A dataset of continental river discharge based on JRA-55 for use in a global ocean circulation model

Abstract

A dataset of historical river discharge into oceans was created using the CaMa-Flood global river routing model and adjusted runoff from the land component of JRA-55. The major rivers were well resolved with a 0.25° horizontal resolution. The total runoff on each drainage basin exhibits a distinctive bias on decadal time scales. The input runoff data were modified using 5-year low-pass-filtered multiplicative factors to fit the annual mean climatology and decadal variations in the reference dataset. The model incorporated data from 1958 to 2016. The yearly and seasonal variations of the major rivers are well represented by the model.

A global eddying hindcast ocean simulation with OFES2

“…3c of Kutsuwada et al, 2019). The similarity between momentum fluxes in OFES2 and the satellite observations comes from modifications of 10-m wind in JRA55-do using the satellite observations (Tsujino et al, 2018).…”

“…We used the 3-hourly atmospheric surface dataset JRA55-do ver.08 (Tsujino et al, 2018) to estimate surface fluxes in OFES2. This dataset is based on the JRA55 atmospheric reanalysis at a horizontal resolution of approximately 55 km (Kobayashi et al, 2015).…”

“…The river runoff in CORE version 2 (Large and Yeager, 2004) is weak, and so a more realistic product, such as JRA55-do (Suzuki et al, 2018), may be required to improve the biases. There are large fresh biases in the Arctic Ocean and large salty bias in the Nordic Sea.…”

“…S1). These reductions in OFES2 are likely a result of using the bulk formula (Large and Yeager, 2004) and the atmospheric surface data (JRA55-do), which are optimized to drive OGCMs (Tsujino et al, 2018). Additionally, the implementation of a sea-ice model in OFES2 may contribute to the decreases in the warm biases in the Arctic Ocean and the Sea of Okhotsk.…”

Impact of Continental Freshwater Runoff on Coastal Sea Level

“…While this dataset represents unprecedented and valuable information on continental discharge into the global ocean, for individual river systems where in situ discharge observations are not available, estimates from Dai et al (2009) have difficulty in reproducing the interannual variability characterized by large anomalous events. This is the case for instance after 1996 for the Ganges-Brahmaputra, which might have strong impacts on the coastal ocean at various timescales (Durand et al 2011 1 3 Do et al 2018;Gudmundsson et al 2018;Suzuki et al 2018) also provide new global and long-term datasets of continental discharge estimates and freshwater flux to the oceans.…”