The largest warming over the last several decades has been observed in high latitudes. Cai (2005) proposed that part of the large amplitude climate warming in high latitudes could be explained by the "dynamical amplifier" feedback. This study will first provide observational and modeling evidences to validate the dynamical amplifier theory. The second part will address the question whether part of the differences in the CGCM's global warming projections can be explained by the dynamical amplifier theory. The theory predicts an upward trend of the net radiation surplus (deficit) in low (high) latitudes forced by anthropogenic greenhouse gases. The radiation budget at the top of the atmosphere (TOA) using the ERA40 reanalysis and climate model simulations forced by anthropogenic radiative forcings made at 14 climate centers were analyzed. The results indicate that both the radiation energy surplus in low latitudes and deficit in high latitudes at the TOA have been strengthened over the last several decades. Such an intensification of the radiation energy imbalance at the TOA is also confirmed by most of the climate model simulations. Furthermore, the analysis of the net radiation budget between the surface and the TOA confirms that the change in the TOA energy imbalance is indeed due to the upward trend in the poleward heat transport, in accordance with the dynamical amplifier theory. There is a large model-to-model variability of the intensification of the poleward heat transport among the 14 climate model simulations. It is found that about 59% of the global warming projection uncertainties, which varies from 1.5K to 4K, forced by the 2×CO2 forcing can be explained by the variation of the intensification of the poleward heat transport among models. The inter-model variability of the change in the poleward heat transport explains about 66% of the warming projection uncertainties for the Northern Hemisphere (NH) and 54% for the Southern Hemisphere (SH). The differences in the poleward heat transport intensification also explain about 71% and 49% of the warming uncertainties in the NH and SH high latitudes. Therefore, it can be concluded that a large part of the uncertainties in the CGCM's global warming projections can be explained by the dynamical amplifier theory. / A Thesis submitted to the Department of Meteorology in partial fulfillment of the requirements for the degree of Master of Science. / Summer Semester, 2005. / June 28, 2005. / Dynamical Amplifier Theory, High Latitude Warming, Models' Sensitivity, Global Warming, Heat Flux, Radiations, Top of the Atmosphere, Warming Projections, Models' Uncertainties, IPCC, Poleward Heat Transport / Includes bibliographical references. / Ming Cai, Professor Directing Thesis; Kwang-Yul Kim, Committee Member; Paul H. Ruscher, Committee Member.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_182254 |
| Contributors | Castet, Christelle Clémence (authoraut), Cai, Ming (professor directing thesis), Kim, Kwang-Yul (committee member), Ruscher, Paul H. (committee member), Department of Earth, Ocean and Atmospheric Sciences (degree granting department), Florida State University (degree granting institution) |
| Publisher | Florida State University, Florida State University |
| Source Sets | Florida State University |
| Language | English, English |
| Detected Language | English |
| Type | Text, text |
| Format | 1 online resource, computer, application/pdf |
| Rights | This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s). The copyright in theses and dissertations completed at Florida State University is held by the students who author them. |
Page generated in 0.0018 seconds