Channel concavity controls planform complexity of branching drainage networks Earth Surface Dynamics DOI 10.5194/esurf-12-1347-2024 10 December 2024 To explore the pattern formed by rivers as they crisscross the land, we developed a way to measure how these patterns vary, from straight to complex, winding paths. We discovered that a river’s degree of complexity depends on how the river slope changes downstream. Although this is strange (i.e., why would changes in slope affect twists of a river in map view?), we show that this dependency is almost inevitable and that the complexity could signify how arid the climate is or used to be. Read more
Opinion: Challenges and needs of tropospheric chemical mechanism development Atmospheric Chemistry and Physics DOI 10.5194/acp-24-13317-2024 9 December 2024 Chemical mechanisms describe the chemical processes in atmospheric models that are used to describe the changes in the atmospheric composition. Therefore, accurate chemical mechanisms are necessary to predict the evolution of air pollution and climate change. The article describes all steps that are needed to build chemical mechanisms and discusses the advances and needs of experimental and theoretical research activities needed to build reliable chemical mechanisms. Read more
Exploring drought hazard, vulnerability, and related impacts on agriculture in Brandenburg Natural Hazards and Earth System Sciences DOI 10.5194/nhess-24-4237-2024 5 December 2024 Droughts are a threat to agricultural crops, but different factors influence how much damage occurs. This is important to know to create meaningful risk maps and to evaluate adaptation options. We investigate the years 2013–2022 in Brandenburg, Germany, and find in particular the soil quality and meteorological drought in June to be statistically related to the observed damage. Measurement of crop health from satellites is also related to soil quality and not necessarily to anomalous yields. Read more
Weak liquid water path response in ship tracks Atmospheric Chemistry and Physics DOI 10.5194/acp-24-13269-2024 5 December 2024 Ship emissions can form artificially brightened clouds, known as ship tracks, and provide us with an opportunity to investigate how aerosols interact with clouds. Previous studies that used ship tracks suggest that clouds can experience large increases in the amount of water (LWP) from aerosols. Here, we show that there is a bias in previous research and that, when we account for this bias, the LWP response to aerosols is much weaker than previously reported. Read more
Modeling 2020 regulatory changes in international shipping emissions helps explain anomalous 2023 warming Earth System Dynamics DOI 10.5194/esd-15-1527-2024 4 December 2024 On 1 January 2020, international shipping vessels were required to substantially reduce the amount of particulate they emit to improve air quality. In this work we demonstrate how this regulatory change contributed to the anomalous warming observed in recent months using climate model simulations that include such a change. Future policies should also perhaps consider their impact on climate, and climate modelers should promptly include those changes in future modeling efforts. Read more
Cross-scale causal information flow from the El Niño–Southern Oscillation to precipitation in eastern China Earth System Dynamics DOI 10.5194/esd-15-1509-2024 2 December 2024 The El Niño–Southern Oscillation (ENSO) is a gigantic natural orchestra playing with the temperature of Pacific waters and influencing air temperature and rainfall worldwide. Naturally, the “loudness” or amplitude of ENSO has effects on climate; however, consonance of its various tones, or phases of different ENSO oscillatory components, can exert causal effects on rainfall in some areas in China. In different regions, different aspects of ENSO dynamics can predict rainfall amounts. Read more
Microbial response to deliquescence of nitrate-rich soils in the hyperarid Atacama Desert Biogeosciences DOI 10.5194/bg-21-5305-2024 29 November 2024 We studied unique nitrate-rich soils in the hyperarid Atacama Desert that form brines at night under high relative humidity. Despite providing water for microorganisms, these soils exhibit extremely low microbial activity, indicating that the high nitrate levels inhibit microbial life. On the other hand, enriched organic matter indicates their potential preservation. This research helps to understand the limits of life in extreme environments and aids in the search for signs of life on Mars. Read more
Microbial strong organic-ligand production is tightly coupled to iron in hydrothermal plumes Biogeosciences DOI 10.5194/bg-21-5233-2024 29 November 2024 Hydrothermally derived iron can be transported kilometers away from deep-sea vents, representing a significant flux of vital micronutrients to the ocean. However, the mechanisms that support the stabilization of dissolved iron remain elusive. Using electrochemical, spectrometry, and genomic methods, we demonstrated that strong ligands exert an important control on iron in plumes, and high-affinity iron-binding siderophores were identified in several hydrothermal plume samples for the first time Read more
Representation of the terrestrial carbon cycle in CMIP6 Biogeosciences DOI 10.5194/bg-21-5321-2024 28 November 2024 This study investigates present-day carbon cycle variables in CMIP5 and CMIP6 simulations. Overall, CMIP6 models perform better but also show many remaining biases. A significant improvement in the simulation of photosynthesis in models with a nitrogen cycle is found, with only small differences between emission- and concentration-based simulations. Thus, we recommend using emission-driven simulations in CMIP7 by default and including the nitrogen cycle in all future carbon cycle models. Read more
Opinion: Beyond global means – novel space-based approaches to indirectly constrain the concentrations of and trends and variations in the tropospheric hydroxyl radical (OH) Atmospheric Chemistry and Physics DOI 10.5194/acp-24-13001-2024 28 November 2024 Trace gases emitted to or formed within the atmosphere may be chemically or physically removed from the atmosphere. One trace gas, the hydroxyl radical (OH), is responsible for initiating the chemical removal of many trace gases, including some greenhouse gases. Despite its importance, scientists have not been able to adequately measure OH. In this opinion piece, we discuss promising new methods to indirectly constrain OH using satellite data of trace gases that control the abundance of OH. Read more