Search Results

You are looking at 1 - 4 of 4 items for

  • Author or Editor: Matthew D. Therrell x
  • Refine by Access: All Content x
Clear All Modify Search
Matthew D. Therrell and Makayla J. Trotter

Pictographic calendars called waniyetu wówapi or “winter counts” kept by several Great Plains Indian cultures (principally the Sioux or Lakota) preserve a record of events important to these peoples from roughly the seventeenth through the nineteenth centuries. A number of these memorable events include natural phenomena, such as meteor storms, eclipses, and unusual weather and climate. Examination of a selection of the available winter count records and related interpretive writings indicates that the Lakota and other native plains cultures recorded many instances of unusual weather or climate and associated impacts. An analysis of the winter count records in conjunction with observational and proxy climate records and other historical documentation suggests that the winter counts preserve a unique record of some of the most unusual and severe climate events of the early American period and provide valuable insight into the impacts upon people and their perceptions of such events in the ethnographically important region of the Great Plains.

Full access
Matthew D. Therrell, David W. Stahle, and Rodolfo Acuña Soto

Sixteenth-century Aztec codices preserve a record of at least 13 drought years in central Mexico during the prehispanic and early colonial period. Climate-sensitive tree-ring records recently developed for Mexico confirm 9 of the 13 Aztec drought dates, including the extended drought related to the infamous “famine of One Rabbit” in 1454. One Rabbit is the first year of the 52-yr Aztec calendar cycle, and folklore suggests that famine and catastrophe accompany its return. The Mexican treering data indicate that severe drought occurred immediately before 10 of the 13 One Rabbit years during and before the Aztec era a.d. 882–1558. This relationship between drought and the year preceding One Rabbit is statistically significant and suggests a real climatic origin for the “curse of One Rabbit.”

Full access
Carlos Le Quesne, David W. Stahle, Malcolm K. Cleaveland, Matthew D. Therrell, Juan Carlos Aravena, and Jonathan Barichivich


An expanded network of moisture-sensitive tree-ring chronologies has been developed for central Chile from long-lived cypress trees in the Andean Cordillera. A regional ring width chronology of cypress sites has been used to develop well-calibrated and verified estimates of June–December precipitation totals for central Chile extending from a.d. 1200 to 2000. These reconstructions are confirmed in part by historical references to drought in the seventeenth and eighteenth centuries and by nineteenth-century observations on the position of the Río Cipreses glacier. Analyses of the return intervals between droughts in the instrumental and reconstructed precipitation series indicate that the probability of drought has increased dramatically during the late nineteenth and twentieth centuries, consistent with selected long instrumental precipitation records and with the general recession of glaciers in the Andean Cordillera. This increased drought risk has occurred along with the growing demand on surface water resources and may heighten socioeconomic sensitivity to climate variability in central Chile.

Full access
Daniel L. Druckenbrod, Michael E. Mann, David W. Stahle, Malcolm K. Cleaveland, Matthew D. Therrell, and Herman H. Shugart

This study presents two independent reconstructions of precipitation from James Madison's Montpelier plantation at the end of the eighteenth century. The first is transcribed directly from meteorological diaries recorded by the Madison family for 17 years and reflects the scientific interests of James Madison and Thomas Jefferson. In his most active period as a scientist, Madison assisted Jefferson by observing the climate and fauna in Virginia to counter the contemporary scientific view that the humid, cold climate of the New World decreased the size and number of its species. The second reconstruction is generated using tree rings from a forest in the Montpelier plantation and connects Madison's era to the modern instrumental precipitation record. These trees provide a significant reconstruction of both early summer and prior fall precipitation. Comparison of the dendroclimatic and diary reconstructions suggests a delay in the seasonality of precipitation from Madison's era to the mid-twentieth century. Furthermore, the dendroclimatic reconstructions of early summer and prior fall precipitation appear to track this shift in seasonality.

Full access