Different atmospheric moisture divergence responses to extreme and moderate El Niños

Abstract

divergence fields was performed. The SOM analysis captures the range of responses to ENSO, including the distinction between the moderate and strong El Niños identified by the EOF analysis. The work demonstrates the potential for the application of SOM to large scale climatic analysis, by virtue of its easier interpretation, relaxation of orthogonality constraints and its versatility for serving as an alternative classification method. Both the EOF and SOM analyses suggest a classification of "moderate" and "extreme" El Niños by their differences in the magnitudes of the hydrological cycle responses, spatial patterns and evolutionary paths. Classification from the moisture divergence point of view shows consistency with results based on other physical variables such as SST.

Does Extreme El Niño Have a Different Effect on the Stratosphere in Boreal Winter Than Its Moderate Counterpart?

“…In the tropical stratosphere, out‐of‐phase temperature variations (cooling) in the middle stratosphere and in‐phase variations (warming) in the tropical lower stratosphere are found during extreme El Niño events, with larger amplitudes than those during moderate events. The intense tropical variations during extreme El Niño are consistent with previous studies (Rao & Ren, , ; Xu et al, ) and can be accounted for by the traditional paradigm (Calvo et al, ; Free & Seidel, ; Hardiman et al, ; Randel, ). Interestingly, the composite pattern of the stratospheric polar vortex in the NH high latitudes is cooled and strengthened.…”

The role of the subtropical North Atlantic water cycle in recent US extreme precipitation events

“…The increased moisture flux from the subtropical North Pacific mainly converges in the tropical oceans ( Fig. 1c), consistent with the typical circulation pattern induced by ENSO events (e.g., Seager et al 2012;Xu et al 2015). However, the moisture from the North Pacific barely converges onto the Southern US, indicating that the El Niño induced water cycle change does not directly influence the MFC that is a pre-requisite for the 2015 extreme precipitation event ( Fig.…”

Windspharm: A High-Level Library for Global Wind Field Computations Using Spherical Harmonics

“…• iris > = 1. [12], and has been used in a significant number of publications that the author is aware of [14,15,16,17,18,19,20,21,22,23,24]. The library is also provided as part of the JASMIN Analysis Platform [25], indicating it has a significant user base.…”