Spatial and Temporal Variation of Land Surface Temperature in New Guinea and Borneo Island

Abstract

Increased temperature is one of the signals of global warming. Land Surface Temperature (LST) can be used to measure climate change. This study aimed to investigate the pattern and variation of LST on New Guinea and Borneo Island using a cubic spline and a multivariate regression model. The correlation between LST and the normalized difference vegetation index (NDVI) was also examined using Pearson correlation. The LST and NDVI data were obtained from 2000 to 2019 from the National Aeronautics and Space Administration Moderate Resolution Imaging Spectroradiometer database for each sub-region. New Guinea was divided into two analyses. The first analysis consisted of 45 sub-regions (210-pixels distance) while the second analysis consisted of 90 sub-regions (105-pixels) on the island. The overall mean increase of LST per decade for 45 sub-regions was +0.012oC with a 95% confidence interval (-0.052, 0.077)oC. The 90 sub-regions had a significant overall mean increase in LST of +0.086oC, with 95% confidence interval (0.028, 0.144)oC. The first analysis the result show that there were two super-regions A (north-west) and C (central-south) that had significant mean decrease and increase of LST with -0.107oC and 0.201oC respectively. The second analysis had five super-regions with significant mean variation of LST. There were four super-regions with the mean LST increase in B1 (central-north1), C1 (central-south1), C2 (central-south2) and E2 (south-east2) with 0.008oC, 0.042oC, 0.185oC, 0.217oC, respectively, and one of super-region of A2 (north-west2) has mean LST decrease by -0.122oC. Borneo Island was divided into eight super-regions with a 105-pixel distance between sub-regions resulting in 72 sub-regions covering the entire island. The overall mean increase in LST was +0.203oC per decade with 95% confidence interval (0.138, 0.267). The changes differed by region; a significant increase was found in Sarawak, North Kalimantan, West Kalimantan, West-central Kalimantan, Central-east Kalimantan region, and a slight decrease was seen in Sabah and Brunei Darussalam (Sabah & Brunei) region. There was a slight increase in East Kalimantan and a stable trend in South Kalimantan. The correlations between LST and NDVI in Boneo Island were low and varied for each sub-region. Most of the correlations in the sub-regions were positive. Most of the sub-regions showed that the pattern of LST and NDVI were similar at the beginning and the end of the year.