Preheat broiler to high. Position oven rack approximately 8 inches beneath heating element. Line baking sheet with aluminum foil and set aside.
Add 1 teaspoon onion powder, 1 teaspoon garlic powder, 1 teaspoon smoked paprika, ½ teaspoon dried thyme, ½ teaspoon salt, ¼ teaspoon cumin, ¼ teaspoon nutmeg, ¼ teaspoon cinnamon, and 1 pinch cayenne to small mixing bowl. Stir spices together until well blended. Set aside.
Place 4 6-ounce salmon fillets skin-side down on foil-lined baking sheet, leaving space between each fillet. Pat salmon fillets completely dry with paper towels.
Brush 1 teaspoon neutral oil evenly onto tops of salmon fillets, then cover fillets evenly with jerk seasoning blend.
Place baking sheet under preheated broiler. Broil fillets 2 minutes, then check doneness with internal meat thermometer. Continue broiling fillets, checking every minute, until preferred internal temperature is reached. See Notes below for temperature suggestions.
When desired internal temperature is achieved, carefully remove baking sheet from oven. Set aside and let rest 5 minutes, then transfer salmon fillets to serving plates with mango salsa and prepared white rice. Serve immediately.