The second Global Soil Wetness Project (GSWP2) is an ongoing scientific activity that aims at primary producing state-of-the-art global datasets of land surface fluxes, state variables and related hydrologic quantities by integrating uncoupled land surface schemes. As of 31^st July 2004, 12 institutes have submitted their baseline simulation (Bucket, CLM2-TOP, ISBA, LaD, MOSES2, NOAH, NSIPP-CATCH, ORCHIDEE, SSiB, SiBUC, SWAP and VISA). In this report, preliminary result of their intercomparison is shown using global, 10-year average fluxes and state variables components.

Prior to the analysis, the outputs are closely examined whether energy and water is balanced. First, energy components are well balanced for all models. Water components, however, are not fully balanced for several models. It may be caused by recharge of soil moisture from below the bottom soil layer since most of them increases water amount in their system.

The energy and water balance is shown in Table 1 and Table 2. Even using global, 10-year average, energy and water partitioning has large discrepancy between models. Bowen Ratio (= Sensible Heat / Latent Heat) ranges from 0.473 (SWAP) to 2.767 (NOAH), the average of 12 schemes is 0.948. Runoff Ratio (= Total Runoff / Total Precipitation) ranges from 0.32 (SWAP, NSIPP-CATCH) to 0.70 (NOAH). Table 1 Global energy balance components (unit: W/m³, global, 10-year average)

	SWnet	Lwnet	lE	H	G	Qfusion	Qsublim	Qrain	Balance
BUCK	144.7	-77.2	41.0	24.2	1.4	1.3	-0.4	0.0	-0.1
CLM2	128.8	-66.1	35.9	26.4	0.3	1.1	0.2	0.0	-1.3
ISBA	142.8	-57.6	37.4	45.6	0.2	0.0	1.1	0.0	1.0
LaD_	141.0	-64.9	42.0	31.5	0.0	1.2	1.3	0.0	-0.1
MOSE	142.4	-68.2	37.5	35.5	0.0	1.2	0.0	0.0	0.0
NOAH	143.0	-66.7	19.0	52.6	-0.3	4.8	-3.2	0.0	3.4
NSIP	143.3	-60.4	44.1	39.6	-0.2	1.4	-0.6	-1.2	-0.2
ORCH	133.5	-64.3	30.3	37.6	0.1	0.9	-1.3	0.0	1.5
SSiB	143.7	-63.4	31.7	47.4	1.3	0.9	0.1	0.0	-1.0
SWAP	141.5	-74.4	45.5	21.5	0.0	0.8	-0.7	0.0	0.0
SiBU	139.5	-67.1	36.4	25.2	8.6	0.8	0.0	0.0	1.4
VISA	151.2	-69.9	44.0	34.2	2.1	0.9	0.1	0.0	0.0
Mean	141.3	-66.7	37.1	35.1	1.1	1.3	-0.3	-0.1	0.4

Table 2 Global water balance components (unit: km³/year, global, 10-year average)

	Rainf	Snowf	Evap	Qs	Qsb	Balance
BUCK	97774	14654	70865	43610	0	-2047
CLM2	93766	8688	62165	3842	36588	-142
ISBA	99921	13902	66344	15060	32561	-142
LaD_	99722	13909	74729	0	38716	186
MOSE	99923	13902	65066	16306	32376	76
NOAH	97774	14654	31847	2590	75840	2152
NSIP	96730	13244	74352	20152	15339	131
ORCH	96865	13514	51031	3746	71168	-15566
SSiB	105979	7967	55700	37446	20926	-126
SWAP	104603	9220	77158	10938	25654	73
SiBU	102621	11182	65540	27761	25648	-5146
VISA	99921	13902	76116	12380	30110	-4782
Mean	99633	12395	64243	16153	33744	-2111

To validate outputs, total runoff (= Surface Runoff + Subsurface Runoff) of each model is integrated using a global runoff routing model, namely TRIP, and compared with 270 river gauging stations globally for 1987-88. Most of models tend to overestimate discharge in North America, Europe to western Siberia and Africa around Gulf of Guinea, in other hand; slightly underestimate in eastern Siberia to Southeast Asia. It may be attributed to the characteristics of forcing precipitation data. Root mean square error (RMSE) is smaller for models with smaller runoff ratio, since the simulation has generally overestimation tendency.

In the annual meeting, both regionally and temporally detailed analyses and their background mechanism will be presented.