|
Document Type |
: |
Thesis |
|
Document Title |
: |
SUBTROPICAL JET STREAM CLIMATOLOGY IN WINTER SEASON AND ITS RELATIONSHIP TO THE ENSO PHENOMENA مناخ التيار النفاث شبه المداري في فصل الشتاء وعلاقته بظاهرة الإنسو |
|
Subject |
: |
Faculty of Meteorology, Environment and Arid Land Agriculture |
|
Document Language |
: |
Arabic |
|
Abstract |
: |
In this work, a climatology of the winter season subtropical jet stream in the Northern Hemisphere using NCEP/NCAR reanalysis datasets for the period 1958-2015 is constructed with emphasize on its relationship to the El Niño–Southern Oscillation (ENSO). Based on examining the changes in the wind speeds and vertical profiles of the subtropical jet, three regions, confined between 20°N and 45°N, namely, the American domain (AM: 130°W– 30°W), the African domain (AF: 25°W–75°E), and the Asian domain (AS: 80°E–180°E) are selected for the objective analysis.
Results show that the wind speed in the jet stream is found to be highest in the winter season and lowest in the summer. The jet stream movement shows seasonal behavior; it moves northward in spring compared with its winter mean position, moves further to the north in the summer and shifts back south in autumn. The winter season (annual) jet stream wind speeds are: 31.40 (22.26), 32.91 (24.71) and 45.71 (30.16) m/s for the AM, AF, and AS region respectively.
During the El Niño (La Niña) years, the jet stream shifts by about 200 km to the south (north) compared with its mean position. These shifts are more prominent in the winter season. In the El Niño (La Niña) years, the wind speeds increase (decrease) over the Arabian Peninsula, particularly over the southern parts. In the winter season, the core of the jet stream tends to be confined in relatively smaller areas over the three regions, which is a reason for precaution for Civil Aviation.
The winter season jet stream maximum wind speeds are: 51.15, 56.10 and 75.85 m/s respectively for the AM, AF and AS region. The wind speeds are increasing over all three regions in the last three decades. The use of climate model data in jet stream analysis is suggested for future study to investigate the effects of climate change on the jet stream characteristics and climatology. |
|
Supervisor |
: |
Prof. Abdulwahab Suliman Mashat |
|
Thesis Type |
: |
Master Thesis |
|
Publishing Year |
: |
1438 AH
2017 AD |
|
Co-Supervisor |
: |
Prof. Mohsin Jamil Butt |
|
Added Date |
: |
Monday, May 29, 2017 |
|
Researchers
| معاذ هاشم الحبشي | Alhebshi, Muaadh Hashim | Researcher | Master | |
|