Central Equatorial Pacific Experiment (CEPEX); An Airborne Experiment to Address Issues Concerning the Role of Cloud-Radiation Feedbacks in El-Nino and Global Warming

“恒温器假说”依赖于三个假设。首先，超级温室效应确实存在。卫星数据显示，在最温暖的海洋上方的大气非常潮湿，导致它捕获了海洋发射的大部分红外能量。此外，红外捕获（即温室效应）随着对流区海温的增加而急剧增加。这就产生了一种不稳定性，需要某种负反馈（例如恒温器）来保持海洋和大气目前的稳定状态。其次，存在一个阈值温度，超过这个阈值温度深层对流就开始了。第三，明亮的卷云顶，其高度达到16公里（55,000英尺），延伸超过数万平方公里，将大量的太阳能反射回太空，使海洋表面冷却，因此，恒温器。CEPEX的目标是测试恒温器假说，从而了解水蒸气温室效应、云辐射相互作用和蒸发在调节海温中的作用。CEPEX将部署三架飞机：一架高空飞机——在海拔55,000 - 60,000英尺的砧云上空飞行——收集云反射的太阳能、地表-大气系统辐射的红外能量以及卷云砧顶和砧底高度的数据；一架中间飞机——在3.5万至4万英尺的高空飞行——用于测量超级温室效应、砧云的能量调节以及水蒸气和温度的垂直分布；还有一架低空飞机，用来测量从大约150英尺的高度从海洋到大气的蒸发和热量释放。由于中心目标是测量海温差异的影响，飞行计划将跨越赤道太平洋中部，距离日期变更线两侧约700海里。该区域包含所需的海温范围，在日期变更线的西部和南部对流频繁，但在东部很少。测量辐射能的飞行将从斐济岛（17oS, 178oE）出发。斐济和赤道之间的区域也有较大的海温梯度，在27℃到30℃的期望范围内。将沿瑙鲁岛和圣诞岛之间的赤道进行蒸发测量。高空测量将在大约从1993年3月1日开始的一个月期间内进行。高级和中级飞机大约每隔一天飞行一次，每架总共飞行100小时。地面蒸发测量将由低空飞机在实验的前半部分进行。热带海温是如何被调节的，这个问题对于理解地球气候的总体调节是很重要的；特别是，在预计全球变暖的情况下，暖池区域的大气行为可能会变得更加广泛。

The "thermostat hypothesis" depends upon three postulates. First, a super-greenhouse effect exists. Satellite data reveal that the atmosphere over the warmest oceans is very humid, causing it to trap a significant fraction of the infrared energy emitted by the ocean. Furthermore, the infrared trapping - known as the greenhouse effect - increases very sharply with increasing SST in regions of convection. This creates an instability which requires some sort of negative feedback (e.g. thermostat) in order to keep the ocean and atmosphere in their present, stable state. Second, there is a threshold temperature above which deep convection begins. Third, bright cirrus anvils, which reach altitudes of 16 km (55,000 ft.) and extend over tens of thousands of square kilometers, reflect significant amounts of solar energy back to space so that the sea surface cools down, hence, the thermostat. The goal of CEPEX is to test the thermostat hypothesis and thus understand the role of the water vapor greenhouse effect, cloud-radiative interactions and evaporation in regulating SSTs. Three aircraft will be deployed in CEPEX: A high altitude aircraft - flying above the anvil clouds at altitudes of 55,000 - 60,000 feet - to collect data on solar energy reflected by clouds, infrared energy radiated by the surface-atmosphere system, and the top and bottom altitudes of the cirrus anvils; an intermediate aircraft - flying below the anvils at 35,000 - 40,000 feet - to measure the super-greenhouse effect, the energy regulation by anvil clouds, and the vertical distributions of water vapor and temperature; and a low altitude aircraft to measure the evaporation and heat release from the ocean to the atmosphere from an altitude of about 150 feet. Since the central objective is to measure the impact of SST differences, flight plans will span the central equatorial Pacific, about 700 nautical miles to either side of the date line. This region encompasses the desired SST range, with frequent convection west and south of the date line, but little to the east. The flights measuring radiant energy will originate from Fiji island (17oS, 178oE). The region between Fiji and the equator also contains large SST gradients in the desired range between 27oC and 30oC. Evaporation measurements will be made along the equator between Nauru Island and Christmas Island. The high altitude measurements will be made over a one month period beginning approximately March 1, 1993. The high and intermediate aircraft will fly about every other day for a total of 100 flight hours each. Surface evaporation measurements will be taken by the low-level aircraft during the first half of the experiment. The question of how tropical SSTs are regulated is important to understanding the regulation of the Earth's climate in general; in particular, the atmospheric behavior in the warm pool region may become more widespread in the event of anticipated global warming.