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albedo.F90 in branches/dev_002_LIM/NEMO/OPA_SRC/SBC – NEMO

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source: branches/dev_002_LIM/NEMO/OPA_SRC/SBC/albedo.F90 @ 828

Last change on this file since 828 was 828, checked in by rblod, 16 years ago
Complete previous commit in correcting a few compilation bugs, see ticket #71
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 15.5 KB

Rev	Line
[152]	1	MODULE albedo
	2	!!======================================================================
	3	!! * MODULE albedo *
	4	!! Ocean forcing: bulk thermohaline forcing of the ocean (or ice)
	5	!!=====================================================================
	6	!!----------------------------------------------------------------------
[719]	7	!! flx_blk_albedo : albedo for ocean and ice (clear and overcast skies)
[152]	8	!!----------------------------------------------------------------------
[719]	9	!! * Modules used
[152]	10	USE oce ! ocean dynamics and tracers
[719]	11	USE dom_oce ! ocean space and time domain
	12	USE cpl_oce ! ???
[152]	13	USE phycst ! physical constants
[719]	14	USE daymod
	15	USE blk_oce ! bulk variables
	16	USE flx_oce ! forcings variables
	17	USE ocfzpt ! ???
[152]	18	USE in_out_manager
[719]	19	USE lbclnk
[152]	20
	21	IMPLICIT NONE
	22	PRIVATE
	23
[719]	24	!! * Accessibility
	25	PUBLIC flx_blk_albedo ! routine called by limflx.F90 in coupled
	26	! and in flxblk.F90 in forced
	27	!! * Module variables
	28	INTEGER :: & !: nameos : ocean physical parameters
	29	albd_init = 0 !: control flag for initialization
[165]	30
[719]	31	REAL(wp) :: & ! constant values
	32	zzero = 0.e0 , &
	33	zone = 1.0
[152]	34
[719]	35	!! * constants for albedo computation (flx_blk_albedo)
[152]	36	REAL(wp) :: &
[719]	37	c1 = 0.05 , & ! constants values
	38	c2 = 0.10 , &
[827]	39	#if defined key_lim3
	40	albice = 0.53 , & ! albedo of melting ice in the arctic and antarctic (Shine & Hendersson-Sellers)
[828]	41	#else
[719]	42	albice = 0.50 , & ! albedo of melting ice in the arctic and antarctic (Shine & Hendersson-Sellers)
[827]	43	#endif
[703]	44	cgren = 0.06 , & ! correction of the snow or ice albedo to take into account
[719]	45	! effects of cloudiness (Grenfell & Perovich, 1984)
[152]	46	alphd = 0.80 , & ! coefficients for linear interpolation used to compute
	47	alphdi = 0.72 , & ! albedo between two extremes values (Pyane, 1972)
[719]	48	alphc = 0.65 , &
	49	zmue = 0.40 ! cosine of local solar altitude
[152]	50
	51	!!----------------------------------------------------------------------
[719]	52	!! OPA 9.0 , LOCEAN-IPSL (2005)
	53	!! $Header$
	54	!! This software is governed by the CeCILL licence see modipsl/doc/NEMO_CeCILL.txt
[152]	55	!!----------------------------------------------------------------------
	56
	57	CONTAINS
	58
[827]	59	#if defined key_lim3 \|\| defined key_lim2
[152]	60	!!----------------------------------------------------------------------
[827]	61	!! 'key_lim3' OR 'key_lim2' LIM 2.0 or LIM 3.0 ice model
[152]	62	!!----------------------------------------------------------------------
	63
[719]	64	SUBROUTINE flx_blk_albedo( palb , palcn , palbp , palcnp )
[152]	65	!!----------------------------------------------------------------------
[719]	66	!! * ROUTINE flx_blk_albedo *
[152]	67	!!
	68	!! ** Purpose : Computation of the albedo of the snow/ice system
[719]	69	!! as well as the ocean one
[152]	70	!!
	71	!! ** Method : - Computation of the albedo of snow or ice (choose the
[719]	72	!! rignt one by a large number of tests
[152]	73	!! - Computation of the albedo of the ocean
	74	!!
[719]	75	!! References :
	76	!! Shine and Hendersson-Sellers 1985, JGR, 90(D1), 2243-2250.
	77	!!
	78	!! History :
	79	!! 8.0 ! 01-04 (LIM 1.0)
	80	!! 8.5 ! 03-07 (C. Ethe, G. Madec) Optimization (old name:shine)
[827]	81	!! 9.0 ! 01-06 (M. Vancoppenolle) LIM 3.0
[703]	82	!!----------------------------------------------------------------------
[719]	83	!! * Modules used
[827]	84	#if defined key_lim3
[828]	85	USE par_ice
[719]	86	USE ice ! ???
[827]	87	#elif defined key_lim2
	88	USE ice_2 ! ???
	89	#endif
[719]	90
	91	!! * Arguments
[827]	92	#if defined key_lim3
	93	REAL(wp), DIMENSION(jpi,jpj,jpl), INTENT(out) :: &
	94	#elif defined key_lim2
[719]	95	REAL(wp), DIMENSION(jpi,jpj), INTENT(out) :: &
[827]	96	#endif
[719]	97	palb , & ! albedo of ice under overcast sky
[827]	98	palbp ! albedo of ice under clear sky
	99	REAL(wp), DIMENSION(jpi,jpj), INTENT(out) :: &
[719]	100	palcn , & ! albedo of ocean under overcast sky
	101	palcnp ! albedo of ocean under clear sky
	102
	103	!! * Local variables
	104	INTEGER :: &
[827]	105	ji, jj, jl ! dummy loop indices
[719]	106	REAL(wp) :: &
	107	zmue14 , & ! zmue**1.4
[152]	108	zalbpsnm , & ! albedo of ice under clear sky when snow is melting
	109	zalbpsnf , & ! albedo of ice under clear sky when snow is freezing
	110	zalbpsn , & ! albedo of snow/ice system when ice is coverd by snow
	111	zalbpic , & ! albedo of snow/ice system when ice is free of snow
	112	zithsn , & ! = 1 for hsn >= 0 ( ice is cov. by snow ) ; = 0 otherwise (ice is free of snow)
[827]	113	zitmlsn , & ! = 1 freezinz snow (t_su >=rt0_snow) ; = 0 melting snow (t_su<rt0_snow)
[152]	114	zihsc1 , & ! = 1 hsn <= c1 ; = 0 hsn > c1
	115	zihsc2 ! = 1 hsn >= c2 ; = 0 hsn < c2
[827]	116	#if defined key_lim3
	117	REAL(wp), DIMENSION(jpi,jpj,jpl) :: &
	118	#elif defined key_lim2
[719]	119	REAL(wp), DIMENSION(jpi,jpj) :: &
[827]	120	#endif
[719]	121	zalbfz , & ! ( = alphdi for freezing ice ; = albice for melting ice )
	122	zficeth ! function of ice thickness
[827]	123	#if defined key_lim3
	124	LOGICAL , DIMENSION(jpi,jpj,jpl) :: &
	125	#elif defined key_lim2
[719]	126	LOGICAL , DIMENSION(jpi,jpj) :: &
[827]	127	#endif
[719]	128	llmask
[152]	129	!!---------------------------------------------------------------------
	130
[719]	131	! initialization
	132	IF( albd_init == 0 ) CALL albedo_init
[165]	133
[719]	134	!-------------------------
[152]	135	! Computation of zficeth
[719]	136	!--------------------------
[827]	137	#if defined key_lim3
	138	llmask = (ht_s(:,:,:) == 0.e0) .AND. ( t_su(:,:,:) >= rt0_ice )
	139	#elif defined key_lim2
[152]	140	llmask = (hsnif == 0.e0) .AND. ( sist >= rt0_ice )
[827]	141	#endif
[152]	142	WHERE ( llmask ) ! ice free of snow and melts
	143	zalbfz = albice
	144	ELSEWHERE
	145	zalbfz = alphdi
	146	END WHERE
	147
[827]	148	#if defined key_lim3
	149	DO jl = 1, jpl
	150	DO jj = 1, jpj
	151	DO ji = 1, jpi
	152	IF( ht_i(ji,jj,jl) > 1.5 ) THEN
	153	zficeth(ji,jj,jl) = zalbfz(ji,jj,jl)
	154	ELSEIF( ht_i(ji,jj,jl) > 1.0 .AND. ht_i(ji,jj,jl) <= 1.5 ) THEN
	155	zficeth(ji,jj,jl) = 0.472 + 2.0 * ( zalbfz(ji,jj,jl) - 0.472 ) * ( ht_i(ji,jj,jl) - 1.0 )
	156	ELSEIF( ht_i(ji,jj,jl) > 0.05 .AND. ht_i(ji,jj,jl) <= 1.0 ) THEN
	157	zficeth(ji,jj,jl) = 0.2467 + 0.7049 * ht_i(ji,jj,jl) &
	158	& - 0.8608 * ht_i(ji,jj,jl) * ht_i(ji,jj,jl) &
	159	& + 0.3812 * ht_i(ji,jj,jl) * ht_i(ji,jj,jl) * ht_i (ji,jj,jl)
	160	ELSE
	161	zficeth(ji,jj,jl) = 0.1 + 3.6 * ht_i(ji,jj,jl)
	162	ENDIF
	163	END DO
	164	END DO
	165	END DO
	166	#elif defined key_lim2
[152]	167	DO jj = 1, jpj
	168	DO ji = 1, jpi
	169	IF( hicif(ji,jj) > 1.5 ) THEN
	170	zficeth(ji,jj) = zalbfz(ji,jj)
	171	ELSEIF( hicif(ji,jj) > 1.0 .AND. hicif(ji,jj) <= 1.5 ) THEN
	172	zficeth(ji,jj) = 0.472 + 2.0 * ( zalbfz(ji,jj) - 0.472 ) * ( hicif(ji,jj) - 1.0 )
	173	ELSEIF( hicif(ji,jj) > 0.05 .AND. hicif(ji,jj) <= 1.0 ) THEN
	174	zficeth(ji,jj) = 0.2467 + 0.7049 * hicif(ji,jj) &
	175	& - 0.8608 * hicif(ji,jj) * hicif(ji,jj) &
	176	& + 0.3812 * hicif(ji,jj) * hicif(ji,jj) * hicif (ji,jj)
	177	ELSE
	178	zficeth(ji,jj) = 0.1 + 3.6 * hicif(ji,jj)
	179	ENDIF
	180	END DO
	181	END DO
[827]	182	#endif
[152]	183
	184	!-----------------------------------------------
	185	! Computation of the snow/ice albedo system
	186	!-------------------------- ---------------------
	187
	188	! Albedo of snow-ice for clear sky.
	189	!-----------------------------------------------
[827]	190	#if defined key_lim3
	191	DO jl = 1, jpl
	192	DO jj = 1, jpj
	193	DO ji = 1, jpi
	194	! Case of ice covered by snow.
	195
	196	! freezing snow
	197	zihsc1 = 1.0 - MAX ( zzero , SIGN ( zone , - ( ht_s(ji,jj,jl) - c1 ) ) )
	198	zalbpsnf = ( 1.0 - zihsc1 ) * ( zficeth(ji,jj,jl) + ht_s(ji,jj,jl) * ( alphd - zficeth(ji,jj,jl) ) / c1 ) &
	199	& + zihsc1 * alphd
	200
	201	! melting snow
	202	zihsc2 = MAX ( zzero , SIGN ( zone , ht_s(ji,jj,jl) - c2 ) )
	203	zalbpsnm = ( 1.0 - zihsc2 ) * ( albice + ht_s(ji,jj,jl) * ( alphc - albice ) / c2 ) &
	204	& + zihsc2 * alphc
	205
	206
	207	zitmlsn = MAX ( zzero , SIGN ( zone , t_su(ji,jj,jl) - rt0_snow ) )
	208	zalbpsn = zitmlsn * zalbpsnm + ( 1.0 - zitmlsn ) * zalbpsnf
	209
	210	! Case of ice free of snow.
	211	zalbpic = zficeth(ji,jj,jl)
	212
	213	! albedo of the system
	214	zithsn = 1.0 - MAX ( zzero , SIGN ( zone , - ht_s(ji,jj,jl) ) )
	215	palbp(ji,jj,jl) = zithsn * zalbpsn + ( 1.0 - zithsn ) * zalbpic
	216	END DO
	217	END DO
	218	END DO
	219
	220	! Albedo of snow-ice for overcast sky.
	221	!----------------------------------------------
	222	palb(:,:,:) = palbp(:,:,:) + cgren ! Oberhuber correction
	223
	224	#elif defined key_lim2
	225
[152]	226	DO jj = 1, jpj
	227	DO ji = 1, jpi
	228	! Case of ice covered by snow.
	229
	230	! melting snow
	231	zihsc1 = 1.0 - MAX ( zzero , SIGN ( zone , - ( hsnif(ji,jj) - c1 ) ) )
	232	zalbpsnm = ( 1.0 - zihsc1 ) * ( zficeth(ji,jj) + hsnif(ji,jj) * ( alphd - zficeth(ji,jj) ) / c1 ) &
	233	& + zihsc1 * alphd
	234	! freezing snow
	235	zihsc2 = MAX ( zzero , SIGN ( zone , hsnif(ji,jj) - c2 ) )
	236	zalbpsnf = ( 1.0 - zihsc2 ) * ( albice + hsnif(ji,jj) * ( alphc - albice ) / c2 ) &
	237	& + zihsc2 * alphc
	238
	239	zitmlsn = MAX ( zzero , SIGN ( zone , sist(ji,jj) - rt0_snow ) )
	240	zalbpsn = zitmlsn * zalbpsnf + ( 1.0 - zitmlsn ) * zalbpsnm
	241
	242	! Case of ice free of snow.
	243	zalbpic = zficeth(ji,jj)
	244
	245	! albedo of the system
	246	zithsn = 1.0 - MAX ( zzero , SIGN ( zone , - hsnif(ji,jj) ) )
	247	palbp(ji,jj) = zithsn * zalbpsn + ( 1.0 - zithsn ) * zalbpic
	248	END DO
	249	END DO
	250
	251	! Albedo of snow-ice for overcast sky.
	252	!----------------------------------------------
	253	palb(:,:) = palbp(:,:) + cgren
[827]	254	#endif
[152]	255
	256	!--------------------------------------------
	257	! Computation of the albedo of the ocean
	258	!-------------------------- -----------------
	259
[719]	260	! Parameterization of Briegled and Ramanathan, 1982
	261	zmue14 = zmue**1.4
	262	palcnp(:,:) = 0.05 / ( 1.1 * zmue14 + 0.15 )
	263
	264	! Parameterization of Kondratyev, 1969 and Payne, 1972
	265	palcn(:,:) = 0.06
	266
	267	END SUBROUTINE flx_blk_albedo
[152]	268
	269	# else
	270	!!----------------------------------------------------------------------
	271	!! Default option : NO sea-ice model
	272	!!----------------------------------------------------------------------
	273
[719]	274	SUBROUTINE flx_blk_albedo( palb , palcn , palbp , palcnp )
[152]	275	!!----------------------------------------------------------------------
[719]	276	!! * ROUTINE flx_blk_albedo *
[152]	277	!!
[719]	278	!! ** Purpose : Computation of the albedo of the snow/ice system
	279	!! as well as the ocean one
[152]	280	!!
[719]	281	!! ** Method : Computation of the albedo of snow or ice (choose the
	282	!! wright one by a large number of tests Computation of the albedo
	283	!! of the ocean
[152]	284	!!
[719]	285	!! History :
	286	!! 8.0 ! 01-04 (LIM 1.0)
	287	!! 8.5 ! 03-07 (C. Ethe, G. Madec) Optimization (old name:shine)
[152]	288	!!----------------------------------------------------------------------
[719]	289	!! * Arguments
	290	REAL(wp), DIMENSION(jpi,jpj), INTENT(out) :: &
	291	palb , & ! albedo of ice under overcast sky
	292	palcn , & ! albedo of ocean under overcast sky
	293	palbp , & ! albedo of ice under clear sky
	294	palcnp ! albedo of ocean under clear sky
[152]	295
[719]	296	REAL(wp) :: &
	297	zmue14 ! zmue**1.4
	298	!!----------------------------------------------------------------------
[152]	299
[719]	300	!--------------------------------------------
	301	! Computation of the albedo of the ocean
	302	!-------------------------- -----------------
[152]	303
[719]	304	! Parameterization of Briegled and Ramanathan, 1982
	305	zmue14 = zmue**1.4
	306	palcnp(:,:) = 0.05 / ( 1.1 * zmue14 + 0.15 )
	307
	308	! Parameterization of Kondratyev, 1969 and Payne, 1972
	309	palcn(:,:) = 0.06
	310
	311	palb (:,:) = palcn(:,:)
	312	palbp(:,:) = palcnp(:,:)
	313
	314	END SUBROUTINE flx_blk_albedo
	315
[152]	316	#endif
[165]	317
	318	SUBROUTINE albedo_init
	319	!!----------------------------------------------------------------------
	320	!! * ROUTINE albedo_init *
	321	!!
	322	!! ** Purpose : initializations for the albedo parameters
	323	!!
	324	!! ** Method : Read the namelist namalb
[719]	325	!!
	326	!! ** Action :
	327	!!
	328	!!
	329	!! History :
	330	!! 9.0 ! 04-11 (C. Talandier) Original code
[165]	331	!!----------------------------------------------------------------------
[719]	332	NAMELIST/namalb/ cgren, albice, alphd, alphdi, alphc
	333	!!----------------------------------------------------------------------
	334	!! OPA 9.0, LODYC-IPSL (2004)
	335	!!----------------------------------------------------------------------
[165]	336
[719]	337	! set the initialization flag to 1
	338	albd_init = 1 ! indicate that the initialization has been done
	339
	340	! Read Namelist namalb : albedo parameters
	341	REWIND( numnam )
[165]	342	READ ( numnam, namalb )
	343
[719]	344	! Control print
	345	IF(lwp) THEN
[165]	346	WRITE(numout,*)
[719]	347	WRITE(numout,*) 'albedo_init : albedo '
[165]	348	WRITE(numout,*) '~~~~~~~~~~~'
[719]	349	WRITE(numout,*) ' Namelist namalb : set albedo parameters'
	350	WRITE(numout,*)
	351	WRITE(numout,*) ' correction of the snow or ice albedo to take into account cgren = ', cgren
	352	WRITE(numout,*) ' albedo of melting ice in the arctic and antarctic albice = ', albice
	353	WRITE(numout,*) ' coefficients for linear alphd = ', alphd
	354	WRITE(numout,*) ' interpolation used to compute albedo alphdi = ', alphdi
	355	WRITE(numout,*) ' between two extremes values (Pyane, 1972) alphc = ', alphc
	356	WRITE(numout,*)
[165]	357	ENDIF
[719]	358
[703]	359	END SUBROUTINE albedo_init
[152]	360	!!======================================================================
	361	END MODULE albedo

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