Sarcouncil Journal of Engineering and Computer Sciences

Abstract: Water vapor is the most abundant greenhouse gas and a key regulator of radiative balance, hydrologic cycling, and electromagnetic propagation. Across the United States, sustained increases in atmospheric moisture are reshaping regional climate dynamics and subtly degrading the reliability of high-frequency communication systems that support national security and economic infrastructure. This study integrates atmospheric and communication-engineering perspectives to quantify decadal water vapor trends over U.S. regions and translate them into measurable impacts on signal attenuation, link margins, and system performance. A hybrid narrative and systematic review was conducted across Web of Science, Scopus, IEEE Xplore, and allied databases from 1990 to 2025, yielding forty peer-reviewed studies. PRISMA-based screening and cross-domain search criteria ensure coverage of both atmospheric and telecommunications literature. Observational datasets from radiosonde, GNSS, satellite, and reanalysis sources were synthesized, and random-effects meta-analysis provided regional trend estimates. These were then converted to attenuation increments for Ka-to-V bands using ITU-R propagation models. Results indicate consistent moistening across humid and coastal regions, with median precipitable water vapor increases of roughly 0.6 to 1.4 mm per decade (about 3 to 6 percent). The pooled Southeastern U.S. trend is 0.9 mm per decade (95 percent CI: 0.5–1.3), corresponding to an additional 0.01 to 0.03 dB per 100 km of clear-air attenuation at 30–50 GHz, with compounding risks from cloud and rain effects. Overall, decadal moistening is redefining baseline propagation conditions across the continental network environment. Integrating evolving water-vapor climatology into design standards, monitoring systems, and policy frameworks is essential for ensuring resilient and climate-aware communication infrastructure in the decades ahead.