Downscaling Satellite Gravimetry Observation for Terrestrial Hydrology
Using a Conditional Generative Adversarial Network
Abstract
Understanding the spatiotemporal characteristics of terrestrial water
storage (TWS) variation is crucial for evaluating climate change and
promoting sustainable water resource management. Numerical
hydrological models and satellite data, particularly information
obtained from gravity variations through the Gravity Recovery and
Climate Experiment (GRACE) mission, are widely utilized for the
analysis of TWS fluctuations. Even though GRACE holds excellent
promise for large-scale exploration, these measurements are too coarse
for localized quantification. Therefore, enhancing the resolution of
GRACE measurements holds significant potential for application at the
local to regional scale. The objective of this study is to produce
higher-resolution images capable of depicting the local-scale TWS
anomalies (TWSA) in the South America continent using a modified
version of the Generative Adversarial Network (GAN). Our results
demonstrate that the conditional WGAN-GP model can effectively
replicate the structures of the TWSA signals with a reasonably close
resemblance. This indicates that the model can successfully execute
the downscaling task and harness high-resolution spatiotemporal
structures within the low-resolution satellite observation for unseen
temporal data.