Tropical Peatland Hydrology Simulated With a Global Land Surface Model.

Area of Science:

• Earth and Environmental Sciences
• Climate Science
• Ecosystem Modeling

Background:

• Tropical peatlands are critical carbon sinks, with water dynamics influencing carbon storage.
• Existing global land surface models (LSMs) do not accurately represent tropical peatland hydrology, which differs from northern peatlands.

Purpose of the Study:

• To integrate tropical peat-specific hydrology modules into a global LSM for the first time.
• To improve the representation of tropical peatland hydrological processes in Earth system models.
• To assess the model's performance against in situ data for natural and drained tropical peatlands.

Main Methods:

• Developed and integrated tropical peat-specific hydrology modules (PEATCLSM) into the NASA Catchment Land Surface Model (CLSM).
• Created literature-based parameter sets for natural (PEATCLSM_Trop,Nat) and drained (PEATCLSM_Trop,Drain) tropical peatlands.
• Forced simulations with global meteorological reanalysis data across major tropical peatland regions and evaluated against in situ water level and evapotranspiration data.

Main Results:

• The new model (PEATCLSM_Trop,Nat) demonstrated improved bias and correlation compared to the default CLSM.
• PEATCLSM_Trop,Drain significantly outperformed other model versions over drained peatland sites in Southeast Asia.
• Model performance varied across regions, suggesting the need to capture more nuanced peatland hydrologic responses.

Conclusions:

• Integrating tropical peat-specific hydrology into LSMs is crucial for accurately simulating these carbon-dense ecosystems.
• The developed model shows promise but requires further refinement to account for regional hydrological variations.
• Future work should focus on improving meteorological forcing data and incorporating more complex peatland hydrological processes.