Shop Windows to the Universe

Arches National Park Geology Tour provides an extensive, visually rich description of the geology of Arches, by Deborah Ragland, Ph.D. See our DVD collection.

    Courtesy of Dara Salcedo

From: Dara Salcedo
T0, March 15, 2006

The other side of the wall

As I promised in my last postcard, I am showing what is in "the other side of the wall". We have several instruments to measure particle properties, all of the them connected to the inlet. The one on the left is called a SMPS (Scanning Mobility Particle Sizer). The SMPS measures the number of particles in ambient air as a function of particle size. On the left, there is another similar instrument called nano-SMPS, which measures the number of the very small particles (in the nanometer range). There is also a CCN counter. CCN stands for "cloud condensation nuclei" and refers to those particles that can grow and become clouds. Finally, in front of the table, we have an AMS (Aerosol Mass Spectrometer), which measures the composition of the particles. The data from the instruments is automatically saved in computers so it can be analyzed later. Most of the instruments belong to Prof. Jose Luis Jimenez from the University of Colorado at Boulder.

We have been recording data from all the instruments continuously for the last four days. The air has been very dirty with episodes of high concentrations of organic compounds, probably due to fires occurring around Mexico City.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Light extinction of particles

Not all particles are the same, many of them have different shape, size, and composition. Some of them reflect or scatter light, and others absorb it. Two instruments on the image, photometer and nephelometer,...more

What does Tecamac mean?

Measuring site T1 is in Tecámac. This is a little town close to Mexico City. The name Tecámac is a Náhuatl word, an ancient Mexico's language, spoken by Aztecs. In Náhuatl, Tetl or Tec means stone, camatl...more

Peroxides Measured at the T1 Site

Hello again: We are nearing the end of our field campaign in Mexico. It has been a real adventure, with friendly people, great food, and interesting science. I obtained some good hydrogen peroxide measurements...more

Cerro del Chiquihuite

Here is an example of how polluted the City is. This is a picture of "Cerro del Chiquihuite", which is situated around 5km (3miles) north from us. Chiquihuite is very close, indeed. However, we can barely...more

Ruins at Zempoala

On one of our down days, we took a little trip to a small town about 20 km from Veracruz. In the little town of Zempoala (also called Cempoala), there is a large area of partially restored ruins of ancient...more

T0

This is a picture of the site where I am going to be measuring particles (I am in the room on the top of the building). We call it T0 because it is inside of the city and we can consider that the pollutants...more

Boxes

Our boxes crossed the border yesterday and, after a 15 hours drive from Laredo, finally arrived this morning! The fun begins!!...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA