The precipitable water vapour (PWV) is the crucial parameter that determines the atmospheric transparency for sub-millimetre observations. At the APEX site on Llano de Chajnantor the amount of PWV is typically 1.0 mm and falls below 0.5 mm up to 25% of the time.
Check here the current weather conditions at the APEX site in Chajnantor: PWV, temperature, humidity, pressure, wind speed. Access also historical data…
To prepare the observations and make time estimates for different atmospheric conditions check our instrument setup tool, based on the ATM model .
You can find here an interface to check only the atmospheric transmission without the instrumental layouts.
Forecast and satellite imagery
Here there are some links to relevant weather forecasts
And here you find links to some interesting sites with relevant satellite images