05 April 2004

Monday, 5 April 2004

Science on the high seas

Today was very much like others – high winds, intervals of sun, and some rain showers. There was swell of few metres running for most of the day. The routine of mapping the patch continues, with CTDs both inside and outside the fertilized area. With the passage of time it has become apparent that the patch is moving clockwise around an eddy. The part we are focussing on is spread over an area of 6km by 6km which makes it easier to track than the earlier narrow filament.

The autonomous profiler SkinDeEP was deployed 2 nights ago, and continues to make measurements through today. The plan is to recover tomorrow. This will be the longest single deployment in its 5 year life. It is also the roughest conditions under which it has been deployed. SkinDeEP is making high resolution vertical profiles of temperature, salinity, irradiance, and fluorescence. This will tell us how sunlight penetrates the water to stimulate plankton growth.

The sea surface skin temperatures from the M-AERI are also being made under the highest winds speed conditions to date, so this should prove to be a very interesting dataset for studying the surface where atmosphere and ocean meet.

The microspar was deployed tonight, and will remain in the water until tomorrow. This instrument is a prototype and has a sensitive pressure sensor attached below the waterline. The spar buoy, which is essentially a tube of about 5 metres in length, moves with the waves, and this causes a change in pressure. By analysing the pressure signal, it is possible to derive information of the wave field. These data will then be compared with the radar, which remotely senses wave parameters.

Meal times continue to be a highlight of the day because of the quality and variety of the food on offer.

Brian Ward (WHOI)
Peter Minnett (RSMAS)

First mate Alexander Morrice on the bridge

Typical ocean view during this voyage

Launching the inflatable with Brian Ward (left), Peter Healey, and Craig Stevens (right) for deployment of the autonomous profilers.

Deploying the 5 metre long "micro"-spar for wave measurements.

Histogram of wind speeds since the start of the voyage. Most of the winds are in the 20-40 knot range, which is equivalent to 37-74 km per hour.

Research subject: Oceans