Large-Scale Gravity Current over the Middle Hills of the Nepal Himalaya: Implications for Aircraft Accidents

• DOI: 10.1175/jamc-d-16-0073.1
• Publication Date: 2016-11-02T17:58:21Z
• Authors: Ram P. Regmi; Toshihiro Kitada; Jimy Dudhia; Sangeeta Maharjan
• Keywords: 13. Climate action; 15. Life on land; 01 natural sciences; 0105 earth and related environmental sciences

Abstract Nepal has been the location of a series fatal aircraft accidents, raising serious concerns about civil aviation security and safety passengers. However, significant studies on weather patterns associated with airports air routes Himalayan complex terrain their implications for activities are yet to be carried out. The present study numerically reconstructs prevailing conditions puts forward some possible causes behind most recent accident in foothills western Himalaya at 0730 UTC (1315 LST) 16 February 2014. have simulated 1-km 2 horizontal grid resolution using Weather Research Forecasting (WRF) modeling system. reconstructed situation shows existence low-level cloud ceiling, supercooled water hail, trapped mountain waves, supercritical descent strong tail wind, development turbulence altitude flight path followed by aircraft. might gone through hazards including visibility obstruction, moderate turbulence, abnormal loss altitude, icing. It is concluded that over region was adverse enough affect small therefore it played an important role leading accident. hazardous may attributed previously unanticipated large-scale easterly gravity current middle hills Himalaya. originated from central high mountainous located northeast Kathmandu valley traveled more than 200 km, reaching