Periodic Reporting for period 1 - SEAFIRE (Path towards a sustainable Mediterranean Sea: mitigation actions to cope with Marine Heat Waves)
Período documentado: 2023-05-16 hasta 2025-11-15
The ocean has stored at least 89% of the excess heat due to human-induced greenhouse gas emissions, making climate change irreversible [1]. Ocean warming trends over the past 50 years have not been homogenous, and some regions known as Marine Hotspots have experienced warming at a rate faster than 90% of the rest of the oceans [2]. Superimposed on these long-term trends, devastating Marine Heat Waves (MHWs) are defined as episodes of anomalous warming in the ocean that can last from a few days to months [3]. These extreme events have drawn scientific and public attention in recent years due to their dramatic consequences on marine ecosystems and their associated strong socio-economic impacts [4]. To this date, the reported economic losses owing to MHWs modification of ecosystem services amount to billions of dollars [5]. Due to their abrupt nature, MHWs can rapidly push marine ecosystems beyond the limits of resilience preventing adaptation and acclimatisation [6]. In this sense, these extreme events can have worse effects than those emanating from progressive long-term global warming. Understanding how marine ecosystems respond to climate change, and in particular to MHWs, has been recognized as a major societal challenge, and there is an evident socio-economic need for a wide range of tools such as management and conservation plans to cope with the disruptive MHWs in order to prevent species depletion and ensure seafood provisioning [7]. Coupling physics and ecosystem functioning is necessary to address these needs. Within this context, SEAFIRE aims at (i) providing relevant information about the impact of MHWs by characterising them, (ii) improving our understanding of the marine ecosystem’s responses to these extreme events, (iii) proposing mitigation actions and testing their potential effectiveness on the Western Mediterranean Sea, a major marine Hotspot.
References:
[1] Von Schukmann et al., (2020), Earth Syst. Sci. 12,2013-2041, [2] Hobday and Pecl (2014). Fish.Biol 24, 415-425, [3] Hobday et al., (2016). Progress in Oceanography, 141, 227-238, [4] Olivier et al., (2020), Annual Review of Marine Science,13,313-342,[5] Smith et al., (2021) Science, 374(6566), eabj3593 [6] Gruber et al., (2021), Nature, 600 (7889), 395-407,[7] Boyce et al., (2020) Nat.Commun. 11, 2235,
References:
[1] Von Schukmann et al., (2020), Earth Syst. Sci. 12,2013-2041, [2] Hobday and Pecl (2014). Fish.Biol 24, 415-425, [3] Hobday et al., (2016). Progress in Oceanography, 141, 227-238, [4] Olivier et al., (2020), Annual Review of Marine Science,13,313-342,[5] Smith et al., (2021) Science, 374(6566), eabj3593 [6] Gruber et al., (2021), Nature, 600 (7889), 395-407,[7] Boyce et al., (2020) Nat.Commun. 11, 2235,
Within WP1 (“MHWs and physics”) the following tasks were completed:
-Task 1.1: MHWs Detection. Taking advantage of Mercator Ocean physical (MOP) models, surface and subsurface MHWs were detected over the Western Mediterranean. MHWs were detected following existing literature and MHWs detection algorithms. The following MHWs metrics were computed after detection: duration, intensity, frequency, vertical and spatial extension, number and of discrete events.
- Task 1.2: MOP validation during MHWs :The MOP-detected surface MHWs were compared with satellite-detected MHWs. Overall, the MOP-detected MHWs compare well to the satellite-detected MHWs in terms of duration, intensity, frequency and spatial extension and do not show any systematic bias.
-Task 1.3: MHWs characterisation: A K-means clustering method was applied to the MOP-detected MHWs to characterise them in terms of their intensity, duration and frequency. The outcome of this task is a map with the regionalization of the MHWs based on their belonging group and, therefore, their characteristics. Time series of MHWs spatial occurrences (% of pixels occupied by MHWs) for each group were generated allowing for statistics correlation with ecosystem time series.
Whitin WP2 (“MHWs and ecosystem”) the following tasks are in progress:
- Task 2.1: Assessment of the impact of each type of MHW on key biogeochemical parameters. A preliminary analysis was conducted in order to identify the most suitable biogeochemical oceanic model (MOB) to be used to investigate the impact of MHWs in biogeochemical parameters. The performance of the existing MOB models for the Mediterranean Sea was assessed by comparing the MOB outputs to chlorophyll data. The remainder of the task will be completed in the future by the fellow and by the PhD students from the IMARES group. Specifically, the impact of each type of MHWs on the primary production, oxygen, pH and stratification at the surface and subsurface will be quantified. Time series for each biogeochemical parameter will be contrasted with time series obtained for each MHWs group in task 1.3.
-Task 2.3: Assessment of the responses of marine ecosystems to different MHWs characteristics. This task has been initiated. The inputs to force the ecosystem models based on the MHW detection (WP1) have been produced and the model will run soon. Study cases will be selected based on the MHWs characteristics (intensity, duration, frequency, etc).
-Task 1.1: MHWs Detection. Taking advantage of Mercator Ocean physical (MOP) models, surface and subsurface MHWs were detected over the Western Mediterranean. MHWs were detected following existing literature and MHWs detection algorithms. The following MHWs metrics were computed after detection: duration, intensity, frequency, vertical and spatial extension, number and of discrete events.
- Task 1.2: MOP validation during MHWs :The MOP-detected surface MHWs were compared with satellite-detected MHWs. Overall, the MOP-detected MHWs compare well to the satellite-detected MHWs in terms of duration, intensity, frequency and spatial extension and do not show any systematic bias.
-Task 1.3: MHWs characterisation: A K-means clustering method was applied to the MOP-detected MHWs to characterise them in terms of their intensity, duration and frequency. The outcome of this task is a map with the regionalization of the MHWs based on their belonging group and, therefore, their characteristics. Time series of MHWs spatial occurrences (% of pixels occupied by MHWs) for each group were generated allowing for statistics correlation with ecosystem time series.
Whitin WP2 (“MHWs and ecosystem”) the following tasks are in progress:
- Task 2.1: Assessment of the impact of each type of MHW on key biogeochemical parameters. A preliminary analysis was conducted in order to identify the most suitable biogeochemical oceanic model (MOB) to be used to investigate the impact of MHWs in biogeochemical parameters. The performance of the existing MOB models for the Mediterranean Sea was assessed by comparing the MOB outputs to chlorophyll data. The remainder of the task will be completed in the future by the fellow and by the PhD students from the IMARES group. Specifically, the impact of each type of MHWs on the primary production, oxygen, pH and stratification at the surface and subsurface will be quantified. Time series for each biogeochemical parameter will be contrasted with time series obtained for each MHWs group in task 1.3.
-Task 2.3: Assessment of the responses of marine ecosystems to different MHWs characteristics. This task has been initiated. The inputs to force the ecosystem models based on the MHW detection (WP1) have been produced and the model will run soon. Study cases will be selected based on the MHWs characteristics (intensity, duration, frequency, etc).
The SEAFIRE project had an early termination since the fellow secured a permanent research position in France at IRD. As a result, the project at ICM-CISC lasted for 6 months. Despite the premature conclusion, the objectives of SEAFIRE will be fulfilled, as the fellow will perform some related research activities in the new center. In addition, the fellow will also contribute to the work of two PhD students at ICM-CSIC who will conduct research aligned with SEAFIRE project objectives. In the past six months MHWs in the Western editerranean were identified and characterized using satellite data and model outputs from Mercator Ocean Reanalysis and environmental data has been processed and generated in order to force ecosystem models.