Influence of global climate signals on groundwater anomalies in High
Plains aquifer
Abstract
The Gravity Recovery and Climate Experiment (GRACE) mission and the
Follow-On mission (GRACE-FO) have been widely used to estimate
Groundwater (GW) at different scales. With improved releases and data
longevity of these missions it becomes possible to analyze changes on GW
and its link with global climate patterns such as El Niño-Southern
Oscillation (ENSO), which can contribute to better management of this
resource, especially in zones where it is crucial for the livelihoods
and food security of the community. In the current study, TWS-derived
from GRACE, Soil Moisture and Snow simulated by the Global Land Data
Assimilation System (GLDAS) were used in the period 2002-2020 to
estimate fluctuations in High Plains Aquifer (HPA). Trend and annual
cycle were analyzed, and then Principal Component Analysis (PCA) was
carry out to observe spatio-temporal oscillation modes and its
relationship with Oceanic Niño Index (ONI) through Spectral Analysis.
Furthermore, to validate GRACE-derived GW and evaluate a larger period
pattern such as Pacific Decadal Oscillation (PDO), Depth to Water data
from United States Geological Survey (USGS) wells distributed in the
aquifer were selected with a longer period looking for teleconnections.
Results shows increasing trend in Northern High Plains while a
decreasing in the central and southern part of it. GW peak occurs in
August in most of HPA, three month later than rainfall peak. First four
components explain 77% of total variance. GW derived from GRACE and
GRACE-FO as well as GW from wells could detect periodicities that
suggest connections of GW variability with PDO more than with ENSO in
HPA.