weather & climate

If the temperature is low enough or the humidity high, you can observe condensation (i.e., "fog") forming in your exhaled breath. This calculator estimates whether your exhaled breath will condense, and if so, the range of mixing ratios for which the "fog" will form and the maximum condensed water content (the higher it is, the "thicker" the condensation).

If you're interested, there is a much more detailed explanations of the condensation process.

Exhaled Condensation Calculator
Using the above equations, we can calculate whether the exhaled air will condense. Enter the conditions of the outside air (and modify the exhaled air parameters if you wish), to see whether your breath will condense, or not.

Based on the analysis of whether falling snow will melt as it descends, it is possible to estimate the probability with which falling precipitation will be snow.

Did you ever wonder how can it snow at above freezing temperatures? Well, the naive explanation is that it simple takes time for the snowflakes to melt once they penertrate above freezing air, as they descent downwards to the ground. As it turns out, this is the reaons why hail can fall in warm weather. The hail stones simple fall fast, too fast to let the warm air melt the hail.

With snow flakes, this isn't the case. The flakes fall very slowly and the large surface to volume ratio ensure that the flakes can reach thermal equilibrium with the environment on time scales much shorter than their descend time. So, how can the flakes remain frozen as they fall?

A quick review of the cosmic ray / climate link.

Is 20th century global warming due to anthropogenic sources (i.e., greenhouse gasses) or natural variability? Find out here.

On long time scales, it appears that our journey through the Milky Way is responsible for large climate variations. Each time we pass through spiral arms of the galaxy, we witness a higher flux of cosmic rays, which in turn reduce the global temperature. Read more about the effect and the evidence in this article.

Under which conditions can you get frost dendrites on your window?

Ever wondered why and when does your exhaled breath condense?