Past Variability of Mediterranean Sea Marine Heatwaves

Abstract

Marine heatwaves (MHWs) are episodes of anomalous warming in the ocean, responsible for widespread impacts on marine ecosystems. For the first time summer MHW variability at surface and three ecosystem‐relevant depths of the upper Mediterranean Sea are assessed here for 1982–2017. We apply a MHW detection algorithm on a hindcast simulation, performed with a high‐resolution, fully coupled regional climate system model. Identified surface events last, on average, 15 days with a mean intensity of 0.6 °C above threshold and a maximum sea surface coverage of around 39%. Subsurface events are seasonally shifted and appear, on average, longer and more intense but less frequent and less extended in space than surface MHWs. We also find significant trends of increase in most MHW properties throughout the period, with severe surface MHWs detected for the first time in 2012, 2015, and 2017. However, MHW spatial ≪ hot spots ≫ are inhomogeneously distributed in surface and deeper layers.

HCLIM38: a flexible regional climate model applicable for different climate zones from coarse to convection-permitting scales

“…However, the coupling of ALARO with SURFEX as used in HCLIM38 resulted in evaporation from oceans that is too weak in low latitudes, causing considerable underestimation of atmospheric moisture content and consequently a lack of precipitation in long climate simulations. Similar issues have not been observed at high latitudes (Toivonen et al, 2019), imply- Boone 2000and Decharme et al (2011) Vegetation and carbon-related processes Jarvis-based stomatal resistance; soil organic carbon for soil thermal and hydrological properties Noilhan and Planton (1989) and Decharme et al (2016) Subgrid hydrology Subgrid runoff, Horton runoff Dümenil and Todini (1992) and Decharme and Douville (2006) Snow ISBA-ES explicit snow scheme (12 layers) Boone and Etchevers (2001) and Decharme et al (2016) Town Town Energy Balance (TEB) Masson (2000) Inland water Freshwater lake model (FLake) Mironov et al (2010) ing that ALARO can be used there. However, it is not the default option in HCLIM38 because the modelling system should be applicable at all latitudes.…”

Modulation of radiative aerosols effects by atmospheric circulation over the Euro-Mediterranean region

“…The land surface is simulated using the Interaction Soil Biosphere Atmosphere -CNRM version of Total Runoff Integrating Pathways (ISBA-CTRIP) coupled land surface modelling system (http://www.umr-cnrm. fr/spip.php?article1092&lang=en, last access: 16 July 2020) described in detail in Decharme et al (2019). To summarize, the ISBA land surface model computes the energy and water budgets at the surface-atmosphere interface, while the CTRIP river-routing model simulates river discharge to the sea using the total runoff calculated by ISBA.…”

Along-Path Evolution of Biogeochemical and Carbonate System Properties in the Intermediate Water of the Western Mediterranean

“…In the Sicily Channel, IW showed increases of 0.024 • C yr −1 and 0.006 yr −1 in θ and S, respectively, during the last 2 decades (Schroeder et al, 2017). Anomalous heatwaves in large regions of the Mediterranean basin caused high SST in 2003 (Olita et al, 2007) and in most recent years (Bensoussan et al, 2019;Darmaraki et al, 2019a).…”