Under the aegis of the AGS-PRF (post-doctoral research fellowship) solicitation, the researcher aims to use modern and paleoclimate data to examine the occurrence of extreme weather and climatic events in Mongolia such as the dzud. A dzud event is characterized by summer drought followed by a harsh winter. The impact of such severe events on nomadic persons and the landscape they occupy could be profound since environmental conditions dictate resource availability. By examining the climatology and spatial and temporal variations of the dzud, the researcher seeks to better understand the relationship between climate and environment.
Specifically, the researcher aims to: 1) identify and quantify the spatial and temporal changes in the landscape (e.g. vegetation abundance, drought stress and desertification) that increase vulnerability to climate change; 2) evaluate the spatial coherence of dzud and other extreme events and identify and map vulnerable regions; 3) evaluate the ocean/atmosphere dynamics during known events and identify any patterns or commonalities; and 4) model and reconstruct dzud and extreme events using data and knowledge gained from objective 1, 2 and 3, as well as historical, meteorological, satellite, and paleoclimatic data.
The broader impacts involve enabling greater interface between climate science and economics, internationally, and creating partnerships with risk management professionals regarding issues surrounding climate dynamics.
This AGS PRF project resulted in three major papers (listed below with summaries) and as a result of being supported by this postdoctoral award I have was able to collaborate as a co-author on 18 additional peer-review papers on related research (www.researchgate.net/profile/Nicole_Davi). I have also participated in five professional development workshops and attending several professional meetings. As a result of this award I have been in communication with "climate resilience" communities including the Asian Pacific Adaptation Network (APAN). The research outcomes on livestock mortality and climate variability/extremes will help inform these resilience programs in terms of improving insurance products and developing short-term forecasting products. 1. Rao PM, Davi N, Wang S, D’Arrigo R, Skees J, Lyon B, Leland, C (in Review). Climate, Dzuds, droughts, and livestock mortality in Mongolia. Environmental Research Letters. Abstract: Recent incidences of mass livestock mortality have called into question the sustainability of pastoral nomadic herding, the cornerstone of Mongolian culture. Close to 20 million livestock perished in the combined mortality events of 2000-2002, and 2009-2010. To mitigate the effects of such events on the lives of herders, international agencies such as the World Bank are taking increasing interest in developing tailored market-based solutions like index-insurance. Their ultimate success depends on understanding the historical context and underlying causes of mortality. In this paper we examine mortality in 21 Mongolian aimags (provinces) between 1955-2007 in order to explain its cause(s). We show for the first time that livestock mortality is most strongly linked to winter temperatures, with incidences of mass mortality being most likely to occur because of an anomalously cold winter or ‘dzud’. Additionally, we find summer drought to be an important trigger for mortality that intensifies the effect of upcoming winter temperatures on livestock. 2. Davi NK, D’Arrigo R, Jacoby GC, Cook ER, Anchukaitis K, Nachin B, Rao MP, and Leland C (in review). A long-term context (931-2005 C.E.) for rapid warming over Central Asia. Quaternary Science Reviews. Abstract: Warming over Mongolia and Central Asia has been unusually rapid over the past few decades, particularly in the summer, with surface temperature anomalies higher than for much of the globe. With few temperature station records available in this remote region prior to the 1950s, paleoclimatic data must be used to understand annual-to-centennial scale climate variability, local response to large-scale forcing mechanisms, and the significance of major features of the past millennium such as the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) both of which can vary globally. Here we use an extensive collection of living and subfossil wood samples from temperature-sensitive trees to produce a millennial-length, validated reconstruction of summer temperatures for Mongolia and Central Asia from 931 to 2005 CE. This tree-ring reconstruction shows general agreement with the MCA (warming) and LIA (cooling) trends, a significant volcanic signature, and warming in the 20th and 21st Century. Recent warming (2000-2005) exceeds that from any other time and is concurrent with, and likely exacerbated, the impact of extreme drought (1999-2002) that resulted in massive livestock loss across Mongolia. 3. Davi N, Pederson N, Leland C, Suran B, Nachin B, Jacoby G. (2013). Four centuries of hydroclimatic context for the recent drying in east central Mongolia. Water Resources Research. DOI: 10.1029/2012WR011834 Abstract: Temperatures in semi-arid Mongolia have rapidly risen over the past few decades while increases in drought, urban development, mining and agricultural have intensified demands on limited water resources. Understanding long-term stream flow variation is critical for Mongolia, particularly if alterations in streamflow are being considered and because of the potential negative impacts of drought on the animal agriculture sector. Here, we present a temporally and spatially improved streamflow reconstruction for the Kherlen River. We have added 11 new records, compared to two in the original 2001 reconstruction. This new reconstruction extends from 1630-2007 and places the most recent droughts in a multi-centennial perspective. We find that variations in streamflow have been much greater in the past than originally found. There was higher variability in the mid to late 1700s— ranging from severe and extended drought conditions from 1723-1739 and again in 1768- 1778, to two decadal length episodes of very wet conditions in the mid and late 1700s. Reduced amplitude is seen in the mid 1800s and several pluvial events are reconstructed for the 1900s. While recent droughts are severe and disturbing economic and ecological systems in Mongolia and it appears that eastern Mongolia is drying, the drying trend since the late 1900s might in fact be the result of a return to more characteristic hydroclimatic conditions of the past four centuries in Mongolia after a prolonged era of repeated and extended wet episodes. Decadal length droughts and pluvials are not uncommon in the context of the past four centuries.
