Advances in Soil Moisture Mapping Techniques and Disaggregation Algorithms for Environmental and Agricultural Applications

Tipping points are abrupt, rapid, and sometimes irreversible changes, and numerous approaches have been proposed to detect them in advance. Such approaches have been termed early warning signals and represent a set of methods for identifying changes in the underlying behaviour of a system across time or space that might indicate an approaching tipping point. Here, we review the literature to explore where, how, and which early warnings have been used in real-world case studies so far.

Global navigation satellite system signals are used to measure the perturbations induced in the ionosphere by earthquakes related to volcanic eruptions. The study uses data from ground stations and satellites measuring the signals reflected on the ocean or during radio occultation. The results shows a small correlation, but given the small magnitude of the earthquakes, it is difficult to apply this concept to any practical application that finds earthquake proxies in ionospheric perturbations.