Improved Convective Parametrization for Precipitation Modeling over the Horn of Africa
| dc.contributor.advisor | Mengistu, Gizaw (PhD) | |
| dc.contributor.author | Gebremariam, Temesgen | |
| dc.date.accessioned | 2018-07-04T12:27:24Z | |
| dc.date.accessioned | 2023-11-09T11:24:31Z | |
| dc.date.available | 2018-07-04T12:27:24Z | |
| dc.date.available | 2023-11-09T11:24:31Z | |
| dc.date.issued | 2011-06 | |
| dc.description.abstract | The study compared the performance of four di erent cumulus parametrization schemes in the ICTP's Regional Climate Model RegCM4 for the period 1989-2008 over the Horn of Africa. The Horn of Africa has been delineated in to 12 homogeneous region based on clustering method that minimizes a sum of dissimilarities. Grell-FC scheme best captured the mean climatology. Within the 12 clustered regions positive/negative precipitation biases are obtained in Emanuel/Grell-AS and Kuo convective schemes while intermediate values closer to zero are obtained in Grell-FC. Grell-FC scheme is then selected for customization over the Horn of Africa. To improve the simulation of rainfall using the selected Grell-FC scheme, several sensitivity experiments are performed by adjusting the minimum and maximum precipitation e ciency, the minimum and maximum shear e ect on precipitation e ciency, the minimum and maximum convective heating and the available buoyant energy removal time scale. Setting the minimum and maximum shear e ect on precipitation e ciency to 0.10 and 0.30 respectively improve the correlation, which implies a better simulation of precipitation. Setting the minimum and maximum convective heating to -150 and 400 respectively minimize the positive bias over most of the regions. 17 years long period run revealed that using the new values of shear e ect on precipitation e ciency improve the correlation and representation of the inter-annual variability | en_US |
| dc.identifier.uri | http://10.90.10.223:4000/handle/123456789/6441 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Modeling over the Horn of Africa | en_US |
| dc.title | Improved Convective Parametrization for Precipitation Modeling over the Horn of Africa | en_US |
| dc.type | Thesis | en_US |