|Title||El Nino phases embedded in Asian and North American drought reconstructions|
|Publication Type||Journal Article|
|Year of Publication||2014|
|Authors||Li J.B, Xie SP, Cook E.R|
|Journal||Quaternary Science Reviews|
|Type of Article||Article|
|Keywords||continental; drought; enso; indo-western pacific; last; millennium; Monsoon Asia; North America; ocean; sea-surface temperature; severity index; soil-moisture; southern-oscillation; summer monsoon; Tree-rings; tropical cyclones; united-states|
The amplitude of El Nil-ID-Southern Oscillation (ENSO) varies substantially at each phase of its evolution, affecting the timing and patterns of atmospheric teleconnections around the globe. Instrumental records are too short to capture the full behavior of ENSO variability. Here we use the well-validated Monsoon Asia Drought Atlas (MADA) and North America Drought Atlas (NADA) for the past 700 years, and show that tree-ring records from different regions represent tropical sea surface temperature (SST) conditions at various phases of ENSO. Three modes of tree-ring based summer drought variability are found to be correlated with ENSO: summer droughts over the Maritime Continent and Southwest North America (NA), and a dipole mode between Central and South Asia. A lagged correlation analysis is performed to determine the time when precipitation and temperature anomaly imprints on summer droughts as recorded in tree-rings. Drought anomalies in the Maritime Continent and Southwest NA represent ENSO at the developing and peak phases respectively, while those over Central/South Asia are associated with tropical-wide SST anomalies (including the Indian Ocean) at the decay phase of ENSO. Thus proxy records from different regions can provide valuable information on long-term behavior of ENSO at different phases. (C) 2013 Elsevier Ltd. All rights reserved.
|Short Title||Quat. Sci. Rev.|
Our findings reported here provide a framework for future efforts aiming at reconstructing ENSO variability more accurately. For example, tree-rings in Southwest NA might be more useful for reconstructing the peak phase ENSO variability, whereas those in the Maritime Continent might be more appropriate for reconstructing the developing phase ENSO variability.