Bolin Centre for Climate Research

Multiyear dual-isotope fingerprinting at South Asian receptor sites constrains carbon monoxide sources and enhanced oxidation

Carbon monoxide (CO) is an indirect short-lived climate forcer with uncertainties both in sources and its role in atmospheric oxidation. Based on nine winter-long dual-isotope campaigns at two South Asian receptor sites intercepting the continental outflow, we quantified CO sourc...

Drivers governing the seasonality of new particle formation in the Arctic

New particle formation (NPF) is the phenomenon wherein gaseous precursors form critical clusters of barely a few nanometres in diameter, after which, under favourable conditions, these particles can grow to climate-relevant sizes. Here we present measurements from 2022 to 2024 of...

An Arctic climatology of particle number size distributions and cloud condensation nuclei during warm and moist intrusions

Abstract Recent studies indicate that warm and moist intrusions are significant sources of aerosols in the Arctic. Yet their contribution to different aerosol particle size modes, cloud condensation nuclei (CCN), and droplet number concentrations ( N d ) remains largely unconstra...

The Cold-Air Outbreaks in the Marine Boundary Layer Experiment model-observation intercomparison project (COMBLE-MIP) – Part 1: Model specification, observational constraints, and preliminary findings

Models struggle to represent the coupled microphysical, turbulent and radiative processes within widespread, long-lived marine cold-air outbreak (CAO) cloud fields, contributing to forecast and climate biases. Here we combine ground-based and satellite measurements to initialize...

The Cloud Feedback Model Intercomparison Project (CFMIP) contribution to CMIP7

Cloud processes constitute one of the key uncertainties for climate change projections. The fourth iteration of the Cloud Feedback Model Intercomparison Project, CFMIP4, contributes to the Coupled Model Intercomparison Project phase 7 (CMIP7), by providing a set of global climate...

Deciduous forest, habitat diversity and distance to water - but not forest edges - drive bat activity in a managed forest-farmland mosaic in south-eastern Sweden

Understanding how landscape composition and configuration influence bats near their northern range limit is essential for their conservation in managed northern European forested environments. We investigated this in a forest–farmland mosaic of south-eastern Sweden. Using passive...

36Cl concentrations from polar ice cores set new constraints on the Carrington event.

The Carrington event of 1859 CE is considered one of the largest geomagnetic storms of the observational era and often used as a benchmark for a worst-case scenario. Yet, there exists no robust evidence of an associated solar energetic particle (SEP) event of a significant magnit...

Interhemispheric perspective on the most extreme surface winds in the storm tracks

Abstract. Extratropical cyclones occur most frequently over the oceans, where they cause the strongest extreme surface winds. In this study, we investigate extreme surface winds during winter months in the Northern and Southern Hemispheres, when the wind storms are the strongest....

Organic carbon pathways across the fluvial-marine transition zone of the Mackenzie River Delta – Beaufort Sea region and implications on ocean color remote sensing

Abstract. Arctic warming and hydrological intensification are accelerating permafrost thaw and increasing the export of terrestrial organic carbon (OC) and sediments from land via rivers and shallow coastal waters into marine waters, yet the fate of these materials in deltaic and...

Recent globally synchronous seasonal warm events unprecedented since 850 CE

Spatially synchronous extreme warm events can amplify environmental and societal impacts by affecting multiple regions simultaneously. However, previous studies have largely focused on June–August (JJA) events during the instrumental period, limiting understanding of their season...

Importance of hydrated aerosol particles for aerosol–fog relationships in the Italian Po Valley

Abstract. Air pollution and fog are closely connected, influencing both visibility and human health. As relative humidity rises, aerosol particles absorb water and grow hygroscopically, potentially activating into fog droplets when supersaturation is reached. Distinguishing betwe...

Grounding-line dynamics in a Stokes ice-flow model (Elmer/Ice v9.0): improved numerical stability allows larger time steps

Abstract. The efficient and accurate simulation of grounding line dynamics in marine ice-sheet models remains a challenge, largely due to restrictive time-step limitations. The restrictive time step size of ice-sheet simulations (∼ ∆t = 0.01−0.5 years) has led to the routine use...

Fitness effects of local seasonal adaptation depend on the timing of reproduction in a range-expanding butterfly

Abstract Local seasonal adaptation across latitudes is ubiquitous, but its fitness consequences are rarely estimated in the field. Using a common-garden field experiment at the northern range margin of the butterfly Lasiommata megera, we show that fitness consequences of among-po...

Regime Shifts and Transformations in Social-Ecological Systems: Advancing Critical Frontiers for Safe and Just Futures

Current research challenges in sustainability science require us to consider nonlinear changes—shifts that do not happen gradually but can be sudden and difficult to predict. Central questions are therefore how we can prevent harmful shifts, promote desirable ones, and better ant...

Quaternary Arctic planktonic foraminifera: morphological differentiation and taxonomic reassessment of subpolar spinose taxa

Abstract. Planktonic foraminifera in the modern Arctic Ocean are dominated by the non-spinose polar species Neogloboquadrina pachyderma. Acmes of two spinose, presumed subpolar taxa in Quaternary central Arctic sediment cores are therefore anomalous, implying significantly differ...

Balancing forage and fear: How people, environment and predators shape reindeer grazing in the Fennoscandian tundra

Abstract The long history of reindeer herding in Fennoscandia has shaped the mountain tundra by influencing its productivity, nutrient and carbon cycling and vegetation structure. By partly limiting shrub expansion, extensive reindeer grazing contributes to ecosystem resilience a...