Statistical downscaling methods (SDMs) are techniques used to downscale and/or bias‐correct climate model results to regional or local scales. The European network VALUE developed a framework to evaluate and inter‐compare SDMs. One of VALUE's experiments is the perfect predictor experiment that uses reanalysis predictors to isolate downscaling skill. Most evaluation papers for SDMs employ simple statistical diagnostics and do not follow a process‐based rationale. Thus, in this paper, a process‐based evaluation has been conducted for the more than 40 participating model output statistics (MOS, mostly bias correction) and perfect prognosis (PP) methods, for temperature and precipitation at 86 weather stations across Europe. The SDMs are analysed following the so‐called “regime‐oriented” technique, focussing on relevant features of the atmospheric circulation at large to local scales. These features comprise the North Atlantic Oscillation, blocking and selected Lamb weather types and at local scales the bora wind and the western Iberian coastal‐low level jet. The representation of the local weather response to the selected features depends strongly on the method class. As expected, MOS is unable to generate process sensitivity when it is not simulated by the predictors (ERA‐Interim). Moreover, MOS often suffers from an inflation effect when a predictor is used for more than one station. The PP performance is very diverse and depends strongly on the implementation. Although conditioned on predictors that typically describe the large‐scale circulation, PP often fails in capturing the process sensitivity correctly. Stochastic generalized linear models supported by well‐chosen predictors show improved skill to represent the sensitivities.

Near‐surface winds over the Adriatic region are examined under present‐day and future climate conditions for two greenhouse gas scenarios (Representative Concentration Pathway 4.5 and Representative Concentration Pathway 8.5) with an ensemble of high‐resolution (0.11°) Coordinated Regional Climate Downscaling Experiment (CORDEX) simulations. The influence of particular combinations of regional climate models and global climate models and emission scenarios on the future changes in the near‐surface wind field has been explored in more detail. Starting with the seasonal climate change signal in large‐scale flow over the entire CORDEX domain, we focus on regional daily wind fields over the Adriatic domain and subdaily features of well‐known regional winds (Bora and Sirocco winds). The analysis reveals the strong sensitivity of the climate change signal in the simulated wind flow to (i) the choice of the global climate model that provides the boundary conditions and (ii) the analyzed locations across the Adriatic region. The results of the 21st‐century projections indicate that the changes in synoptic activity have an impact on the wind field at the (sub)daily time scale. We found a reduction in the number of Bora events and increase in the number of Sirocco events in northern Adriatic during the winter season, with an increase in pressure in the middle of the 21st century. Overall, the mean wind speed during Bora and Sirocco events is reduced, except for Bora in northern Adriatic. For the summer season, we found a large increase in the number of thermally induced flows, which is probably caused by the weakening of the Azores High.

simulations using RCP8.5 show fewer Tramontane events than those using RCP4.5.

Mistral and tramontane are mesoscale winds in southern France. Both winds emerge in valleys and cause deep water formation in the Mediterranean Sea, which makes them interesting phenomena for studying several orographic effects and relevant for Earth system models. However, climate simulations are performed on a finite numerical grid with a coarse-gridded orography and processes on subgrid scales are parameterized. This study surveys the effect of orographic grid spacing (2.6-45 km) on mistral and tramontane by performing idealized simulations with a 1.3 km horizontal numerical grid. Reduction of the orographic detail leads to a wind pattern change and a wind speed reduction. If orographic features on smaller scales are parameterized, the effects of the smoothing are weaker, but a systematic decrease in channeling and wind speed still persists.

The Mediterranean region is a densely populated and economically relevant area with complex orography including mountain ranges, islands, and straits. In combination with pressure gradients, this creates many mesoscale wind systems that cause, e.g., wind gusts and wildfire risk in the Mediterranean. This article reviews the recent state of the science of several mesoscale winds in the Mediterranean and associated processes. Previous work, including case studies on several time ranges and resolutions, as well as studies on these winds under future climate conditions, is discussed. Simulations with grid spacings of 25 to 50 km can reproduce winds driven by large-scale pressure patterns such as Mistral, Tramontane, and Etesians. However, these simulations struggle with the correct representation of winds channeled in straits and mountain gaps and around islands. Grid spacings of 1–3 km are certainly necessary to resolve these small-scale features. The smaller grid spacings are widely used in case studies, but not yet in simulations over large areas and long periods, which also could help to understand the interaction between small-scale phenomena in separate locations. Furthermore, by far not all Mediterranean straits, islands, and mountain gaps were studied in-depth and many interesting Mediterranean small-scale winds still need to be studied.

Maritime Transport is a vital sector for global trade and the world economy. Particularly for islands, there is also an important social dimension introduced since island communities strongly rely on the sector for connection with the mainland and transportation of goods and passengers. Furthermore, islands are exceptionally vulnerable to climate change, as sea-level rise and extreme events are expected to induce severe impacts. Such hazards are anticipated to also affect the operations of the Maritime Transport sector, either in port infrastructures or ships en route. The present study is an effort to comprehend better and assess the future risk of Maritime Transport disruption in six European islands and archipelagos and aims at supporting regional to local policy and decision-making. We employ state-of-the-art regional climate datasets and the widely used Impact Chain approach to identify the different components that might drive such risks. Larger islands (e.g., Corsica, Cyprus, and Crete) are found to be more resilient to the impacts of climate change on maritime operations. Our findings also highlight the importance of adopting a low-emission pathway since this will keep the risk of Maritime Transport disruption similar to present levels, with an even slightly decreased risk for some islands because of enhanced adaptation capacity and advantageous demographic changes.

No abstract

Maritime transport is a vital sector for global trade and the world economy. Particularly for islands, there is also an important social dimension of this sector, since island communities strongly rely on it for a connection with the mainland and the transportation of goods and passengers. Furthermore, islands are exceptionally vulnerable to climate change, as the rising sea level and extreme events are expected to induce severe impacts. Such hazards are anticipated to also affect the operations of the maritime transport sector by affecting either the port infrastructure or ships en route. The present study is an effort to better comprehend and assess the future risk of maritime transport disruption in six European islands and archipelagos, and it aims at supporting regional to local policy and decision-making. We employ state-of-the-art regional climate datasets and the widely used impact chain approach to identify the different components that might drive such risks. Larger islands (e.g., Corsica, Cyprus and Crete) are found to be more resilient to the impacts of climate change on maritime operations. Our findings also highlight the importance of adopting a low-emission pathway, since this will keep the risk of maritime transport disruption similar to present levels or even slightly decreased for some islands because of an enhanced adaptation capacity and advantageous demographic changes.