Long term context for recent drought in northwestern Africa

Abstract

Anthropogenic climate change is projected to exacerbate midlatitude aridity. Here, we analyze newly developed multi‐century tree‐ring records for a long‐term perspective on drought in Tunisia and Algeria. We use a new set of 13 Cedrus atlantica and Pinus halepensis chronologies with a strong signal for warm‐season drought (May–August) to generate a robust, well‐validated reconstruction of the Palmer Drought Severity Index (PDSI) for the period AD 1456–2002. Key features of the reconstruction reveal the magnitude of pre‐instrumental droughts from the historic record. Remarkably, the most recent drought (1999–2002) appears to be the worst since at least the middle of the 15th century. This drought is consistent with the early signature of a transition to more arid midlatitude conditions, as projected by general circulation models.

A review of droughts on the African continent: a geospatial and long-term perspective

“…Anderson et al, 2012;Syroka and Nucifora, 2010) and northwestern Africa (e.g. Touchan et al, 2008Touchan et al, , 2011. There are few studies which attempt to cover more than one region (e.g.…”

“…Such studies can also provide necessary information on the periodic nature of droughts and their relationship with increasing water demand or climate change (Mishra and Singh, 2010). Moreover, the outlook of the current and future drought events in the historic context could facilitate in applying low-risk and long-term plans to use, conserve and sustain water and other natural resources (Touchan et al, 2008). The current efforts by the scientific community in this direction are very limited and require further attention (Mishra and Singh, 2010;Touchan et al, 2008;Vicente-Serrano et al, 2012;Vogel et al, 2010).…”

“…Moreover, the outlook of the current and future drought events in the historic context could facilitate in applying low-risk and long-term plans to use, conserve and sustain water and other natural resources (Touchan et al, 2008). The current efforts by the scientific community in this direction are very limited and require further attention (Mishra and Singh, 2010;Touchan et al, 2008;Vicente-Serrano et al, 2012;Vogel et al, 2010). The available scientific studies do not provide enough geospatial and long-term temporal coverage of past drought events at global and continental levels.…”

A 560 yr summer temperature reconstruction for the Western Mediterranean basin based on stable carbon isotopes from <i>Pinus nigra</i> ssp. <i>laricio</i> (Corsica/France)

“…Located in the transition zone between the west wind drift and the subtropical high pressure belt, the Mediterranean basin already suffers from severe drought during summer months (Touchan et al, 2008a(Touchan et al, ,b, 2011. The expected strong temperature increase and precipitation decrease will intensify drought stress and lead to a northward extension of dry and arid land (Christensen, 2007;Gao and Giorgi, 2008).…”

Regional Summer Temperature Reconstruction in the Khibiny Low Mountains (Kola Peninsula, NW Russia) by Means of Tree-ring Width during the Last Four Centuries

“…Tree-ring records allow, with the development of quantitative and validated paleoclimate reconstructions, understanding of high-resolution climate variability beyond instrumental data (e.g. Touchan et al, 2008). But the question of how well high-frequency climate variability is expressed by tree-ring proxies including the error estimation still requires special consideration (von Storch et al, 2004).…”