The Characterization of Warm Temperature in the Central part of Java during the Monsoon Transition in April 2019

In 2019, a warm temperature was observed in the central part of Java Island-Indonesia during the monsoon transition. Therefore, this research aims to characterize temperature anomaly and explain the contributing factors in terms of radiation balance and latent heat flux to explain the environmental process related to temperature variability. The data from two meteorological stations in the Indonesian Bureau of Meteorology, Climatology, and Geophysics (BMKG) and the National Centers for Environmental Prediction (NCEP/NCAR) Reanalysis Project were used to explain the temperature anomaly. Furthermore, the reanalysis data were used to obtain several parameters, such as near-surface air temperature and humidity, cloudiness, solar and longwave radiation, as well as latent heat flux. Also, descriptive time-series data analysis was used to explain the factors contributing to the April 2019 temperatures. The results showed the effect of the Madden–Jullian Oscillation (MJO) on weather anomalies, where the study area traversed by the MJO causes an increase in humidity followed by an intensive cloud formation and the release of latent heat. This latent heat contributes significantly to the increase in temperature than the short and longwave radiation balance. Therefore, further study on atmospheric phenomena in the tropics especially warmer temperatures is needed because they significantly affect by climate change. ©2023 Faculty of Geography UGM and The Indonesian Geographers Associaton ©2023 by the authors. Licensee Indonesian Journal of Geography, Indonesia.