Float WMO_ID: 5901650

The table below provides basic information about the float, including primary sensors, mission parameters and current status of profiles.

This float was located in the Southern Ocean in an area bounded by 28 to 38 ºE and 53 to 60 º S.

The surface pressure for this float is shown in the plot below. There appears to be no sign of pressure drift in this float.

Potential Temperature-Salinity (a), Location (b, Max Temperature (c) and Sea Surface Salinity (d) plots located below.

Surface temperatures generally varied between -2 and 4 ºC and surface salinities from 33.7 to 34.1.

The plot below shows the potential-temperature/salinity curve for the deepest theta levels where the relationship between the two parameters should show the least variation.

Deep profiles look reasonable for this float. The earlier profiles are saltier than later profiles but given the float has crossed at least two fronts/eddies this is to be expected. There are a couple of outlier values at depth (both fresher and saltier) in some of the earlier profiles that will be checked.

The two plots below show a). the location of this float (black circles) in relation to the position of other nearby argo floats (coloured circles) and b). The potential-temperature/salinity curve for this float (in black) compared to nearby argo floats (coloured).

The potential-temperature/salinity curve for the deepest theta levels for this float (in black) and nearby argo floats (coloured) is displayed below.

This float is within the envelope of neighbouring profiles. There is a high degree of variability evident in most profiles due to the number of fronts in this region.

There were inversions present in profiles 7 (1850 m) and 27 (100 to 130 m). Neither of these inversions were significant and therefore were not flagged.

There were no salt hooks present.

The float did not ground anywhere and there were no missing profiles. The large spike in profile 10 in T & S at 1400 m depth was flagged as QC=4. The last two values of profile 7 were flagged as QC4 as was a spike in the surface mixed layer in profile 1.

Float trajectory overlayed on bathymetry

Potential temperature section with time, (left) surface to 2000m and (right) surface to 500m

Salinity section with time, (left) surface to 2000m and (right) surface to 500m

Potential density section with time, (left) surface to 2000m and (right) surface to 500m

The plot below shows the analysis of salinity drift using the WJO/OW software.

The float was very close to mapped salinity and no correction was required.

The four plots below show the salinity anomalies on theta surfaces compared to (a) the Gouretski and Kolterman climatology, (b) the CARS (CSIRO Atlas of Regional Seas)/WOA (World Ocean Atlas) climatology, (c) the anomalies within the float series itself, (i.e. the salinity anomaly of each profile from the mean profile average for the float and (d) the raw float salinity compared to the CARS and G&K climatological salinity on a theta surface of 0.88 degrees C.

The float was very close to CARS and offset from G&K (especially for the first 12 profiles). However as the float crossed two fronts this kind of variability is reasonable.

The plots below show the raw float salinity data (solid blue line) compared to neighbouring argo floats (coloured symbols) on a potential temperature surface of 0.9 degrees C. The locality map shows the location of the profiles for this float and for neighbouring floats.

There is about a 0.01 to 0.015 spread in the salinities on a deep theta level. However this float is close to the two other floats deployed at a smilar time and given the variability of Southern Ocean fronts this is fine. The sharp fresh offset is most likely due to the float shifting closer to the continent into fresher water masses, several other southerly floats show similar values so do not think this is due to drift.

This float required no salinity drift correction.

The plot below summarises the QC flags and salinity differences for the raw and adjusted salinity fields in the final delayed mode files submitted to the GDAC.

Created 27-07-2010