Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806
ABSTRACTLewis and Clark's entry into to the American West in search of an inland Northwest Passage is considered among the greatest expeditions in American history. The Corps of Discovery were also lucky as their travels west of the 100th meridian occurred during a “window” of generally favorab...
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ftunivnorthcag:oai:libres.uncg.edu/7936 2024-02-11T10:07:14+01:00 Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806 Knapp, Paul A. NC DOCKS at The University of North Carolina at Greensboro 2004 http://libres.uncg.edu/ir/uncg/f/P_Knapp_Window_2004.pdf English eng http://libres.uncg.edu/ir/uncg/f/P_Knapp_Window_2004.pdf 2004 ftunivnorthcag 2024-01-27T23:44:50Z ABSTRACTLewis and Clark's entry into to the American West in search of an inland Northwest Passage is considered among the greatest expeditions in American history. The Corps of Discovery were also lucky as their travels west of the 100th meridian occurred during a “window” of generally favorable climatic conditions. Use of reconstructed summer Palmer drought severity index (PDSI) values from 1700–1978 indicate that drought frequency at locations along the Lewis and Clark trail ranged from 4 to 12 yr and that the probability of encountering a drought either on the outbound or return trip approached 50% at some locations. Exact date comparisons of meteorological conditions during periods of extended encampment (i.e., 1–5 months) between 1804–06 with long-term records of nearby weather stations indicate that the Corps of Discovery avoided drought and traveled during a cooler and/or substantially wetter period than historical averages. Examination of reconstructed Southern Oscillation index (SOI) and Pacific decadal oscillation (PDO) values suggest wetter conditions prevailed in 1804–06 because of the co-occurrence of La Niña conditions during a cold PDO phase. Although the Corps of Discovery suffered hardships because of the wetter conditions, they avoided the more serious consequences of severe droughts that occurred in 1800 and 1808. Drought conditions along the semiarid and arid portions of the trail would have reduced forage yield for the game that were their principal source of food and increased their chances for starvation. Additionally, lower streamflow conditions along their principal navigation routes would have required greater effort and time to haul their supplies to the Continental Divide, perhaps delaying their expedition by a year. Other/Unknown Material Northwest passage University of North Carolina: NC DOCKS (Digital Online Collection of Knowledge and Scholarship) Pacific Northwest Passage Soi ENVELOPE(30.704,30.704,66.481,66.481) |
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University of North Carolina: NC DOCKS (Digital Online Collection of Knowledge and Scholarship) |
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ftunivnorthcag |
language |
English |
description |
ABSTRACTLewis and Clark's entry into to the American West in search of an inland Northwest Passage is considered among the greatest expeditions in American history. The Corps of Discovery were also lucky as their travels west of the 100th meridian occurred during a “window” of generally favorable climatic conditions. Use of reconstructed summer Palmer drought severity index (PDSI) values from 1700–1978 indicate that drought frequency at locations along the Lewis and Clark trail ranged from 4 to 12 yr and that the probability of encountering a drought either on the outbound or return trip approached 50% at some locations. Exact date comparisons of meteorological conditions during periods of extended encampment (i.e., 1–5 months) between 1804–06 with long-term records of nearby weather stations indicate that the Corps of Discovery avoided drought and traveled during a cooler and/or substantially wetter period than historical averages. Examination of reconstructed Southern Oscillation index (SOI) and Pacific decadal oscillation (PDO) values suggest wetter conditions prevailed in 1804–06 because of the co-occurrence of La Niña conditions during a cold PDO phase. Although the Corps of Discovery suffered hardships because of the wetter conditions, they avoided the more serious consequences of severe droughts that occurred in 1800 and 1808. Drought conditions along the semiarid and arid portions of the trail would have reduced forage yield for the game that were their principal source of food and increased their chances for starvation. Additionally, lower streamflow conditions along their principal navigation routes would have required greater effort and time to haul their supplies to the Continental Divide, perhaps delaying their expedition by a year. |
author |
Knapp, Paul A. NC DOCKS at The University of North Carolina at Greensboro |
spellingShingle |
Knapp, Paul A. NC DOCKS at The University of North Carolina at Greensboro Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806 |
author_facet |
Knapp, Paul A. NC DOCKS at The University of North Carolina at Greensboro |
author_sort |
Knapp, Paul A. |
title |
Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806 |
title_short |
Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806 |
title_full |
Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806 |
title_fullStr |
Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806 |
title_full_unstemmed |
Window of Opportunity: The Climatic Conditions of the Lewis and Clark Expedition of 1804–1806 |
title_sort |
window of opportunity: the climatic conditions of the lewis and clark expedition of 1804–1806 |
publishDate |
2004 |
url |
http://libres.uncg.edu/ir/uncg/f/P_Knapp_Window_2004.pdf |
long_lat |
ENVELOPE(30.704,30.704,66.481,66.481) |
geographic |
Pacific Northwest Passage Soi |
geographic_facet |
Pacific Northwest Passage Soi |
genre |
Northwest passage |
genre_facet |
Northwest passage |
op_relation |
http://libres.uncg.edu/ir/uncg/f/P_Knapp_Window_2004.pdf |
_version_ |
1790605419431854080 |