Rei Chemke Assistant Professor, Weizmann Institute of Science, Rehovot, Israel

Title: Climate change shifts the North Pacific storm track polewards

Abstract: Across the North Pacific Ocean, the mid-latitude storm track accounts for most of the heat and moisture transport into the Arctic and western North America, considerably influencing regional precipitation and temperature patterns. By the end of this century, the winter North Pacific storm track is projected to shift polewards, with substantial implications for oceanic ecosystems and land-based water availability. Although atmospheric reanalyses suggest a polewards shift of the storm track, the lack of an observed wind record has left it uncertain whether the storm-track shift has occurred in recent decades, and what role climate change plays in determining the storm-track position. Here we derive an observational constraint for mid-latitude storm tracks and show that the winter North Pacific storm track has shifted substantially polewards, emerging from natural variability. A polewards shift of storm track-induced heat and moisture flux is also evident over western North America, implying regional impacts on precipitation and temperature patterns. Our analysis further reveals that climate models underestimate the polewards shift of the storm track in recent decades, suggesting that the future human-induced impacts on both the North Pacific ecosystem and western North America might be larger than in current predictions.

Alessandro Pieruzzi Sustainability Consultant, Delft University of Technology, Delft, Netherlands

Title: Floating photovoltaics in the long-term energy planning of Easter Nile Basin countries

Abstract: This work presents a method for integrating floating photovoltaics (FPVs) into long-term energy planning, addressing rising electricity demands amidst water stress, land competition, and climate vulnerabilities. The integrated framework is applied to four Eastern Nile Basin countries, where renewable technologies are projected to dominate the power mix. Here, FPVs are evaluated for cost-effectiveness, water savings, and land efficiency. The study advances the OSeMOSYS energy planning framework by spatially explicitly modelling water savings and land values for various energy technologies, incorporating CO2 emissions and land use costs in the optimisation. To this end, new methodologies for land-use accounting and FPV potential for reducing evaporation in hydropower reservoirs were developed. We then evaluate FPV potential across a network of hydropower plants, incorporating electricity trade links between basin countries and simulating under different CMIP six climate change scenarios and tax scenarios.

Pankaj Upadhyaya Project Scientist, Indian Institute of Technology, Delhi, India

Title: Advancing Climate Services in South Asia: The SARCI Framework for Actionable Climate Information and Regional Capacity Building

Abstract: South Asia, home to over a quarter of the global population, faces escalating climate risks that demand scientifically credible and actionable information. However, existing global climate models exhibit persistent temperature and precipitation biases—variables central to impact assessments—reaching up to 25% and 100% of their mean values, respectively, over this region, thereby limiting their reliability for climate-informed long-term planning. To address these limitations, we introduce the South Asia Regional Climate Information (SARCI) framework—a regionally optimized framework designed to deliver credible, high-fidelity climate information for South Asia. The framework features a customized atmospheric model, based on NCAR CESM/CAM, with targeted improvements in deep convection, land–atmosphere interactions, and gravity wave dynamics – processes linked to major regional biases. These enhancements are guided by empirical understanding of regional climate behaviour and refined through rigorous model tuning to achieve regional improvements without compromising global performance. The customized model substantially improves simulations of temperature and precipitation, along with a more realistic representation of regional circulation. The framework further incorporates a synthesized lower-boundary forcing component derived from skill-based CMIP models, adjusted to reduce biases in its low-frequency variability. A statistical downscaling module then refines the projections to a quarter degree resolution, providing fine-scale, policy-relevant regional climate information. The SARCI framework demonstrates how regional optimization, co-production, and institutional capacity building can deliver credible, policy-relevant climate information for South Asia, with broader relevance for other regions of the Global South facing similar challenges.