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Abstract The U.S. water supply and carbon sequestration are increasingly threatened by future climate change and air pollution. This study investigates the ecohydrological responses to the individual and combined impacts of climate change and anthropogenic emission (referring only to air pollutants, excluding greenhouse gases) changes at two spatial scales by coupling a regional online‐coupled meteorology and chemistry model (WRF‐Chem) and a water balance model (WaSSI). Combined effects of climate change and anthropogenic emission changes in 2046–2055 relative to 2001–2010 over the US enhance hydrological cycle and carbon sequestration. However, a drying trend occurs in the central and part of the western U.S. Climate change is projected to dominate the ecohydrological changes in most regions. Anthropogenic emission changes under 2001–2010 climate conditions cools down inland water resource regions with 0.01–0.15°C, moisturizes the east and dry the west U.S. More stringent anthropogenic emission control enhances precipitation and ecosystem production in the east and west but has an opposite trend in the central U.S. The ecohydrological modeling in California and North Carolina based on 4‐km resolution meteorological data in 2050 and 2005 shows varying changes in magnitudes and spatial patterns compared to results based on 36‐km resolution meteorological data. Projected changes in air pollutant emissions may accelerate climatic warming in coastal areas and the state of New Mexico and decrease precipitation, runoff, and carbon sequestration in part of the western U.S. Strategies to address future possible problems such as heatwaves, water stress, and ecosystem productivity should consider the varying interplay between air quality control and climate change at different spatial scales. 

This study focuses on the process of updating and upgrading a large-scale legacy software system to ensure its compatibility with modern computing environments. The evolution and maintenance of legacy software pose significant challenges in software engineering, especially given the rapid advancements in technology, computing platforms, and dependent libraries. These challenges become even more pronounced when new systems are built upon existing open-source software, which may become outdated due to discontinued maintenance or lack of community support. In this work, we examine the problem from a sustainable computing perspective through the case study of the CyberWater project—an innovative cyberinfrastructure framework designed to support open data access and open model integration in water science and engineering. CyberWater is built on top of VisTrails, an open-source scientific workflow system. VisTrails has not been actively maintained since 2017, requiring an upgrade to ensure CyberWater’s continued functionality, compatibility, and long-term sustainability. This paper presents our work on upgrading VisTrails, including the complete upgrade process, tools developed and utilized, testing strategies, and the final outcomes. We also share key experiences and lessons learned, with a focus on the sustainability challenges and considerations that arise when maintaining and evolving large-scale open-source software systems in scientific computing environments. 

Workflow management systems (WMSs) are commonly used to organize/automate sequences of tasks as workflows to accelerate scientific discoveries. During complex workflow modeling, a local interactive workflow environment is desirable, as users usually rely on their rich, local environments for fast prototyping and refinements before they consider using more powerful computing resources. However, existing WMSs do not simultaneously support local interactive workflow environments and HPC resources. In this paper, we present an on-demand access mechanism to remote HPC resources from desktop/laptopbased workflow management software to compose, monitor and analyze scientific workflows in the CyberWater project. Cyber- Water is an open-data and open-modeling software framework for environmental and water communities. In this work, we extend the open-model, open-data design of CyberWater with on-demand HPC accessing capacity. In particular, we design and implement the LaunchAgent library, which can be integrated into the local desktop environment to allow on-demand usage of remote resources for hydrology-related workflows. LaunchAgent manages authentication to remote resources, prepares the computationally-intensive or data-intensive tasks as batch jobs, submits jobs to remote resources, and monitors the quality of services for the users. LaunchAgent interacts seamlessly with other existing components in CyberWater, which is now able to provide advantages of both feature-rich desktop software experience and increased computation power through on-demand HPC/Cloud usage. In our evaluations, we demonstrate how a hydrology workflow that consists of both local and remote tasks can be constructed and show that the added on-demand HPC/Cloud usage helps speeding up hydrology workflows while allowing intuitive workflow configurations and execution using a desktop graphical user interface.