| 1. |
- Shen, Tianyin, et al.
(författare)
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Secular Changes of the Decadal Relationship Between the Northern Hemisphere Land Monsoon Rainfall and Sea Surface Temperature Over the Past Millennium in Climate Model Simulations
- 2022
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Ingår i: Journal of Geophysical Research: Atmospheres. - 2169-897X .- 2169-8996. ; 127:23
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Tidskriftsartikel (refereegranskat)abstract
- Understanding the decadal variability of Northern Hemisphere land monsoon rainfall (NHLMR) is crucial to social-economic development. However, due to the temporal limitation of instrumental data, the decadal relationship between NHLMR and sea surface temperature (SST) remains uncertain. The extended El Niño–Southern Oscillation (XEN) SST index and the North Atlantic–south Indian Ocean dipole (NAID) SST index can be the predictors to help us understand the decadal relationship between NHLMR and SST. In this study, using the Community Earth System Model-Last Millennium Ensemble (CESM-LME) simulations, we find a significant and stable decadal correlation between the NHLMR and XEN in the all-forcing (AF) (with natural and anthropogenic forcings, AF), control (internal variability only), and other external forcings run over the past millennium, which means that this simulated NHLMR-XEN relationship is caused by internal variability. The AF experiments show that the decadal relationship between NHLMR and NAID is practically non-existent until an abrupt and significant increase in volcanic eruptions at about 1700, which is also indicated by the Paleoclimate Modeling Intercomparison Project Phase 3 (Paleoclimate Modeling Intercomparison Project Phase 3) simulations. Using the volcanic forcing sensitivity experiments, we find that the successive strong volcanic eruptions in the Northern Hemisphere (NH) significantly strengthen the synchronous changes of NHLMR and NAID after 1700, with a periodicity of 20–40-year for NHLMR and NAID. Specifically, successive NH eruptions weaken the north-south hemispheric thermal contrast, contributing to the weakened NAID index. The cross-equator flow is thus weakened, decreasing the NHLMR, which cause a resonant behavior of NHLMR and NAID.
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| 2. |
- Sun, Weiyi, et al.
(författare)
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Multi-centennial ENSO-like variability response to solar activity during the holocene
- 2024
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Ingår i: CLIMATE DYNAMICS. - 0930-7575 .- 1432-0894.
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Tidskriftsartikel (refereegranskat)abstract
- Previous reconstructions suggest a possible correlation between solar and El Nino-Southern Oscillation (ENSO) on the centennial-millennial time scales, but the mechanism remains controversial. This study conducts Holocene transient simulations and finds a significant 350-500-year cycle of ENSO-like variability during the mid-late Holocene under solar activity forcing, supported by multiple reconstructions. This multi-centennial ENSO-like variability is caused by the solar-forced low-latitude process, not the high-latitude process or internal variability. When solar radiation increases, the subtropical Asian continent-Indian Ocean thermal contrast is enhanced, increasing precipitation over the India and Bay of Bengal, which generates easterly anomaly over the Indo-Pacific warm pool. Increased solar radiation also enhances the evaporation in the cloud-free regions of western North and South Pacific, and the moisture is transported to the Maritime Continent by easterly. This increases precipitation there and strengthens the easterly anomaly over the equatorial western Pacific, which triggers the La Nina-like state. The leading coupling process for the development of La Nina-like state is zonal advective and upwelling feedback, and poleward heat advection further amplifies the equatorial eastern Pacific cooling. Findings from this study suggests that a centennial-scale El Nino-like condition might occur under solar forcings if the forecast predicts a solar minimum at the end of the 21st century.
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| 3. |
- Xie, Kefan, et al.
(författare)
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Research on the group decision-making about emergency event based on network technology
- 2011
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Ingår i: Information Technology and Management. - : Springer. - 1385-951X .- 1573-7667. ; 12:2, s. 137-147
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Tidskriftsartikel (refereegranskat)abstract
- In order to improve decision-making efficiency about emergency event, this paper proposes a novel concept, i.e., Agile-Delphi Method, which is an integration of agile decision and Delphi Method implicating that the decision-makers instantly deliver, respond, treat, and utilize information via Delphi process while conducting group decision-making about emergency event. The paper details the mechanism of group decision-making about emergency event based on network technology and Agile-Delphi Method. Finally, the paper conducts an empiric analysis taking the “111 event”, i.e., the liquid ammonia spill event happened on November 1, 2006 in a phosphorus chemical company in China, as an example.
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