Dissertation > Excellent graduate degree dissertation topics show

Study on the Variability of NAO and Polar Vortex

Author: ZhuZhiHui
Tutor: LuoDeHai
School: Ocean University of China
Course: Atmospheric Physics and Atmospheric Environment
Keywords: North Atlantic Oscillation (NAO) Polar vortex Interannual variability Decadal changes
CLC: P731.2
Type: Master's thesis
Year: 2009
Downloads: 197
Quote: 0
Read: Download Dissertation

Abstract


In this paper, the NCEP / NCAR reanalysis data, analysis of the four seasons of spring, summer, autumn and winter North Atlantic Oscillation polar vortex changes cycle, its interannual and decadal variation. Mainly come to the following conclusions: Winter PV (APolar Vortex Area) index basic anti-phase change and NA (ONorth Atlantic Oscillation) index was winter PVA index has a significant downward trend. NAO index, PVA index, PVI (Polar Vortex Intension) index has multiple periodic variation, with a more consistent interannual and decadal change cycle, have a quasi-9a Decadal Oscillation cycle and 4-5a interannual oscillation cycle; interannual variability scale, the winter NAO polar vortex relationship mainly in the polar vortex 2-pole distribution and polar vortex tend to the Atlantic side of the Pacific side is weak, is typical of the North Atlantic NAO local distribution; an abrupt change around 1988, the NAO index winter the PVI index in 1976 before and after an abrupt change, slightly ahead of mutations than the climate of the winter NAO index winter PVA index no apparent abrupt change. After the mutation of the NAO index anomaly north of 60 ° N central location farther east, more intense. Changes in decadal scales, the the Winter NAO and the relationship of the polar vortex is mainly The polar vortex performance for 3-pole type, the significant change in the center of the main performance center in abnormally high near 40 ° N, and Global lap, not polar vortex advantage eccentric characteristics. Spring NAO index, PVA index, PVI index showed a downward trend, the downward trend of the spring PVA index and PVI index more significant. Spring NAO index, PVA index, PVI index decadal-scale changes. Scales of interannual variability, the spring NAO and the polar vortex relationship mainly to the polar vortex is a multi-polar distribution showed NAO distribution also showed NPO (North Pacific Oscillation) distribution patterns, addition in the eastern part of Asia and the Americas region, the polar vortex performance. Spring NAO index in 1986 is a distinct mutations. Spring PVA index mutation occurred in about 1978, a little earlier than spring NAO index climate mutations. The spring the PVI index of the mutation in the same place around 1978. Before and after the spring NAO index mutation, the polar vortex did not change significantly. Summer NAO index, PVA index, PVI index showed a downward trend. Summer PVA index has a significant downward trend. Summer NAO index has multiple cycle interannual and decadal PVA index, PVI index decadal oscillation cycle exists. Interannual variability scale, summer NAO mainly with the polar vortex relationship polar vortex eccentric, more significantly in the North Atlantic Ocean on one side, while in the North Pacific Ocean side of the weak. Summer NAO index before and after 1991, once relatively significant mutations PVA index mutation occurred in 1971 before and after PVI index of mutations occurred in 1982 before and after the three mutations are time inconsistent. Change scale decadal summer NAO and the polar vortex relationship performance for the summer polar vortex did not significantly change. Fall NAO index, PVA index and PVI index tended to decrease. NAO index and PVA index has a clear downward trend, the PVI index downward trend is not obvious. Fall NAO index PVA index and PVI index have multiple cycles of change. Interannual scales fall NAO polar vortex relationship polar vortex for 2-pole distribution and polar vortex tend to the Atlantic side, the Pacific side is weak. Fall NAO index in 1988 once more obvious mutation. Fall PVA index mutation occurred 1986 years ago, and more consistent fall mutation NAO index time. Fall the PVI index of the abrupt climate change occurred late in 1996. Decadal scales, autumn NAO relationship with the polar vortex mainly for the fall of the polar vortex is not very significant change. In the winter, the decadal scale, not only is the NAO the high latitude anomaly centers eastward shift of the characteristic the NAO overall slightly eastward shift. Of decadal NAO high latitude anomaly centers eastward shift of the NAO positive and negative phase conversion. The eastward shift in the jet stream and storm track interdecadal may be an important reason for the eastward shift of the NAO overall. The North Atlantic Oscillation (ENSO) and the relationship of the polar vortex, just do a preliminary study, there are many issues that need further research.

Related Dissertations

  1. Interannual Variability of the Intermediate Water in the South China Sea,P731.1
  2. Temporal Variations and Influencing Factors of Stem Respiration for Major Temperate Tree Species in Northeastern China,S718.4
  3. North Pacific meridional heat transport of salt,P732
  4. The Role of Tropical Monsoon and the Sea-land Thermal Difference on the Sub-tropical Monsoon in East Asia,P732
  5. Interannual Variations of Snow Cover over China and Possible Changes in Next 40 Years,P468.025
  6. Spatial and Temporal Variations of Spring/Summer Extreme Low Temperature in North-east China and Its Relationship with SST Anomaly,P731.11
  7. Inter-annual Climate Variability of China and Climate Effects of the Three Gorges Dam as Simulated by a Regional Climate Model,P467
  8. The Impacts of Indian Ocean SSTA Interannual Variation on the Atmospheric Circulation in the East Asian,P461.2
  9. Characteristics of Sea Fog Frequency over the Northern Pacific,P426.4
  10. The study of the variation of the Yellow Sea and East China Sea suspended solids,P734.23
  11. Taohe River Main Current Runoff Change Characteristic Analysis,P333
  12. Oscillation in the tropical Indian Ocean MJO structure and SST season and its interannual variations,P732
  13. Study on Seasonal and Inter-annual Variations of the Yellow Sea Warm Current,S931
  14. Interannual Variability Characteristic of the Temperature, Salinity, Geostrophic Current and Correlative Analyse between the 137°E Section and PN、TK Sections,P731.1
  15. Rainy climate variability of the past century the middle and lower reaches of the Yangtze River causes,P467
  16. Annual and Interannual Variability of the South China Sea Warm Water,P731.1
  17. Climate Characteristics of Sea Surface Temperature (SST) Variation in the Changjiang Estuary,P731.11
  18. The Climatic Characteristics and Interdecadal Changes of the Global Heat Source,P461
  19. The Variation of the Latent Heat Flux and Its Relationship with the Winter Air Temperature in China,P461.2
  20. The Character, Mechanisms and Interannual Variation of China Inshore Sea Fog,P732.1

CLC: > Astronomy,Earth Sciences > Oceanography > Marine basic science > Marine hydrology > Ocean dynamics
© 2012 www.DissertationTopic.Net  Mobile