Estimating the landscape and soil freeze-thaw (FT) dynamics in the Northern Hemisphere is crucial for understanding permafrost response to global warming and changes in regional and global carbon budgets. A new framework is presented for surface FT-cycle retrievals using L-band microwave radiometry based on a deep convolutional autoencoder neural network. This framework defines the landscape FT-cycle retrieval as a time series anomaly detection problem considering the frozen states as normal and thawed states as anomalies. The autoencoder retrieves the FT-cycle probabilistically through supervised reconstruction of the brightness temperature (TB) time series using a contrastive loss function that minimizes (maximizes) the reconstruction error for the peak winter (summer). Using the data provided by the Soil Moisture Active Passive (SMAP) satellite, it is demonstrated that the framework learns to isolate the landscape FT states over different land surface types with varying complexities related to the radiometric characteristics of snow cover, lake-ice phenology, and vegetation canopy. The consistency of the retrievals is evaluated over Alaska, against in situ ground-based observations, showing reduced uncertainties compared to the traditional methods that use thresholding of the normalized polarization ratio.

Changes in climate can greatly affect the phenology of plants, which can have important feedback effects, such as altering the carbon cycle. These phenological feedback effects are often induced by a shift in the start or end dates of the growing season of plants. The normalized difference vegetation index (NDVI) serves as a straightforward indicator for assessing the presence of green vegetation and can also provide an estimation of the plants' growing season. In this study, we investigated the effect of soil temperature on the timing of the start of the season (SOS), timing of the peak of the season (POS), and the maximum annual NDVI value (PEAK) in subarctic grassland ecosystems between 2014 and 2019. We also explored the impact of other meteorological variables, including air temperature, precipitation, and irradiance, on the inter-annual variation in vegetation phenology. Using machine learning (ML) techniques and SHapley Additive exPlanations (SHAP) values, we analyzed the relative importance and contribution of each variable to the phenological predictions. Our results reveal a significant relationship between soil temperature and SOS and POS, indicating that higher soil temperatures lead to an earlier start and peak of the growing season. However, the Peak NDVI values showed just a slight increase with higher soil temperatures. The analysis of other meteorological variables demonstrated their impacts on the inter-annual variation of the vegetation phenology. Ultimately, this study contributes to our knowledge of the relationships between soil temperature, meteorological variables, and vegetation phenology, providing valuable insights for predicting vegetation phenology characteristics and managing subarctic grasslands in the face of climate change. Additionally, this work provides a solid foundation for future ML-based vegetation phenology studies.

Soil temperature is one of the most significant parameters that plays a crucial role in glacier energy, dynamics of mass balance, processes of surface hydrological, coaction of glacier-atmosphere, nutrient cycling, ecological stability, the management of soil, water, and field crop. In this work, we introduce a novel approach using transformer models for the purpose of forecasting soil temperature prediction. To the best of our knowledge, the usage of transformer models in this work is the very first attempt to predict soil temperature. Experiments are carried out using six different FLUXNET stations by modeling them with five different transformer models, namely, Vanilla Transformer, Informer, Autoformer, Reformer, and ETSformer. To demonstrate the effectiveness of the proposed model, experiment results are compared with both deep learning approaches and literature studies. Experiment results show that the utilization of transformer models ensures a significant contribution to the literature, thence determining the new state-of-the-art.

Farmers across the world could jack up giant profits using an Artificial Intelligence soil monitoring system developed at Brunel University London. By collecting data about soil and growing conditions, the'magic bean' helps farmers boost crops, cut waste and save time, money and water. It comes after France this year saw record temperatures of 49.5 ºC, the US had its wettest spring since 1995 and severe frost threatened Brazil's coffee harvest. The Brunel algorithms could help producers work around freak weather triggered by climate change and unplanned supply problems after Brexit. "We have a way of using data to make crops grow better, worldwide," said electronic engineer Dr Tatiana Kalganova.