## 2 Materials and Methods
### Satellite Data  
In this study, we utilised satellite-based SIF records obtained from the Global Ozone Monitoring Experiment-2 (GOME-2) onboard the MetOp-B platform. This dataset is the retrieval of the far-red chlorophyll fluorescence peaking at 740 nm, based on a simplified radiative transfer model in the company of a principal component analysis [22]. Monthly global coverage of SIF data at a 0.5\({}^{\circ}\)\(\times\) 0.5\({}^{\circ}\) spatial resolution (level 3, Version 28) from March 2013 to March 2019 was obtained from NASA Goddard Space Flight Centre ([[https://avdc.gsfc.nasa.gov/](https://avdc.gsfc.nasa.gov/)]([https://avdc.gsfc.nasa.gov/](https://avdc.gsfc.nasa.gov/)), accessed on 1 July 2020). The daily orbital data (level 2, Version) were also used to aggregate 16-day interval records for higher temporal resolution analysis. Given that the data provider of GOME-2 SIF suspended updating in March 2019, we introduced a novel SIF product (from July 2018 to June 2019) derived from TROPOMIonboard the Sentinel-5 Precursor satellite as a supplementary in this study. A data-driven method was employed to retrieve the SIF signal using spectral measurements ranging from 743 nm to 758 nm. The daily orbital TROPOMI SIF at a 0.05\({}^{\circ}\) spatial resolution (obtained from [[ftp://fluo.gps.caltech.edu/data/tropomi/](ftp://fluo.gps.caltech.edu/data/tropomi/)]([ftp://fluo.gps.caltech.edu/data/tropomi/](ftp://fluo.gps.caltech.edu/data/tropomi/)), accessed on 1 August 2020) was likewise aggregated to 16-day series by the mean value. We used the Moderate Resolution Imaging Spectroradiometer (onboard Aqua, Collection 6) MYD13C1 (0.05\({}^{\circ}\), 16-day) and MYD13C2 (0.05\({}^{\circ}\), monthly) Vegetation Indices' products from January 2007 to June 2019 downloaded from NASA Earth Observation data ([[https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)]([https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)), accessed on 1 August 2020). EVI is an optimized version of vegetation indices that effectively reduces soil background influences and is widely used as a proxy of canopy greenness. The equation of EVI is:  
\[EVI=2.5\frac{\rho_{NIR}-\rho_{red}}{\rho_{NIR}+6\rho_{red}-7.5\rho_{blue}+1} \tag{1}\]  
where \(\rho_{blue}\), \(\rho_{red}\), and \(\rho_{NIR}\) are reflectance in the blue, red, and near-infrared bands, respectively. To reduce noise and uncertainties, only the best-quality data were retained in this study by removing pixels for which the quality control flag of the first 2 bits was neither 00 nor 01, and pixelwise EVI time series data were smoothed using the Savitzky-Golay filter. MODIS daytime Land Surface Temperature (LST, MYD11C3, Version 6) at a monthly scale and a 0.05\({}^{\circ}\) spatial resolution was included in this study, collected from NASA Earth Observation data ([[https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)]([https://search.earthdata.nasa.gov/search](https://search.earthdata.nasa.gov/search)), accessed on 1 August 2020). Similarly, bad-quality data were removed by eliminating pixels with a quality control flag. To examine the impact of solar radiation on vegetation seasonality, monthly photosynthetic active radiation (PAR) at a 1\({}^{\circ}\) spatial resolution was downloaded from the  
Figure 1: (**a**) Land cover map of the Northern Australian Tropical Transect (NATT) study area (data source: Dynamic Land Cover Dataset). Black triangles refer to the five flux tower sites. Photographs show the ground-view of each flux tower site linked with the black arrow (image source: www.ozflux.org.au, accessed on 1 October 2020). (**b**) The locations of the study area over the Australian continent (image source: Google Earth).