The main goals are to study the performance of gridded SST datasets in the coastal waters by comparing to the homogenized in situ SST records. In recognizing that local data may reflect local effects, we focus on dominant EOFs of the in situ SSTs and localized gridded datasets, examining patterns, variabilities and trends. We conclude that gridded datasets need improvement in the pre-satellite time, by re-examining in detail archives of local SST records in many data-sparse regions.

The pelagic in situ observation system (PELAGIOS) is a new towed observation system with HD video camera and environmental sensors. It is used for pelagic video transects down to 3000 m. The system enables the visualization and exploration of pelagic organisms (> 1 cm), in particular delicate gelatinous fauna, that cannot be captured by nets. The video and hydrographic data gives insight in the biodiversity, abundance and distribution of oceanic pelagic organisms, from the surface to the deep sea.

We revisit the sources for the upper limb of the overturning circulation in the South Atlantic by tracking fluid particles in a high-resolution ocean model. Our results suggest that the upper limb’s transport is dominantly supplied by waters with Indian Ocean origin, but the contribution of waters with Pacific origin is substantially larger than previously estimated with coarse-resolution models. Yet, a large part of upper limb waters get their thermohaline properties within the South Atlantic.

This study shows how the Mississippi river influenced the spreading of oil in the Gulf of Mexico after the DeepWater Horizon disaster. High resolution numerical models for ocean and atmosphere circulation are used to force an oil drift model. The circulation is totally different when river input is removed in the ocean model. The study also showcase the importance of the choice of oil droplet size distribution. Model output is compared with satellite observation of surface oil.

To better exploit the observational information available for all scales in data assimilation systems, we investigate a new method to introduce scale separation in the algorithm. It consists in carrying out the analysis with spectral localisation for the large scales and spatial localisation for the residual scales. The performance is then checked explicitly and separately for all scales. Results show that accuracy can be improved for the large scales while preserving reliability at all scales.

The paper presents a correlation that can potentially improve the signal obtained from ocean color remote sensing. Results come from a modelling applied to the atmosphere-ocean system in different regions of the southern Baltic, two seasons, and two wind speeds, each for nine visible spectral bands. The results show that the variability of the maximum of DoP depends more on seasonal than regional changes and can be explained to a large degree by the seawater absorption-to-attenuation ratio.

Sea surface temperature (SST) is related to ocean heat content, an important topic in the debate over global warming. In this manuscript, we propose a novel SST predicting method based on the hybrid improved EMD algorithms and BP neural network method. SST prediction results based on the hybrid EEMD-BPNN and CEEMD-BPNN models are compared and discussed. Cases study of SST in the North Pacific shows that the proposed hybrid CEEMD-BPNN model can effectively predict the time-series SST.

We analyse how surface drifters separate when being released as pairs or triplets in close proximity to wind farms. There is some tentative evidence that these drifters experience turbulent flows arising from an interaction between tidal currents and wind turbine towers. However, more comprehensive studies would be needed to clearly distinguish such wind farm related effects from the effects of turbulence that naturally occurs in a complex coastal environment.

Satellite wind data were used to understand surface wind variability in the eastern Austral Pacific Ocean, a region dominated generally by strong westerlies but, the empirical orthogonal function demonstrated that wind variability was dominated by synoptic scale. Nighttime heat waves events were detected producing air temperature maxima which exceeded the normal midday maxima caused by solar radiation. Downwelling conditions prevailed in the study region, owing to onshore Ekman transport.

Inspired by the known virtue of fish oil to still angry seas, a study has been made on the interaction between wind-waves, paddle-waves and airflow in a tank containing a thin fish oil film. It is rather peculiar that in the wind-only condition the wave field does not grow from the rest condition. This equilibrium was altered by paddle waves. We stress the benefit of experiments with surfactants to explore in detail the physics at, and the exchanges across, the wavy air-water interface.

This modelling study aimed to recreate the Agulhas transport proxy within a regional HYCOM of the Agulhas Current System, attempting to test the validity of the underlying assumptions on which the satellite-altimeter proxy was based. Results showed that the proxy is sensitive to subsurface variability in the model but that the proxy remained robust regarding the time periods needed to build a sufficient linear relationship between transport and SSH slope.

Sea surface temperature is affected by sun energy which in turn varies in time due to astronomical factors and sun activity. The activity can be estimated by sun spots (SS). Some oceanographic events like inter-annual El/La Niño/Niña as well as decadal processes should be affected by SS. It was found correlation between SS and various oceanographic indexes in time series from 1954 to 2017. This fact should be considered when dealing and modelling forecasts of such indexes.

Two decades of observations of the Arctic Mediterranean (AM) exchanges shows that the exchanges have been stable in terms of volume transport during a period when many other components of the global climate system have changed. The total AM-import is found to be 9.1 Sv and has a seasonal variation of amplitude close to 17 Sv and maximum import in October. Roughly one third of the imported water leaves the AM as surface outflow with the remain two thirds leaving.

Dissipation of ocean waves due to Whitecapping is one of the most important processes that affect generation of gravity waves by wind. Different behavior of traditional approaches used for quantifying Whitecapping dissipation under different wave conditions has always been a challenge to choose the most appropriate approach for a given area. The present paper examines the performance of two popular Whitecapping approaches incorporated in SWAN during the winter storms along the U.S East Coast.

A novel predictive model is built for eddy propagation trajectory using the multiple linear regression method. This simple model has related various oceanic parameters to eddy propagation position changes in the South China Sea (SCS). The performance of the proposed model is examined in the SCS based on twenty years of satellite altimeter data, and demonstrates its significant forecast skills over a 4-week forecast window comparing to the traditional persistence method.

Earth Observation satellites routinely monitor sea-surface temperature. However, they require in situ references for calibration and validation. To support this step, drifting buoys carrying sensors with improved calibration were deployed. This paper finds that sea-state and immersion depth are important to better understand the buoy measurements. A new drifting buoy was designed as a result, in the framework of the European Union Copernicus programme, with an accuracy found to be within 0.01 °C.

How to force a model where no suitable observation exists? We here determine using MITgcm the relative influence of the choice of wind, initial hydrography, and sea ice cover on the resulting ocean circulation in Nares Strait, northwest Greenland. The input with the largest effect is the density gradient in the upper layer. We argue that it should be prioritised over high resolution wind for cost-effective simulations of the Arctic straits, crucial for modelling the Arctic freshwater export.

Errors of observations and numerical model data are analysed with a focus on heterogeneous coastal areas. An extension of the triple collocation method is proposed, which takes into account gradients in the collocation of datasets separated by distances, which maybe not acceptable for a nearest neigbour approximation, but still be feasible for linear or higher order interpolations. The technique is applied to wave height data from insitu stations, models and the SENTINEL-3a altimeter.

In this contribution we investigate the hydrodynamic response in Alfacs Bay (Delta Ebro, NW Mediterranean Sea) to freshwater flows and inner bay-open sea connections. The numerical model ROMS is applied nested to Copernicus models, and validated with in-situ data. Considering the results only the modification of freshwater flows is recommended due to its lower impact on the environment and associated economic costs. None of the proposed solutions solve the problem related to warm waters.

This work deals with the use of Sea Surface Salinity measurements from space in the context of operational oceanography. The salinity plays an important role in the ocean-atmosphere coupling, especially when a El-Nino event occurs in the Tropical Pacific. However, it is still difficult to use such data in ocean models due to a large extent to large scales biases. This study shows that with recent data treatment improvements it is possible to have positive impact on weekly forecast.