Satellite and In Situ Salinity: Understanding Near-surface Stratification and Sub-footprint Variability
|Author(s)||Boutin J.1, Chao Y.2, Asher W. E.3, Delcroix T.4, Drucker R.5, Drushka K.3, Kolodziejczyk Nicolas1, Lee T.6, Reul Nicolas7, Reverdin G.1, Schanze J.8, Soloviev A.9, Yu L.10, Anderson J.5, Brucker L.11, 12, Dinnat E.13, 14, Santos-Garcia A.15, Jones W. L.15, Maes C.16, Meissner T.17, Tang W.6, Vinogradova N.18, Ward B.19, 20|
|Affiliation(s)||1 : Univ Paris 06, Sorbonne Univ, LOCEAN Lab, CNRS,IRD,MNHN, Paris, France.
2 : Remote Sensing Solut, Pasadena, CA USA.
3 : Univ Washington, Appl Phys Lab, Seattle, WA 98105 USA.
4 : Lab Etud Geophys & Oceanog Spatiale, Toulouse, France.
5 : Univ Washington, Sch Oceanog, Seattle, WA 98195 USA.
6 : Jet Prop Lab, Pasadena, CA USA.
7 : IFREMER, Lab Oceanog Space, Toulon, France.
8 : Earth & Space Res, Seattle, WA USA.
9 : Nova Southeastern Univ, Dania, FL USA.
10 : Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA.
11 : Univ Space Res Assoc, Greenbelt, MD USA.
12 : NASA, Goddard Space Flight Ctr, Greenbelt, MD USA.
13 : NASA, Goddard Space Flight Ctr, Cryospher Sci Lab, Greenbelt, MD USA.
14 : Chapman Univ, Ctr Excellence Earth Syst Modeling & Observat, Orange, CA USA.
15 : Univ Cent Florida, Elect & Comp Engn Dept, Orlando, FL 32816 USA.
16 : UBO, Ifremer, IRD, Lab Phys Oceans,CNRS, Plouzane, France.
17 : Remote Sensing Syst, Santa Rosa, CA USA.
18 : Atmospher & Environm Res, Lexington, MA USA.
19 : Natl Univ Ireland, Sch Phys, AirSea Lab, Galway, Ireland.
20 : Natl Univ Ireland, Ryan Inst, Galway, Ireland.
|Source||Bulletin Of The American Meteorological Society (0003-0007) (Amer Meteorological Soc), 2016-08 , Vol. 97 , N. 8 , P. 1391-1407|
|WOS© Times Cited||93|
|Abstract||Remote sensing of salinity using satellite-mounted microwave radiometers provides new perspectives for studying ocean dynamics and the global hydrological cycle. Calibration and validation of these measurements is challenging because satellite and in situ methods measure salinity differently. Microwave radiometers measure the salinity in the top few centimeters of the ocean, whereas most in situ observations are reported below a depth of a few meters. Additionally, satellites measure salinity as a spatial average over an area of about 100x100 km2. In contrast, in situ sensors provide pointwise measurements at the location of the sensor. Thus, the presence of vertical gradients in, and horizontal variability of, sea surface salinity complicates comparing satellite and in situ measurements. This paper synthesizes present knowledge of the magnitude, and the processes that contribute to the formation and evolution of, vertical and horizontal variability in near-surface salinity. Rainfall, freshwater plumes and evaporation can generate vertical gradients of salinity, and in some cases these gradients can be large enough to affect validation of satellite measurements. Similarly, mesoscale to submesoscale processes can lead to horizontal variability that can also affect comparisons of satellite data to in situ data. Comparisons between satellite and in situ salinity measurements must take into account both vertical stratification and horizontal variability.|