Evaluating the performance of a WRF initial and physics ensemble over Eastern Black Sea and Mediterranean regions in Turkey

2021-01-15
The physics- and initial-based ensemble approach for Weather Research and Forecasting (WRF) model is applied for predicting four different extreme precipitation events that occurred in summer and autumn over the two most flood-prone regions of Turkey, namely; the Eastern Black Sea (EBS) and Mediterranean (MED). A total of 48 runs, each of which includes two nested domains, is designed considering four microphysics (MP), three cumulus (CU), two planetary boundary layer (PBL) schemes, and two initial forcing datasets (ERA5 and Global Forecast System (GFS)) for each event. The forecast skill of the runs is measured through the hierarchic application of the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method using five categorical and four statistical metrics. The best ten members for each event are validated on the independent events. The MP scheme is the most influential on precipitation estimates between the schemes, especially for the autumn events. However, the choice of a specific MP scheme varies with season and region. Similarly, PBL and CU schemes show a high dependency on event timing and location. Forecasts based on ERA5 yield the highest accuracy over EBS, while GFS-based forecasts are better in the MED region. Most of the top ten members are represented by runs from the 9-km domain. The model parameterization generally shows a more significant impact than model initiation on precipitation variability through spatiotemporal runs. Also, the dynamic downscaling of ERA5 through the WRF model indeed produces better precipitation estimates than ERA5 products over topographically complex regions.
Atmospheric Research

Suggestions

Assessing nonstationarity impacts for historical and projected extreme precipitation in Turkey
Aziz, Rizwan; Yücel, İsmail (Springer Science and Business Media LLC, 2021-01-01)
The temporal variability in yearly and seasonal extreme precipitation across Turkey is investigated using stationary and nonstationary frequency approach. Four frequency distributions namely, generalized extreme value (GEV), gumbel, normal, and lognormal distributions are used for the historical period (1971-2016) as well as the projection period (2051-2100). The nonstationarity impacts are determined by calculating the percentage difference of return levels (30 years) between stationary and nonstationary c...
Sensitivity and sea surface temperature analyses of WRF model for predicting heavy rainfall events observed in Eastern Black Sea and Mediterranean regions of Turkey
Pilatin, Heves; Yücel, İsmail; Kentel Erdoğan, Elçin; Department of Earth System Science (2020-8)
With this thesis it is aimed to enhance the prediction accuracy of the Weather Research and Forecasting (WRF) model on the extreme precipitation events of Mediterranean and Eastern Black Sea regions of Turkey. While the first part of sensitivity analysis was conducted for the physical parameters (microphysics, cumulus and PBL) and the initial boundary conditions, the second part has only focused on the impact of sea surface temperature (SST). After choosing 4 microphysics, 3 cumulus, 2 PBL and 2 input meteo...
Assessment of changes in climate indices of the mediterranean climate region of Turkey
Çetinkaya , İzem; Yücel, İsmail; Department of Civil Engineering (2020-10-28)
As a consequence of climate change, frequency and intensity changes in extreme weather events have occurred. One of the most vulnerable regions of the world that is affected by the climate change is the Mediterranean region. Turkey as a Mediterranean country has a great importance to investigate the changes in climate behavior. 57 stations from Mediterranean climate region of Turkey have been selected as the study area for this thesis. This study aims to assess the climate indices that carry the valua...
Evaluating the hydro-estimator satellite rainfall algorithm over a mountainous region
Yücel, İsmail; Gochis, David J. (2011-01-01)
This study investigates the performance of the National Oceanic and Atmospheric Administration/National Environmental Satellite, Data, and Information Service (NOAA/NESDIS) operational rainfall estimation algorithm, called the hydro-estimator (HE), with and without its orographic correction method, in its depiction of the timing, intensity and duration of convective rainfall in general, and of the topography-rainfall relationship in particular. An event-based rainfall observation network in north-west Mexic...
Evaluating a mesoscale atmosphere model and a satellite-based algorithm in estimating extreme rainfall events in northwestern Turkey
Yücel, İsmail (Copernicus GmbH, 2014-01-01)
Quantitative precipitation estimates are obtained with more uncertainty under the influence of changing climate variability and complex topography from numerical weather prediction (NWP) models. On the other hand, hydrologic model simulations depend heavily on the availability of reliable precipitation estimates. Difficulties in estimating precipitation impose an important limitation on the possibility and reliability of hydrologic forecasting and early warning systems. This study examines the performance o...
Citation Formats
E. Düzenli, İ. Yücel, and M. T. Yılmaz, “Evaluating the performance of a WRF initial and physics ensemble over Eastern Black Sea and Mediterranean regions in Turkey,” Atmospheric Research, pp. 0–0, 2021, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/52235.