Robots on the Roof

Hello, my name is Brent Holben. I'm the project scientist for the AERONET project and I'd like to welcome you all to Mount AERONET here on the top of building 33 where we provide calibration for all of our instruments that are in the network.

AERONET is a relatively small program that is designed to measure aerosol concentrations and properties from a ground-based network of sun photometers, these guys here, for primarily for validation of satellite retrievals of aerosols.

We know the energy at the top of the atmosphere. We're measuring it at the bottom of the atmosphere with these guys. We can actually point it at the sun. It has a filter wheel here that, uh, looks at nine spectral channels and we use that difference between the top and the bottom of the atmosphere to characterize the properties, as well as to measure the concentration of those aerosols.

Also, there is a very large land surface community that doesn't care anything about aerosols, but they want to see what's going on with the vegetation and surface characteristics. So, they need to remove the atmosphere.

So, the data from this basically provides that information to correct the satellite imagery so you can get a better view of the surface characterization. There's also the ocean community which is interested in ocean color and the concentration of chlorophyll and particulates in the water.

And aerosols contributed approximately 90% of the signals, so it's very important to very accurately remove the aerosol signal from that satellite ocean color signal.

All together, there are about 450 sites worldwide and they're very well distributed. In all kinds of ecosystems and all kinds of aerosol environments. And as satellites come and go, this project is simple enough and robust enough that it keeps producing more and more information at a higher and higher data rate, at a higher and higher distribution.

So, I suspect that in the long term, we're going to grow to several thousand instruments. And because it's a relatively inexpensive program, I think that the future bodes very well for providing more data for not just NASA, but the entire globe.