<descriptor thcode="62"><thesaurus thcode="62" name="Coastal and Marine Ecological Classification Standard" scope="Categories of ecosystems for coastal, estuarine, and marine environments." creator="FGDC" rights="public domain" date="2017-05-10" codetype="alpha" prefix="cmecs" uri="https://www2.usgs.gov/science/CMECS" tblname="cmecs" root_code="root" contact="pschweitzer"><category><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/><term thcode="25" code="16" name="hierarchical" parent="11" scope="Substantive broader-narrower relationships exist among the terms."/></category><altlabel><altlabel>CMECS</altlabel><altlabel>CMECS</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel><altlabel>Coastal and Marine Ecological Classification Standard (CMECS)</altlabel></altlabel></thesaurus><term thcode="62" code="WC-640" name="Residual Current" parent="WC-627" scope="Hydroform: Current movement resulting from asymmetry in tidal flow?notably within a partially enclosed estuary or embayment?that results in characteristic estuarine circulation patterns."/><bt><term thcode="62" code="WC-627" name="Current" parent="WC-C012" scope="Hydroform Class: Water that is undergoing coherent mass movement, either as laminar or turbulent flow, relative to surrounding waters and fixed structural, landform or geologic features. ..."/><term thcode="62" code="WC-C012" name="Hydroform" parent="WC-C001"/><term thcode="62" code="WC-C001" name="Water Column" parent="root"/><term thcode="62" code="root" name="CMECS" scope="Coastal and Marine Ecological Classification Standard: Category terms encompassing waters from the head of tide or inland incursion of ocean salinity to the splash zone of the coasts to the deepest portions of the oceans and the deep waters of the Great Lakes."/></bt><nt><term thcode="62" code="WC-659" name="Fjord Circulation" parent="WC-640" scope="Hydroform Type: Circulation in estuaries that possess a sill at the seaward end, inhibiting inflow of seawater into the bottom waters. ..."/><term thcode="62" code="WC-660" name="Partially Mixed Domain" parent="WC-640" scope="Hydroform Type: An estuarine circulation with an intermediate level of advective and tidal energy, that can disrupt the density barrier between the fresher upper and salty lower water column of an estuary, entraining water in both directions. ..."/><term thcode="62" code="WC-661" name="Reverse Estuarine Flow" parent="WC-640" scope="Hydroform Type: An estuarine circulation where evaporation greatly exceeds freshwater input, as in hot dry climes, salinity is concentrated within the estuarine basin. This results in a salinity maximum in the estuary that can far exceed seawater salinity."/><term thcode="62" code="WC-662" name="Salt Wedge Domain" parent="WC-640" scope="Hydroform Type: Portions of estuaries that have an unimpeded connection of bottom waters to the sea develop a wedge-shaped formation of high-salinity water in the bottom, with lower salinity water from upstream freshwater loading in the upper water column. ..."/><term thcode="62" code="WC-663" name="Well-mixed Domain" parent="WC-640" scope="Hydroform Type: Reaches of estuaries where the tidal flux and/or the river discharge is sufficient to overcome the salt-wedge structure, the water column becomes well-mixed and vertical homogeneous."/></nt></descriptor>