My crystal ball model says Noctilucent clouds, which we have almost no data on, must be man-made!



Scientists wondered whether climate change was affecting super high clouds that people rarely see and there is virtually no data on. So they used models which fail on clouds and water vapor only ten kilometers above the Earth and tried to predict what happened to both way up at 80 kilometers up and 150 years ago. They “found” (their phrase, not mine) the increase was man made. So once again, your car exhaust and dinner steak are to blame for changing these night-shining clouds.

How could it be any other way?

This is pure crystal ball science that starts with errors and ends with extrapolations. Researchers are fooling themselves using words like “results”, “indicator” and “significant” as if this was an actual experiment.

PUBLIC RELEASE: 2-JUL-2018

Climate change is making night-shining clouds more visible

AMERICAN GEOPHYSICAL UNION

WASHINGTON — Increased water vapor in Earth’s atmosphere due to human activities is making shimmering high-altitude clouds more visible, a new study finds. The results suggest these strange but increasingly common clouds seen only on summer nights are an indicator of human-caused climate change, according to the study’s authors.

Noctilucent, or night-shining, clouds are the highest clouds in Earth’s atmosphere. They form in the middle atmosphere, or mesosphere, roughly 80 kilometers (50 miles) above Earth’s surface. The clouds form when water vapor freezes around specks of dust from incoming meteors. Watch a video about noctilucent clouds here. [Or not, there is no link? - Jo]

Humans first observed noctilucent clouds in 1885, after the eruption of Krakatoa volcano in Indonesia spewed massive amounts of water vapor in the air. Sightings of the clouds became more common during the 20th century, and in the 1990s scientists began to wonder whether climate change was making them more visible.

Or was it just that there were six billion more people to notice the noctilucents? Who can tell?

In a new study, researchers used satellite observations and climate models to simulate how the effects of increased greenhouse gases from burning fossil fuels have contributed to noctilucent cloud formation over the past 150 years. Extracting and burning fossil fuels delivers carbon dioxide, methane and water vapor into the atmosphere, all of which are greenhouse gases.

Why bother with satellites, we can just simulate space and history…

In the new study, Lübken and colleagues ran computer simulations to model the Northern Hemisphere’s atmosphere and noctilucent clouds from 1871 to 2008. They wanted to simulate the effects of increased greenhouse gases, including water vapor, on noctilucent cloud formation over this time period.

Who needs observations?

“We speculate that the clouds have always been there, but the chance to see one was very, very poor, in historical times,” said Franz-Josef Lübken, an atmospheric scientis t at the Leibniz Institute of Atmospheric Physics in Kühlungsborn, Germany and lead author of the new study in Geophysical Research Letters, a journal of the American Geophysical Union.

The researchers found the presence of noctilucent clouds fluctuates from year to year and even from decade to decade, depending on atmospheric conditions and the solar cycle. But over the whole study period, the clouds have become significantly more visible.

Over the whole study period? Meaning during the last ten minutes…

Read the introduction of the paper. “Little is known”, “observations are rather challenging” but there is a consensus…

Noctilucent clouds (NLC), also called polar mesospheric clouds (PMC), are made of water ice particles, which are sporadically observed by the naked eye at midlatitudes when these particles are illuminated by the Sun when it is several degrees below the horizon (Gadsden & Schröder, 1989). NLC can exist around the summer mesopause at middle and high latitudes since this region is extremely cold (130–140 K), actually being the coldest place in the Earth’s atmosphere (Lübken, 1999). Some scientists claim that NLC are sensitive indicators for climate change due to a combination of cooling and/or an increase of water vapor (Hervig, Berger, & Siskind, 2016; Russell et al., 2015; Thomas, 1996, 2003; Thomas et al., 1989). This has been questioned because the database regarding long-term trends of NLC is still rather poor and too little is known about long-term trends and episodic changes of the background atmosphere at these altitudes (Thomas et al., 2003; von Zahn, 2003; von Zahn et al., 2004). Observations in the upper mesosphere/lower thermosphere region are rather challenging. Very little is known about trends of basic parameters such as temperature and water vapor mixing ratio on centennial time scales. There is general consensus that an increase of greenhouse gases causes a cooling of the mesosphere due to an enhanced escape of infrared photons to space. There is one exception, however, namely, the summer mesopause region, where this effect is compensated for by increased absorption of photons from lower altitudes. Therefore, trends in this height region are very small (negative) or even positive (Berger & Lübken, 2011; Garcia et al., 2007; Marsh et al., 2013; Roble & Dickinson, 1989). Furthermore, it was shown recently that trends are not uniform in time but show episodic modulations (Lübken et al., 2013).

REFERENCE

This paper is freely available for 30 days. Journalists and public information officers (PIOs) can download a PDF. [Today I'm a PIO -- Jo]. Multimedia accompanying this press release can be downloaded.

Images supplied. Credit: Leibniz Institute of Atmospheric Physics

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