interface (skin temperature, hereafter SSST) or at typically a 624 few tens of centimeters below the surface (bulk sea surface temperature, 625 hereafter SST). 626 % 609 627 The SSST differs from the SST due to the contributions of two effects of 610 opposite sign, the \emph{cool skin} and \emph{warm layer} (hereafter CSWL). The 611 \emph{cool skin} refers to the cooling of the millimeter-scale uppermost layer 612 of the ocean, in which the net upward flux of heat to the atmosphere is 613 ineffectively sustained by molecular diffusion. As such, a steep vertical 614 gradient of temperature must exist to ensure the heat flux continuity with 615 underlying layers in which the same flux is sustained by turbulence. 616 The \emph{warm layer} refers to the warming of the upper few meters of the ocean 617 under sunny conditions. 618 The CSWL effects are most significant under weak wind conditions due to the 619 absence of substancial surface vertical mixing (caused by \eg breaking waves). 620 The impact of the CSWL on the computed TASFs is discussed in section 621 \ref{s_res1}.\ref{ss_skin}. 622 623 624 %%%% Second set of equations (rad): 625 where $a$ and $\delta$ are the albedo and emissivity of the sea surface, 626 respectively. 627 Thus, we use the computed $Q_L$ and $Q_H$ and the 3-hourly surface downwelling 628 shortwave and longwave radiative fluxes ($Q_{sw\downarrow}$ and 629 $Q_{lw\downarrow}$, respectively) from ERA-Interim to correct the daily SST 630 every 3 hours. Due to the implicitness of the problem implied by the dependence 631 of $Q_{nsol}$ on $T_s$, this correction is done iteratively during the 632 computation of the TASFs. 628 opposite sign, the \emph{cool skin} and \emph{warm layer} (hereafter CS and WL, 629 respectively). 630 % 631 Technically, when the ECMWF or COARE* bulk parameterizations are selected 632 (\np[=.true.]{ln_ECMWF}{ln\_ECMWF} or \np[=.true.]{ln_COARE*}{ln\_COARE\*}), 633 $T_s$ is the SSST, as opposed to the NCAR bulk parameterization 634 (\np[=.true.]{ln_NCAR}{ln\_NCAR}) for which $T_s$ is the bulk SST (\ie~temperature 635 at first T-point level). 636 637 638 For more details on all these aspects the reader is invited to refer 639 to \citet{brodeau.barnier.ea_JPO17}. 633 640 634 641 … … 654 661 \subsubsection{Appropriate use of the NCAR algorithm} 655 662 656 NCAR bulk parameterizations (formerly know as CORE) is meant to be used with the CORE II atmospheric forcing (XXX). Hence the following namelist parameters must be set as follow: 663 NCAR bulk parameterizations (formerly know as CORE) is meant to be used with the 664 CORE II atmospheric forcing \citep{large.yeager_CD09}. Hence the following 665 namelist parameters must be set: 657 666 % 658 667 \begin{verbatim} … … 758 767 759 768 thanks to the \href{https://brodeau.github.io/aerobulk/}{Aerobulk} package 760 (\citet{brodeau.barnier.ea_JPO1 6}):769 (\citet{brodeau.barnier.ea_JPO17}): 761 770 762 771 The choice is made by setting to true one of the following namelist
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