Improved representation of river runoff in Estimating the Circulation and Climate of the Ocean Version 4 (ECCOv4) simulations: implementation, evaluation, and impacts to coastal plume regions

Abstract. In this study, we improve the representation of global river runoff in Estimating Circulation and Climate Ocean Version 4 (ECCOv4) framework, allowing for a more realistic treatment coastal plume dynamics. We use suite experiments to explore sensitivity regions forcing, model grid resolution, type. The results show that simulated sea surface salinity (SSS) is reduced as resolution increases. Compared Soil Moisture Active Passive (SMAP) observations, SSS closest SMAP when using daily, point-source (DPR) intermediate-resolution LLC270 grid. Willmott skill score, which quantifies agreement between models SMAP, yields up 0.92 large rivers such Amazon. There was no major difference tropical temperate type changed from ECCO v4 latitude–longitude–polar-cap ECCO2 cube–sphere also found DPR forcing increasing coarse-resolution LLC90 elevated area, volume, stabilized stratification shoal mixed layer depth (MLD). Additionally, find impacts high-resolution LLC540 are regionally dependent. Mississippi River Plume sensitive than other regions, possibly because wider shallower Texas–Louisiana shelf drives stronger baroclinic effect, well relatively weak sub-grid vertical mixing adjustment region. Since deliver amounts freshwater anthropogenic materials improving global, will advance studies hypoxia, carbon cycling, regional weather climate ultimately help predict land–ocean–atmospheric feedbacks seamlessly next generation Earth system models.