Collaborative Research: Global Cloud Climatology from Surface Observations: Analyses and Decadal Update

学术价值：一项关于各种云的全球分布及其季节和日变化的研究，以及一项关于云在过去半个世纪中如何变化的研究，正在进行中。正在建立数据库，旨在有助于澄清云与气候系统其他组成部分的相互作用，并推断云辐射强迫的变化。对于涉及云的全球变化研究，有长期的全球覆盖记录和一致的观测程序是必要的。从陆地观测站和海洋船舶对云进行的常规地面天气观测满足这些要求。在美国国家科学基金会之前的两笔拨款下，ppi已经制作了一份气气学，包括1952-1997年海洋和1971-1996年陆地上的5度和10度网格箱的云型数量，按季节和按月计算，每天8次。对于这个更新的研究项目，这两个数据库将以1997-2006年十年的云观测资料进行更新。还将作出安排，在本项目结束后继续定期更新海洋云观测数据库。陆地和海洋的年际变化和趋势分析将更新到2006年。将进行若干研究以检查这些数据的特征：描述日周期，比较白天趋势与夜间趋势，比较岛屿观测与附近船只的观测，量化区域和全球时间序列的不确定性，调查北极云的年际变化和趋势，并确定云底高度与海面温度的关系。更广泛的影响：这项研究的更广泛的影响是在气候研究领域。在这个项目下产生的数据库将广泛分发，供科学界使用。它们将在气候建模、云过程研究以及气候变化的探测和归因方面得到应用。

Intellectual merit: A study of the global distribution of the various cloud types and their seasonal and diurnal variations, as well as a study of how clouds have changed in the past half-century, are underway. Databases are being created that are designed to be useful in clarifying the interactions of clouds with other components of the climate system and to infer changes in cloud radiative forcing. For global-change studies involving clouds, a long period of record with global coverage and with consistent observing procedures is necessary. Routine surface weather observations of clouds from land stations and from ships in the ocean meet these requirements. Under two previous NSF grants the PIs have produced a climatology of cloud-type amounts for 5-degree and 10-degree grid boxes, seasonally and monthly, for eight times per day for the years 1952-1997 over the oceans and 1971-1996 over land. For this renewed research project, both databases will be updated with cloud observations for the decade 1997-2006. Arrangements will also be made for continuation of routine updating of the cloud-observations database for the ocean after termination of this project. The analysis of interannual variations and trends for land and ocean will be updated to 2006. A number of studies will be done to examine characteristics of the data: describing diurnal cycles, comparing day trends to night trends, comparing island observations to those of nearby ships, quantifying uncertainties in regional and global time-series, investigating interannual variations and trends of Arctic clouds, and determining the relation of cloud base height to sea-surface temperature. Broader impact: The broader impact of the research is in the area of climate research. The databases produced under this project will be distributed widely for use by the scientific community. They will find applications in climate modeling, cloud process studies, and in detection and attribution of climate change.