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This study presents daily high-resolution (5 km × 5 km) grids of mean, minimum, and maximum temperature and relative humidity for Germany and its catchment areas, from 1951 to 2015. These observational datasets (HYRAS) are based upon measurements gathered for Germany and its neighbouring countries, in total more than 1300 stations, gridded in two steps: first, the generation of a background field, using non-linear vertical temperature profiles, and then an inverse distance weighting scheme to interpolate the residuals, subsequently added onto the background field. The modified Euclidian distances used integrate elevation, distance to the coast, and urban heat island (UHI) effect. A direct station-grid comparison and cross-validation yield low errors for the temperature grids over most of the domain and greater deviations in more complex terrain. The interpolation of relative humidity is more uncertain due to its inherent spatial inhomogeneity and indirect derivation using dew point temperature. Compared with other gridded observational datasets, HYRAS benefits from its high resolution and captures complex topographic effects. HYRAS improves upon its predecessor by providing datasets for additional variables (minimum and maximum temperature), integrating temperature inversions, maritime influence and UHI effect, and representing a larger area. With a long-term observational dataset of multiple meteorological variables also including precipitation, various climatological analyses are possible. We present long-term historical climate trends and relevant indices of climate extremes, pointing towards a significantly warming climate over Germany, with no significant change in total precipitation. We also evaluate extreme events, specifically the summer heat waves of 2003 and 2015.

In a temperate climate, understory trees leaf out earlier than canopy trees, but the cause of this discrepancy remains unclear. This study aims to investigate whether this discrepancy results from ontogenic changes or from microclimatic differences. Seedlings of five deciduous tree species were grown in spring 2012 in the understory and at canopy height using a 45-m-high construction crane built into a mature mixed forest in the foothills of the Swiss Jura Mountains. The leaf development of these seedlings, as well as conspecific adults, was compared, taking into account the corresponding microclimate. The date of leaf unfolding occurred 10–40 d earlier in seedlings grown at canopy level than in conspecific adults. Seedlings grown in the understory flushed c. 6 d later than those grown at canopy height, which can be attributed to the warmer temperatures recorded at canopy height (c. 1°C warmer). This study demonstrates that later leaf emergence of canopy trees compared with understory trees results from ontogenic changes and not from the vertical thermal profile that exists within forests. This study warns against the assumption that phenological data obtained in warming and photoperiod experiments on juvenile trees can be used for the prediction of forest response to climate warming.

While building the steel–concrete composite girder bridge by means of the incremental launching method, the steel box is directly in the sunlight, and the temperature impact should not be neglected. However, the existing specifications fail to offer the temperature gradient pattern applicable to the steel box featuring a significant height–width ratio and straight web. This paper, relying on the Fenshui River Bridge situated in the southwest region of China, carried out a temperature test. By analyzing the experimental data, the rules of temperature changes at the measuring points in various positions of the steel box were studied, and the temperature disparities of the steel box across different seasons were contrasted. Through the analysis of the test data, the rule governing temperature distribution across the height dimension of the cross-section and its change with time were studied, and a model designed to represent the temperature gradient within the steel box was put forward. By utilizing the numerical model, the effect of the temperature gradient on the force acting on the structure in the process of incremental launching was analyzed. The findings indicate that the temperature of the top plate of the steel box is the highest from 14:00 to 16:00. There is a lag phenomenon in the temperature rise in the bottom plate. The greatest temperature disparity between the upper and lower plates of the steel box is not always present in the season when the temperature is comparatively high. The curve of temperature gradient change exhibits nonlinear features, and the variation in temperature is considerable within the scope of 1 m. In this article, a double-broken line temperature gradient model is put forward, with the corresponding temperature gradient of 17.8 °C. The temperature gradient obviously affects the structural stress, changing the stress distribution, and it notably impacts the deformation. The deformation generated on the guide beam due to the temperature gradient makes up 39% of the total deformation. The temperature gradient is not a fixed value. When the steel box girder is under the jacking process, especially while the structure remains in its maximum cantilever condition and is about to cross the pier, the time should be avoided when the temperature gradient is at its highest.

This paper presents a proposed LSTM-based vertical-gradient prediction combined with three-dimensional kriging that enables reconstruction of greenhouse 3D temperature fields under sparse-sensor deployments while capturing temporal dynamics and spatial correlations. In northern China, winter solar greenhouses rely on standardized structures and passive climate-control strategies, which often lead to non-uniform thermal conditions that complicate precise regulation. To address this challenge, 24 sensors were deployed, and their time-series data were used to train a long short-term memory (LSTM) model for vertical temperature-gradient prediction. The predicted values at multiple heights were fused with in situ observations, and three-dimensional ordinary kriging (3D-OK) was applied to reconstruct the spatiotemporal temperature field. Compared with conventional 2D monitoring and computationally intensive CFD, the proposed approach balances accuracy, efficiency, and deployability. LSTM–Kriging validation showed Trend + Residual Kriging had the lowest RMSE (0.45558 °C) and bias (−0.03148 °C) (p < 0.01), outperforming Trend-only RMSE (3.59 °C) and Kriging-only RMSE (0.48 °C); the 3D model effectively distinguished sunny and rainy dynamics. This cost-effective framework balances accuracy, efficiency, and deployability, overcoming limitations of 2D monitoring and CFD. It provides critical support for adaptive greenhouse climate regulation and digital-twin development, directly advancing precision management and yield stability in CEA.

In view of the fact that the specification does not specify the calculation model for the temperature gradient of the concrete box-shaped arch rib without wing plates, and there is also a lack of relevant research on the temperature model of this type of arch rib, this paper carries out research on the impact of sunshine temperature on a section of concrete box arch rib without a flange plate based on the 355 m Shuiluohe Bridge. Firstly, a temperature experiment of the arch rib without flange plates was conducted. According to the experimental data, the temperature distribution and changing rules of the arch rib cross-section were analyzed. Then, according to the measured temperature data, a calculation mode of the vertical temperature gradient of the arch rib was proposed and compared with the specification. Finally, in view of the most disadvantageous phases of the arch rib in the construction process, the influence of different gradient modes on the structural mechanical behavior was analyzed by means of a simulation model. The results show that along the span from the springing to L/2, the maximal temperatures of the top plate, web plate and bottom plate gradually increase. The temperature gradient of the box’s top plate is the largest, that of the web plate is the second largest, and that of the bottom plate is the smallest. The vertical temperature difference of the key section of the arch rib gradually increases from the springing to L/2, and the maximal temperature difference of the section at L/2 is 16.3 °C, which is 4.2 °C higher than that of the springing section. The vertical temperature gradient proposed in this paper is a four-fold nonlinear model. Compared with the temperature gradient distribution range specified in the specification, the vertical temperature gradient in this article has a wider distribution range in the cross-section height, and the temperature varies more quickly along the cross-section height. The temperature gradient model proposed has more adverse effects on the mechanical behavior of the structure. The temperature gradient model proposed in this paper not only fills the gap in the specification but also provides suggestions for the design and construction of bridges. Meanwhile, the temperature distribution model of this type of arch rib also lays a theoretical foundation for the further development of corresponding thermal insulation materials for concrete surfaces or new concrete materials.

In this paper, we study the onset and development of three-dimensional convection in a tilted porous layer saturated with a liquid. The layer is subjected to a gravitational field and a strictly vertical temperature gradient. Typically, problems of thermal convection in tilted porous media saturated with a liquid are studied by assuming constant different temperatures at the boundaries of the layer, which prevent these systems from supporting conductive (non-convective) states. The boundary conditions considered in the present work allow a conductive state and are representative of typical geological applications. In an earlier work, we carried out a linear stability analysis of the conductive state. It was shown that at any layer tilt angles, the most dangerous type of disturbances are longitudinal rolls. Moreover, a non-zero velocity component exists in -direction. In the present work, three-dimensional non-linear convection regimes are studied. The original three-dimensional problem is reduced to two-dimensional one with an analytical expression for the velocity -component . It is shown that the critical Rayleigh number values obtained through numerical solutions of the obtained 2D problem by a finite difference method for different layer inclination angles, are in a good agreement with those predicted by the linear theory. The number of convective rolls realized in nonlinear calculations also fits the linear theory predictions for a given cavity geometry. Calculations carried out at low supercriticalities show that a direct bifurcation takes place. With increasing supercriticality, no transitions to other convective regimes are detected. The situation studied in this problem can be observed in oil-bearing rock formations under the influence of a geothermal temperature gradient, where the ensuing fluid convection can affect the distribution of oil throughout the layer.

The temperature distribution of the bridge and its thermal effect has always been an important issue for researchers. To investigate the temperature distribution and thermal stress in the steel-concrete composite bridge deck, a 1:4 ratio temperature gradient effect experimental study was carried out in this paper. First, a set of experimental equipment for laboratory temperature gradient loading was designed based on the principle of temperature gradient caused by solar radiation, the temperature gradient obtained from the measurements were compared with the specifications and verified by the FE method. Next, the loading of the steel-concrete composite deck at different temperatures was performed. The thermal stress response and change trend of the simply supported and continuously constrained boundary conditions under different temperature loads were analyzed. The experimental results show that the vertical temperature of steel-concrete composite bridge deck is nonlinear, which is consistent with the temperature gradient trend of specifications. The vertical temperature gradient has a great influence on the steel-concrete composite bridge deck under different constraints, and the extreme stress of concrete slab and steel beam is almost linear with the temperature gradient. Finally, some suggestions for steel-concrete composite deck design were provided based on the research results.

To understand the actual vertical temperature gradient mode of steel box girder webs in cold regions, nearly 1.5 million data measured for over a year by a comprehensive temperature collection system of a steel box girder bridge in a cold region were used to verify the typicality of the temperature screening samples, and a cluster analysis was performed to verify the statistical symmetry of temperature at the symmetry points of webs on both sides of the bridge. One years’ worth of daily temperature difference data were used to investigate the vertical temperature difference distribution on the web and to determine the probability distribution curve form. After selecting the extreme temperature difference samples, the standard vertical temperature difference of the web was calculated, and the actual vertical temperature gradient model of the steel box girder web was established. Results show that the probability distribution model of temperature at the symmetrical points of webs on both sides of the steel box girder was symmetric. The vertical temperature differences of the web demonstrated significant seasonal changes. The probability distribution of the positive and negative temperature differences can be described based on the sum of two Weibull distribution functions. The temperature gradients at all levels in the proposed vertical temperature gradient model were generally greater than the values indicated in the relevant specifications.

The shelf area off Vladivostok in the Sea of Japan is known by the intense internal wave activity investigated for many years. The present contribution to these studies is based on data collected on 3–14 October 2022, from four moorings aligned across isobaths and equipped with thermostrings. Multivariate analysis is performed in the depth–time domain, while timescales and directions and speeds of temperature anomaly movement are estimated from wavelet transform. Approximately 50% of the variance results from vertical stratification changes, i.e., thermocline deepening or shoaling, and temperature anomalies on different timescales moved towards the shoaling seafloor. For the first time, near-inertial (NI) oscillations are detected throughout the record and turn out to be the most intense among the 6 to 70 h timescales, moving with the speeds of 0.41–0.55 m/s, although previous attention was paid to the semidiurnal internal tide. A frequency decrease, i.e., red shift, of the NI oscillations is detected towards shallower water, with the frequency eventually becoming subinertial, and is explained by anticyclonic relative vorticity at the eastern side of the mushroom-like structure detected from thermal satellite imagery. The semidiurnal and two-day oscillations were detected, moving with the speeds of 0.95–1.11 and 0.15–1.17 m/s, respectively. The two-day timescale, never reported before, is considered as a difference one caused by nonlinearity. These results are interpreted as the propagation of an internal wave generated at the steep slope offshore to the inner shelf.

Identifying pre-seismic atmospheric and ionospheric anomalies is of research importance but also meets difficulties, especially for earthquakes with varying magnitudes, focal depths and focal mechanisms. In this paper, atmospheric‒ionospheric disturbances associated with earthquakes in Nepal (April 25, 2015, M  = 7.8 and May 12, 2015, M = 7.3) are investigated using atmospheric and ionospheric parameters. Ionospheric (vertical total electron content (VTEC)) and atmospheric (outgoing long wave radiation (OLR), cloud mask, vertical temperature gradient (VTG)) parameters are archived from IGS GPS stations and INSAT 3D data from Indian Meteorological Department (IMD) of Ministry of Earth Sciences, Government of India. The abnormal VTEC signal was noticed 3 days and 10 days prior to April 25, 2015 event and 2 days and 6 days prior to the May 12, 2015 event. Inter-quartile range (IQR) and associated running median over one day were determined as the upper limit reference to a signature of VTEC for the 51-days period of the Nepal earthquake, it can be clearly observed that the total electron content (TEC) has increased from the limits of UB (upper bound) at the stations closest to the earthquake epicentre such as LCK-4, LHAZ than the far stations such as IISC, HYDE, SGOC and URUM. Prior to these earthquakes, UB observed a 54‒60% increase in relative amplitude of VTEC. The overall geomagnetic storm condition was thoroughly examined using the global planetary index (K p ) and storm time disturbance index (D st ) over the 51-days period. The IQR range method was used to analyse its abnormal positive and negative signals. We found no geomagnetic signatures caused by geomagnetic storms during the seismic regime The OLR varied from 240 to 340 watts/m 2 observed 4 days before the event. The vertical temperature gradient varied from 4.3 to 23.2 K. Daily variations of 51 days for the OLR showed good anomalous atmospheric responses a few days before the event. The shallow depth of the earthquake gives the best coupling, releasing a large amount of energy from the seismic zones, and could be a causal factor in the enhancement of anomalous VTEC patterns.