Nature Communications Paper: Significant increase of global anomalous moisture uptake feeding landfalling Atmospheric Rivers

 On October 8th a new paper was published in Nature Communications with the contribution of IDL researchers Alexandre M. Ramos and Ricardo M. Trigo, coordinated by long-term collaborators from EphysLab (University of Vigo).

The results of this work reveal a significant increase in the amount of atmospheric moisture coming from the regions that supply precipitable water, which is transported to the continents by the Atmospheric Rivers (ARs). The ARs correspond to relatively narrow bands, but which extend for thousands of kilometers, characterized by a strong concentration of water vapor, and are often associated with episodes of extreme precipitation. They are responsible for the greater part of humidity transport in the low atmosphere between tropical regions and the mid-latitudes. Therefore, ARs are an important component of the hydrological cycle and their increased occurrence in a given region can lead to an increased occurrence of floods in coastal regions.

Full citation: Algarra, I., Nieto, R., Ramos, A.M., Eiras-Barca, J., Trigo, R.M, & Gimeno, L. (2020): Significant increase of global anomalous moisture uptake feeding landfalling Atmospheric Rivers. Nature Communications 11:5082 https://doi.org/10.1038/s41467-020-18876-wAbstract:One of the most robust signals of climate change is the relentless rise in global mean surface temperature, which is linked closely with the water-holding capacity of the atmosphere. A more humid atmosphere will lead to enhanced moisture transport due to, among other factors, an intensification of atmospheric rivers (ARs) activity, which are an important mechanism of moisture advection from subtropical to extra-tropical regions. Here we show an enhanced evapotranspiration rates in association with landfalling atmospheric river events. These anomalous moisture uptake (AMU) locations are identified on a global scale. The interannual variability of AMU displays a significant increase over the period 1980-2017, close to the Clausius-Clapeyron (CC) scaling, at 7 % per degree of surface temperature rise. These findings are consistent with an intensification of AR predicted by future projections. Our results also reveal generalized significant increases in AMU at the regional scale and an asymmetric supply of oceanic moisture, in which the maximum values are located over the region known as the Western Hemisphere Warm Pool (WHWP) centred on the Gulf of Mexico and the Caribbean Sea.Press release (in Portuguese) https://ciencias.ulisboa.pt/servicos/comunicadosImprensa/download/164