Maybe the rain

Over at Chemtrails North NZ, Clare Swinney makes the claim that

Evidence suggests that rain clouds approaching Northland are being handicapped by human intervention, probably, in part, to promote the perception of “climate change.”

…and provides evidence of this by posting some satellite imagery of cloud cover covered in arrows pointing to (supposedly) man-made ‘holes’, which are (presumably) evidence of manipulation.

Putting aside the problem that the water in these holes still has to go somewhere, and that there’s still millions of tonnes of water left in the remaining cloud cover, the main problem with Clare’s argument is that her main point…

Rainfall levels appear to being reduced significantly.

…is plain wrong. Here’s the last two years of rainfall data from Whangarei Airport, measured against the historical average.


In fact, in the last five months, rainfall figures have been above or about average. June, July and August were really wet: double the average.  Before that March/April/May were drier than usual (May especially so), but that was after a wet February. And before that, a dry January, and a slightly above-average December. In other words, natural variability at play. There’s certainly no way you could make the argument that rainfall levels have been ‘reduced significantly’.

Well, I suppose you could, but…

Chemcloud v. Cirrus

cirrus-v-chemcloudsOn the left, chemclouds over Nelson as spotted by Ngaire Smith, and posted on Clare Swinney’s Northland NZ Chemtrail watch site.

On the right, cirrus clouds as documented in the 1896 publication Atlas international des nuages (International Cloud Atlas)

(See also this image containing a drawing of cirrus, from 1815’s Researches about Amospheric Phaenomena)

Learn the difference!

Chemtrail formation on a warm day

One of the requirements for contrail formation is cold air with high humidity. So, Angela Truman makes an interesting observation over on the Chemtrails over NZ facebook group


Putting aside for the moment the concept that 21ºC is ‘hot’, she does seem to have a point. If it’s too hot for contrails, then surely the trails spotted must be chemtrails.

But how hot was it at flight altitude? It does, after all, get a lot colder as you go higher. Luckily, it seems there are a few websites that collate and display the upper air readings made around NZ each day. I assume the source is the MetService upper air data, but their display of the data is unreadable, and learning how to interpret Met VUWs tehphigrams is something I’m going to put aside for another day. The best place I could find that displays the data in nice human-readable format was (of all places) the University of Wyoming’s Department of Atmospheric Sciences, where you can plug in a station code to get the corresponding data back.

Here’s the two readings from Paraparaumu (closest station to Wellington) for that day (one in the morning, one in the evening). As you can see on the 21Z reading, when it’s nearly 21 degrees at ground level, it’s actually somewhere between -35ºC and -50ºC up at flight altitudes. Cold enough for contrails to form?

I looked around the NZ chemtrails sites to find out the best way to interpret these results, and found that Clare Swinney recommends the use of the Appleman Chart — a simple enough chart that allows you to determine the likelihood of contrails forming given various altitude/temperature/pressure/humidity combinations). Again, an excellent tool for determining what might and might not be a chemtrail — if the conditions aren’t right, a contrail can’t form, therefore what’s left is mostly likely a chemtrail! So, plotting those numbers from a typical cruising altitude of 35000ft (250hPA, -46.9ºC, 27% rel/humidity), we get…

appleman… ‘maybe contrails’.