Dear Colleagues,

Salinity plays an important role in the global ocean including water mass formation, density and circulation, heat storage, air–sea interactions, and the hydrological cycle. Understanding salinity variability is therefore paramount toward understanding global climate. In the past, salinity measurements have been sparse. The launch of the Soil Moisture and Ocean Salinity (SMOS), Aquarius, and Soil Moisture Active Passive (SMAP) satellites opened up a new era for providing global oceans’ surface salinity observations, which have improved our understanding of salinity variability and dynamics, among others. The scientific value of data collected by these salinity satellites is fostering both oceanographic and climate-related studies.

The aim of this Special Issue is to highlight the successes, applications, and impacts of satellite-derived sea surface salinity measurements on oceanographic research. It also highlights several ongoing innovative, synergetic uses of other satellite-derived parameters (e.g., SST, altimetry, scatterometry, ocean color), in situ measurements and numerical models to further our understanding of the global earth system, especially ocean variability, dynamics, and air–sea interactions. In this Special Issue, we welcome papers exploring all areas in remote sensing of salinity.

The topics of interest include, but are not limited to:

• Successes, and challenges of satellite-derived sea surface salinity missions;
• Improvements in sea surface salinity retrieval and products;
• Improving retrieval techniques for coastal sea surface salinity;
• Effects of rain on satellite salinity retrieval;
• Comparison, evaluation, and validation of satellite-derived sea surface salinity;
• Sea surface salinity variability using satellite(s), in situ observations, and ocean models;
• Ocean salinity budgets, fluxes, and transports;
• Salinity-influenced stratification, and air–sea interactions;
• Use of satellite-derived sea surface salinity in understanding freshwater plumes;
• Data assimilation of satellite-derived sea surface salinity to improve ocean studies and forecasting;
• Role of satellite-derived sea surface salinity in understanding ocean and climate change;
• Using satellite-derived sea surface salinity products to improve understanding of the hydrological cycle;
• Novel applications of satellite-derived sea surface salinity products.

Dr. Ebenezer Sackitey Nyadjro
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Remote Sensing is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2500 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

• sea surface salinity
• SMAP
• SMOS
• Aquarius
• remote sensing
• data assimilation
• freshwater dynamics

Title: Characteristics of Internal Waves of Tidal Period from ECCO Salinity Estimates and observations in the Bay of Bengal
Authors: Bulusu Subrahmanyam; V.S.N. Murty; Sarah B. Hall
Affiliation: University of South Carolina
Abstract: Internal Waves (IWs) are generated throughout all of the Earth’s oceans, especially in regions that receive a large amount of freshwater from nearby rivers which promote highly stratified waters to produce a shallow pycnocline, causing the formation and propagation of IWs. When barotropic tides encounter shallow bottom-topography, IWs of tidal period (known as internal tides) are generated and propagated along the pycnocline. The Bay of Bengal (BoB) and Andaman Sea particularly receive a large volume of freshwater from major rivers and monsoonal reversals that drive continental runoff and net precipitation. This study addresses the characteristics of internal tides in the BoB and Andaman Sea using the NASA’s Estimating the Circulation and Climate of the Ocean (ECCO) project’s high resolution (1/48° and hourly) salinity estimates at 1 m depth (hereafter written as ECCO salinity) during September 2011 – October 2012, time-series of temperature and salinity profiles from moored-buoys and the NASA’s Soil Moisture Ac-tive Passive (SMAP) salinity. The time-series of ECCO salinity and observed salinity are subjected to bandpass filtering with 11–14 hour period and 22–26 hour period to detect the semi-diurnal period and diurnal period internal tides and to estimate their characteristics. Our analysis reveals that the ECCO salinity captured well the surface imprints of diurnal period internal tide propagating through shallower pycnocline depth (~50 m depth) due to halocline, and the latter suppresses the impact of semi-diurnal period internal tides propagating at thermocline depth (~100 m depth) reaching the sea surface. The semi-diurnal (diurnal) period internal tides have their wavelengths and phase speeds increased (decreased) from central Andaman Sea to Sri Lanka coast.