A Joint Reconstruction and Model Selection Approach for Large Scale Inverse Modeling
Malena Sabaté Landman, Julianne Chung, Jiahua Jiang, Scot Miller, and Arvind Saibaba
Geosci. Model Dev. Discuss., https//doi.org/10.5194/gmd-2024-90,2024
Preprint under review for GMD (discussion: open, 0 comments)
Making an informed decision about what prior information to incorporate or discard in an inverse model is important yet very challenging, as it is often not straightforward to distinguish between informative and non-informative variables. In this study, we develop a new approach for incorporating prior information in an inverse model using predictor variables, while simultaneously selecting the relevant predictor variables for the estimation of the unknown quantity of interest.
A wave-resolving 2DV Lagrangian approach to model microplastic transport in the nearshore
Isabel Jalón-Rojas, Damien Sous, and Vincent Marieu
Geosci. Model Dev. Discuss., https//doi.org/10.5194/gmd-2024-100,2024
Preprint under review for GMD (discussion: open, 2 comments)
This study presents a novel modeling approach for understanding microplastic transport in coastal waters. The model accurately replicates experimental data and reveals key transport mechanisms. The findings enhance our knowledge of how microplastics move in nearshore environments, aiding in coastal management and efforts to combat plastic pollution globally.
5 years of Sentinel-5P TROPOMI operational ozone profiling and geophysical validation using ozonesonde and lidar ground-based networks
Arno Keppens, Serena Di Pede, Daan Hubert, Jean-Christopher Lambert, Pepijn Veefkind, Maarten Sneep, Johan De Haan, Mark ter Linden, Thierry Leblanc, Steven Compernolle, Tijl Verhoelst, José Granville, Oindrila Nath, Ann Mari Fjæraa, Ian Boyd, Sander Niemeijer, Roeland Van Malderen, Herman G. J. Smit, Valentin Duflot, Sophie Godin-Beekmann, Bryan J. Johnson, Wolfgang Steinbrecht, David W. Tarasick, Debra E. Kollonige, Ryan M. Stauffer, Anne M. Thompson, Angelika Dehn, and Claus Zehner
Atmos. Meas. Tech., 17, 3969–3993, https://doi.org/10.5194/amt-17-3969-2024, 2024
The Sentinel-5P satellite operated by the European Space Agency has carried the TROPOspheric Monitoring Instrument (TROPOMI) around the Earth since October 2017. This mission also produces atmospheric ozone profile data which are described in detail for May 2018 to April 2023. Independent validation using ground-based reference measurements demonstrates that the operational ozone profile product mostly fully and at least partially complies with all mission requirements.
The Vlasiator 5.2 Ionosphere – Coupling a magnetospheric hybrid-Vlasov simulation with a height-integrated ionosphere model
Urs Ganse, Yann Pfau-Kempf, Hongyang Zhou, Liisa Juusola, Abiyot Workayehu, Fasil Kebede, Konstantinos Papadakis, Maxime Grandin, Markku Alho, Markus Battarbee, Maxime Dubart, Leo Kotipalo, Arnaud Lalagüe, Jonas Suni, Konstantinos Horaites, and Minna Palmroth
Geosci. Model Dev. Discuss., https//doi.org/10.5194/gmd-2024-101,2024
Preprint under review for GMD (discussion: open, 0 comments)
Vlasiator is a kinetic space-plasma model that simulates the behaviour of plasma, solar wind and magnetic fields in near-Earth space. So far, these simulations had been run without any interaction wtih the ionosphere, the uppermost layer of Earth's atmosphere. In this manuscript, we present the new methods that add an ionospheric electrodynamics model to Vlasiator, coupling it with the existing methods and presenting new simulation results of how space Plasma and Earth's ionosphere interact.
Mid-field tsunami hazards in greater Karachi from seven hypothetical ruptures of the Makran subduction thrust
Haider Hasan, Hira Ashfaq Lodhi, Shoaib Ahmed, Shahrukh Khan, Adnan Rais, and Muhammad Masood Rafi
Nat. Hazards Earth Syst. Sci. Discuss., https//doi.org/10.5194/nhess-2024-110,2024
Preprint under review for NHESS (discussion: open, 0 comments)
Our study models tsunami risks for Karachi, identifying two hazard zones with varying wave heights and arrival times. Karachi Port is at higher immediate risk. We conducted this research to understand the city's vulnerability to tsunamis from the Makran Subduction Zone and to improve emergency response plans. Using simulations of seven potential earthquake scenarios, we highlight the need for tailored disaster strategies and effective early warning systems to protect coastal communities.
Abstract
Comprehensive studies comparing impacts of building and street levels interventions on air temperature at metropolitan scales are still lacking despite increased urban heat-related mortality and morbidity. We therefore model the impact of 9 interventions on air temperatures at 2 m during 2 hot days from the summer 2018 in the Greater London Authority area using the WRF BEP-BEM climate model. We find that on average cool roofs most effectively reduce temperatures (∼−1.2°C), outperforming green roofs (∼0°C), solar panels (∼−0.5°C) and street level vegetation (∼−0.3°C). Application of air conditioning across London (United Kingdom) increases air temperatures by ∼+0.15°C. A practicable deployment of solar panels could cover its related energetic consumption. Current practicable deployments of green roofs and solar panels are ineffective at large scale reduction of temperatures. We provide a detailed decomposition of the surface energy balance to explain changes in air temperature and guide future decision-making.
Abstract
In this study, we explore the impact of oceanic moisture fluxes on atmospheric blocks using the ECMWF IFS. Artificially suppressing surface latent heat flux over the Gulf Stream (GS) region reduces atmospheric blocking frequency across the Northern Hemisphere by up to 30%. Affected blocks show a shorter lifespan (−6%), smaller spatial extent (−10%), and reduced intensity (−0.4%), with an increased number of individual blocking anticyclones (+17%). These findings are robust across various blocking detection thresholds. Analysis reveals a qualitatively consistent response across all resolutions, with Tco639 (∼18 km) showing the largest statistically significant change across all blocking characteristics, although differences between resolutions are not statistically significant. Exploring the broader Rossby wave pattern, we observe that diminished moisture fluxes favor eastward propagation and higher zonal wavenumbers, while air-sea interactions promote stationary and westward-propagating waves with zonal wavenumber 3. This study underscores the critical role of the GS in modulating atmospheric blocking.
Abstract
The Kyzylkum Desert, as a transition area of different dust source in Central Asia, provides and reserves a large amount of dust transported by different atmospheric circulation systems, affecting Uzbekistan and downwind East Asia. However, there remains very few investigations about sediment sources and control factors of the desert. We hereby first present a provenance study on the Kyzylkum Desert, utilizing detrital zircon U-Pb ages of samples composed of desert sand, alluvial sediments from Amu Darya River and piedmont of Southwest Tianshan Mountains. The results reveal that the Southwest Tianshan Mountains contribute the majority of the Kyzylkum desert sand, and the river system, dominated by Syr Darya, controls the sediment provenance of the desert. Moreover, little contribution from the Kyzylkum and Nurata segments indicates that wind erosion on the bedrocks is weak. However, the aeolian process is still crucial but deposit and storage of dust are determined by local topography.
Abstract
We performed a passive seismic monitoring of the La Praz ∼14,000 m3 unstable slope (French Alps) spanning over 10 years. During the last 6 months prior to collapse, we detected a clear 24% decrease in the slope's fundamental resonance frequency, f
0, caused by a reduction in overall rock mass stiffness. The combined study of f
0 and slope deformation suggested the alternating importance of sudden brittle failure processes versus more ductile phases with possible sliding. Seismic monitoring revealed slope damage that remained ambiguous or undetected with ground surface deformation monitoring, and highlighted critical periods with intense damage. Only some of these critical damage periods could be related to clear external forcing factors such as intense rainfall episodes. These new insights into rock slope's structural condition at depth represent an asset for future monitoring systems. Surface deformation and passive seismic stiffness tracking combined could reveal active slopes with ongoing damage processes.
Abstract
The creation of fractures in bedrock dictates water movement through the critical zone, controlling weathering, vadose zone water storage, and groundwater recharge. However, quantifying connections between fracturing, water flow, and chemical weathering remains challenging because of limited access to the deep critical zone. Here we overcome this challenge by coupling measurements from borehole drilling, groundwater monitoring, and seismic refraction surveys in the central California Coast Range. Our results show that the subsurface is highly fractured, which may be driven by the regional geologic and tectonic setting. The pervasively fractured rock facilitates infiltration of meteoric water down to a water table that aligns with oxidation in exhumed rock cores and is coincident with the adjacent intermittent first-order stream channel. This work highlights the need to incorporate deep water flow and weathering due to pervasive fracturing into models of catchment water balances and critical zone weathering, especially in tectonically active landscapes.
Abstract
Non-tidal ocean loading (NTOL) signals are known to be a significant source of geophysically induced noise in gravimetric and geodetic observations also far-away from the coast and especially during extreme events such as storm surges. Operationally available corrections suffer from a low temporal and spatial resolution and reveal too small amplitudes on continental stations. Dedicated high-resolution sea-level modeling of the North and Baltic Sea provides an improved prediction of NTOL signals. Superconducting gravimeter and Global Navigation Satellite Systems observations on the small offshore island of Heligoland in the North Sea are used for an evaluation of the model values revealing largely increased correlations of up to 0.9 and signal reductions of up to 50% during a storm surge period of one month in January and February 2022. Evaluations on additional continental superconducting gravimeter stations also show significant improvements through the recommended high-resolution modeling for improved signal separation further away from the coast.
Abstract
Historically, the precipitation trend over the past few decades in the Contiguous United States (CONUS) exhibits a “Dry-West Wet-East” pattern; this is manifested by recent droughts/floods in the western/eastern US. However, it remains elusive what atmospheric phenomenon has potentially driven such a remarkable, and impactful precipitation pattern. Here we found that a coupled climate mode—the Pacific Meridional Mode (PMM) exerted strong impacts on the precipitation pattern over the CONUS during the summer season. We discovered a significant association between the PMM index and precipitation across the majority of the CONUS; this was manifested as a zonal dipole pattern—negative correlations in the western U.S. along with positive correlations in the eastern and central U.S. Overall, the physical mechanisms based on observations were supported by using Atmospheric Model Intercomparison Project simulations available from the Coupled Model Intercomparison Project Phase 6.
Abstract
Distinctive synoptic-scale (∼1,500 km) flow features are identified within the core of the stratospheric polar-night vortex at stratopause altitudes (∼50 km). Typically they comprise a train or a complex pattern of transient vortices, each characterized by enhanced values of potential vorticity (PV) and relative vorticity but with a weaker thermal signal. In the MERRA-2 (and two other) reanalysis fields these cyclone-like features persist for several days, occur episodically, and form essentially within the core of the polar-night vortex itself. Their origin is plausibly linked to a form of barotropic instability associated with a radiatively-induced annular ring of enhanced PV. Moreover, their ubiquity and dynamics carries possible implications for: - the structure of the larger-scale polar vortex and its preconditioning ahead of a Sudden Stratospheric Warming event; the distribution of trace-constituents within the core; and the features representation in extended range/seasonal prediction and climate models.
Quantifying hazard resilience by modeling infrastructure recovery as a resource-constrained project scheduling problem
Taylor Glen Johnson, Jorge Leandro, and Divine Kwaku Ahadzie
Nat. Hazards Earth Syst. Sci., 24, 2285–2302, https://doi.org/10.5194/nhess-24-2285-2024, 2024
Reliance on infrastructure creates vulnerabilities to disruptions caused by natural hazards. To assess the impacts of natural hazards on the performance of infrastructure, we present a framework for quantifying resilience and develop a model of recovery based upon an application of project scheduling under resource constraints. The resilience framework and recovery model were applied in a case study to assess the resilience of building infrastructure to flooding hazards in Accra, Ghana.
Abstract
A machine learning method is used to identify sources of long-term ENSO predictability in the ocean (sea surface temperature (SST) and heat content) and the atmosphere (near-surface zonal wind (U10)). Tropical SST represents the primary source of predictability skill. While U10 does not increase the skill when associated with SST, our analysis suggests U10 alone has apredictive skill comparable to that of SST between 11 and 21 months in advance, from late fall up to late spring. The long-lead signal originates from coupled wind-SST interactions across the Indian Ocean (IO) and propagates across the Pacific via an atmospheric bridge mechanism. A linear correlation analysis supports this mechanism, suggesting a precursor link between anomalies in SST in the western and wind in the eastern IO. Our results have important implications for ENSO predictions beyond 1 year ahead and identify the key role of U10 over the IO.
Abstract
Spacecraft-to-spacecraft radio occultations experiments are being conducted at Mars between Mars Express (MEX) and Trace Gas Orbiter (TGO), the first ever extensive inter-spacecraft occultations at a planet other than Earth. Here we present results from the first 83 such occultations, conducted between 2 Nov 2020 and 5th of July 2023. Of these, 44 observations have to-date resulted in the extraction of vertical electron density profiles. These observations are the successful results of a major feasibility study conducted by the European Space Agency to use pre-existing relay communication equipment for radio science purposes. Mutual radio occultations have numerous advantages over traditional spacecraft-to-ground station occultations. In this work, we demonstrate how raw data are transformed into electron density values and validated with models and other instruments.
No abstract is available for this article.
