Climatology of Lyapunov exponents: The influence of atmospheric rivers on large-scale mixing variability
Daniel Garaboa-Paz, Jorge Eiras-Barca, and Vicente Pérez-Muñuzuri
Group of Nonlinear Physics, Faculty of Physics, University of Santiago de Compostela, 15782 Santiago de Compostela, Spain
Received: 02 Jan 2017 – Accepted for review: 25 Jan 2017 – Discussion started: 26 Jan 2017
Abstract. Large-scale tropospheric mixing and Lagrangian transport properties have been analyzed for a long-term period 1979–2014 in terms of the finite-time Lyapunov exponents (FTLE). Wind fields reanalysis from the European Centre for Medium-Range Weather Forecasts were used to calculate Lagrangian trajectories of large ensembles of particles. The FTLE climatology shows large correlation values with the baroclinic instability growth rate. Larger values of the inter and intra-annual mixing variabilities highlight El Niño Southern Oscillation, the storm track or the Intertropical Convergence Zone among other large-scale structures. As a case study, the role that atmospheric rivers have on the large-scale atmospheric mixing and the precipitation rates observed in the Sahara-Morocco and British Isles regions have been analyzed. Atmospheric rivers contribution to tropospheric mixing is found to decrease from 15 % in Sahara-Morocco to less than 5 % for UK-Ireland regions, in agreement to their contribution to precipitation that is 40 % larger in the former than for the latter region.
Garaboa-Paz, D., Eiras-Barca, J., and Pérez-Muñuzuri, V.: Climatology of Lyapunov exponents: The influence of atmospheric rivers on large-scale mixing variability, Earth Syst. Dynam. Discuss., doi:10.5194/esd-2017-1, in review, 2017.