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Influence of reanalysis datasets on dynamically downscaling the recent past
- Source :
- Climate Dynamics. 49:1239-1255
- Publication Year :
- 2016
- Publisher :
- Springer Science and Business Media LLC, 2016.
-
Abstract
- Multiple reanalysis datasets currently exist that can provide boundary conditions for dynamic downscaling and simulating local hydro-climatic processes at finer spatial and temporal resolutions. Previous work has suggested that there are two reanalyses alternatives that provide the best lateral boundary conditions for downscaling over southern Africa. This study dynamically downscales these reanalyses (ERA-I and MERRA) over southern Africa to a high resolution (10 km) grid using the WRF model. Simulations cover the period 1981–2010. Multiple observation datasets were used for both surface temperature and precipitation to account for observational uncertainty when assessing results. Generally, temperature is simulated quite well, except over the Namibian coastal plain where the simulations show anomalous warm temperature related to the failure to propagate the influence of the cold Benguela current inland. Precipitation tends to be overestimated in high altitude areas, and most of southern Mozambique. This could be attributed to challenges in handling complex topography and capturing large-scale circulation patterns. While MERRA driven WRF exhibits slightly less bias in temperature especially for La Nina years, ERA-I driven simulations are on average superior in terms of RMSE. When considering multiple variables and metrics, ERA-I is found to produce the best simulation of the climate over the domain. The influence of the regional model appears to be large enough to overcome the small difference in relative errors present in the lateral boundary conditions derived from these two reanalyses.
- Subjects :
- Atmospheric Science
Complex topography
010504 meteorology & atmospheric sciences
Meteorology
Mean squared error
0208 environmental biotechnology
02 engineering and technology
Grid
01 natural sciences
020801 environmental engineering
La Niña
13. Climate action
Weather Research and Forecasting Model
Climatology
Environmental science
Boundary value problem
Precipitation
0105 earth and related environmental sciences
Downscaling
Subjects
Details
- ISSN :
- 14320894 and 09307575
- Volume :
- 49
- Database :
- OpenAIRE
- Journal :
- Climate Dynamics
- Accession number :
- edsair.doi...........6ee2c2739559e60bfdcf32affda5776e
- Full Text :
- https://doi.org/10.1007/s00382-016-3378-y