- 著者
- HAYNES Peter HITCHCOCK Peter HITCHMAN Matthew YODEN Shigeo HENDON Harry KILADIS George KODERA Kunihiko SIMPSON Isla
- 出版者
- Meteorological Society of Japan
- 雑誌
- 気象集誌. 第2輯 (ISSN:00261165)
- 巻号頁・発行日
- pp.2021-040, (Released:2021-03-24)
- 被引用文献数
- 31
Observational and model studies suggest that the stratosphere exerts a significant influence on the tropical troposphere. The corresponding influence, through dynamical coupling, of the stratosphere on the extratropical troposphere has over the last 15-20 years been intensively investigated, with consequent improvement in scientific understanding which is already being exploited by weather forecasting and climate prediction centres. The coupling requires both communication of dynamical effects from stratosphere to troposphere and feedbacks within the troposphere which enhance the tropospheric response. Scientific understanding of the influence of the stratosphere on the tropical troposphere is far less developed. This review summarises the current observational and modelling evidence for that influence, on timescales ranging from diurnal to centennial. The current understanding of potentially relevant mechanisms for communication and for feedbacks within the tropical troposphere and the possible implications of the coupling for weather and climate prediction are discussed. These include opportunities for model validation and for improved subseasonal and seasonal forecasting and the effects, for example, of changes in stratospheric ozone and of potential geoengineering approaches. Outstanding scientific questions are identified and future needs for observational and modelling work to resolve these questions are suggested.
- 著者
- JAIN Shipra CHHIN Rattana DOHERTY Ruth M. MISHRA Saroj K. YODEN Shigeo
- 出版者
- Meteorological Society of Japan
- 雑誌
- 気象集誌. 第2輯 (ISSN:00261165)
- 巻号頁・発行日
- pp.2021-021, (Released:2021-01-13)
Equilibrium climate sensitivity (ECS) is defined as the change in global-mean surface air temperature due to the doubling or quadrupling of CO2 in a climate model simulation. This metric is used to determine the uncertainty in future climate projections, and therefore the impact of model changes on ECS is of large interest to the climate modeling community. In this paper, we propose a new graphical method, which is an extension of the Gregory's linear regression method, to represent the impact of model changes on ECS, climate forcing and climate feedbacks in a single diagram. Using this visualization method, one can quantify (a) whether the model- or process-change amplifies, reduces, or has no impact on global warming, and evaluate (b) the percentage changes in ECS, climate forcing and climate feedbacks and (c) ranges of the uncertainties in the estimated changes. We demonstrate this method using an example of climate sensitivity simulations with and without interactive chemistry. This method can be useful for multi-model assessments where the response of multiple models for the same model experiment (e.g., usage of interactive chemistry as compared to the prescribed chemistry as shown here) can be assessed simultaneously, which is otherwise difficult to compare and comprehend. We also demonstrate how this method can be used to examine the spread in ECS, climate forcing and climate feedbacks with respect to the multi-model mean (or one benchmark model) for multi-model frameworks like Coupled Model Intercomparison Project Phase 5 or for different ensemble members in a large ensemble of simulations carried out using a single model.