## 3 Results
### Distributions of the CCs and RICs of Different Influencing Factors  
Figure 2 shows the latitude-longitude distributions of the CCs between the mean LS GW Ep and each of the nine factors. In most areas of the Indian Peninsula, the mean LS GW Ep is strongly negatively correlated with the mean eastward wind speeds in both of two height ranges, 15-17 km (Figure 2a) and 20-30 km (Figure 2e), with the CCs generally smaller than \(-\)0.4. It is also negatively correlated with the OLR (Figure 2i), which is the proxy for convective activity. Over the Bay of Bengal and its surrounding land area, the mean LS GW Ep is also negatively correlated with the mean northward wind speeds between 15 and 17 km (Figure 2b) and 20 and 30 km (Figure 2f), while the influence of the mean northward wind speed between 20 and 30 km on the mean LS GW Ep is not as strong as the mean northward wind speed between 15 and 17 km according to the magnitudes of the CCs. In the northern part of the Indian Peninsula, the mean LS GW Ep has positive correlations with the mean eastward wind shear between 15 and 17 km (Figure 2c), generally with the CCs between 0.3 and 0.6. In the middle and southern parts of the Indian Peninsula and over the Indian Ocean, strong positive correlations exist between the mean LS GW Ep and the mean eastward wind shear in the 20-30 km height range (Figure 2g), with the CCs generally higher than 0.5. Over the Bay of Bengal and its surrounding land area, the mean LS GW Ep is positively correlated with the mean northward wind shear between 15 and 17 km (Figure 2d) and the mean eastward wind shear between 20 and 30 km (Figure 2g), generally with the CCs of 0.3-0.6. In comparison, over the Indian Peninsula and the Bay of Bengal, the correlations between the mean LS GW Ep and the mean northward wind shears in the 20-30 km height range (Figure 2h) are comparatively smaller, mostly with the CCs of 0-0.4. Figure 1: Latitude–longitude distributions of the mean LS GW Ep over the Indian region in different seasons: (**a**) MAM, (**b**) JJA, (**c**) SON, and (**d**) DJF during December 2019 and November 2021. Figure 2: Latitude–longitude distributions of the CCs between the time series of the mean LS GW Ep and those of the nine influencing factors over the Indian region during December 2019 and November 2021. The nine influencing factors are **(a)** 15–17 km zonal wind speed; **(b)** 15–17 km meridional wind speed; **(c)** 15–17 km zonal wind shear; **(d)** 15-17 km meridional wind shear; **(e)** 20–30 km zonal wind speed; **(f)** 20–30 km meridional wind speed; **(g)** 20–30 km zonal wind shear; **(h)** 20–30 km meridional wind shear; and **(i)** OLR as the proxy of convection activity, respectively. The eastward/northward wind phases are defined as positive of zonal/meridional winds. Figure 2 demonstrates that over the Indian Peninsula, the mean LS GW Ep has strong correlations with different factors, and the correlations might be positive or negative. The correlation analysis above indicates that these factors should play important roles in the generation and propagation of GWs over the Indian region, which is consistent with previous studies [30; 39; 53]. However, it is not objective enough to evaluate the influence of each factor on the LS GW activity only according to the magnitudes of the CCs. For example, in the central region of the Indian Peninsula between 15\({}^{\circ}\)N and 25\({}^{\circ}\)N, the mean wind speeds in the two altitude ranges, 15-17 km and 20-30 km, and OLR all have strong negative correlations with the mean LS GW Ep, with their CCs generally smaller than \(-0.4\). On the other hand, in the same region, the mean zonal wind shears between 15 and 17 km, 20 and 30 km, and the mean meridional wind shears between 15 and 17 km all have strong positive correlations with the mean LS GW Ep, with the CCs generally larger than 0.4. It is difficult to evaluate the relative importance of the above factors on the LS GW activity in this region based on the CCs only.