Dynamical downscaling of ERA40 reanalysis data over southern Africa: added value in the simulation of the seasonal rainfall characteristics

2010 ◽  
Vol 31 (15) ◽  
pp. 2338-2349 ◽  
Author(s):  
A. Haensler ◽  
S. Hagemann ◽  
D. Jacob
Keyword(s):  
Southern Africa ◽  
Dynamical Downscaling ◽  
Reanalysis Data ◽  
Seasonal Rainfall ◽  
Added Value ◽  
Rainfall Characteristics ◽  
Era40 Reanalysis

Rainfall Characteristics from Convection-Permitting Downscaling over the Western Maritime Continent

2021 ◽  
Author(s):  
Venkatraman Prasanna ◽  
Sandeep Sahany ◽  
Aurel F. Moise ◽  
Xin Rong Chua ◽  
Gerald Lim ◽  
...  
Keyword(s):  
Climate Model ◽  
Dynamical Downscaling ◽  
Regional Climate ◽  
Sea Surface ◽  
Added Value ◽  
Maritime Continent ◽  
Variable Resolution ◽  
Rainfall Characteristics ◽  
Satellite Retrievals

<p>Long-term convection-permitting dynamical downscaling has been carried out over the western Maritime Continent, using the Singapore Variable Resolution Regional Climate Model (SINGV-RCM) at 8km and 2km spatial resolutions. The SINGV-RCM is forced with ERA-5 reanalyses data for a 36-year period (1979-2014) at 8km resolution over Southeast Asia (79E-160E;16S-24N) with regular update of the sea surface temperature at 6-hr interval; further, this 8km domain simulation is used for forcing a smaller domain over the western Maritime continent at a resolution of 2km (93E-110E;7.2S-9.9N) for a 20-year period (1995-2014). Rainfall characteristics including the diurnal cycle and extremes from the two simulations evaluated against satellite retrievals, and the added value from dynamical downscaling will be presented.</p>

scholarly journals Precipitation over southern Africa: Is there consensus among GCMs, RCMs and observational data?

2021 ◽  
Author(s):  
Maria Chara Karypidou ◽  
Eleni Katragkou ◽  
Stefan Pieter Sobolowski
Keyword(s):  
Climate Change ◽  
Southern Africa ◽  
Regional Climate ◽  
Coupled Model ◽  
Added Value ◽  
Rain Gauges ◽  
Climate Simulations ◽  
Observational Uncertainty ◽  
Direct Contrast ◽  
Improved Performance

Abstract. The region of southern Africa (SAF) is highly vulnerable to the impacts of climate change and is projected to experience severe precipitation shortages in the coming decades. Ensuring that our modelling tools are fit for the purpose of assessing these changes is critical. In this work we compare a range of satellite products along with gauge-based datasets. Additionally, we investigate the behaviour of regional climate simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX) – Africa domain, along with simulations from the Coupled Model Intercomparison Project Phase 5 (CMIP5) and Phase 6 (CMIP6). We identify considerable variability in the standard deviation of precipitation between satellite products that merge with rain gauges and satellite products that do not, during the rainy season (Oct–Mar), indicating high observational uncertainty for specific regions over SAF. Good agreement both in spatial pattern and the strength of the calculated trends is found between satellite and gauge-based products, however. Both CORDEX-Africa and CMIP5 ensembles underestimate the observed trends during the analysis period. The CMIP6 ensemble displayed persistent drying trends, in direct contrast to the observations. The regional ensemble exhibited improved performance compared to its forcing (CMIP5), when the annual cycle and the extreme precipitation indices were examined, confirming the added value of the higher resolution regional climate simulations. The CMIP6 ensemble displayed a similar behaviour to CMIP5, however reducing slightly the ensemble spread. However, we show that reproduction of some key SAF phenomena, like the Angolan Low (which exerts a strong influence on regional precipitation), still poses a challenge for the global and regional models. This is likely a result of the complex climatic process that take place. Improvements in observational networks (both in-situ and satellite), as well as continued advancements in high-resolution modelling will be critical, in order to develop a robust assessment of climate change for southern Africa.

scholarly journals Projected effects of 1.5 °C and 2 °C global warming levels on the intra-seasonal rainfall characteristics over the Greater Horn of Africa

2020 ◽  
Vol 15 (3) ◽  
pp. 034037 ◽  
Author(s):  
Masilin Gudoshava ◽  
Herbert O Misiani ◽  
Zewdu T Segele ◽  
Suman Jain ◽  
Jully O Ouma ◽  
...  
Keyword(s):  
Global Warming ◽  
Seasonal Rainfall ◽  
Horn Of Africa ◽  
Rainfall Characteristics ◽  
Greater Horn Of Africa

scholarly journals Accurate Quantification of Seasonal Rainfall and Associated Climate–Wildfire Relationships

2010 ◽  
Vol 49 (12) ◽  
pp. 2559-2573 ◽  
Author(s):  
Matthew G. Slocum ◽  
William J. Platt ◽  
Brian Beckage ◽  
Steve L. Orzell ◽  
Wayne Taylor
Keyword(s):  
Daily Rainfall ◽  
Seasonal Rainfall ◽  
Wet Season ◽  
Rainfall Characteristics ◽  
Central Florida ◽  
South Central ◽  
Multiple Regression Technique ◽  
Precise Quantification ◽  
Rainfall Anomalies ◽  
Force Range

Abstract Wildfires are often governed by rapid changes in seasonal rainfall. Therefore, measuring seasonal rainfall on a temporally finescale should facilitate the prediction of wildfire regimes. To explore this hypothesis, daily rainfall data over a 58-yr period (1950–2007) in south-central Florida were transformed into cumulative rainfall anomalies (CRAs). This transformation allowed precise estimation of onset dates and durations of the dry and wet seasons, as well as a number of other variables characterizing seasonal rainfall. These variables were compared with parameters that describe ENSO and a wildfire regime in the region (at the Avon Park Air Force Range). Onset dates and durations were found to be highly variable among years, with standard deviations ranging from 27 to 41 days. Rainfall during the two seasons was distinctive, with the dry season having half as much as the wet season despite being nearly 2 times as long. The precise quantification of seasonal rainfall led to strong statistical models describing linkages between climate and wildfires: a multiple-regression technique relating the area burned with the seasonal rainfall characteristics had an of 0.61, and a similar analysis examining the number of wildfires had an of 0.56. Moreover, the CRA approach was effective in outlining how seasonal rainfall was associated with ENSO, particularly during the strongest and most unusual events (e.g., El Niño of 1997/98). Overall, the results presented here show that using CRAs helped to define the linkages among seasonality, ENSO, and wildfires in south-central Florida, and they suggest that this approach can be used in other fire-prone ecosystems.

Process‐Based Analysis of the Added Value of Dynamical Downscaling Over Central Africa

2020 ◽  
Vol 47 (17) ◽  
Author(s):  
Alain T. Tamoffo ◽  
Alessandro Dosio ◽  
Derbetini A. Vondou ◽  
Denis Sonkoué
Keyword(s):  
Dynamical Downscaling ◽  
Central Africa ◽  
Added Value

scholarly journals Spatial Interpolation of Historical Seasonal Rainfall Indices over Peninsular Malaysia

2018 ◽  
Vol 34 ◽  
pp. 02048
Author(s):  
Zulkarnain Hassan ◽  
Ahmad Haidir ◽  
Farah Naemah Mohd Saad ◽  
Afizah Ayob ◽  
Mustaqqim Abdul Rahim ◽  
...  
Keyword(s):  
Spatial Interpolation ◽  
Rainfall Intensity ◽  
Southwest Monsoon ◽  
Peninsular Malaysia ◽  
Seasonal Rainfall ◽  
Seasonal Patterns ◽  
Northeast Monsoon ◽  
Rainfall Characteristics ◽  
Distance Weighted ◽  
Inverse Distance

The inconsistency in inter-seasonal rainfall due to climate change will cause a different pattern in the rainfall characteristics and distribution. Peninsular Malaysia is not an exception for this inconsistency, in which it is resulting extreme events such as flood and water scarcity. This study evaluates the seasonal patterns in rainfall indices such as total amount of rainfall, the frequency of wet days, rainfall intensity, extreme frequency, and extreme intensity in Peninsular Malaysia. 40 years (1975-2015) data records have been interpolated using Inverse Distance Weighted method. The results show that the formation of rainfall characteristics are significance during the Northeast monsoon (NEM), as compared to Southwest monsoon (SWM). Also, there is a high rainfall intensity and frequency related to extreme over eastern coasts of Peninsula during the NEM season.

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