Dendroclimatic Characterization of Southwestern Paleoclimate During the Past 2000 Years

迪恩博士和格雷比尔博士将继续他们的树木气候学 重建美国西南部过去的气候。 因为年轮的大小和结构 树木受到降雨和其他环境变化的影响。 变量，可以用它们来重建过去的 气候变化 此外，由于树木的年轮是沉积在一个 每年的基础上，他们允许这种变化的准确日期。 迪恩博士和格雷比尔博士将为已经大量的数据 通过分析来自活树的额外核心， 在亚利桑那州、新墨西哥州、犹他州和科罗拉多。 他们的初步 研究表明，大约在公元1300年出现了一次重大的气候扰动; 这对应于一个重大的文化变革的时间， 西南 亚利桑那队将把注意力集中在此 问题. 他们将重建每年和季节变化的 降水量、温度、生长季节长度的变化， 帕尔默干旱严重程度指数和水流变化。 在美国西南部，前西班牙裔 时代，复杂的文化，其中涵盖了大部分的 几个国家。 这些考古建筑群不断扩大， 随着时间的推移收缩，最大的一个在 西班牙人的到来 考古学家推测， 这些文化变化实际上是对 环境和西南提供了一个很好的变化， 人的反应。 树木年轮数据将大大有助于 这样的分析。 这项研究不仅对考古学家很重要， 古生态学家和对气候感兴趣的科学家 动态和变化。 温度和降水量的变化 今天如此令人关注的事件在过去发生过多次。 理解它们和了解人类如何 社会回应。

Drs. Dean and Graybill will continue their dendroclimatological work to reconstruct past climates in the United States Southwest. Because the size and configuration of annual growth rings in trees are affected by changes in rainfall and other environmental variables, it is possible to use them to reconstruct past climatic change. Also, since tree rings are deposited on an annual basis, they permit an accurate dating of this change. Drs. Dean and Graybill will add to an already substantial data base through the analysis of additional cores from living trees in Arizona, New Mexico, Utah, and Colorado. Their preliminary work show a major climatic peturbation at approximately 1300 AD; this corresponds to a time of major cultural change in the Southwest. The Arizona team will focus their attention on this issue. They will reconstruct changing annual and seasonal variations in precipitation, temperature, growing season length, the Palmer Drought Severity Index, and changes in stream flow. The Southwestern United States saw the rise, in pre Hispanic times, of complex cultures which covered large portions of several states. These archaeological complexes expanded and contracted over time and the largest disintegrated before the arrival of the Spanish. Archaeologists have hypothesized that these cultural changes were in fact responses to variation in the environment and that the Southwest offers an excellent change and human response. The tree ring data will significantly aid in analyses of this kind. This research will be important not only for archaeologists, but also paleoecologists and scientists interested in climate dynamics and changes. Changes in temperature and precipitation which are of such concern today occurred many times in the past. It is important both to understand them and to learn how human societies responded.