Hydroclimate Variations across North-Central China during the Past 530 Years and Their Relationships with Atmospheric Oscillations

Detailed study of historical drought events in North-Central China (NCC) is important to understand current hydroclimate variability the background global warming. Here, we combined 12 published tree-ring chronologies and dryness/wetness indices (DWI) reconstruct dry wet climate across NCC. These 24 proxy records showed similarly significant responses warm season (May–June–July–August–September, MJJAS) moisture signals. A new 530-year-long reconstruction self-calibrating Palmer Drought Severity Index (scPDSI) values for NCC was determined using a nested principal component regression (PCR) approach. The shows correlations with instrumental MJJAS scPDSI data during period AD 1901–2012. reconstructed revealed seven severe dry/wet from 1470 2012. periods 1701–1727 1985–2011 represent longest periods, 1920s identified as most one over past 530 years. Our interannual spectral peaks at frequency domain 2–7 years, together relatively weaker decadal frequencies 16, 24, 78 results superposed epoch analysis (SEA) show that extreme North Atlantic Oscillation (NAO) years may modulate