Machine learning for numerical weather and climate modelling: a review Geoscientific Model Development DOI 10.5194/gmd-16-6433-2023 13 November 2023 Machine learning (ML) is an increasingly popular tool in the field of weather and climate modelling. While ML has been used in this space for a long time, it is only recently that ML approaches have become competitive with more traditional methods. In this review, we have summarized the use of ML in weather and climate modelling over time; provided an overview of key ML concepts, methodologies, and terms; and suggested promising avenues for further research. Read more
ESD Ideas: Arctic amplification’s contribution to breaches of the Paris Agreement Earth System Dynamics DOI 10.5194/esd-14-1165-2023 10 November 2023 The Arctic is warming several times faster than the rest of the planet. Here, we use climate model projections to quantify for the first time how this faster warming in the Arctic impacts the timing of crossing the 1.5 °C and 2 °C thresholds defined in the Paris Agreement. We show that under plausible emissions scenarios that fail to meet the Paris 1.5 °C target, a hypothetical world without faster warming in the Arctic would breach that 1.5 °C target around 5 years later. Read more
Opinion: A critical evaluation of the evidence for aerosol invigoration of deep convection Atmospheric Chemistry and Physics DOI 10.5194/acp-23-13791-2023 8 November 2023 As atmospheric particles called aerosols increase in number, the number of droplets in clouds tends to increase, which has been theorized to increase storm intensity. We critically evaluate the evidence for this theory, showing that flaws and limitations of previous studies coupled with unaddressed cloud process complexities draw it into question. We provide recommendations for future observations and modelling to overcome current uncertainties. Read more
Mechanisms controlling giant sea salt aerosol size distributions along a tropical orographic coastline Atmospheric Chemistry and Physics DOI 10.5194/acp-23-13735-2023 6 November 2023 Sea salt aerosol is an important marine aerosol that may be produced in greater quantities in coastal regions than over the open ocean. This study observed these particles along the windward coastline of O’ahu, Hawai’i, to understand how wind and waves influence their production and dispersal. Overall, wave heights were the strongest variable correlated with changes in aerosol concentrations, while wind speeds played an important role in their horizontal dispersal and vertical mixing. Read more
Rejuvenating the ocean: mean ocean radiocarbon, CO2 release, and radiocarbon budget closure across the last deglaciation Climate of the Past DOI 10.5194/cp-19-2177-2023 3 November 2023 Radiocarbon is best known as a dating tool, but it also allows us to track CO2 exchange between the ocean and atmosphere. Using decades of data and novel mapping methods, we have charted the ocean’s average radiocarbon ″age” since the last Ice Age. Combined with climate model simulations, these data quantify the ocean’s role in atmospheric CO2 rise since the last Ice Age while also revealing that Earth likely received far more cosmic radiation during the last Ice Age than hitherto believed. Read more
Rate-induced tipping in ecosystems and climate: the role of unstable states, basin boundaries and transient dynamics Nonlinear Processes in Geophysics DOI 10.5194/npg-30-481-2023 1 November 2023 Many systems in nature are characterized by the coexistence of different stable states for given environmental parameters and external forcing. Examples can be found in different fields of science, ranging from ecosystems to climate dynamics. Perturbations can lead to critical transitions (tipping) from one stable state to another. The study of these transitions requires the development of new methodological approaches that allow for modelling, analysing and predicting them. Read more
A spectrum of geoscience communication: from dissemination to participation Geoscience Communication DOI 10.5194/gc-6-131-2023 30 October 2023 In this article, I explore the various ways the geosciences can be communicated to a wider audience. I focus on creative methods that range from sharing information to involving the public in the research process. By using examples from my own work and the wider literature, I demonstrate how these approaches can engage diverse communities and promote greater recognition for geoscience communication. Read more
N2O as a regression proxy for dynamical variability in stratospheric trace gas trends Atmospheric Chemistry and Physics DOI 10.5194/acp-23-13283-2023 27 October 2023 This paper presents a technique for understanding the causes of long-term changes in stratospheric composition. By using N2O as a proxy for stratospheric circulation in the model used to calculated trends, it is possible to separate the effects of dynamics and chemistry on observed trace gas trends. We find that observed HCl increases are due to changes in the stratospheric circulation, as are O3 decreases above 30 hPa in the Northern Hemisphere. Read more
Opinion: Recent developments and future directions in studying the mesosphere and lower thermosphere Atmospheric Chemistry and Physics DOI 10.5194/acp-23-13255-2023 25 October 2023 The mesosphere or lower thermosphere region of the atmosphere borders the edge of space. It is subject to extreme ultraviolet photons and charged particles from the Sun and atmospheric gravity waves from below, which tend to break in this region. The pressure is very low, which facilitates chemistry involving species in excited states, and this is also the region where cosmic dust ablates and injects various metals. The result is a unique and exotic chemistry. Read more
Mapping Antarctic crevasses and their evolution with deep learning applied to satellite radar imagery The Cryosphere DOI 10.5194/tc-17-4421-2023 23 October 2023 The presence of crevasses in Antarctica influences how the ice sheet behaves. It is important, therefore, to collect data on the spatial distribution of crevasses and how they are changing. We present a method of mapping crevasses from satellite radar imagery and apply it to 7.5 years of images, covering Antarctica’s floating and grounded ice. We develop a method of measuring change in the density of crevasses and quantify increased fracturing in important parts of the West Antarctic Ice Sheet. Read more
