EAPS
PAOC Colloquium: Liz Moyer (University of Chicago)
| Date |
Time |
Location |
| February 12th, 2018 |
12:00pm-1:00pm |
54-915 |
Using in-situ measurements of the water vapor isotopic ratio to understand convective transport in the Asian Summer Monsoon
The Asian monsoon is one of the worldâs largest weather systems, and is often claimed to be a significant pathway by which water enters the stratosphere. Satellite measurements of water vapor isotopic ratio, a strong tracer of convective origin, have howeversuggested significant differences in transport behavior between the Asian and North American monsoons, with strong isotopic enhancement, occurring only over North America. We report here on preliminary results from the July/August 2017 StratoClim campaign,in which instruments aboard the high-altitude M-55 Geophysica aircraft made the first in-situ tracer measurements in the upper troposphere/lower stratosphere region over the Asian Monsoon. The payload included the new Chicago Water Isotope Spectrometer (Chi-WIS),which measures HDO and H2O; its measurements confirm the distinct isotopic signature of the Asian monsoon. Both isotopic and other tracers suggest a reason: while the Asian monsoon experiences frequent convective up to 400 K potential temperature, there appearsto be limited overshoot above this level. Convection-driven water vapor perturbations from the Asian monsoon may therefore provide only a limited contribution to the overall stratospheric water budget.