Improved Understanding of the Causes and Effects of Marine Heatwaves

New Marine Heatwave Research by CAREHeat

The CAREHeat project, funded by the European Space Agency, addresses the pressing issue of marine heatwaves (MHWs) and their significant impacts on marine ecosystems and coastal communities. With rising ocean temperatures posing alarming threats, the project plays a crucial role in generating essential research and findings to guide future strategies for managing marine resources in a changing climate.

Integrative Approaches to Identify MHWs Drivers and their impact

The CAREHeat project has made substantial progress in understanding the drivers and the effects of marine heatwaves. The project has identified key drivers of MHW occurrence and intensity, including atmospheric circulation patterns, anthropogenic influences, and natural climate variability.

Key achievements include the application of novel methodologies that employ advanced techniques for detecting and characterising MHWs through state-of-the-art remote sensing and in-situ data collection. This integrative approach allows for comprehensive assessments of the impacts of extreme ocean temperatures on marine biodiversity, including shifts in species distribution, habitat loss, and changes in trophic dynamics. 

Notably, CAREHeat’s findings reveal that winter MHW events significantly reduce phytoplankton carbon biomass in spring, leading to a depletion of organic carbon stocks that affects higher trophic levels.

Furthermore, the consortium has explored the interplay between MHWs and other extreme events, such as acidification extremes. These compound events can affect crucial processes, including greenhouse gas exchanges, and may lead to irreversible tipping points in marine ecosystems.

Adding Value to Impacted Communities and Policymaking

A significant focus of the project has been enhancing community involvement. Collaborative efforts with local stakeholders have empowered coastal communities to monitor and effectively address the effects of marine heatwaves. The findings can lead to the establishment of early warning systems and adaptive management strategies, equipping these communities to better prepare for and respond to the challenges posed by rising sea temperatures.

CAREHeat’s results have facilitated a synergistic approach in MHW research, integrating multiple data sources and methodologies for a comprehensive understanding of MHWs and their impacts. This comprehensive analysis offers new insights for predicting MHW events and assessing the associated risks, providing valuable information to a wide range of stakeholders, including scientists, resource managers, coastal communities, and policymakers.

Advancing MHW Science to Boost Future Action

The project has produced substantial scientific outputs, including datasets which will be made publicly available. These resources lay the groundwork for future interdisciplinary studies, fostering collaboration among scientists, policymakers, and resource managers in tackling the multifaceted challenges posed by marine heatwaves.

Moreover, the insights gained from CAREHeat can inform the development of more effective early warning systems and guide future scientific inquiries, as outlined in the CAREHeat roadmap. As the project reaches its conclusion, its findings can help shape future policies and practices aimed at conserving marine ecosystems amid climate change. CAREHeat not only underscores the pressing challenges posed by marine heatwaves but also highlights the importance of collaboration and innovation in addressing these critical issues.

Disseminating New MHW Knowledge with CAREHeat’s Scientific Publications

The CAREHeat project has led to significant research advances, contributing to a deeper understanding of Marine Heatwaves (MHWs) and their impact on ecosystems. Here are some key publications that resulted from the project:

• Marine Heatwaves in the Mediterranean Sea: A Literature Review
  Synthesises research on marine heatwaves, discussing their driving mechanisms, impacts, and the need for enhanced monitoring and forecasting capabilities.
   
• Detection, characterization and trends of Marine Heat waves in the global warming scenario: the CAREHeat Project
  Outlines the multidisciplinary approach used by the CAREHeat project to detect and analyse MHWs, leveraging satellite Earth observations and advanced technologies. It introduces the CAREHeat Global Atlas, which tracks MHW variability from 1981 onwards and assesses the impacts on marine ecosystems.
   
• How to Better Characterize Marine Heatwaves
  Discusses the CAREHeat project's efforts to improve MHW detection by revisiting current methodologies and applying machine learning to reconstruct 4D temperature fields. These developments allow for a more detailed analysis of how MHWs propagate through ocean depths and their effects on ecosystems.
   
• Has the Frequency of Mediterranean Marine Heatwaves Really Increased in the Last Decades?
  Addresses the critical issue of using long-term SST baselines to detect MHWs. It examines the influence of climate change on MHW frequency and discusses the evolution of the 2022 event, one of the most prolonged and intense MHWs in recent history.
   
• Evolution of Marine Heatwaves in Warming Seas: The Mediterranean Sea Case Study
  Provides a comprehensive analysis of MHWs, identifying an intensification in their frequency, intensity, and duration over four decades. Includes a catalogue of the most significant MHWs, such as the exceptionally long and intense event of 2022.
   
• Record-breaking Persistence of the 2022/23 Marine Heatwave in the Mediterranean Sea
  Documents the longest marine heatwave recorded in the Mediterranean over the past four decades, emphasizing the role of atmospheric conditions in driving warm anomalies.
   
• Phytoplankton Spring Bloom Inhibited by Marine Heatwaves in the North-Western Mediterranean Sea
  Highlights the significant impact of MHWs on phytoplankton spring blooms, noting the substantial reduction in carbon biomass due to increased ocean stratification, which limits nutrient supply.
   
• Extreme Events Contributing to Tipping Elements and Tipping Points
  Highlights how weather and climate extremes influence tipping elements and trigger tipping points in the Earth System, emphasizing examples like Amazon rainforest dieback, Atlantic circulation collapse, and coral reef degradation, while underscoring the need for Earth observations to understand these links and improve predictive models.
   
• Opportunities for Earth Observation to Inform Risk Management for Ocean Tipping Points
  Evaluates the role of Earth Observation in addressing risks linked to ten major ocean tipping elements, highlighting the need for long-term data, integration within situ observations, and alignment with models to enhance monitoring, early warnings, and climate model development.

Stay updated with the project by visiting the CAREHeat website or following us on Twitter/X.