测量卫星的长期温度趋势是可能的,但困难由于各种各样的原因。这是正在进行的研究。简而言之:天气卫星建立测量,而不是气候。我们有大气层的卫星测量自1960年代以来,自1970年代末和操作。这些总是包括红外辐射计测量,这意味着,在原则上,我们可以构造一个表面(包括陆地和海洋)的记录和大气温度至少在过去的40年。传感器本身不是很复杂,但我们需要确定趋势很有信心对自己的不确定性、稳定性和inter-satellite可变性。如果你仅仅需要40年HIRS红外测量和阴谋,你不知道这些变化是由于大气或工具的变化。从2015年到2019年,我是[FIDUCEO] (http://www.fiduceo.eu/)项目的一部分,旨在带来的科学计量学测量(科学)卫星观测。在40年的AVHRR(对于海洋表面温度)或HIRS(大气温度和湿度)测量,仪器的16个不同的版本在一段40年。但AVHRR建于看云的照片。 If you look at pictures of clouds, the user doesn't care if one satellite has its pictures 0.5% brighter than the previous one. They just tweak their monitor a bit! But if you take the global climate system, then that corresponds to more than 1K temperature difference, which for the oceans, would be huge. In FIDUCEO, we aimed to: * Develop a metrology of Earth Observation * Produce *Fundamental Climate Data Records* (FCDRs) for various operational meteorological instruments in visible, infrared, and microwave, meaning: * Per-datum metrologically traceable uncertainty characterisation; * Per-datum information on correlation structures: which component of the error estimate cancels out when averaging and which component remains; * Harmonisation between the various satellite sensors. Here are 40 years of [HIRS](https://www.wmo-sat.info/oscar/instruments/view/183) (versions 2, 3, and 4), on which we tried to do some harmonisation. The top panel shows global average temperature per 24-hour period, as measured by chnanel 2 which peaks somewhere in the UTLS area: [![40 years of HIRS][1]][1] The different colours indicate different satellites. As you can see, there are both jumps between satellites, and trends within one satellite. Some of this is expected, as polar-orbiting sun-synchronous satellites have a drifting local equator crossing time, but some of it is due to instrumental problems. Some of those problems are captured by the structured uncertainty in the bottom panel, but not all of it. This is for a global average. To do this regionally would add additional complications. The [CLARREO](https://www.wmo-sat.info/oscar/satelliteprogrammes/view/21) programme is proposed to be the first in-orbit SI reference for accurate calibration. Had we had that for the past 40 years, our job would be easier. But CLARREO is still waiting for funding. So the answer to your question is: with what we have now — not good enough — yet. [1]: https://i.stack.imgur.com/AyHIE.png
Baidu
map