Representing the function and sensitivity of coastal interfaces in Earth system models

Abstract

Between the land and ocean, diverse coastal ecosystems transform, store, and transport material. Across these interfaces, the dynamic exchange of energy and matter is driven by hydrological and hydrodynamic processes such as river and groundwater discharge, tides, waves, and storms. These dynamics regulate ecosystem functions and Earth's climate, yet global models lack representation of coastal processes and related feedbacks, impeding their predictions of coastal and global responses to change. Here, we assess existing coastal monitoring networks and regional models, existing challenges in these efforts, and recommend a path towards development of global models that more robustly reflect the coastal interface. T he coastal interface, where the land and ocean realms meet (e.g., estuaries, tidal wetlands, tidal rivers, continental shelves, and shorelines), is home to some of the most biologically and geochemically active and diverse systems on Earth 1. Although this interface only represents a small fraction of the Earth's surface, it supports a large suite of ecosystem services,

The Case for a Critical Zone Science Approach to Research on Estuarine and Coastal Wetlands in the Anthropocene

“…Indeed, coastal and estuarine wetlands are multifaceted systems, and the coupling of material and energy fluxes that link sediments, geomorphology, hydrodynamics and biogeochemical processes ('ecomorphodynamics', see d'Alpaos et al 2019) introduces considerable complexity, the significance of which is heightened by the fact that they are characterized by high levels of both biodiversity and productivity. Coastal ecosystems represent 'hot spots' for processing and transforming both materials and energy (Ward et al 2020). In general, these ecosystems act globally as a carbon sink and form an important component of the so-called Blue Carbon cycle (McCreadle et al 2017).…”

“…The fact that carbon flux not only varies spatially but also interannually and seasonally (see Gao et al 2018) adds even more complexity and further research to constrain the magnitude of this important process at high temporal resolution is clearly still lacking. Moreover, there are many other kinds of material and energy fluxes that remain poorly understood at the coastal interface, and their meaningful incorporation into Earth system models is imperative, albeit very challenging (Ward et al 2020). Adopting a CZS modelling approach would therefore seem warranted, especially if conducted at an intensively studied long-term environmental observatory site.…”

“…The inclusion of human activities within the concept, as suggested by Minor et al (2020), is also illustrated realization of simultaneous long-term observation and systematic analysis of coupled physical, chemical and biological processes across multi-interface and multi-temporal scales in order to reveal the underlying mechanisms controlling the evolution of coastal wetlands. Considering these processes across the entire range of spatial scales, from the molecular to catchment, is essential but poorly understood, and the range of timescales over which these interconnections operate has not yet been examined (Ward et al 2020). An integrated CZS approach would certainly help to address this shortfall.…”

Improved representation of river runoff in Estimating the Circulation and Climate of the Ocean Version 4 (ECCOv4) simulations: implementation, evaluation and impacts to coastal plume regions

“…The European Space Agency (ESA) Soil Measure and Ocean Salinity (SMOS, Mecklenburg et al, 2012) with 33 km/10 day and National Aeronautics and Space Administration (NASA) Soil Moisture Active Passive (SMAP) missions with 40 km/8 day space/time gridding are acquiring SSS observations with sufficient resolution to track the plume pathways and evaluate coastal plume dynamics (Fournier et al 2016a, b;2017a,b;Gierach et al 2013;Liao et al, 2020). To date, however, the coastal plume regions has not been explicitly resolved in most global Ocean General Circulation Models (OGCMs), Earth System Models (ESMs), and Global Ocean Data Assimilation System (GODAS) products (Ward et al, 2020). As a result, the plume region produced by OGCMs, ESMs, and GODAS are not consistent with satellite observations.…”

Open Data, Collaborative Working Platforms, and Interdisciplinary Collaboration: Building an Early Career Scientist Community of Practice to Leverage Ocean Observatories Initiative Data to Address Critical Questions in Marine Science

“…These arrays give scientists unprecedented access to explore the seafloor, water column, and air-sea interface over multi-year periods. Sea-state, weather, and vessel capability all limit data collection from ships to periods of relatively calm weather conditions resulting in data gaps during extreme weather events (e.g., Ondoa et al, 2019) that have a disproportionate influence on ocean systems (e.g., Ward et al, 2020), coastal infrastructure (e.g., Gough et al, 2019;Mendez-Tejeda et al, 2020), and coastal ecology (Adame et al, 2019;Yang et al, 2020). Ocean observing arrays are beginning to fill these gaps by continuously measuring parameters during these local or global events when observations would traditionally be limited.…”