Understanding the dynamics of soil respiration (Rs) in response to freeze-thaw cycles is crucial due to permafrost degradation on the Qinghai-Tibet Plateau (QTP). We conducted continuous in situ observations of Rs using an Li-8150 automated soil CO2 flux system, categorizing the freeze-thaw cycle into four stages: completely thawed (CT), autumn freeze-thaw (AFT), completely frozen (CF), and spring freeze-thaw (SFT). Our results revealed distinct differences in Rs magnitudes, diurnal patterns, and controlling factors across these stages, attributed to varying thermal regimes. The mean Rs values were as follows: 2.51 (1.10) mu mol center dot m(-2)center dot s(-1) (CT), 0.37 (0.04) mu mol center dot m(-2)center dot s(-1) (AFT), 0.19 (0.06) mu mol center dot m(-2)center dot s(-1) (CF), and 0.68 (0.19) mu mol center dot m(-2)center dot s(-1) (SFT). Cumulatively, the Rs contributions to annual totals were 89.32% (CT), 0.79% (AFT), 5.01% (CF), and 4.88% (SFT). Notably, the temperature sensitivity (Q10) value during SFT was 2.79 times greater than that in CT (4.63), underscoring the significance of CO2 emissions during spring warming. Soil temperature was the primary driver of Rs in the CT stage, while soil moisture at 5 cm depth and solar radiation significantly influenced Rs during SFT. Our findings suggest that global warming will alter seasonal Rs patterns as freeze-thaw phases evolve, emphasizing the need to monitor CO2 emissions from alpine meadow ecosystems during spring.

Global climate change and permafrost degradation have significantly heightened the risk of geological hazards in high-altitude cold regions, resulting in severe casualties and property damage, particularly in the Qinghai-Tibet Plateau of China. To mitigate the risk of geological disasters, it is crucial to identify the primary disaster-inducing factors. Therefore, to address this issue more effectively, this study proposes a spatiotemporal-scale approach for detecting disaster-inducing factors and investigates the disaster-inducing factors of geological hazards in high-altitude cold regions, using the Kanchenjunga Basin as a case study. As the world's third-highest peak, Kanchenjunga is highly sensitive to climate fluctuations. This study first integrates the frost heave model and multitemporal interferometric synthetic aperture radar techniques to monitor ascending and descending track line-of-sight deformation of the frozen active layer in the study area. Subsequently, the surface parallel flow constrained model is employed to decompose the 3-D time-series deformation of geological hazards in the basin, with remote sensing imagery and field surveys used to identify a total of 94 disaster sites. In parallel, a database of potential conditioning factors is constructed by leveraging Google Earth Engine remote sensing inversion technology and relevant data provided by the China Geological Survey. Finally, by integrating monitoring results with a database of potential geological conditioning factors, the spatiotemporal-scale approach for detecting disaster-inducing factors proposed in this study is applied to investigate the disaster-inducing factors in the Kanchenjunga Basin. The research results highlight that surface temperature is the primary driving factor of geological hazards in the Kanchenjunga Basin. This research helps bridge the data gap in the region and offers critical support for local government decision-making in disaster prevention, risk assessment, and related areas.

Laboratory description of clay normally distinguishes the scale of atoms from the scale of clay particles and aggregates. Contemporary constitutive models for clay tend to ignore this scale separation, and rather focus on phenomenology. By considering scale separation, this paper introduces a robust physics-based phenomenological constitutive model for clay that qualitatively captures their broad spectrum of rate-dependent mechanical features. The model is derived using the thoroughly rigorous hydrodynamic procedure. While some imagine that by considering rigour and physics, their models would get complicated, the resulting set of equations reveal a surprising degree of simplicity. The derivation strongly benefits from the principle of two-stage irreversibility, which describes energy flow within the material from the continuum scale down to the atomistic micro-scale, through the meso-scale of clay aggregates. While thermal and meso-related temperatures capture atomistic and clay aggregate fluctuating motions, a sink term from the latter to the former underpins the direction of the energy flow. The model's standout feature is in pinpointing new transport coefficients that drive both volumetric and shear plastic flows in a thermodynamically coupled manner. A novel scheme is then proposed to calibrate these coefficients from conventional steady-state observations. Thanks to the formulation the model shows a remarkable level of predictiveness, despite being relatively simple mathematically. In particular, the model readily explains the broad spectrum of rate-dependent phenomena during transient loading, along with creep and relaxation processes. Given the generality of hydrodynamics, it is anticipated that the new model could be expanded to capture fluid-solid transitions between liquid-like soft mud and plastic-like stiff clay responses, contingent on water content variations.

Crater degradation and erosion control the lifetime of craters in the meter-to-kilometer diameter range on the lunar surface. A consequence of this crater degradation process is that meter-scale craters survive for a comparatively short time on the lunar surface in geologic terms. Here, we derive crater lifetimes for craters of

The nonlinear equation is obtained describing the dynamics of nonlinear wave structures in the dusty plasma above the illuminated surface of the Moon in the case of low frequencies and pancake-like shape of wave packet in the direction along the external magnetic field. This equation is the modified Zakharov-Kuznetsov equation. The analytical formula for the one-dimensional soliton solution is derived. The analysis of the stability of one-dimensional soliton solution was performed.

Modified Kadomtsev-Petviashvili equation describing nonlinear dynamics of nearly one-dimensional wave structures in dusty plasma above illuminated part of the Moon in the situation in which localization along magnetic-field vector is much stronger than along other directions is derived. The equation differs from the ordinary Kadomtsev-Petviashvili equation by the nonlinear term being non-analytical. Modified Kadomtsev-Petviashvili differs from generalizations of the Kadomtsev-Petviashvili equation in which nonlinearity retains the same form as in the ordinary Kadomtsev-Petviashvili equation but higher-order corrections for dispersion are taken into account. An analytical expression governing one-dimensional soliton solution to the modified Kadomtsev-Petviashvili equation is obtained. The solution differs from the well-known one-dimensional soliton solutions to the Korteweg-De Vries and ordinary Kadomtsev-Petviashvili equations. Stability analysis of the one-dimensional soliton solution showed that it is stable. Possible applications of the discussed solitons from the point of view of description of the so-called transient lunar phenomena representing short-lived light, changes in color or appearance on the surface of the Moon are discussed.

Oceanic variability and eddy dynamics during snowball Earth events, under a kilometer of ice and driven by a very weak geothermal heat flux, are studied using a high-resolution sector model centered at the equator, where previous studies have shown the ocean circulation to be most prominent. The solution is characterized by an energetic eddy field, equatorward-propagating zonal jets, and a strongly variable equatorial meridional overturning circulation (EMOC), on the order of tens of Sverdrups (Sv; 1 Sv 10(6) m(3) s(-1)), restricted to be very close to the equator. The ocean is well mixed vertically by convective mixing, and horizontal mixing rates by currents and eddies are similar to present-day values. There are two main opposite-sign zonal jets near the equator that are not eddy driven, together with multiple secondary eddy-driven jets off the equator. Barotropic stability analyses, the Lorenz energy cycle (LEC), and barotropic-to-baroclinic energy conversion rates together indicate that both baroclinic and barotropic instabilities serve as eddy-generating mechanisms. The LEC shows a dominant input into the mean available potential energy (APE) by geothermal heat flux and by surface ice melting and then transformation to eddy APE, to eddy kinetic energy, and finally to mean kinetic energy via eddy-jet interaction, similarly to the present-day atmosphere and unlike the present-day ocean. The EMOC variability is due to the interaction of warm plumes driven by geothermal heating that reach the ocean surface, leading to ice-melt events that change the stratification and, therefore, the EMOC. The results presented here may be relevant to the ocean dynamics of planetary ice-covered moons such as Europa and Enceladus.