33 
deep regions as the North Pacific, Southwest Atlantic and Eastern Indian Ocean the last 
level of the WOA01 climatology is more than 250 meters above the bottom since the deepest 
gridded level is at 5500 meters. 
5.2 Comparison of derived quantities 
A comparison of steric height anomaly fields (Fig.21) reveals a high degree of similarity 
between the two climatologies. The shape and geographical location of many of circulation 
patterns (e.g. subtropical gyres, equatorial currents, Gulfstream and Kuroshio, Antarctic 
Circumpolar Current) are visually almost identical. The main difference is a considerably 
higher contrast between the regions of high and low steric height anomaly values. Thus, for 
the layer 50-1000 meters the steric height anomaly difference between the Ross Sea and the 
centre of the subtropical gyre is a factor of 1.3 higher for the WGHC climatology (130 cm 
comared with 100 cm for WOA01). The WGHC climatology better resolves such western 
boundary currents as the Gulfstream, Kuroshio, Agulhas. The ACC also appears as a more 
concentrated, narrower current in the WGHC climatology. The differences in terms of 
volume transports are better seen on individual sections. We present geostrophic volume 
transports between the grid points calculated relative to the deepest common level and 
accumulated transports for a 35.5°N section across the North Atlantic and for the section 
along 20.5°E across the ACC (Fig. 22). 
Longitude 
I 0 m I 5-100 m 101-250 m ■ >250 m 
Fig.20: Difference (WGHC-WOA01) between the depths of the last gridded level.