This is a guide on how to take professional looking pictures of the sun on the horizon with proper reflectivity and exposure. This uses the simple practices of HDR or High Dynamic Range.
Step 1: High Exposure
Set your exposure to a high level. This will serve as the exposure for the dark ground.
Step 2: Low Exposure
Set it to a low level exposure. This will correctly expose the sky and sun.
Step 3: Combine
Using photoshop(automatic function), combine the photos to highlight the best exposed in each picture. Since you took two images, you'll have a combination of nicely exposed ground, and well exposed sky. Good luck!