P2C2: Hydroclimatic response of the tropical Pacific to past changes in mean state: Observations and synthesis

GSTDTAP

项目编号	1606764
	P2C2: Hydroclimatic response of the tropical Pacific to past changes in mean state: Observations and synthesis
	Michael Evans
主持机构	University of Maryland College Park
项目开始年	2016
	2016-08-01
项目结束日期	2018-07-31
资助机构	US-NSF
项目类别	Standard Grant
项目经费	140988(USD)
国家	美国
语种	英语
英文摘要	How will El Niño events change as the climate changes? There is currently no consensus on the answer to this question from climate change projections for the 21st century. Yet even small changes in El Niño event strength, duration or frequency have significant effects, both in the US and internationally, on water resources, wildfires, agriculture and ecosystems. This project will contribute new observations and analysis of El Niño/Southern Oscillation (ENSO) activity during two past time intervals for which there are very few data from the tropical Pacific, yet for which the global climate is thought to have been relatively warm and relatively cold, respectively. Results will be compared to climate simulations for the same periods, so that we can better understand if, how and why global climate change can cause changes in El Niño activity. The project will also provide mentored, international, collaborative, and multidisciplinary training for a PhD student and an undergraduate researcher, including educational, outreach and dissemination activities. It will contribute inputs for modeling the interactions between people, fisheries and climate in a location and region with a rich archaeological history of pre-modern settlement, voyaging and exploration. These studies, which are beyond the scope of this project, may ultimately help us understand how societies have and may adapt to past and future climate change. Specifically, paired oxygen isotope and Sr/Ca data series will be developed from existing and diagenetically screened coral samples dating to the Little Ice Age (LIA) and Medieval Climate Anomaly (MCA) time windows from Aitutaki, southern Cook Islands (18.85S, 159.79W). Preliminary analysis suggests interannual variations in present day (PD) coral oxygen isotopic composition from the region primarily reflect sea surface salinity (SSS) variability resulting from changes in the position and strength of the South Pacific Convergence Zone associated with ENSO activity. In conjunction with other hydroclimatic and oceanographic paleoclimate data available for these time windows and the PD, the research team will test whether there were differences in interannual event amplitude and recurrence interval in the LIA and MCA relative to the PD. The team will compare the results to those obtained from similarly sampled, PMIP3-compliant physical climate simulations with both complete and single external radiative forcings. Comparison of observations and simulations, within the context of their uncertainties, will be used to assess if and the extent to which the observed hydroclimatic response is forced or unforced, and by what mechanisms.
来源学科分类	Geosciences - Ocean Sciences
文献类型	项目
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/69900
专题	环境与发展全球科技态势
推荐引用方式 GB/T 7714	Michael Evans.P2C2: Hydroclimatic response of the tropical Pacific to past changes in mean state: Observations and synthesis.2016.