In-stream large wood moderates flow dynamics, enhances sediment and nutrient storage, and supports biodiversity through habitat creation. While the significance of large wood in stream systems has been well documented, wood behavior in avalanche-prone landscapes remains poorly understood. Here, we generate a conceptual framework for large wood jam complexes observed in avalanche-prone landscapes that incorporates valley morphology, snowpack regime, and wood characteristics. We examined six avalanche-prone drainage basins in Colorado, USA, with visible snow avalanche and large wood interactions. We identified jams using high-resolution aerial imagery and measured jam structure, orientation, and hydrologic and sediment impacts. We determined that snow avalanche debris jam complexes fall into two primary categories: blanket jams and transport jams. Blanket jams are large, valley-floor spanning structures that experience minimal post-avalanche transport. They extend for 62.5 m along the channel and increase channel widths by 4.9x. Transport jams experience a higher degree of post-avalanche transport, yet they maintain a structural link to the debris field on the floodplain. Transport jam complexes span 30 m in length and widen channels by 3.4x. We further explored geomorphic controls and found that transport jams are associated with steeper (38 degrees vs 31 degrees) and rougher hillslopes, which are prone to more frequent-and potentially lower magnitude-snow avalanches. Log lengths are longer in blanket jam complexes, with a mean of 11.7 and 7.7 m for blanket and transport jams. We propose that jam complex style is a function of avalanche frequency and magnitude, which is controlled by the climate and valley morphology. Our framework is the first to systematically address large wood in avalanche-prone landscapes and provides a foundation for regional comparison of LW dynamics in high alpine settings. This framework can also serve as a basis to understand the impacts of changing snowpack and shifting forest ecozones on large wood accumulations and valley bottoms.
Earth has experienced extreme past climates, and recent studies posit a controversial hypothesis that a cold global climate, including tropical low-altitude glaciation, existed in the Pennsylvanian Period. Paleohydraulic analysis of storm-generated, hummocky bedforms in shallow marine Pennsylvanian deposits of the Ancestral Rocky Mountains of Pangea allows for reconstruction of wave parameters, which reflect paleoclimate because physical marine conditions and ocean-atmospheric linkages are highly latitude-and temperature-dependent. The results indicate large waves and gale to hurricane strength winds of cyclonic storms, driven by high Coriolis vorticity and high sea-surface temperatures. These refute both published extremely low paleolatitude (<5 degrees) estimates for the Colorado (USA) region, and the idea of a cold equatorial Pennsylvanian climate, the latter of which has profound implications for biological, geochemical, and oceanographic reconstructions.
We propose a reconstruction of the full (x, ξ, t) dependence of unpolarized isovector proton generalized parton distributions (GPDs) H^u-d and E^u-d from lattice QCD data in the pseudo-distribution formalism. For the first time, we extract double distributions (DDs) directly from lattice data, enforcing therefore an important property of GPDs linked to Lorentz symmetry. We use the flexible framework of multidimensional Gaussian process regression to regularize the inverse problem and present an assessment of the impact of model dependence on the systematic uncertainty. Our lattice ensemble corresponds to a pion mass m_π= 358 MeV and a lattice spacing a = 0.094 fm. We use larger hadron momenta, up to 2.7 GeV, and kinematic coverage compared to our previous computations and extract additional skewness-dependent moments of the GPD.
We calculate the gluon momentum fraction of the nucleon using lattice quantum chromodynamics (QCD), with a nonperturbative renormalization technique based on the gradient flow. The gluon momentum fraction is determined on a single Wilson-clover ensemble using Nf = 2+1 flavors with pion mass 358 MeV and lattice spacing 0.094 fm. We employ the variational method to reduce excited-state contamination and apply the distillation framework to ensure a large operator basis. To reduce systematic uncertainties, we apply Bayesian model averaging to all fit procedures. We apply matching coefficients to the flow-time dependent lattice results to recover the gluon momentum fraction in the MS-scheme at 2 GeV. Our final result is _g(μ= 2 GeV) = 0.482(35), where we quote only statistical uncertainties.
Domestic climate lawsuits are proliferating, and their framing and resolution increasingly suggest connections to broader global climate governance. This article examines the agency of domestic judges in shaping these connections. By reviewing 1,573 domestic climate decisions for references to five international environmental law (IEL) concepts (norms, principles, and emergent concepts), we demonstrate that domestic judges across regions and legal systems are connecting individual disputes to global climate discourse. Through qualitative review of decisions (n = 143) that exhibit evidence of reference to IEL concepts, we next characterize domestic judges' engagement. We show that, collectively, judges' incorporation of IEL concepts (through norm pairing and norm usage) can support their domestic adoption in ways that simultaneously advance global climate governance and reinforce the global effect of those concepts. Ultimately, we urge broader recognition of domestic judges as key agents of norm development in global climate governance and additional global environmental politics analysis of the collective agency exercised by domestic judges.
