{'fraction_non_alphanumeric': 0.02069425901201602, 'fraction_numerical': 0.0020026702269692926, 'mean_word_length': 5.752252252252252, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Challenges of Establishing and Maintaining Reliable Water Level Observations Across the United States Diverse Coastal Environments

The United States National Oceanic and Atmospheric Administration (NOAA) National Ocean Service (NOS) Center for Operational Oceanographic Products and Services (CO-OPS) is responsible for maintenance and continued development of the National Water Level Observing Network (NWLON). NWLON consists of over 200 long-term stations that provide real-time water level observations throughout all U.S. coastal regions, including Atlantic, Pacific, and Arctic Ocean coasts, Gulf of Mexico, the Great Lakes, and Pacific and Caribbean island territories. One major challenge of maintaining and evolving NWLON is providing optimal spatial coverage to adequately resolve all water level processes of interest to a broad user group. Coastlines of the U.S. and its island territories cover a vast range of environment types resulting in many site specific NWLON system design and installation challenges. Meeting regional coverage needs involves establishing and maintaining a number of long-term stations where environmental conditions present significant challenges to delivery of high quality data and long-term station survivability. This paper provides an overview of CO-OPS existing long-term water level stations located in challenging environment types along with examples of latest measurement system research and development efforts to address future network expansion.