## 3 Results
### The SST-SIF Link during the Onset Phase of Summer Monsoon
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Oceanic Region**} & \multicolumn{3}{c}{**Partial Correlation Coefficient (r) between Indian Ocean SST and SIF Limiting NINO3 Index and DMI**} \\  & \multirow{2}{*}{**ACZ**} & \multirow{2}{*}{**June**} & \multirow{2}{*}{**AcZ**} & \multicolumn{2}{c}{**August**} & \multirow{2}{*}{**ACZ**} & \multirow{2}{*}{**September**} \\  & & & & & & & & & **Independent Variables** \\  & & **NINO3** & & & & & **NINO3** & & **DMI** \\ \hline \multirow{8}{*}{WIO} & ECPH & \(-0.55\) & \(-0.38\) & WCPG & \(+0.51\) & \(+0.16\) & WCPG & \(+0.58\) & \(+0.316\) \\  & EPH & \(-0.63\) & \(-0.56\) & LGP & \(-0.59\) & \(-0.32\) & TGP & \(-0.37\) & \(-0.69\) \\  & CPH & \(-0.56\) & \(-0.66\) & & & & & WDR & \(-0.34\) & \(-0.72\) \\  & SPH & \(-0.49\) & \(-0.37\) & & & & & & \\  & TGP & \(-0.57\) & \(-0.59\) & & & & & & \\  & UGP & \(-0.62\) & \(-0.52\) & & & & & & \\  & WHR & \(-0.55\) & \(-0.50\) & & & & & & \\ \hline \multirow{8}{*}{NIO} & EPH & \(-0.51\) & \(-0.49\) & WCPG & \(+0.59\) & \(+0.54\) & WCPG & \(+0.46\) & \(+0.24\) \\  & CPH & \(-0.58\) & \(-0.65\) & & & & & & \\  & TGP & \(-0.45\) & \(-0.47\) & & & & & & \\  & UGP & \(-0.51\) & \(-0.49\) & & & & & & \\  & MGP & \(-0.52\) & \(-0.52\) & & & & & & \\  & WHR & \(-0.46\) & \(-0.47\) & & & & & & \\ \hline \multirow{8}{*}{CIO} & EPH & \(-0.66\) & \(-0.72\) & GPH & \(+0.55\) & \(+0.58\) & ECPH & \(+0.55\) & \(+0.48\) \\  & WPH & \(-0.65\) & \(-0.66\) & WDR & \(+0.46\) & \(+0.53\) & EPH & \(+0.53\) & \(+0.48\) \\ \cline{1-1}  & CPH & \(-0.72\) & \(-0.74\) & & & & & & \\ \cline{1-1}  & TGP & \(-0.46\) & \(-0.50\) & & & & & & \\ \cline{1-1}  & UGP & \(-0.51\) & \(-0.59\) & & & & & & \\ \cline{1-1}  & MGP & \(-0.52\) & \(-0.58\) & & & & & & \\ \cline{1-1}  & GPH & \(-0.58\) & \(-0.61\) & & & & & & \\ \cline{1-1}  & WHR & \(-0.50\) & \(-0.56\) & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Partial Correlation coefficient was determined to understand the independent influence of SST fluctuations in Indian Ocean basins over the months of June, August and September, where SST anomalies due to ENSO and IOD events were kept as fixed variables. The highlighted Agro-climatic zones contain the impact of climatic oscillations in the observed SST-SIF relationship. The correlation coefficients (r) shown in bold text are statistically significant at 95% CI. The influence of CIO was predominantly observed in the Indo-Gangetic Plains and the northern and central regions of India (Figure 5c,f). As with the SST interactions from WIO, the SST anomalies in CIO govern the vegetation photosynthesis of EPH, CPH, UGP, TGP and WHR. Furthermore, GPH, WPH and MGP also showed linkages with CIO (Table 5). Contrary, GPH failed to exhibit significant linkage with CIO SST anomalies, as depicted in the density contours of SIF anomalies. At the same time, SIF anomalies in the WDR were found to be closely associated with positive SST anomalies in the CIO (Figure 5c). However, the composites of SIF anomalies almost agree with the observed SST-SIF correlations. During years of warmer than normal surface waters in the tropical Indian Ocean regions, negative anomalies of the specific humidity (Figure 6a-c), rainfall (Figure 7a-c), and soil moisture (Figure 8a-c) together with positive air temperature anomalies (Figure 9a-c) were dominantly observed in India. The consequent water stress condition reduces vegetation productivity and thus exhibits negative anomalies of SIF. Similarly, negative anomalies of air temperature (Figure 9d-f), together with positive anomalies of specific humidity (Figure 6d-f), rainfall (Figure 7d-f) and soil moisture (Figure 8d-f), occur corresponding to the negative SST anomalies in WIO, NIO and CIO. This reduces the chances of the vegetation experiencing water stress and thus exhibits positive SIF anomalies. The bias exists in the implications of warm and cold SST anomalies are clearly evident in the density plots of specific humidity, rainfall, soil moisture and air temperature anomalies.