资源环境科技发展态势分析平台

To account for the wet mid‐Holocene (ca 6 ka) Sahara‐Sahel region, we exploit teleconnections from four large‐scale ocean‐atmosphere‐land forcings: El Nino‐Southern Oscillation (ENSO), Atlantic Multidecadal Oscillation (AMO), hemispherical temperature difference, and net energy input at the equator; they offer theoretical bases for estimating effects of large‐scale forcing on mid‐Holocene Sahara‐Sahel rainfall. Together, these forcings explain 16%–64% of historical rainfall variability, with the highest percentages in the Sahel region. With estimates for mid‐Holocene time, latitudes where rainfall today averages 1000, 500, or 200 mm/yr are reconstructed to have lain ~2.5° farther north. Calculated mid‐Holocene rainfall at 15°N, 17.5°N, and 20°N exceeds that today by ~250, 100, and 20 mm/yr. These shifts account for more than half of paleoclimatic estimates of mid‐Holocene rainfall, and are comparable with the GCM runs that match paleo‐rainfall estimates most closely. Mid‐Holocene radiation may have affected Sahel precipitation indirectly via teleconnections from oceanic regions.