The word "more upsurging" can be replaced with various synonyms to give your writing more variety and depth. Some alternative words that could be used in place of "more upsurging" include escalating, surging, soaring, intensifying, increasing, and growing. Each of these words conveys a sense of growth and development, but with slightly different connotations. If you're looking for a more impactful or emotive word, you might use "exploding," "booming," or "flourishing" to describe a sudden surge of activity or growth. Whatever word you choose, be sure to use it consistently throughout your writing to maintain its flow and coherence.