ovewh

• Liang, Shuna; Wang, Bin; Zhang, Yurui; Yang, Junhua; Haugvaldstad, Ove Westermoen & Tang, Hui (2026). Gobi-sourced dust and dust–climate feedbacks in the March 2023 East Asian storm. Atmospheric research. ISSN 0169-8095. 334, s. 1–12. doi: 10.1016/j.atmosres.2025.108735. Fulltekst i vitenarkiv Vis sammendrag

  Amid escalating climate change and environmental instability, understanding the origins, transport mechanisms, and climatic-environmental impacts of intensifying East Asian dust storms has become crucial for global sustainability science. However, current research still faces critical limitations with lacking city- or site-level resolution for source apportionment, and quantitative assessments of the climatic and environmental effects of severe dust events are still insufficient. Here, we integrated in situ measurements, reanalysis datasets, and numerical simulations to investigate the extreme East Asian dust storm in March 2023. Results indicated that the Gobi Desert was the dominant source, contributing approximately 74.9–94.6 % to PM10 levels across four northern Chinese cities. Fine particles (2.5–5.0 μm) exhibited faster and higher-altitude transport than coarse particles (>7.5 μm), with consistent northwestward advection. Size-dependent deposition regimes emerged – dry deposition peaked for 7.5–10 μm particles, while wet deposition shifted from 5 to 7.5 μm in source regions to 2.5–5.0 μm in downwind North China. Crucially, we quantify the dust–climate feedback loop where aerosol-induced surface cooling by reducing surface solar radiation of 2.4–4.8 W m−2, which in turn suppresses surface turbulent kinetic energy and decrease the boundary layer height up to 40 m. The enhanced boundary layer stability subsequently promoted futher dust accumulation. By elucidating this positive feedback mechanism, our study moves beyond established correlations to reveal a key process amplifying extreme dust storms, with critical implications for predicting their intensity and impacts under a changing climate.

• Haugvaldstad, Ove Westermoen; Oliviè, Dirk Jan Leo; Storelvmo, Trude & Schulz, Michael (2025). Dust radiative forcing in CMIP6 Earth System models: insights from the AerChemMIP piClim-2xdust experiment. Atmospheric Chemistry and Physics (ACP). ISSN 1680-7316. 25, s. 13199–13219. doi: 10.5194/acp-25-13199-2025. Fulltekst i vitenarkiv Vis sammendrag

  Mineral dust significantly affects the downwelling and upwelling shortwave (SW) and longwave (LW) radiative fluxes, and changes in dust can therefore alter the Earth's energy balance. This study analyses the dust effective radiative forcing (DuERF) in nine CMIP6 Earth System Models (ESMs) using the piClim-2xdust experiment from AerChemMIP. The piClim-2xdust experiment uses a global dust emission tuning factor to double the emission flux. The DuERF is decomposed into contributions from dust-radiation (direct DuERF) and dust-cloud (cloud DuERF) interactions. The net direct DuERF ranges from −0.56 to 0.05 W m−2. Models with lower (higher) dust absorption and a smaller (larger) fraction of coarse dust show the most negative (positive) direct DuERF. The cloud DuERF is positive in most models, ranging from −0.02 to 0.2 W m−2, however, they differ in their LW and SW flux contributions. Specifically, NorESM2-LM shows a positive LW cloud DuERF attributable to the effect of dust on cirrus clouds. The dust forcing efficiency varies tenfold among models, indicating that uncertainty in DuERF is likely underestimated in AerChemMIP. There is a consistent fast precipitation response associated with dust decreasing atmospheric radiative cooling (ARC). Models with strongly absorbing dust show reduced precipitation, explainable by decreased clear-sky ARC (up to 3.2 mm yr−1). In NorESM2-LM, this decrease is associated with a cloudy sky ARC due to an increase in cirrus clouds (up to 5.6 mm yr−1). Taken together, these findings suggest that the fast precipitation response induced by dust alone may be significant and comparable to that caused by anthropogenic black carbon.

• Bohm, K.; Wasiljeff, J.; Stevens, T.; Salminen, J.; Tang, Hui & Lahaye, Y. [Vis alle 10 forfattere av denne artikkelen] (2024). Modern-Type Eolian Regime and Global Cooling-Modulated Dust Provenance in the Late Paleogene of Central-East Asia. Geochemistry Geophysics Geosystems. 25(2). doi: 10.1029/2023GC011167. Fulltekst i vitenarkiv Vis sammendrag

  Atmospheric mineral dust is a poorly constrained yet extremely important component of the climate system. Provenance studies from geologic dust archives are crucial to understand the drivers of the dust cycle over long time scales. Our multi-technique provenance analysis of a rare Paleogene (35–27 Ma) eolian dust sequence from Ulantatal, ∼400 km northwest of the Chinese Loess Plateau (CLP), shows that Paleogene dust transporting winds generally varied between northwesterly and westerly, the same as those in the late Neogene-Quaternary bipolar icehouse. We propose that, as today, westerly wind circulation patterns would have been modulated by an Arctic Oscillation (AO)-like situation, and that the warm Eocene favored a long-term negative phase of AO, leading to meridional westerly circulation and the dominance of a northwesterly dust transport pathway. After the Eocene-Oligocene transition (EOT), long-term positive phase of AO-like conditions initiated, leading to stronger and more zonal westerlies. The Siberian High (SH) also formed or strengthened at the EOT and started to control dust storm activity along the northwesterly transport pathway. We argue that increased Paleogene Northern Hemisphere (NH) ice volume was the ultimate driver of this modern-type dust transport regime in the Ulantatal region, possibly also controlling initial Ulantatal dust sequence formation via the development of the SH and modern-type eolian regime. The similarity between the Ulantatal and late Neogene northern CLP dust provenance signals suggests that the increased NH ice volume, via its control on the northwesterly dust transport, could have promoted increased loess formation also in the late Miocene.

• Haugvaldstad, Ove Westermoen; Tang, Hui; Kaakinen, Anu; Bohm, Katja; Zwaaftink, Christine Groot & Grythe, Henrik [Vis alle 9 forfattere av denne artikkelen] (2024). Spatial Source Contribution and Interannual Variation in Deposition of Dust Aerosols Over the Chinese Loess Plateau. Journal of Geophysical Research (JGR): Atmospheres. ISSN 2169-897X. 129(14), s. 1–24. doi: 10.1029/2023JD040470. Fulltekst i vitenarkiv Vis sammendrag

  The Chinese Loess Plateau (CLP) in northern China is home to one of the most prominent loess records in the world, reflecting past eolian dust activity in East Asia. However, their interpretation is hampered by ambiguity in the origin of loess-forming dust and an incomplete understanding of the circulation forcing dust accumulation. In this study, we used a novel modeling approach combining a dust emission model FLEXDUST with simulated back trajectories from FLEXPART to trace the dust back to where it was emitted. Over 21 years (1999–2019), we modeled back trajectories for fine (∼2 μm) and super-coarse (∼20 μm) dust particles at six CLP sites during the peak dust storm season from March to May. FLEXPART source-receptor relationships are combined with the dust emission inventory from FLEXDUST to create site-dependent high-resolution maps of the source contribution of deposited dust. The nearby dust emission areas were found to be the main source of dust to the CLP. Dust deposition across the CLP was found to predominantly occur via wet removal, with also some super-coarse dust from distant emission regions being wet deposited following high-level tropospheric transport. The high topography located on the downwind side of the emission area plays an essential role in forcing the emitted super-coarse dust upward. On an interannual scale, the phase of the Arctic Oscillation in the preceding winter was found to have a strong association with the spring deposition rate on the CLP, while the strength of the East Asian Winter Monsoon was less influential.

Se alle arbeider i NVA

• Haugvaldstad, Ove Westermoen; Oliviè, Dirk Jan Leo; Schulz, Michael & Storelvmo, Trude (2022). Decomposing the direct and indirect radiative effects by mineral dust aerosols in CMIP6. Fulltekst i vitenarkiv
• Haugvaldstad, Ove Westermoen (2025). Drivers and impacts of windblown dust in a changing climate. Universitetet i Oslo. Fulltekst i vitenarkiv Vis sammendrag

  Windblown mineral dust is an essential agent in the climate system which affects the planet’s energy balance, cloud characteristics, atmospheric chemistry, and biogeochemistry. Historical records of the dust cycle preserved in the natural archives of dust deposition suggest that the emission of windblown dust has increased substantially since the beginning of the industrial period. This increase likely had a significant influence on the Earth’s climate. However, the current state-of-the-art Earth System Models (ESMs)—the primary tools used to understand the drivers of climate change—cannot simulate trends in dust emissions consistent with observations. This raises questions about whether ESMs are currently reproducing historical temperature change for the right reasons. Using multiple ESMs and a range of modelling frameworks, this work offers a broad perspective on the relationship between changes in climate variables and dust cycle processes (emission, transport and deposition), the climate forcing due to increases in windblown dust over the historical, and the gaps in ESMs ability to simulate dust radiative effects.

Se alle arbeider i NVA