The role of groundwater in modulating the global mean sea level variations during ENSO events
Abstract
Accurate prediction of the inter-annual variability of sea level is critical, especially for people who live in low land coastal regions. Variations in global mean sea level (GMSL) are closely linked with both climate change and natural climate variability, including oscillations such as the El Niño Southern Oscillation (ENSO). The partitioning between mass and steric components of the trend of GMSL has been well studied; however, the temporal co-evolution of these two components of sea level changes during ENSO events have rarely been explored. In this study, we use multiple sources of observational data from satellite altimetry, satellite gravity (GRACE), and in-situ ocean floats (ARGO) to demonstrate that mass and steric ocean states have specific temporal characteristics during ENSO events. We show that while global steric ocean variability leads the evolution of ENSO in time, global ocean mass variability lags ENSO by four months. Changes in ocean mass are compared with changes in terrestrial water storage (TWS). We use land surface models, including Community Land Model version 4 (CLM4), to show the dominant effects of groundwater and river water storage variability. This mechanism is obvious primarily in tropical regions including the Amazon.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFM.H41S2010L
- Keywords:
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- 3322 Land/atmosphere interactions;
- ATMOSPHERIC PROCESSES;
- 1630 Impacts of global change;
- GLOBAL CHANGE;
- 1829 Groundwater hydrology;
- HYDROLOGY;
- 6324 Legislation and regulations;
- POLICY SCIENCES