000840115 001__ 840115 000840115 005__ 20210131030728.0 000840115 0247_ $$2doi$$a10.1016/j.advwatres.2017.11.003 000840115 0247_ $$2WOS$$aWOS:000418592800016 000840115 0247_ $$2altmetric$$aaltmetric:29918864 000840115 037__ $$aFZJ-2017-07678 000840115 082__ $$a550 000840115 1001_ $$0P:(DE-Juel1)161265$$aZhang, Hongjuan$$b0$$eCorresponding author 000840115 245__ $$aComparison of different assimilation methodologies of groundwater levels to improve predictions of root zone soil moisture with an integrated terrestrial system model 000840115 260__ $$aAmsterdam [u.a.]$$bElsevier Science$$c2018 000840115 3367_ $$2DRIVER$$aarticle 000840115 3367_ $$2DataCite$$aOutput Types/Journal article 000840115 3367_ $$0PUB:(DE-HGF)16$$2PUB:(DE-HGF)$$aJournal Article$$bjournal$$mjournal$$s1511947472_9734 000840115 3367_ $$2BibTeX$$aARTICLE 000840115 3367_ $$2ORCID$$aJOURNAL_ARTICLE 000840115 3367_ $$00$$2EndNote$$aJournal Article 000840115 520__ $$aThe linkage between root zone soil moisture and groundwater is either neglected or simplified in most land surface models. The fully-coupled subsurface-land surface model TerrSysMP including variably saturated groundwater dynamics is used in this work. We test and compare five data assimilation methodologies for assimilating groundwater level data via the ensemble Kalman filter (EnKF) to improve root zone soil moisture estimation with TerrSysMP. Groundwater level data are assimilated in the form of pressure head or soil moisture (set equal to porosity in the saturated zone) to update state vectors. In the five assimilation methodologies, the state vector contains either (i) pressure head, or (ii) log-transformed pressure head, or (iii) soil moisture, or (iv) pressure head for the saturated zone only, or (v) a combination of pressure head and soil moisture, pressure head for the saturated zone and soil moisture for the unsaturated zone. These methodologies are evaluated in synthetic experiments which are performed for different climate conditions, soil types and plant functional types to simulate various root zone soil moisture distributions and groundwater levels. The results demonstrate that EnKF cannot properly handle strongly skewed pressure distributions which are caused by extreme negative pressure heads in the unsaturated zone during dry periods. This problem can only be alleviated by methodology (iii), (iv) and (v). The last approach gives the best results and avoids unphysical updates related to strongly skewed pressure heads in the unsaturated zone. If groundwater level data are assimilated by methodology (iii), EnKF fails to update the state vector containing the soil moisture values if for (almost) all the realizations the observation does not bring significant new information. Synthetic experiments for the joint assimilation of groundwater levels and surface soil moisture support methodology (v) and show great potential for improving the representation of root zone soil moisture. 000840115 536__ $$0G:(DE-HGF)POF3-255$$a255 - Terrestrial Systems: From Observation to Prediction (POF3-255)$$cPOF3-255$$fPOF III$$x0 000840115 7001_ $$0P:(DE-Juel1)140349$$aKurtz, Wolfgang$$b1 000840115 7001_ $$0P:(DE-Juel1)151405$$aKollet, Stefan$$b2 000840115 7001_ $$0P:(DE-Juel1)129549$$aVereecken, Harry$$b3 000840115 7001_ $$0P:(DE-Juel1)138662$$aHendricks-Franssen, Harrie-Jan$$b4$$eCorresponding author 000840115 773__ $$0PERI:(DE-600)2023320-6$$a10.1016/j.advwatres.2017.11.003$$p224-238$$tAdvances in water resources$$v111$$x0309-1708$$y2018 000840115 8564_ $$uhttps://juser.fz-juelich.de/record/840115/files/1-s2.0-S0309170817304888-main.pdf$$yRestricted 000840115 8564_ $$uhttps://juser.fz-juelich.de/record/840115/files/1-s2.0-S0309170817304888-main.gif?subformat=icon$$xicon$$yRestricted 000840115 8564_ $$uhttps://juser.fz-juelich.de/record/840115/files/1-s2.0-S0309170817304888-main.jpg?subformat=icon-1440$$xicon-1440$$yRestricted 000840115 8564_ $$uhttps://juser.fz-juelich.de/record/840115/files/1-s2.0-S0309170817304888-main.jpg?subformat=icon-180$$xicon-180$$yRestricted 000840115 8564_ $$uhttps://juser.fz-juelich.de/record/840115/files/1-s2.0-S0309170817304888-main.jpg?subformat=icon-640$$xicon-640$$yRestricted 000840115 8564_ $$uhttps://juser.fz-juelich.de/record/840115/files/1-s2.0-S0309170817304888-main.pdf?subformat=pdfa$$xpdfa$$yRestricted 000840115 909CO $$ooai:juser.fz-juelich.de:840115$$pVDB:Earth_Environment$$pVDB 000840115 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)161265$$aForschungszentrum Jülich$$b0$$kFZJ 000840115 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)140349$$aForschungszentrum Jülich$$b1$$kFZJ 000840115 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)151405$$aForschungszentrum Jülich$$b2$$kFZJ 000840115 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)129549$$aForschungszentrum Jülich$$b3$$kFZJ 000840115 9101_ $$0I:(DE-588b)5008462-8$$6P:(DE-Juel1)138662$$aForschungszentrum Jülich$$b4$$kFZJ 000840115 9131_ $$0G:(DE-HGF)POF3-255$$1G:(DE-HGF)POF3-250$$2G:(DE-HGF)POF3-200$$3G:(DE-HGF)POF3$$4G:(DE-HGF)POF$$aDE-HGF$$bErde und Umwelt$$lTerrestrische Umwelt$$vTerrestrial Systems: From Observation to Prediction$$x0 000840115 9141_ $$y2017 000840115 915__ $$0StatID:(DE-HGF)0420$$2StatID$$aNationallizenz 000840115 915__ $$0StatID:(DE-HGF)0100$$2StatID$$aJCR$$bADV WATER RESOUR : 2015 000840115 915__ $$0StatID:(DE-HGF)0200$$2StatID$$aDBCoverage$$bSCOPUS 000840115 915__ $$0StatID:(DE-HGF)0300$$2StatID$$aDBCoverage$$bMedline 000840115 915__ $$0StatID:(DE-HGF)0600$$2StatID$$aDBCoverage$$bEbsco Academic Search 000840115 915__ $$0StatID:(DE-HGF)0030$$2StatID$$aPeer Review$$bASC 000840115 915__ $$0StatID:(DE-HGF)0199$$2StatID$$aDBCoverage$$bThomson Reuters Master Journal List 000840115 915__ $$0StatID:(DE-HGF)0110$$2StatID$$aWoS$$bScience Citation Index 000840115 915__ $$0StatID:(DE-HGF)0150$$2StatID$$aDBCoverage$$bWeb of Science Core Collection 000840115 915__ $$0StatID:(DE-HGF)0111$$2StatID$$aWoS$$bScience Citation Index Expanded 000840115 915__ $$0StatID:(DE-HGF)1160$$2StatID$$aDBCoverage$$bCurrent Contents - Engineering, Computing and Technology 000840115 915__ $$0StatID:(DE-HGF)9900$$2StatID$$aIF < 5 000840115 920__ $$lyes 000840115 9201_ $$0I:(DE-Juel1)IBG-3-20101118$$kIBG-3$$lAgrosphäre$$x0 000840115 980__ $$ajournal 000840115 980__ $$aVDB 000840115 980__ $$aI:(DE-Juel1)IBG-3-20101118 000840115 980__ $$aUNRESTRICTED