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RoadSurf 1.1: open-source road weather model library
Virve Eveliina Karsisto
Geosci. Model Dev., 17, 4837–4853, https://doi.org/10.5194/gmd-17-4837-2024, 2024
RoadSurf is an open-source library that contains functions from the Finnish Meteorological Institute’s road weather model. The evaluation of the library shows that it is well suited for making road surface temperature forecasts. The evaluation was done by making forecasts for about 400 road weather stations in Finland with the library. Accurate forecasts help road authorities perform salting and plowing operations at the right time and keep roads safe for drivers.

Evaluation of CMIP6 model simulations of PM2.5 and its components over China
Fangxuan Ren, Jintai Lin, Chenghao Xu, Jamiu A. Adeniran, Jingxu Wang, Randall V. Martin, Aaron van Donkelaar, Melanie S. Hammer, Larry W. Horowitz, Steven T. Turnock, Naga Oshima, Jie Zhang, Susanne Bauer, Kostas Tsigaridis, Øyvind Seland, Pierre Nabat, David Neubauer, Gary Strand, Twan van Noije, Philippe Le Sager, and Toshihiko Takemura
Geosci. Model Dev., 17, 4821–4836, https://doi.org/10.5194/gmd-17-4821-2024, 2024
We evaluate the performance of 14 CMIP6 ESMs in simulating total PM2.5 and its 5 components over China during 2000–2014. PM2.5 and its components are underestimated in almost all models, except that black carbon (BC) and sulfate are overestimated in two models, respectively. The underestimation is the largest for organic carbon (OC) and the smallest for BC. Models reproduce the observed spatial pattern for OC, sulfate, nitrate and ammonium well, yet the agreement is poorer for BC.

The carbon stored globally by plants is shorter-lived and more vulnerable to climate change than previously thought, according to a new study.

Microfossil analysis allows us to map the subsurface and understand past geological times. In research labs all over the world, geologists spend countless hours looking through the microscope identifying and counting microfossils extracted from sedimentary rock below the seabed.

A team of Los Alamos National Laboratory scientists plan to use artificial intelligence modeling to forecast, and better understand, a growing threat to water caused by toxic algal blooms. Fueled by climate change and rising water temperatures, these harmful algal blooms, or HABs, have grown in intensity and frequency. They have now been reported in all 50 U.S. states.

Communications companies such as Starlink plan to launch tens of thousands of satellites into orbit around Earth over the next decade or so. The growing swarm is already causing problems for astronomers, but recent research has raised another question: What happens when they start to come down?

Our planet was born around 4.5 billion years ago. To understand this mind-bendingly long history, we need to study rocks and the minerals they are made of.

At approximately 4:10 p.m. on January 1, 2024, the Noto region of Ishikawa Prefecture in Japan was hit by a large earthquake with a moment magnitude (Mw) of 7.5. This earthquake, known as the 2024 Noto Peninsula earthquake, registered a maximum seismic intensity of 7 on the Japanese scale and caused widespread damage, including numerous casualties.

Abstract

Land monsoon rainfall has a distinct annual cycle. Under global warming, whether the phase and amplitude of this annual cycle would be changed is still unclear. Here, a global investigation is conducted using 34 CMIP6 and 34 CMIP5 models under a high emission scenario. Seasonal delays would occur in the Southern Hemisphere (SH) American (3.43 days), Northern Hemisphere (NH) African (5.98 days) and SH African (3.76 days) monsoon regions, while no robust signal is found in other monsoon regions. Except NH American monsoon, amplitude is enhanced in all the monsoon regions. Compared to amplitude, the phase changes dominate the future changes of precipitation in the SH American, NH African and SH African monsoon regions. In these phase-dominated regions, atmospheric energetic framework is proved to be reliable at regional scale and the enhanced effective atmospheric heat capacity is found to be the dominant factor.

Abstract

Rapid intensification (RI) of tropical cyclones (TCs) not only plays a crucial role in the development of major TCs but also poses great challenges to operational forecasting. Previous studies predominantly focused on RI over 24-hr periods, overlooking the potential for extended durations with intermittent moments. Here, we investigate the actual duration of RI and show that, when considering the interruption and intermittent moments, the longest RI can persist for up to 90 hr. Declines and resurgences in maximum potential intensity (MPI) and tropical cyclone heat potential (TCHP) are associated with the interruption of RI process. Given that the error in TC track prediction is much lower compared with that in intensity prediction, such a local minimum in MPI and TCHP could be better forecasted and potentially assist the prediction of RI, ultimately reducing TC-related hazards.

Abstract

The dynamics shaping the El Niño-Southern Oscillation's (ENSO) response to present and future climate change remain unclear, partly due to limited paleo-ENSO records spanning past abrupt climate events. Here, we measure Mg/Ca ratios on individual foraminifera to reconstruct east Pacific subsurface temperature variability, a proxy for ENSO variability, across the last 25,000 years, including the millennial-scale events of the last deglaciation. Combining these data with proxy system model output reveals divergent ENSO responses to Northern Hemisphere stadials: enhanced variability during Heinrich Stadial 1 (H1) and reduced variability during the Younger Dryas (YD), relative to the Holocene. H1 ENSO likely intensified through meltwater-induced changes to ocean/atmospheric circulation, a response observed in models, but the lack of a similar response during the YD challenges model simulations. We suggest the tropical Pacific mean state during H1 primed ENSO for larger fluctuations under meltwater forcing, whereas the YD mean state likely buffered against it.

Abstract

We investigate the role of ocean heat transport (OHT) in driving the decadal variability of the Arctic climate by analyzing the pre-industrial control simulation of a high-resolution climate model. While the OHT variability at 65°N is greater in the Atlantic, we find that the decadal variability of Arctic-wide surface temperature and sea ice area is much better correlated with Bering Strait OHT than Atlantic OHT. In particular, decadal Bering Strait OHT variability causes significant changes in local sea ice cover and air-sea heat fluxes, which are amplified by shortwave feedbacks. These heat flux anomalies are regionally balanced by longwave radiation at the top of the atmosphere, without compensation by atmospheric heat transport (Bjerknes compensation). The sensitivity of the Arctic to changes in OHT may thus rely on an accurate representation of the heat transport through the Bering Strait, which is difficult to resolve in coarse-resolution ocean models.

Abstract

Understanding how changing seasonal precipitation will affect ecosystems and water resources can benefit from understanding how precipitation from different seasons contributes to runoff versus evapotranspiration (ET). We use stable-isotope data from 23 National Ecological Observatory Network watersheds to quantify the fractions of winter and summer precipitation that supply ET, and the fractions of ET supplied by summer versus winter precipitation. Across 20 watersheds, 34%–101% of summer precipitation supplied ET, with 8%–105% of ET supplied by summer precipitation; these end-member-splitting solutions were poorly constrained in the other three watersheds. These precipitation partitioning fractions were significantly correlated with many topographic, climatic, and vegetation metrics. This first empirical study of seasonal precipitation partitioning fractions across diverse ecoregions demonstrates that they can be well-constrained in many locations using existing public data sets, and that partitioning-fraction variations are largely explained by climate variations.

Abstract

This study investigates boreal spring events of Pacific Meridional Mode (PMM) from 1950 to 2022, revealing that cold PMM is more effective in triggering subsequent La Niña compared to warm PMM's induction of following El Niño. This asymmetry stems from the varying origins and sub-efficacies of PMM groups. The cold PMM is primarily initiated by pre-existing La Niña, while the warm PMM is comparably activated by pre-existing El Niño and internal atmospheric dynamics. PMMs initiated by pre-existing El Niño or La Niña play a crucial role in determining the efficacies of PMMs in triggering subsequent El Niño-Southern Oscillation (ENSO). The strong discharge of pre-existing El Niño hampers warm PMM's induction of subsequent El Niño, whereas weak recharge from pre-existing La Niña enhances the efficacy of cold PMM in inducing subsequent La Niña. Comprehending not only the PMM phase but also its origin is crucial for ENSO research and prediction.

Abstract

We report in situ observation of magnetic reconnection between magnetic flux rope (MFR) and magnetic hole (MH) in the magnetosheath by the Magnetospheric Multiscale mission. The MFR was rooted in the magnetopause and could be generated by magnetopause reconnection therein. A thin current sheet was generated due to the interaction between MFR and MH. The sub-Alfvénic ion bulk flow and the Hall field were detected inside this thin current sheet, indicating an ongoing reconnection. An elongated electron diffusion region characterized by non-frozen-in electrons, magnetic-to-particle energy conversion, and crescent-shaped electron distribution was detected in the reconnection exhaust. The observation provides a mechanism for the dissipation of MFRs and thus opens a new perspective on the evolution of MFRs at the magnetopause. Our work also reveals one potential fate of the MHs in the magnetosheath which could reconnect with the MFRs and further merge into the magnetopause.

Abstract

Martian CO2 ice clouds are intriguing features, representing a rare occurrence of atmospheric condensation of a major component. These clouds play a crucial role due to their radiative properties, interactions with surface, and coupling with microphysical cycles of aerosols. Observations have been limited, prompting modeling studies to understand their formation and dynamics. Here, we present the first high-resolution 3D simulations of CO2 ice clouds using a Large-Eddy Simulation (LES) model incorporating CO2 microphysics. We investigate cloud formation in idealized temperature perturbations in the polar night. A reference simulation with a −2K perturbation demonstrates that the formed CO2 ice cloud possesses a convective potential, leading to its ascent in the troposphere. We determine the timescales and orders of magnitude of various phenomena involved in the lifecycle of a CO2 ice cloud. Sensitivity tests show that convection can be inhibited or intensified by the thermodynamic and microphysical conditions of the simulated environment.

Author(s): Da-Chao Deng and Hui-Chun Wu

An efficient plasma compression scheme using azimuthally polarized light is proposed. Azimuthally polarized light possesses a donutlike intensity pattern, enabling it to compress and accelerate ions toward the optical axis across a wide range of parameters. When the light intensity reaches the relat…

[Phys. Rev. E 109, 065211] Published Thu Jun 20, 2024

Author(s): Nichen Yu, Dong Huang, and Yan Feng

The analytical expression for the conditions of the solid-fluid phase transition, i.e., the melting curve, for two-dimensional (2D) Yukawa systems is derived theoretically from the isomorph theory. To demonstrate that the isomorph theory is applicable to 2D Yukawa systems, molecular dynamical simula…

[Phys. Rev. E 109, 065212] Published Thu Jun 20, 2024

Author(s): Yichong Chen, Livio Gibelli, and Matthew K. Borg

The impact of nanoscale wall roughness on rarefied gas transport is widely acknowledged, yet the associated scattering dynamics largely remain elusive. In this paper, we develop a scattering kernel for surfaces having nanoscale roughness that distinctly characterizes the two major types of interacti…

[Phys. Rev. E 109, 065308] Published Thu Jun 20, 2024

Author(s): Barbara Wirthl, Vitaly Wirthl, and Wolfgang A. Wall

Magnetic nanoparticles have emerged as a promising approach to improving cancer treatment. However, many nanoparticle designs fail in clinical trials due to a lack of understanding of how to overcome the in vivo transport barriers. To address this shortcoming, we develop a computational model aimed …

[Phys. Rev. E 109, 065309] Published Thu Jun 20, 2024