Recent findings by Viljoen et al. (2024, Nature Climate Change) reveal contrasting phytoplankton trends above and below the mixed layer depth in the Sargasso Sea between 2011 and 2022, linked to ongoing ocean warming. Building on these observations, the current study by Zheng et al. seeks to replicate the detected patterns and unravel the drivers of these decadal changes. To this end, the authors develop a two-layer ecosystem model that conceptualizes stratified ocean systems as comprising two distinct ecological regimes: one within the surface mixed layer and another beneath it. Their results offer valuable insights into how phytoplankton communities may respond to future climate-driven stratification and highlight the critical need for improved monitoring efforts capable of capturing subsurface biological dynamics beyond the reach of satellite observations.

This study advances our understanding of sources and distributions of alkylamines, particularly in the Southern Ocean and Antarctica, where they play an important role in marine nutrient cycling and food webs. Alkylamines are also important components of aerosols, influencing cloud formation and climate processes. This study is an important contribution for a better understanding ecosystem dynamics in polar environments and their implications for atmospheric processes in Antarctica, where the sources, distributions and marine biogeochemical cycles of nutrients are poorly understood.

The magnitude of the soil sink is a major uncertainty of the atmospheric molecular hydrogen (H2) budget. This manuscript provides critical data for understanding this process, though a yearlong set of H2 flux measurements at a deciduous woodland and a managed grassland in Scotland. Net fluxes are related to soil temperature, moisture and type, major factors that regulate the biological uptake of H2. While soil moisture is the dominant control on H2 fluxes in the grassland site, the variability of the larger magnitude fluxes at the woodland site illustrates that more work needs to be done to identify local controllers on H2 soil uptake.