| Titre | The seasonality of precipitation signals embedded within the North American Drought Atlas |
| Auteur | St. George, S; Meko, D M; Cook, E R |
| Source | The Holocene vol. 20, issue 6, 2010 p. 983-988, https://doi.org/10.1177/0959683610365937 |
| Année | 2010 |
| Séries alt. | Secteur des sciences de la Terre, Contribution externe 20090241 |
| Éditeur | Sage publications |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1177/0959683610365937 |
| Media | papier; en ligne; numérique |
| Formats | pdf |
| Province | Colombie-Britannique; Alberta; Saskatchewan; Manitoba; Ontario; Québec; Nouveau-Brunswick; Nouvelle-Écosse; Île-du-Prince-Édouard; Terre-Neuve-et-Labrador; Territoires du Nord-Ouest; Yukon;
Nunavut |
| SNRC | 1; 2; 3; 10; 11; 12; 13; 14; 15; 16; 20; 21; 22; 23; 24; 25; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37; 38; 39; 40; 41; 42; 43; 44; 45; 46; 47; 48; 49; 52; 53; 54; 55; 56; 57; 58; 59; 62; 63; 64; 65;
66; 67; 68; 69; 72; 73; 74; 75; 76; 77; 78; 79; 82; 83; 84; 85; 86; 87; 88; 89; 92; 93; 94; 95; 96; 97; 98; 99; 102; 103; 104; 105; 106; 107; 114O; 114P; 115; 116; 117; 120; 340; 560 |
| Sujets | précipitation; dendrochronologie; établissement de modèles; La Nina; géologie de l'environnement; Nature et environnement |
| Illustrations | location maps |
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| Programme | Impacts des changements climatiques et adaptation dans le secteur des ressources naturelles et d'autres secteurs clés de l'économie, Géosciences de changements climatiques |
| Résumé | (disponible en anglais seulement)
We examine how the seasonality of precipitation signals embedded within the North American Drought Atlas varies across the continent. Instrumental records of
average summer (JJA) Palmer Drought Severity Index (PDSI) are characterized by major regional differences in the relative importance of precipitation during summer and winter (DJF). The Atlas, which is based on a network of drought-sensitive
tree-ring records, is able to reproduce the main geographic patterns of these biases, but tree-ring reconstructions exaggerate the influence of seasonal precipitation anomalies in the southwestern United States and northern Mexico (towards a stronger
winter signal) and western Canada (towards a stronger summer signal). Drought reconstructions from the Southwest and Tex-Mex regions are tuned mainly to winter precipitation and display strong teleconnections to both El Niño and La Niña. In contrast,
winter precipitation signals are either weak or absent in drought reconstructions from northwestern North America, and tree-ring estimates of PDSI show a much less robust association with the El Niño-Southern Oscillation. Geographical differences in
the relative strength of seasonal precipitation signals are likely due
to (i) local factors that influence tree growth but are not incorporated into the PDSI algorithm and (ii) real differences in regional climatology. These seasonal biases must
be taken into account when comparing drought reconstructions across North America, when comparing tree-ring PDSI to drought records developed from other proxies or when attempting to use the Drought Atlas to link past droughts to potential forcing
mechanisms. |
| GEOSCAN ID | 248089 |
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