4 results
Search Results
2. Combining Regional Mesh RefinementWith Vertically Enhanced Physics to Target Marine Stratocumulus Biases.
- Author
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Bogenschutz, Peter A., Hsiang-He Lee, Qi Tang, and Takanobu Yamaguchi
- Subjects
- *
GENERAL circulation model , *STRATOCUMULUS clouds , *MARINE biodiversity - Abstract
In this paper we develop a novel framework aimed to significantly reduce biases related to marine stratocumulus clouds in general circulation models (GCMs) while circumventing excessive computational cost requirements. Our strategy is to increase the horizontal resolution using a regionally refined mesh (RRM) over our region of interest in addition to using the Framework for Improvement of Vertical Enhancement (FIVE) to increase the vertical resolution only for specific physical processes that are important for stratocumulus. We apply the RRM off the coast of Peru in the Southeast Pacific, a region that climatologically contains the most marine stratocumulus in the subtropics. We find that our new modeling framework is able to replicate the results of our high resolution benchmark simulation with much fidelity, while reducing the computational cost by several orders of magnitude. In addition, this framework is able to greatly reduce the longstanding biases associated with marine stratocumulus in GCMs when compared to the standard resolution control simulation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
3. Investigation of Mesosphere and Lower Thermosphere Dynamics over Central and Northern Peru Using SIMONe Systems.
- Author
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Conte, J. Federico, Chau, Jorge L., Yiğit, Erdal, Suclupe, José, and Rodríguez, Rodolfo
- Subjects
MESOSPHERE ,THERMOSPHERE ,GENERAL circulation model ,GRAVITY waves ,MEDIAN (Mathematics) - Abstract
One year of Spread spectrum Interferometric Multistatic meteor radar Observing Network (SIMONe) measurements are analyzed and compared for the first time between two low-latitude locations in Peru: Jicamarca (12°S, 77°W) and Piura (5°S, 80°W). Investigation of the mean horizontal winds and tides reveals that mesosphere and lower thermosphere (MLT) planetary-scale dynamics are similar between these two locations, although differences can be seen in some tidal components, e.g., the diurnal tide. On the other hand, 28-day median values of the momentum fluxes obtained with 4-h, 4-km time–altitude bins indicate that the mesoscale dynamics differ significantly between Jicamarca and Piura, places separated by approximately 850 km. From the middle of July until October 2021, a strong acceleration of the background zonal wind by westward-propagating gravity waves (GWs) is observed above ∼90 km at both locations, although with larger amplitudes over Jicamarca. From the middle of January until April 2022, a second strong acceleration of the background zonal wind, again by westward-propagating GWs, is observed, but this time with larger amplitudes over Piura. The latter is further supported by the dominance of negative vertical gradients of the zonal momentum flux above 89 km of altitude. Thus, these results observationally confirm the previous studies based on general circulation model simulations indicating that the directions of the zonal GW drag and the zonal background wind coincide in the low-latitude MLT. The weak correlations between the horizontal wind gradients over Jicamarca and Piura reinforce the fact that the mesoscale dynamics are different at these two locations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. Integrated modelling of a megacity water system – The application of a transdisciplinary approach to the Lima metropolitan area.
- Author
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Schütze, Manfred, Seidel, Jochen, Chamorro, Alejandro, and León, Christian
- Subjects
- *
METROPOLITAN areas , *MEGALOPOLIS , *GENERAL circulation model , *WATER supply , *WATER , *OIL field brines , *GRAYWATER (Domestic wastewater) , *WATERSHEDS - Abstract
• Combining hydrology, social sciences and modelling leads to ownership of solutions. • Modelling, simulation and visualisation results in system understanding and awareness. • For Lima, a megacity with particular challenges, an Action Plan has been adopted. • Adaptation of the simulator and of the methodology developed to other regions is possible. The rapidly growing urban centres throughout the world are facing serious problems due to the fast-changing developments in all of their environmental spheres (nature, society, politics, culture and economics). Therefore, strategic planning becomes even more important in order to develop strategies that allow cities to adapt to new challenges and to prevent or to mitigate negative trends. This paper presents a transdisciplinary approach to water management, which combines adaptation and application of methods from hydrology, social sciences, water engineering and modelling; furthermore, this approach also involves stakeholders in this process. This methodology assists cities in addressing risks by elaborating solutions, which are characterised by ownership and acceptance of the stakeholders involved. The presented methodology proposed here has been applied to the water system of the desert megacity of Lima/Peru. As a city of almost 10 million inhabitants and with an annual rainfall of about 10 mm per year, Lima presents a unique case with particular challenges regarding water supply. In order to assess the changes in precipitation and temperature for the next decades, two global circulation models and three scenarios have been used. Changes in discharge was addressed using the conceptual rainfall-runoff model HBV applied in both the Atlantic and Pacific catchments relevant to the capital city Lima in terms of water supply. A scenario methodology, combining qualitative and quantitative elements, based on the Cross-Impact Balance Analysis, has been developed and applied. From the millions of theoretically possible combinations of future developments of "descriptors" (driving forces) of the water system, four have been identified as the (only) consistent potential developments of the future. Local stakeholders, stemming from a wide range of institutions have been actively involved in the definition of these driving forces and the set of scenarios. The evaluation of these scenarios and potential options to adapt the water system to future developments was carried out by modelling and simulation, using a purpose-built, yet general, simulator which represents the entire water and wastewater system and includes the important inherent feedback loops (e.g. water demand by irrigation, reuse of treated and untreated wastewaters). The setup of the simulator and the implemented models was done in a way that the simulator formed an integral element in the design of strategies and measures, derived by this innovative combination of qualitative scenario building, quantitative modelling and stakeholder participation. As a core result of this process, the Action Plan "Lima 2040" has been developed and adopted, in which the signatories (the main institutions and organisations responsible for the water sector of Lima) commit themselves to specific actions to be implemented over the years to come. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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