Climate noise effect on uncertainty of hydrological extremes: numerical experiments with hydrological and climate models
Other literature type
Gelfan, A. N.
Semenov, V. A.
Motovilov, Yu. G.
(issn: 2199-899X, eissn: 2199-899X)
An approach has been proposed to analyze the simulated hydrological extreme
uncertainty related to the internal variability of the atmosphere ("climate
noise"), which is inherent to the climate system and considered as the
lowest level of uncertainty achievable in climate impact studies. To assess
the climate noise effect, numerical experiments were made with climate model
ECHAM5 and hydrological model ECOMAG. The case study was carried out to
Northern Dvina River basin (catchment area is 360 000 km<sup>2</sup>), whose
hydrological regime is characterised by extreme freshets during
spring-summer snowmelt period. The climate noise was represented by ensemble
ECHAM5 simulations (45 ensemble members) with identical historical boundary
forcing and varying initial conditions. An ensemble of the ECHAM5-outputs
for the period of 1979–2012 was used (after bias correction post-processing)
as the hydrological model inputs, and the corresponding ensemble of 45
multi-year hydrographs was simulated. From this ensemble, we derived flood
statistic uncertainty caused by the internal variability of the atmosphere.