[02-Nov-2021] We used a high resolution (~ 2 km) ocean model to determine subfootprint variability (SFV), the standard deviation within a satellite footprint. The model run was one year long and covered the global (non Arctic) ocean. SFV time series were computed on a 2° X 2° evaluation grid over the one year run.
[22-Oct-2021] Sea surface salinity satellites have a large footprint (40 100km) due to the way in which they make their measurements. The satellite makes an average over this footprint, but ignores potentially significant variations within it, so called subfootprint variability (SFV). We wish to determine the size of SFV, to help understand the uncertainty in the satellite measurements.
[24-Feb-2021] This paper presents one example showing how both SMAP observations and model show freshening associated with the Yukon River discharge delta. This is a significant finding in that it would allow the application of remote sensing to monitor changes in river discharge associated with possible changes in climate and changes in precipitation and ice melt.
[17-Feb-2021] Large rivers, key components of the land-ocean branch of the global water and biogeochemical cycles, can have important impacts on coastal oceans. Sea surface salinity (SSS) is a critical observable for monitoring river plumes and studying their impacts. Satellite and in-situ SSS gridded products have been used to characterize the variability of some river plumes. However, their consistency has not been examined systematically for near major river mouths of the world ocean.
[26-Jan-2021] Due to strong winds and intense heat, momentum and freshwater fluxes, Tropical Cyclones (TCs) can have a profound impact on the thermal and salinity structure of the upper ocean. In particular, the present study tries to answer the following questions: 1. What is the typical impact of TC rainfall, evaporation and winds on sea surface salinity (SSS) in terms of climate characteristics at global scale? 2. How do TC intensity, translation speed and preexisting ocean conditions affect the ocean response?
[23-Jan-2021] We use a combination of satellite wind, sea level anomaly, SST, and sea surface salinity anomaly data along with a high-resolution circulation model to examine wind impacts on SSSA. The primary objective is to determine if changes in regional winter wind patterns can explain most of the recently observed GoMSSS change.
[18-Jan-2021] Observations of sea surface salinity (SSS) from NASA's Soil Moisture Active-Passive (SMAP) and ESA's Soil Moisture and Ocean Salinity (SMOS) satellite missions are used independently, using two different analysis methods, to characterize and quantify the contribution of mesoscale eddies to the ocean transport of salt.
[16-Jan-2021] For strong storms, both sea surface salinity (SSS) and sea surface temperature (SST) wakes develop to the right of storm's track. The present global satellite-based analysis also emphasizes the influences of salt-stratified barrier layers.
[31-Dec-2020] Seasonal comparisons of sea surface salinity (SSS) data sets in previous studies were limited by not including mooring data. Incorporating these data sets allows a more detailed comparison of amplitude and phase than in any previous studies.
[20-Nov-2020] Barrier layers (BLs) play an important role in regulating the transfer of heat, momentum, and freshwater across the ocean's surface and into the ocean interior. BLs are shallow layers near the ocean surface where vertical density change is controlled by salinity.
[08-Nov-2020] Newly available satellite observations of sea surface salinity (SSS) from Aquarius and SMAP satellites are used to characterize SSS variability in the South China Sea.
[18-Sep-2020] Seasonal cycle is the dominant signal of sea surface salinity (SSS) variability. Previous analyses of seasonal SSS were based on the World Ocean Atlas (WOA) 1998 constructed from inhomogeneous sampling. This study revisits the seasonal harmonic patterns using four 0.25° satellite (SMAP and SMOS) and two 1° in situ (Argo and EN4) products and compare with the latest 0.25° WOA 2018.
[30-Jun-2020] Satellite L-band remote sensing in the past 10 years has proven the capability of resolving SSS spatiotemporal variability in the tropical and subtropical oceans. However, fidelity of SSS retrievals in cold waters at mid-high latitudes is yet to be established.
[12-Jun-2020] Working groups (WGs) were formed to address several priority areas identified at the April 2020 virtual salinity workshop. The WGs are intended to enhance collaborations among salinity investigators who are involved or interested in the WG topics in order to have more coherent effort for satellite SSS assessment (e.g., identifying strengths and weaknesses), for providing feedbacks to satellite SSS retrieval teams, and for supporting NASA salinity science through scientific results derived from the related analyses.
[06-Jun-2020] Saildrone is an unmanned surface vehicle that has the capability for measuring multiple atmospheric and oceanographic parameters. Because it has one minute continuous sampling, it provides a unique opportunity for the validation of SST and SSS gradients. For this study, direct comparisons were done with six satellite-derived SST products and two satellite-derived SSS products from SMAP.
[09-May-2020] The ocean plays a dominant role in the global water cycle. It is the center of action for global evaporation and precipitation, and supplies the moisture that falls as continental precipitation. It also acts to some extent as Nature's rain gauge as sea surface salinity integrates the complex multifactorial variations in the water cycle.
[08-May-2020] The advent of the SMAP mission has allowed for the observation of sea surface salinity (SSS) at an unprecedented scale. Despite this, SSS has largely been neglected in monsoon studies, and thus this study focused on how SMAP salinity can be useful for monitoring weather/synoptic related 3-7-day oscillations and monsoon variability.
[09-Mar-2020] Hudson Bay (HB) is the largest semi-inland sea in the Northern Hemisphere, located at the southern margin of the Arctic Ocean. The bay is completely covered by ice and snow in winter, and open water in summer. For about six months each year, satellite remote sensing of sea surface salinity is retrieved over open water.
[17-Dec-2019] Sea surface salinity (SSS) is a critical parameter in the Arctic Ocean, having potential implications for climate and weather. A systematic evaluation of satellite SSS products in the Arctic Ocean across different missions has not been done, hindering the ongoing cal/val and potential applications.
[18-Nov-2019] Subfootprint Variability (SFV) is a significant source of mismatch between satellite and in situ, but has not been quantified on a global basis. These heavily-sampled regions tell us that SFV can be found using high-resolution models and mooring data, which are much more common than intensive field campaigns such as SPURS.
[27-Aug-2019] The concentration of dissolved salt in our ocean is known as salinity. Since 2011, data from NASA satellites have unveiled changing salinity patterns. But to get a simple measurement like salinity, you need to untangle a lot of complicated signals.
[21-Aug-2019] Validation of remote sensing data sets in coastal waters. Overall this is a difficult problem, as global arrays such as ARGO do not provide data in coastal regions. Yet, these areas are critical as coastal upwelling is essential for maintaining the world's fisheries.
[05-Aug-2019] Results of this research provide insights into variations in sea surface salinity in the subtropical gyre and contribute to the broader understanding of global ocean dynamics.
[05-Jul-2019] Here we present an observation-based study of the coupled land-ocean regions of influence for the transformation of precipitation over land into coastal river plume structure in the Gulf of Mexico.
[14-Jun-2019] Previous studies of salinity processes have contained gaps that have constrained the ability to answer significant questions such as "How does the ocean integrate rainfall and evaporation that can alter ocean salinity at the surface?" The SPURS-2 (Salinity Processes in the Upper ocean Regional Studies - 2) field campaign collected new data and may help answer such important questions about salinity processes, especially in the tropics.
[14-Jun-2019] The Salinity Processes Upper-ocean Regional Study 2 (SPURS-2) field campaign was designed to examine processes affecting the near-surface salinity structure and variability beneath the Intertropical Convergence Zone (ITCZ). Within the tropical Pacific, seasonally-varying rainfall driven by the ITCZ coincides with the formation of a vast low salinity band crossing the entire Pacific Ocean. To better understand this, a high-resolution numerical model was formulated focusing on smallscale processes impacting sea surface salinity (SSS) in the region.
[08-May-2019] The Maritime Continent (MC) is a low-latitude chokepoint of the world oceans with the Indonesian throughflow (ITF) linking the Indo-Pacific oceans, influencing global ocean circulation, climate, and biogeochemistry. While previous studies suggested that South-China-Sea freshwaters north of the MC intruding the Indonesian Seas weaken the ITF during boreal winter, the impact of the MC water cycle on the ITF has not been investigated.
[01-Oct-2018] River discharge, and its resulting region of freshwater influence (ROFI) in the coastal ocean, has a critical influence on physical and biogeochemical processes in seasonally stratified shelf ecosystems. Multi-year (2010-2016) observations of satellite-derived sea surface salinity (SSS) and in situ water column hydrographic data during summer 2016 were used to investigate physical aspects of the ROFI east of the Mississippi River Delta to better assess regional susceptibility to hypoxia in the summer months.
[11-Sep-2018] SMAP ocean surface salinity data track advection of unusually warm salty surface water into the Gulf of Maine in winter 2017-2018. SMAP results confirmed by buoy measurements inside the Gulf as well as glider data on shelf.
[04-Jun-2018] This study demonstrates that SMAP SSS provides useful information in monitoring large freshwater signals in the Arctic Ocean. Challenges remain in further improvement of SSS retrieval sensitivity in cold water region and having adequate in situ data for calibration and validation.
[17-Dec-2017] The subtropical high pressure of the descending branch of the Hadley circulation is located between 20° and 40° of both north and south latitudes. Within the zone, a pool of sea surface salinity maximum (SSS-max) exists in responding to the excess of evaporation over precipitation.
[17-Nov-2017] The Bay of Bengal receives large amounts of freshwater from the Ganga-Brahmaputra river during the summer monsoon. The resulting upper-ocean freshening influences seasonal rainfall, cyclones, and biological productivity.
[25-Oct-2017] This study investigates sea surface salinity and sea surface temperature variations in the tropical Atlantic east of the Lesser Antilles, a region where freshwater advection from the Amazon and Orinoco Rivers, may potentially impact air-sea interaction.
[15-May-2017] The ocean-surface freshwater budget estimated from the present satellite and atmospheric reanalyses is known to have a large uncertainty. This study explores the potential of using ocean salinity observations (Aquarius, Argo, and WOA) to assess the variability and uncertainty in 12 atmospheric reanalyses and satellite-based evaporation-minus-precipitation (E-P) products.
[22-Mar-2017] Scientists have historically sampled the ocean's chemistry by collecting water on exhaustive field campaigns. More recently, autonomous technologies such as gliders and floats have come on-line, providing greater coverage. Now, oceanographers and climatologists have one more tool to add to their quiver: satellites.
[30-Dec-2016] This is the product specification document for the Level 2B (L2B) passive Sea Surface Salinity (SSS) and Wind Speed (WSPD) product for the Soil Moisture Active Passive (SMAP) project.
[13-Sep-2016] SMAP sea surface salinity (SSS) V2.0 validated release data from Remote Sensing Systems. The near-polar orbit of SMAP allows for complete global coverage of the oceans in 3 days with a repeat cycle of 8 days. The RSS SMAP SSS V2.0 validated release contains 3 products: Level 2, Level 3 8-day running averages, and Level 3 monthly averages. All files are in netCDF4 format and are CF compliant.
[10-Sep-2016] Floods can have damaging impacts on both land and sea, yet studies of flooding events tend to focus on only one side of the land/sea continuum. Here we present the first two-sided analysis, focusing on the May 2015 severe flooding in Texas.
[12-May-2016] Aquarius and SMOS detected large interannual changes of SSS in the Mississippi River mouth that state-of-the-ocean high-resolution global ocean assimilation products (e.g., US Navy's HYCOM operational anlysis) failed to capture. Aquarius/SMOS/SMAP salinity data provide valuable resources to constraint ocean analysis and forecast to study the linkage of ocean and regional water cycle.
[24-Dec-2015] Aquarius is a combined active/passive microwave (L-band) instrument designed to map the salinity of global oceans from space. The specific goal of Aquarius is to monitor the seasonal and interannual variation of the large scale features of the sea surface salinity (SSS) field of the open ocean (i.e. away from land).
[22-Dec-2015] This article presents a method for formally assessing random and systematic uncertainties in the Aquarius salinity retrievals.
[15-May-2015] The Intertropical Convergence Zone (ITCZ) is a major source of the surface freshwater input to the tropical open ocean. Under the ITCZ rain bands, zonally oriented sea surface salinity (SSS) fronts are observed by the Aquarius/SAC-D mission and Argo floats. This study is to investigate the evolution and forcing mechanism of the tropical SSS fronts.
[31-Dec-2013] The SMAP Handbook was produced in 2013 as a compendium of information on the project near its time of launch. The SMAP Science Definition Team and Project personnel wrote this volume together to provide the community with the essential information on programmatic, technological, and scientific aspects of the mission.
[18-Feb-2013] This report documents the Aquarius sea surface salinity measurement error statistics and some residual errors in the V2.0 data release. We also document the effect that changes in the science data processing since V1.3 have on the error statistics by comparing V1.3 with V2.0 results.
[01-Jul-2012] Aquarius/SAC-D Mission feature article from NASA's The Earth Observer newsletter.
[17-Aug-2011] This diagram shows the satellite's roll, pitch and yaw angles during deployment. Click here for more information.
[16-Aug-2011] This diagram shows the satellite's roll angle change about 0.5 degree during deployment. Click here for more information.
[10-Jun-2011] NASA announces the launch of the Aquarius/SAC-D observatory.
[07-Jun-2011] A description of the Delta II launch vehicle for the Aquarius/SAC-D satellite launch.
[03-Jun-2011] An introduction to the Aquarius instrument and how salinity is measured.
[17-May-2011] Science Writers' Guide released by NASA prior to the launch of Aquarius.
[30-Mar-2011] This one-page lithograph summarizes the Aquarius/SAC-D mission and why the concentration of salt in the ocean is a key variable for understanding global ocean circulation.
[30-Mar-2011] A summary of the launch vehicle and details of the deployment of the Aquarius/SAC-D satellite.
[30-Mar-2011] The official mission brochure for the Aquarius/SAC-D Mission.
[28-Mar-2011] CONAE kicks off the launch campaign with information on the Aquarius/SAC-D mission for the press.
[01-Jan-2011] Yi Chao, Aquarius Project Scientist, NASA Jet Propulsion Laboratory describes the new Aquarius mission to Chris Howell in Ocean Bights.
[19-Dec-2010] Written three years before the launch of Aquarius in June 2011, this overview by Dr. Raymond Schmitt summarizes the impacts of climate change on the water cycle and ocean salinity.
[01-Jul-2010] Aquarius/SAC-D Mission feature article from NASA's The Earth Observer newsletter.
[20-May-2010] INSPIRE education specialist Jim Gerard from Kennedy Space Center chats with Yi Chao, Aquarius Project Specialist about the Aquarius satellite mission.
[24-Feb-2010] Presentation from Aquarius PI Gary Lagerloef's plenary talk at the 2010 Ocean Sciences Meeting in Portland, Oregon.
[22-Feb-2010] In this article, written many years before the launch of Aquarius, the authors report that a new satellite program will provide data to reveal how the ocean responds to the combined effects of evaporation, precipitation, ice melt, and river runoff on seasonal and interannual time scales.
[22-Feb-2010] The CLIVAR (Climate Variability and Predictability) Working Group, an international research effort focusing on the variability and predictability of the slowly varying components of the climate system, provides recommendations to improve our understanding, monitoring, modeling and predicting of climate.
[19-Feb-2010] Researchers Igor Yashayev and Allyn Clarke discuss the evolution and interplay of water masses in the subpolar North Atlantic, an important region in terms of deep-ocean circulation
[19-Feb-2010] In this 1996 overview article, Dr. Raymond Schmitt (Woods Hole Oceanographic Institution) summarizes fresh water's effect on ocean phenomena.
[01-Jul-2008] Aquarius/SAC-D Mission feature article from NASA's The Earth Observer newsletter.
[01-Jan-2008] After a four-year development effort, the NASA Goddard Space Flight Center has delivered the Aquarius Radiometer to the Jet Propulsion Laboratory (JPL) in Pasadena, California for integration with the Aquarius instrument.
[11-Jan-2006] The mission overview fold-out covering NASA's priorities through the scientific return.