SURFACE TEMPERATURE OF THE GLOBAL OCEANS

由于对气候变化的担忧，我们需要更准确地了解地球表面温度是如何变化的。由于地球大部分地区被水覆盖，海洋温度是全球温度的主要组成部分。但大片海洋很少有船只或浮标访问，测量的也很少，所以从太空卫星上的红外传感器估计海表面温度(SST)对于了解全球情况至关重要。然而，卫星SST容易出现误差(偏差)，这意味着它们还不够稳定，不能用来研究十年温度趋势。自1991年以来，一系列传感器(沿航迹扫描辐射计，简称ATSR)已在欧洲卫星上飞行。这些传感器经过了更仔细的校准，比任何类似的仪器都更稳定。近年来，仔细的研究表明，如何从ATSR获得SST，我们可以确信这些ATSR在全球范围内的偏差小于十分之一度。值得注意的是，这是通过对基于辐射物理及其与物质相互作用的ATSR观测进行计算机模拟来实现的。这是有用的，因为它使人们相信ATSR SST估计在全球范围内是有效的，即使在几乎没有直接测量可供对照的地区也是如此；这与其他不独立于直接测量的卫星SST形成了对比。在这个项目中，来自ATSR的观测将使用新的最先进的技术重新处理，这些技术旨在最大限度地减少错误，并在错误仍然存在的情况下，彻底了解这些错误。我们希望我们最终获得的海温足够稳定、准确和独立，可以用于气候研究。我们创建的新的SST记录将显著改善我们对数据稀疏海域变化的评估；在通过航运等方式测量温度的地区，新的卫星SST甚至可以让我们深入了解这些直接测量中的误差。我们将创建所有SST观测的新综合体，包括新的卫星SST。这将在哈德利中心使用，以修订近几十年来对全球气候变化模式和速度的最佳估计，并更好地将观察到的气候变化归因于其原因。这些结果在各种情况下都是有用的。它将允许政府在更好的气候变化信息的基础上制定政策，并将纳入关于气候变化科学的政府间评估。海洋表面温度对皇家海军规划作战很有用，因为作战可以在世界任何地方进行。科学家将使用SST来研究大气和海洋之间的热量和气体转移。海洋预报中心使用船舶等对SST的测量，以使其海洋模型与现实保持一致，因此，更好地了解该项目这些输入中的误差也将有助于海洋预报。

We need to know more accurately how the surface temperature of Earth is changing, because of concerns about climate change. Since most of Earth is covered in water, ocean temperatures are a major component of global temperatures. But vast areas of ocean are rarely visited by shipping or buoys and are sparsely measured, so estimates of sea surface temperature (SST) from infrared sensors on satellites in space are essential to getting a global picture. Satellite SSTs, however, are prone to errors (biases) that mean they have not been stable enough to use to study decadal temperature trends. Since 1991, a series of sensors (the Along Track Scanning Radiometers, or 'ATSRs') have been flown on European satellites. These sensors have been more carefully calibrated and are more stable than any similar instruments. Over recent years, careful research has shown how to obtain SSTs from the ATSRs that we can be confident have biases less than about one tenth of a degree globally. Remarkably, this has been done by performing computer simulations of ATSR observations based on the physics of radiation and how it interacts with matter. This is useful, because it gives confidence that the ATSR SST estimates are valid globally, even in regions where there are few direct measurements available to check them against; this is in contrast to other satellite SSTs that are not independent of direct measurements. In this project, the observations from the ATSRs will be re-worked using new state-of-the-art techniques, which are aimed at minimizing errors, and, where errors remain, understanding those errors thoroughly. We expect the SSTs we finally obtain to be sufficiently stable, accurate and independent to be used for climate research. The new SST record we create will significantly improve our assessment of changes in data-sparse seas; and in regions where temperatures are measured by shipping, etc, the new satellite SSTs may even be able to give us insight into the errors in these direct measurements. We will create a new synthesis of all SST observations, including the new satellite SSTs. This will be used at the Hadley Centre to revise the best estimates of the global pattern and rate of climate change over recent decades, and to better attribute observed climate change to its causes. These results will be useful in various contexts. It will allow government policy to be formulated on the basis of better information about climate change, and will feed into intergovernmental assessments about climate change science. Marine surface temperatures are useful to the Royal Navy for planning operations, which can be anywhere in the world. The SSTs will be used by scientists looking at the transfer of heat and gases between the atmosphere and ocean. Ocean forecasting centres use measurements of SST by ships, etc, to keep their ocean model on track with reality, so better understanding of the errors in these inputs from this project will benefit ocean forecasting too.