The Arabian Sea and Sea of Oman have a complex oceanic circulation, strongly influenced by the monsoons. The aim of this article is to describe the mesoscale processes that dominate the region, large eddies with a strong vertical influence, with their seasonal and interannual variability, from their formations, evolutions and interactions. Thus, an emphasis is placed on the highly saline Persian Gulf outflow in the Sea of Oman, and its interaction with the mesoscale circulation.

This paper introduces a potential method for determining the salinity of the ocean surface from long-wave radio signals used for navigation (and potentially other AM radio transmissions). Here we seek to retrieve ocean surface salinity averaged along a path across the North Sea between Denmark and the UK and compare our results with satellite-derived salinity.

We use a suite of transient tracer measurements from a Southern Ocean sector southeast of Africa collected from 1998 and 2012 to quantify ventilation and change in ventilation. We found that the ventilation can be constrained by an inverse Gaussian transit time distribution north of the Subantarctic Front. We do not find any significant changes in upper ocean ventilation during this time period.

1. Argo floats were used to examine tropical cyclone (TC) induced ocean thermal changes on the global scale by comparing temperature profiles before and after TC passage. 2. Global average of the vertical structure of the average ocean thermal response for two different categories: tropical storms/depressions (TS/TD) and hurricanes were presented. 3. Significant differences between weak storm (TS/TD) and strong storm (hurricane) were found.

The Faroe Current is the main ocean current transporting warm Atlantic water into the Arctic region and an important transporter of heat towards the Arctic. This study documents observed transport variations over two decades, from 1993 to 2013. It shows that the volume transport of Atlantic water in this current increased by 9% over the period, whereas the heat transport increased by 18%. This increase will have contributed to the observed warming and sea ice decline in the Arctic.

We describe the seasonal and year-to-year variability of the spatial distribution of the phytoplankton size classes (PSCs) in the Mediterranean Sea using the time series of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) observations (1998 to 2010). We used a chlorophyll-a-based model to estimate the phytoplankton composition. Our results, based on ocean colour data, confirm the seasonal and inter-annual pattern of the phytoplankton community observed from in situ data and in previous studies.

A method which determines the radiance reflectance at the surface as well as the water-leaving and reflected radiances solely from the measurements of upward nadir radiance and downward irradiance in air is presented. A comparison between this method and in situ measurements shows that the average relative deviations between their results are less than or equal to 15% for the reflected radiance, at the studied wavelengths.

The altimetry data assimilation requires the addition of the mean dynamic topography to the altimetric sea level anomaly to match the model sea surface height. The mean dynamic topography is usually computed from the model long-term mean sea surface height. In this study, the impact of different mean dynamic topographies on the sea level anomaly assimilation is examined. Results show that impacts of the mean dynamic topography cannot be neglected.

Results from the ECCO v4 ocean state estimate identify the constraint of fitting Argo profiles as an effective observational basis for inverse estimation of regional turbulent transport rates. The estimated parameters' geography is physically plausible and exhibits close connections with the observed upper-ocean stratification. They yield a clear reduction in the model drift away from observations over multi-century-long simulations, including for independent biochemistry variables.

Quasi-regular eddies are known to be generated in the outflow of dense water through the Faroe Bank Channel. One year long mooring records from the plume region show that (1) the energy associated with the eddies varies by a factor of 10 throughout the year and (2) the frequency of the eddies shifts between 3 and 6 days and is related to the strength of the outflow. Similar variability is shown by a high-resolution regional model and the observations agree with theory on baroclinic instability.