Global Distrubution of Diurnal Cycles and Long-term in Cloud Amounts from Surface Observations

华盛顿大学斯蒂芬·沃伦的ATM-9510170摘要标题：来自地面观测的云量的日周期和长期变化的全球分布对地球的辐射收支有很大的影响，无论是短波还是长波。这些影响对于不同的云型是不同的，净强迫通常会在白天和晚上改变符号。研究云在过去是如何变化的，可能有助于澄清云与气候系统其他部分的相互作用，并推断云辐射强迫的变化。对于涉及云的全球变化研究，有必要有一个覆盖全球、观测程序不变的长时间记录。大约从1952年开始从海洋中的船只和1971年开始从陆地站对云进行常规的地面天气观测，满足了这些要求。建议建立数据库并对这些数据库进行分析，以确定过去40年来云类型及其日循环的变化。陆地和海洋的地面天气观测以前被用来产生总云量类型的全球气候学，涵盖海洋上1952-1981年的30年期间和陆地上1971-1981年的11年期间。这些结果发表在一系列四个气候地图集上，这些地图集在气候研究中发现了许多用途。最近，对分析程序进行了改进，建立了夜间观测的照度标准。通过根据是否有足够的月光或黄昏来筛选夜间观测，可以获得更准确的云量日循环。这一照度标准将用于确定云类型数量的地理分布、其日变化、年际变化和长期趋势。白天和夜间的趋势将分别分析，因为云辐射强迫在白天通常是负的，而在晚上是正的。这项研究包括建立一个由三个数据库组成的层次结构，用于云的气候分析，跨越1952-1996年的45年。(1)编辑的云报告档案(2)使用月光标准，对总云量和11种不同云型的平均云量和日周期进行全球分析。(3)对不同类型云量的年际变化和数十年趋势的地理分布进行全球分析(1954-1996年海洋云量；1971-1996年陆地云量)。这项工作很重要，因为云过程是气候变化中最重要的过程之一，有关云的长期数据对于改善对云过程的理解至关重要。该项目由NSF(ROCEW和地球系统数据库)全球变化倡议和NOAA全球计划办公室共同资助。

Abstract for ATM-9510170 Warren, Stephen, University of Washington Title: Global Distribution of Diurnal Cycles and Long-term Changes in Cloud Amounts from Surface Observations Clouds have large effects on the earth's radiation budget, both shortwave and longwave. These effects are different for different cloud types, and the net forcing usually changes sign from day to night. A study of how clouds have changed in the past may help to clarify the interactions of clouds with other parts of the climate system and to infer changes in cloud radiative forcing. For global-changes studies involving clouds, a long period of record with global coverage and with no change in observing procedures is necessary. Routine surface weather observations of clouds, beginning about 1952 from ships in the ocean and 1971 from land stations, meet these requirements. Creation of databases and analyses of those databases are proposed to determine the changes of cloud types and their diurnal cycles over the past 40 years. Surface weather observations from land and sea have previously been used to produce a global climatology of total cloud cover type amounts, covering the 30-year period 1952-1981 over the ocean and the 11-year period 1971-1981 over land. These results were published in a series of four climatic atlases, which have found numerous uses in climatic research. Recently an improvement to the analysis procedure has been developed establishing an illuminance criterion for nighttime observations. By screening nighttime observations based on the availability of sufficient moonlight or twilight more accurate diurnal cycles of cloud amounts can be obtained. This illuminance criterion will be used to determine the geographical distribution of cloud type amounts, their diurnal variations, interannual variations, and long-term trends. The trends will be analyzed separately for day and night, since cloud radiative forcing is generally negative in daytime but positive at night. The research consists of the creation of a hierarchy of three databases for climatic analyses of clouds, spanning the 45 years 1952-1996. (1) Edited Cloud Reports Archive (2) Global analysis of the average amounts and diurnal cycles of total cloud cover and eleven different cloud types, using the moonlight criterion. (3) Global analysis of the geographical distribution of interannual variations and multi-decadal trends in amounts of the different cloud types (1954-1996 for ocean; 1971-1996 for land). This work is important because cloud processes are among the most important in climate change and long-term data about clouds are essential to an improved understanding of cloud processes. This project is co-funded by NSF (ROCEW and Geosystem Databases) Global Change initiatives and NOAA's Office of Global Programs.