The equatorial and low-latitude ionosphere is a region of profound ionospheric activity and variability, presenting significant challenges for both scientific understanding and operational prediction. Its strong day-to-day (DTD) variability, and its direct impact on the occurrence of plasma irregularities and associated ionospheric scintillations, remains a critical and highly challenging subject in space weather research.

A key obstacle to progress has been the inherent difficulty in obtaining simultaneous, comprehensive observations of the coupled ionosphere-thermosphere system. To truly characterize the sources of DTD variability and determine their relative importance, an integrated, multi-disciplinary approach is essential.

This session invites contributions that explore new and integrated pathways to address these challenges. We are particularly interested in:

· New Observations: Novel ground-based and space-based observational techniques and networks that provide critical data on the equatorial and low-latitude ionosphere-thermosphere system.
· Advanced Modeling: Physics-based and first-principles modeling efforts that seek to simulate and understand the sources of DTD variability and their nonlinear interactions.
· Data-Driven Approaches: Innovative applications of machine learning, data assimilation, and other data-driven techniques to fuse disparate data sets, uncover complex patterns, and improve forecasting capabilities.

The ultimate goal of this session is to foster a dialogue that bridges observation, theory, and application, with a focus on improving the predictability of the equatorial and low-latitude ionosphere and its irregularities across a wide range of solar, geomagnetic, and lower atmospheric conditions.