ATom-2 has started!
But if we have already completed 1 ATom, why do another one???????
The over-arching goal of this campaign (4 in total) is to investigate the seasonality of background air composition and seasonality in the transport of pollution through remote regions. Both of these goals relates to many long standing questions in atmospheric chemistry (think understanding pollution and climate change), and the ATom campaigns provides an excellent opportunity to probe our understanding of transport and remote chemistry.
Normally, as a community, we tend to focus in areas with high concentrations of gases because (a) it’s easier to measure (imagine trying to find 1 red M&M in a container with 100 M&M’s versus trying to find 1 red M&M in a container with 1,000,000 M&M’s–the latter is similar to the difficulty of the measurements we are doing in ATom) and (b) the interest, both as a community and for improving public health, is typically in these regions.
For ATom, the flight pattern is the same, to allow for comparison of each flight leg among the four seasons, and to increase the amount of measurements and statistics we have about the chemistry and transport. The first research flight is from the NASA DC-8’s home base, Palmdale, CA, to the equator, and back. This flight provides information about the transport of pollution over the Pacific to Central America, and to probe the difference in pollution between the Northern and Southern Hemisphere.
The two hemispheres have difference in pollution for two reasons: (1) the Southern Hemisphere has less people and cities, which reduces the amount of pollution, compared to the Northern Hemisphere; and, (2) the equator is like a large wall, due to the very moist, warm air around the equator rising, which slows down the mixing between the two hemispheres.
While collecting the data on the airplane (weeee riding on an airplane with other scientists and taking measurements), many of the scientists have already, very preliminary, observed differences between the flight yesterday and the flight we conducted ~6 months ago (winter (ATom-2) vs summer (ATom-1) for Northern Hemisphere and vice-versa for Southern Hemisphere). These differences will provide valuable information in improving our knowledge in remote chemistry during the seasons and transport during the seasons.
The next flight will be Sunday, to Alaska. I will post again after that flight.