Xianyao Chen1, 2, *, Yuanling Zhang1, 2, Min Zhang1, 2, Ying Feng1, 2, Zhaohua Wu3, Fangli

Intercomparison between Observed and Simulated Variability in Global Ocean Heat Content using Empirical Mode Decomposition,
Part I: Modulated Annual Cycle

Supplementary

Xianyao Chen1, 2, *, Yuanling Zhang1, 2, Min Zhang1, 2, Ying Feng1, 2, Zhaohua Wu3, Fangli Qiao1, 2, and Norden Eh Huang1, 2,4

1 Key Laboratory of Data Analysis and Applications, State Oceanic Administration, China

2 The First Institute of Oceanography, State Oceanic Administration, China

3 Florida State University, US

4 National Central University, Taiwan, China

Figs. A1 - A6 compare the vertical distributions of modulated annual cycle (MACs) and their mean amplitude of the upper ocean heat content (OHC) derived from EN3 dataset in recent periods 1990-2011 with that in the period 1970-1989. It is shown that although the mean amplitude of MACs of OHC is similar with each other in both North Atlantic and South Atlantic, there exists significant difference of the IF of MACs, especially in the depth below 150 m and in winter. This indicates that recent observations in the world ocean obtained by Argo profiles improve the objective analyzed temperature fields, especially in the subsurface ocean and in winter time. Therefore, it should be very carefully when evaluating the model performance in the subsurface ocean by intecomparison with objective analyzed dataset. This also raises the issue to estimate the quality of objective analyzed dataset for the models intercomparison program.

1)The vertical distribution of MAC in the latitude bands 30-40N during 1970-1989, and 1990-2011.

Fig.A1 Mean amplitude of MAC of OHC during the period 1970-1989 (blue) and the period 1990-2011 (red) in the specified area in North Atlantic (30-40oN, 280-360oE). The MACs of OHC in each layer is divided by the thickness of each layer. The unit is in J/m.

Fig.A2 Monthly mean MAC of OHC in each layer in the specific area in the North Atlantic (30-40oN, 280-360oE) in the periods 1979-1989 and 1990-2011, respectively.

Fig.A3 Monthly mean IF of MAC of OHC in each layer in the area in the North Atlantic (30-40oN, 280-360oE)in the periods 1970-1989 and 1990-2011, respectively. The unit is in cycle per year.

2)The vertical distribution of MAC in the latitude bands 40-30oS during 1970-1989, and 2000-2011 (Note that different period as that in North Atlantic is used because significant increase of observation in South Atlantic is after 2005.)

Fig.A4 Same as Figure C4a but for but for the specified area in South Atlantic (40-30oS, 280-360oE).

Fig.A5 Same as Figure C4b but for but for the specified area in South Atlantic (40-30oS, 280-360oE).

Fig.A6 Same as Figure C4c but for but for the specified area in South Atlantic (40-30oS, 280-360oE).

As shown in Figs.A1-A6, in the North Atlantic (30-40oN, 280-360oE), the vertical distribution of the MACs and their mean amplitude during two different periods is very similar with each other, but the IF of MAC during 1990-2011 shows more reasonable pattern than that during 1970-1989, especially in the depth below 150 m and in winter.

In the South Atlantic (40-30oS, 280-360oE), although the vertical distribution of mean amplitude of MAC during two different periods is similar, the vertical distribution of MAC shows different pattern below the 150 m depth, as well as its IF.