TY  - JOUR
AU  - Schröder, Stefan
AU  - Springer, Anne
AU  - Kusche, Jürgen
AU  - Uebbing, Bernd
AU  - Fenoglio-Marc, Luciana
AU  - Diekkrüger, Bernd
AU  - Poméon, Thomas
TI  - Niger discharge from radar altimetry: bridging gaps between gauge and altimetry time series
JO  - Hydrology and earth system sciences
VL  - 23
IS  - 10
SN  - 1607-7938
CY  - Katlenburg-Lindau
PB  - EGU
M1  - FZJ-2019-05164
SP  - 4113 - 4128
PY  - 2019
AB  - The Niger River represents a challenging target for deriving discharge from spaceborne radar altimeter measurements, particularly since most terrestrial gauges ceased to provide data during the 2000s. Here, we propose deriving altimetric rating curves by “bridging” gaps between time series from gauge and altimeter measurements using hydrological model simulations. We show that classical pulse-limited altimetry (Jason-1 and Jason-2, Envisat, and SARAL/Altika) subsequently reproduces discharge well and enables continuing the gauge time series, albeit at a lower temporal resolution. Also, synthetic aperture radar (SAR) altimetry picks up the signal measured by earlier altimeters quite well and allows the building of extended time series of higher quality. However, radar retracking is necessary for pulse-limited altimetry and needs to be further investigated for SAR. Moreover, forcing data for calibrating and running the hydrological models must be chosen carefully. Furthermore, stage–discharge relations must be fitted empirically and may need to allow for break points.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000488980200002
DO  - DOI:10.5194/hess-23-4113-2019
UR  - https://juser.fz-juelich.de/record/865885
ER  -