Polar winter remains the most under-observed season at Earth's high latitudes—and that blind spot, scientists warn, is constraining the accuracy of daily weather forecasts and longer-time environment and climate predictions and projections. In a new Advances in Atmospheric Sciences perspective published on 9 July, 23 Earth scientists from 14 nations call for urgent action to fill these long-standing data and research gaps.
The team defined "polar winter" as the cold seasons spanning November to April in the Arctic and April to November in Antarctica. During these cold seasons, there is reduced solar radiation, extensive sea-ice coverage, and enhanced polar-global interactions across the atmosphere, sea ice, and ocean components of the Earth system, which are much less studied than the summer seasons.
State-of-the-art Earth System Models have largely improved in recent decades. However, substantial uncertainties and biases still exist, especially in the polar regions. Many key polar winter processes, such as cloud formation, structures, and radiative feedback; and energy budgets across the atmosphere, sea ice, and ocean interfaces, are still inadequately captured by the current models due to a lack of systemic observations.
"Better observation and understanding of polar winter processes can help us capture a complete and accurate picture of the polar Earth systems throughout the year. Especially, it has been suggested that polar warming signals and polar-global interactions, such as poleward energy transport, are strongest during winter." said Xiangdong Zhang, a research professor at North Carolina State University.
Polar winter sea-ice and ocean anomalies can disrupt the stratospheric polar vortex. This vortex, a band of strong westerly winds circulating around the poles, only occurs during winter and can influence extreme weather and hydrological events in the densely populated midlatitudes. In late January 2026, one such disruption drove and steered Winter Storm Fern , which brought catastrophic freezing rain and snow from the southern Great Plains to the southeastern U.S., affecting more than 230 million Americans and causing economic losses estimated at over $100 billion.
Scientists note the difficulty of filling the existing winter observational and knowledge gaps in the polar regions, given the complexity of polar Earth systems and the logistical challenges associated with wintertime research at the poles. "Harsh weather and technological challenges have created major barriers that prevent us from conducting extended measurements as we did in summer, limiting our understanding of key winter processes and reducing our ability to accurately predict and project the state and variability of the Earth System," said Xin Yang, a researcher at the British Antarctic Survey and the lead author of the paper.
"The key message is that polar winter matters far beyond the polar regions," said Yang. The team identified three critical research priorities: (1) winter aerosols, clouds, and associated feedback, (2) winter storms and their interactions with sea ice and the ocean, and (3) polar–global teleconnections. The first one is critical for understanding energy budgets, and the second and third ones play decisive roles in extreme events in the polar regions and the midlatitudes. These processes are highly under-observed, because of their high variability, limited historical records, and nonlinear complexities, as well as the financial and logistical limitations of polar winter field work. These interconnected processes play essential roles in linking and influencing other processes.
The international scientific community is planning its research priorities for the coming decade, including a recent report published by the International Arctic Science Committee (IASC). The identified priorities will help shape the research themes for the Fifth International Polar Year. "The specific winter research priorities and implementation recommendations presented in this paper complement the IASC research plan and provide actionable details. So, the paper timely provides tangible information to facilitate the ongoing and near-future polar research and Fifth International Polar Year field campaign planning," said Zhang, who co-led the IASC research priority team and research planning report on the role of the Arctic in the global system.
The authors of the new paper recommend undertaking well-coordinated, multidisciplinary, winter-focused observational and modelling campaigns across the Arctic and Antarctic, integrating field observations, autonomous monitoring systems, remote sensing, laboratory studies, and model development. "Our ultimate goal is to develop a comprehensive understanding of polar winter processes and their links to the global Earth system. This will lead to more accurate Earth System Models, more reliable weather and environment predictions, and better-informed adaptation and risk-management strategies for societies worldwide facing the impacts of hazardous weather and environmental challenges," said Yang.
The international research team includes scientists from the UK, USA, India, Italy, South Africa, Chile, Switzerland, Argentina, Portugal, China, Norway, Canada, Germany, and the Czech Republic.
