Assessing the Impact of Parameterized Gravity Wave Drag on Climate Change Forecasts: A Systematic Investigation with Global Circulation Models

评估参数化重力波阻力对气候变化预测的影响：全球环流模型的系统研究

• 批准号: 0938325
• 负责人: Edwin Gerber
• 金额: $ 37.59万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0938325&HistoricalAwards=false
• 关键词: Assessing; Impact; Parameterized; Gravity; Wave

This project seeks to understand and quantify the uncertainty associated with gravity wave drag (GWD) parameterization in climate models, particularly for climate change forecasts. Gravity waves influence the global circulation of the atmosphere by transporting momentum between and within the troposphere and stratosphere, but are too small to be adequately resolved in state-of-the-art climate models. Hence their effects are estimated, or parameterized, based on the resolved variables of the model. Recent studies have demonstrated that uncertainty in how GWD is parameterized has a first order impact on both the tropospheric and stratospheric response to anthropogenic forcing. Existing studies of parameterizations, largely performed "offline" with fixed background winds, are insufficient to quantify these uncertainties, as the impact of GWD is amplified by interaction with synoptic and planetary waves. To redress these concerns, the investigators will establish a framework for testing GWD parameterizations in an idealized general circulation model (GCM).The idealized GCM captures the stratospheric and tropospheric circulation with fidelity, but with computational efficiency that permits us to systematically assess the impact of GWD parameters on a changing climate, driven both by trends in the troposphere (i.e. tropical upper tropospheric warming) and stratosphere (i.e. the cooling/heating of the polar vortex associated with ozone loss/recovery). The investigators will use the model to understand the influence of GWD on (1) trends in the tropospheric circulation, in particular shifts in the extratropical jet streams, (2) trends in the stratospheric circulation, in particular the Brewer-Dobson Circulation, and (3) stratospheric climate and variability.The broader impacts of the research are (1) to help improve understanding and confidence in climate change forecasts, (2) to educate and mentor students at the undergraduate and graduate level, and (3) to provide a more general understanding of climate forecasting. The inherent uncertainty in climate prediction is a significant problem for the scientific community in communicating with the public. This project provides a case study in how models (in particular GCMs) can be used to quantify uncertainty, and used for outreach directed at undergraduate students.

该项目旨在了解和量化气候模式中与重力波阻力参数化相关的不确定性，特别是用于气候变化预测。重力波通过在对流层和平流层之间和内部输送动量来影响全球大气环流，但由于太小，无法在最先进的气候模型中充分解决。因此，根据模型的解析变量估计或参数化它们的影响。最近的研究表明，如何参数化GWD的不确定性对对流层和平流层对人为强迫的响应具有一阶影响。现有的参数化研究，主要是执行“离线”与固定的背景风，不足以量化这些不确定性，因为全球变暖的影响是放大的天气和行星波的相互作用。为了解决这些问题，研究人员将建立一个框架，用于在理想化的大气环流模式（GCM）中测试GWD参数化。理想化的GCM逼真地捕捉平流层和对流层环流，但计算效率使我们能够系统地评估GWD参数对气候变化的影响，受对流层（即热带对流层上部变暖）和平流层（即与臭氧损失/恢复有关的极涡冷却/加热）趋势的驱动。研究人员将利用该模型了解GWD对（1）对流层环流趋势，特别是对流层外急流的变化，（2）平流层环流趋势，特别是Brewer-Dobson环流，以及（3）平流层气候和变率的影响。该研究的更广泛影响是（1）有助于提高对气候变化预测的理解和信心，（2）教育和指导本科生和研究生水平的学生，（3）提供对气候预测的更全面的理解。气候预测中固有的不确定性是科学界与公众沟通的一个重大问题。该项目提供了一个案例研究模型（特别是大气环流模型）如何可以用来量化不确定性，并用于针对本科生的推广。