Status: this discussion paper is a preprint. It has been under review for the journal Climate of the Past (CP). The manuscript was not accepted for further review after discussion.
Permian Megamonsoon Sensitivity to Paleo-Tethys Warm Pool:
Model Simulations using CCSM3
Christine A. Shieldsand Jeffrey T. Kiehl
Abstract. Simulations of the late Permian (251Ma) are analyzed with respect to the northern hemispheric Pangean megamonsoon. We find that the presence and spatial distribution of the warm pool, and not land-sea temperature differences, are the primary forcing agents for the megamonsoon. The land-sea temperature gradient, as a monsoonal mechanism, is tested by eliminating the Cathyasian peninsula and is found to have little impact on the spatial character of the monsoon. Furthermore, the response of the monsoon to the warm pool was tested by removing all Paleo-Tethys equatorial islands, which allows the warm pool to expand and migrate westward thus shifting the pattern of monsoonal precipitation. Additionally, different CO2 regimes are presented, in which a 10-fold change in forcing produces diverging climates and therefore different warm pool and monsoon locales. Atmospheric mass flux for the monsoonal regime is characterized and shown to change with warm pool movement. Tropical and equatorial ocean currents impact the seasonal progression and location of the warm pool. Experiments were conducted using the low-resolution version of Community Climate System Model, Version 3 (CCSM3) in both coupled and fixed sea surface temperature (SST) context. For validation purposes, a modern control is briefly presented with observations and is shown to represent both the spatial and seasonal progression of the Indian monsoon.
How to cite. Shields, C. A. and Kiehl, J. T.: Permian Megamonsoon Sensitivity to Paleo-Tethys Warm Pool:
Model Simulations using CCSM3, Clim. Past Discuss. [preprint], https://doi.org/10.5194/cp-2017-42, 2017.
Received: 06 Mar 2017 – Discussion started: 03 Apr 2017
The megamonsoon is analyzed for the late Permian (~251Ma) period in Earth's deep climatic past using a sophisticated global climate model that simulates interactions between the atmosphere, ocean, land, and sea ice. We show the location of the megamonsoon is dependent on the location of the warmest sea surface temperatures in tropical and subtropical regions and not the land-sea temperature gradient by performing experiments with geography that impact both atmospheric and oceanic simulations.
The megamonsoon is analyzed for the late Permian (~251Ma) period in Earth's deep climatic past...