Description: Author Posting. © The Author(s), 2016. This is the author's version of the work. It is posted here by permission of Inter-Research for personal use, not for redistribution. The definitive version was published in Marine Ecology Progress Series 561 (2016): 189-201, doi:10.3354/meps11915.

Description: Thalia democratica blooms are a recurrent phenomenon in many coastal areas of the Mediterranean Sea and have significant ecological effects. To better understand the environmental drivers of salp blooms, we conducted 8 surveys to sample T. democratica in contrasting seasonal, temperature and chlorophyll conditions. In each survey, short-term variations in the abundances of different salp stages were assessed by sampling the same population at 30 min intervals. Using these data, we estimated the parameters in a set of stage-classified matrix population models representing different assumptions about the influence of temperature and chlorophyll on each stage. In the model that best explains our observations, only females are affected by changes in water temperature. Whether this is a direct influence of temperature or an indirect effect reflecting low food availability, female reproduction cessation seems to slow population growth under unfavourable conditions. When conditions become favourable again, females liberate the embryo and change sex to male, allowing for mating under extremely low salp densities and triggering the bloom. In contrast to previous findings, our results suggest that females, rather than oozooids, are responsible for the sustainability of salp populations during latency periods.

Description: This work was founded by the Ministerio de Ciencia e Innovación under the Fishjelly project, the European commission ENPI CBC MED project under the Jellyrisk project and the European LIFE Commission under the Cubomed project. M. G. Neubert acknowledges the support of the US National Science Foundation (DEB-1145017 and DEB-1257545).

Description: The data contains brightness temperature data measured by ARIEL at 1.4GHz, during the MOSAIC expedition, in particular from July to September 2022 (LEG4 and LEG5). The ARIEL radiometer is a dual polarization (H & V) total power radiometer with internal calibration. The central frequency is 1.41 GHz, with a bandwidth of 20 MHz. The system has a 2x1 patch antenna, with a beam width of 36 ◦ at 3 dB at the azimuth direction and 70 ◦ at 3 dB at the elevation angle. The radiometric accuracy of ARIEL is 1.06 K at 1 Hz sampling frequency, with the capability to measure at higher sampling rates (up to 10 Hz) at the expenses of the radiometric accuracy. A co-located thermal infrared photodiode to measure the surface temperature and a GPS receiver complete the sensor equipment. Calibration is performed with a hot load and a cold load. To adapt the ARIEL instrument to the harsh and cold conditions of the Arctic, two adaptions were required to increase the internal thermal resistance by adding isolating material and to apply conformal coating to protect the electronics against humidity. The ARIEL accuracy was 2.3 K (instead of 1 K, due to a software error on the sampling rate). This light (7 kg) and small radiometer (40 cm x 60 cm x 20 cm) is ideal for frequent manoeuvres. The radiometer was mounted on a wooden sledge to measure microwave emission at 40 ◦ incidence angle with respect to nadir. A calibration procedure for the radiometers is needed to convert the measured voltages to brightness temperatures. The calibration of the ARIEL was done pointing the radiometer to cold and hot targets. The cold target is the cold sky (approx. temperature of 6 K (from Le Vine and Skou (2006)), while the hot target was absorber material at the instrument frequency stored into a big box (which represent an emissivity of 1). The calibration routines were performed every few days (3-5 days). After filtering the outliers, the data was smoothed to further reduce the noise. A sliding window of 20 samples was applied, which has proven to work better with ARIEL data, reducing standard deviation and therefore the noise of the measurements (Fabregat (2021)). Moreover, since the radiometer was over a moving ice cap, the position with respect to the Polarstern is computed, in addition to the GPS position, to simplify the collocation with other instrument measurements. We used a Python code provided by Dr. Stefan Hendricks (AWI) to compute this relative position (Gitlab reference: https://gitlab.awi.de/floenavi-crs).

Description: Raw data (horizontal and Vertical polarization voltages) of the mobile L-band radiometer, called ARIEL from BALAMIS Company. This raw data can be converted to Brightness Temperature, which can be used to measure ice thickness during the MOSAiC expedition legs PS122/4 and PS122/5. The files contains the horizontal and Vertical polarization voltages measured with the ARIEL radiometer during July and August 2020. The label of each columns are: 1 - On-board computer time stamp [hhmmss] 2 - Internal hot load [Volts] 3 - Antenna polarization 1 [Volts] (V-pol) 4 - Antenna polarization 2 [Volts] (H-pol) 5 - Internal cold load [Volts] 6 - Internal temperature [Celsius] 7 - Heater for temperature stabilization power [%] 8 - IR photodiode reading [Celsius] 9 - GPS time stamps [hhmmss] 10 - GPS latitude 11 - GPS longitude 12 - GPS altitude 13 - GPS connected flag 14 - Ethernet cable connected flag

Description: Highlights • We track the preferential pathways of the Mediterranean Outflow Water (MOW). • A topographic analysis method is used to identify the MOW hydrological avenues. • Contour avenues and cross-slope channels have complementary roles steering the MOW. • The MOW is a density-driven current steered by both bottom topography and the Coriolis force. Abstract The Mediterranean Water leaves the western end of the Strait of Gibraltar as a bottom wedge of salty and warm waters flowing down the continental slope. The salinity of the onset Mediterranean Outflow Water (MOW) is so high that leads to water much denser (initially in excess of 1.5 kg m−3) than the overlying central waters. During much of its initial descent, the MOW retains large salinity anomalies – causing density anomalies that induce its gravity current character – and relatively high westward speeds – causing a substantial Coriolis force over long portions of its course. We use hydrographic data from six cruises (a total of 1176 stations) plus velocity data from two cruises, together with high-resolution bathymetric data, to track the preferential MOW pathways from the Strait of Gibraltar into the western Gulf of Cadiz and to examine the relation of these pathways to the bottom topography. A methodology for tributary systems in drainage basins, modified to account for the Coriolis force, emphasizes the good agreement between the observed trajectories and those expected from a topographically-constrained flow. Both contour avenues and cross-slope channels are important and have complementary roles steering the MOW along the upper and middle continental slope before discharging as a neutrally buoyant flow into the western Gulf of Cadiz. Our results show that the interaction between bottom flow and topography sets the path and final equilibrium depths of the modern MOW. Furthermore, they support the hypothesis that, as a result of the high erosive power of the bottom flow and changes in bottom-water speed, the MOW pathways and mixing rates have changed in the geological past.

Description: We use hydrographic, velocity and drifter data from a cruise carried out in November 2008 to describe the continental slope current system in the upper thermocline (down to 600 m) between Cape Verde and the Canary Islands. The major feature in the region is the Cape Verde Frontal Zone (CVFZ), separating waters from tropical (southern) and subtropical (northern) origin. The CVFZ is found to intersect the slope north of Cape Blanc, between 22°N and 23°N, but we find that southern waters are predominant over the slope as far north as 24°N. South of Cape Blanc (21.25°N) the Poleward Undercurrent (PUC) is a prominent northward jet (50 km wide), reaching down to 300 m and indistinguishable from the surface Mauritanian Current. North of Cape Blanc the upwelling front is found far offshore, opening a near-slope northward path to the PUC. Nevertheless, the northward PUC transport decreases from 2.8 Sv at 18°N to 1.7 Sv at 24°N, with about 1 Sv recirculating ofshore just south of Cape Blanc, in agreement with the trajectory of subsurface drifters. South of the CVFZ there is an abrupt thermohaline transition at σ ϴ =26.85 kg m –3 , which indicates the lower limit of the relatively pure (low salt and high oxygen content) South Atlantic Central Water (SACW) variety that coexists with the dominant locally-diluted (salinity increases through mixing with North Atlantic Central Water but oxygen diminishes because of enhanced remineralization) Cape Verde (SACWcv) variety. At 16°N about 70% of the PUC transport corresponds to the SACW variety but but this is transformed into 40% SACWcv at 24°N. However, between Cape Verde and Cape Blanc and in the 26.85 〈 σ ϴ 〈 27.1 layer, we measure up to 0.8 Sv of SACWcv being transported south. The results strongly endorse the idea that the slope current system plays a major role in tropical-subtropical water-mass exchange.

Description: Despite the considerable impact of meddies on climate through the long-distance transport of properties, a consistent observation of meddy generation and propagation in the ocean is rather elusive. Meddies propagate at about 1000 m below the ocean surface, so satellite sensors are not able to detect them directly and finding them in the open ocean is more fortuitous than intentional. However, a consistent census of meddies and their paths is required in order to gain knowledge about their role in transporting properties such as heat and salt. In this paper we propose a new methodology for processing high-resolution sea surface temperature maps in order to detect meddy-like anomalies in the open ocean on a near-real-time basis. We present an example of detection, involving an atypical meddy-like anomaly that was confirmed as such by in situ measurements.

Description: Capability for sea surface salinity observation was an important gap in ocean remote sensing in the last few decades of the 20th century. New technological developments during the 1990s at the European Space Agency led to the proposal of SMOS (Soil Moisture and Ocean Salinity), an Earth explorer opportunity mission based on the use of a microwave interferometric radiometer, MIRAS (Microwave Imaging Radiometer with Aperture Synthesis). SMOS, the first satellite ever addressing the observation of ocean salinity from space, was successfully launched in November 2009. The determination of salinity from the MIRAS radiometric measurements at 1.4 GHz is a complex procedure that requires high performance from the instrument and accurate modelling of several physical processes that impact on the microwave emission of the ocean’s surface. This paper introduces SMOS in the ocean remote sensing context, and summarizes the MIRAS principles of operation and the SMOS salinity retrieval approach. It describes the Spanish SMOS high-level data processing centre (CP34) and the SMOS Barcelona Expert Centre on Radiometric Calibration and Ocean Salinity (SMOS-BEC), and presents a preliminary validation of global sea surface salinity maps operationally produced by CP34.