An Exploratory Study for Coupling Biota, Energy and the Hydrological Cycle in Simple Nonlinear Models of Planetary Climate

这是一项探索性的跨学科建议，旨在开发一类新的非线性0-D模型，称为动态面积分数模型(DAFMS)。它们被设计用来研究生物群、水文和碳循环、海洋和冰盖以及辐射能量平衡非线性耦合的类地系统的“生理学”。在此背景下，一个著名的模型是Watson和Lovelock(1983)的Daisyworld模型。最近，已经证明(Weber，J.Climate，2000)，当两种雏菊都存在时，雏菊世界中热量输送的参数化方法保持了与太阳辐射无关的平衡局地温度。对雏菊世界的其他严肃批评来自于这样一个事实，即它不包括与地球相似的气候的主要组成部分：1.它没有蒸发、降水和大气循环的水循环；2.它没有海洋；3.它没有冰盖；4.它不包含碳循环。DAFM专门设计用于将表面特性的动态变化与辐射和质量平衡以一种现实的方式相结合。这一目标是通过将盒子模型中区域的相对大小视为随着局部平衡的函数动态更新的预测域来实现的。将进行诊断性研究，以比较不同的参数化对雏菊世界和DAFM之间在温暖的太阳下行星温度动态平衡的影响。简单的非线性数学模型用途广泛，非常适合识别关键参数和反馈，以及模型预测和观测之间的差异，这在GCMS等复杂的气候模型中不是那么容易做到的。这项研究将作为向NSF提交一份为期三年的跨学科综合研究提案的基础。

9903125GuptaThis is an exploratory, interdisciplinary proposal to develop a new class of nonlinear 0-D models, called Dynamic Area Fraction Models (DAFMs). They are designed to investigate the 'physiology' of an Earth-like system in which the biota, the hydrological and carbon cycles, the oceans and ice caps, and the radiative energy balance are nonlinearly coupled. A well-known model on this context is the Daisyworld model of Watson and Lovelock (1983). Recently, it has been shown (Weber, J. Climate, 2000) that the method of parameterization of the heat transport in Daisyworld maintains equilibrium local temperatures independent of solar radiation when both species of daisy are present. Other serious criticisms of the Daisyworld come form the fact that it does not include the major components of an earth-like climate: 1. It has no water cycle with evaporation, precipitation, and atmospheric circulation; 2. It has no oceans; 3. It has no ice caps, and 4. It contains no carbon cycle. DAFMs are designed specifically to couple dynamic changes in surface characteristics to radiative and mass balances in a realistic way. This objective is accomplished by treating the relative size of regions in a box model as prognostic fields that update dynamically with functions of the local balances. Diagnostic studies will be carried out to compare the effect of different parameterizations on the homeostasis of planetary temperature under a warming sun between the Daisyworld and the DAFMs. Simple nonlinear mathematical models are versatile and ideal for identifying key parameters and feedbacks, and discrepancies between model predictions and observations, which is not so easy to do in complex climate models such as GCMs. This study would serve as a basis to submit a three-year comprehensive, interdisciplinary research proposal to NSF.