Inland Penetration of Atmospheric Rivers
Abstract
Precipitable water derived from GPS zenith delays is used to study the onshore penetration of enhanced moisture associated with landfalling atmospheric rivers. Precipitable water is the integral of the water vapor density from the surface to the top of the atmosphere, so its value is dependent on the elevation of the observation site, consequently inland locations, which are typically higher than coastal locations, will typically have lower values of precipitable water. This elevation dependence makes it more difficult to determine the inland penetration of the enhanced moisture associated with atmospheric rivers. Here we use two quantities that partially obviate this problem by normalizing the observed values: (1) the normalized precipitable water index (NPWI) defined by Zeng and Lu, and (2) a Z score that is modified for the lognormal distribution typical of precipitable water. Using these quantities improves the ability to resolve the inland penetration of atmospheric river moisture, and shows that areas along the coast are still relatively enhanced with respect to inland areas.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.A11A0045M
- Keywords:
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- 0394 ATMOSPHERIC COMPOSITION AND STRUCTURE / Instruments and techniques;
- 1220 GEODESY AND GRAVITY / Atmosphere monitoring with geodetic techniques;
- 1895 HYDROLOGY / Instruments and techniques: monitoring;
- 3300 ATMOSPHERIC PROCESSES