Irene Polo

Irene Polo

Profesor Ayudante Doctor

ipolo@ucm.es

I am a postdoctoral researcher studying the processes associated with the ocean-atmosphere interactions and their impact on climate variability. The representation of those processes in models has implications in the predictability of the climate impacts. Climate variability shows a vast range of time-scales (from inter-decadal Thermo-Haline-driven circulation to intra-seasonal weather regimes), understanding the air-sea interactions at different time-scales is important for future predictions. My research comprises climate variability at different scales, from ocean processes with impacts at decadal time-scales, throughout ocean-atmosphere interactions and tele-connections at inter-annual time-scales to weather regimes and their impacts on rainfall.
I am interested in the ocean-atmosphere interactions, upper ocean processes, variability and adjustment in the Atlantic Ocean circulation, Atlantic Meridional Overturning Circulation (AMOC) and Tropical Atlantic Variability (TAV). I am currently working in PREFACE (EU-UCM) and RAMOC (NERC-University of Reading) projects.
PREFACE project aims to understand model biases over the Tropical Atlantic, in that context I analyse TAV and biases in CMIP5 models and in seasonal forecast systems.
RAMOC project aims to improve ocean states estimates using data assimilation of RAPID data at 26N, in this context I analyse density covariances with AMOC at 26N and their associated forcings and timescales.
Research Highlights
(1) Polo et al (2008) analysed the tropical variability modes related to West African Monsoon. The Atlantic Niño was the leading mode of the ITCZ-shifts at inter-annual time-scales and it was also associated with ENSO. Deeper analysis of this inter-basin relationship revealed for the first time how equatorial Atlantic was able to impact the ENSO. This has been described in a series of publications in which I am co-author (Rodriguez-Fonseca et al., 2009; Losada et al., 2009; Polo et al., 2013a; Polo et al., 2015; Martin-Rey et al., 2014; Martin-Rey et al., 2015). From partially coupled simulations, the warming over equatorial Atlantic was able to impact on the walker circulation on tropical Pacific. Anomalous subsidence and divergent winds triggers a Kelvin wave eastward propagating which allows increasing the horizontal and vertical advection due to anomalous zonal velocity and stratification respectively, driven an El Niño event. The inter-basin tele-connection was showed to be modulated at multi-decadal time-scales, mostly due to the AMO, by changing the convection background over west equatorial Atlantic and ENSO variability. From water hosing experiments, changes in the AMOC have shown to have an impact on tropical variability and the Atlantic-Pacific connection.
(2) Analysis of the mechanisms associated with the geostrophic part of the AMOC in a series of ocean simulations have revealed the processes related to wind and buoyancy forcing have different time-scales, which has a potential impact on predictability (Polo et al., 2014). Currently I am contributing in understanding density variability at the boundaries and the decadal prediction of the North Atlantic subpolar gyre.
(3) A series of papers on weather regimes over the North Atlantic European and Mediterranean region has shown that extra-tropics are associated with African rainfall being the Mediterranean Sea an intermediate driver (Polo et al. 2011; Polo et al., 2013b; Garcia-Serrano et al., 2013a). Decadal predictability has been assessed for West African rainfall and Atlantic Niño (Garcia-Serrano et al., 2013b; 2013c).