Validation against Thai Meteorological Department stations and analysis for 1995–2024 found that ERA5 captured rainfall cycles well. El Niño was associated with drier conditions and La Niña with wetter conditions, with seasonal and regional variation.
Key findings
- ERA5 annual rainfall agreed with station observations at R² values of 0.80–0.87. The rainy season supplied most annual precipitation. El Niño was linked to reductions especially in summer and monsoon periods, while La Niña enhanced rainfall particularly in the Northeast and Central regions; weaker winter effects remained visible in the southern peninsula.
Why this matters globally
The results support reanalysis for early warning, agricultural planning and water management where station coverage is uneven, while showing that ENSO guidance should be season- and region-specific.
Thai researcher contribution
Thai researchers evaluated a global reanalysis product specifically for Thailand using direct comparison with national meteorological observations.
Limitations to consider
Representative stations cover only part of the country, ERA5 resolution may miss localized rain and complex terrain, and anomaly associations do not isolate all oceanic and monsoon drivers.