Interactions of Terrestrial and Marine Heatwaves in the Coastal Zone of Southern Java
Halimurrahman (a*, b), Zahidah Hasan (a), Ginaldi Ari Nugroho (b), Asif Awaludin (b), Ibnu Fathrio (b), Mochamad Furqon Azis Ismail (b)

(a) Environmental Sciences Program Study, Graduate School of Universitas Padjadjaran, Indonesia
*halimurrahman24001[at]mail.unpad.ac.id
(b) Research Center for Climate and Atmosphere, National Research and Innovation Agency, Indonesia

Abstract

Coastal regions are increasingly exposed to extreme thermal events both on land and at sea, including terrestrial heatwaves (THWs) and marine heatwaves (MHWs), under intensified climate variability. Along the southern coast of Java, MHWs are influenced by intraseasonal, interannual, and broader regional-to-global variability, including patterns in the Indian and Pacific Oceans. While MHWs have been relatively well studied, THWs remain poorly documented in this region. This study investigates the frequency and overlap of THWs and MHWs along the southern coast of Java, particularly in Pameungpeuk, West Java, from 2000 to 2022. Using satellite-based sea surface temperature and ground-based air temperature data, we identified 23 co-occurring events, with durations often exceeding 10 days. MHWs peaked during the rainy season, while THWs were more frequent in transitional months. Notable meteorological anomalies accompany these extremes: reduced surface wind speeds, increased land temperatures (up to 1.4oC), and varying humidity responses-positive during MHWs and negative during THWs. These patterns highlight the complexity of land-sea thermal interactions and underscore the need for integrated climate risk assessments in coastal regions.

Keywords: Java Island, Climate change, Terrestrial heat waves, Marine heat waves, Interannual variability

Topic: Energy and Environmental Physics