Tramper

Abstract

-TRAMPER is an autonomous benthic crawler equipped with oxygen sensors to perform long-term flux time series measurements at abyssal depth. The crawler is developed within the HGF-Alliance ROBEX. TRAMPER has five main subsystems: the titanium frame with the flotation, the caterpillar drive system, recovery and communication systems, energy and electronics and a multi-optode profiler as the scientific payload. A lithium-ion battery pack provides the energy to run an oxygen profiling system performing consecutive measurements (>52 cycles) along its transecting moving on the seafloor. This new generation of optode-based oxygen monitoring system allows using 18 oxygen optodes and is able to perform in situ calibrations. A video-guided launching system is used to deploy the crawler at the seafloor. At the seafloor the pre-programmed mission scenario is performed consisting of consecutive sleeping, moving and measurement cycles. The aim is to cover a seasonal cycle of settling organic matter on the seafloor and to resolve the impact on the benthic community respiration activity.

Reviews and syntheses: Ocean iron fertilization experiments – past, present, and future looking to a future Korean Iron Fertilization Experiment in the Southern Ocean (KIFES) project

“…Furthermore, after the end of SOIREE, ocean-color satellite images showed continued high chlorophyll a concentrations (> 1 mg m −3 ) in the iron-fertilized patch, which was visible as a long ribbon shape that extended some 150 km for > 40 days (∼ 6 weeks) after the first iron addition (Fig. 10b) Westberry et al, 2013). This indicates that short experimental durations may not be sufficient for detecting the full influence of aOIF on PP and the ecosystem (Figs.…”

“…However, floats tend to drift out of the fertilized patches under strong wind forcing Law et al, 1998;Stanton et al, 1998). NASA airborne oceanographic lidar and ocean-color satellites have also been employed to assess the large-scale effects of iron addition on surface chlorophyll in fertilized patches, as compared to surrounding regions (Martin et al, 1994;Westberry et al, 2013).…”

“…Satellite observations were used to investigate the changing spatial and temporal distribution of chlorophyll a concentration in response to iron fertilization in the fertilized patches compared to the surrounding waters; for example, SOFeX-N and SOFeX-S found elevated chlorophyll a concentrations in fertilized patches after iron addition through satellite images (Fig. 7d) Coale et al, 2004;Westberry et al, 2013).…”

“…To the south of the SO PF, phytoplankton blooms usually occur during early summer (i.e., from late December to early January) due to an increase in the nutrient flux from subsurface waters induced by winter mixing, along with the favorable light conditions provided by a shoaling of the ML (Moore and Abbott, 2002). Weekly and monthly climatological maps of chlorophyll a concentrations derived from satellite data could provide the necessary information for determining the timing of blooms in the SO PF (Westberry et al, 2013). Prior to December, phytoplankton growth is mainly limited due to light availability (Mitchell et al, 1991;Veth et al, 1997;Abbott et al, 2000), while after January (i.e., during late summer and early autumn from February to March) it is mainly limited due to iron and silicate availability (Abbott et al, 2000;Mengelt et al, 2001;Nelson et al, 2001).…”