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dc.contributor.authorScaff, Lucia
dc.contributor.authorRutllant, José A.
dc.contributor.authorRahn, David A.
dc.contributor.authorGascoin, Simon
dc.contributor.authorRondanelli, Roberto
dc.date.accessioned2018-11-15T18:46:36Z
dc.date.available2018-11-15T18:46:36Z
dc.date.issued2017-02-24
dc.identifier.citationScaff, L., Rutllant, J. A., Rahn, D., Gascoin, S., & Rondanelli, R. (2017). Meteorological Interpretation of Orographic Precipitation Gradients along an Andes West Slope Basin at 30° S (Elqui Valley, Chile). Journal of Hydrometeorology, 18(3), 713-727.en_US
dc.identifier.urihttp://hdl.handle.net/1808/27363
dc.description.abstractTo better forecast streamflow and water resource availability, it is important to have an understanding of the meteorological drivers of the orographic precipitation gradient (OPG), especially critical in semiarid mountainous areas. Although forced ascent over topography typically results in precipitation increasing with altitude (positive OPGs), mean annual OPGs and especially OPGs associated with individual storms can change widely in magnitude and even sign. Precipitation measurements from the Elqui Valley in the semiarid Andes of Chile (30°S) reveal a mean annual OPG of 6.3 mm km−1 (millimeters of precipitation over kilometers in elevation) ranging from −42 to 52 mm km−1 for individual storms over the last 35 years (1979–2013). Reanalysis data and precipitation measurements are used to characterize the observed OPG in this region in relation with their synoptic-scale flow. It is found that the Froude number correlates positively with the OPG, reflecting stronger zonal winds and less static stability during storms that have positive OPGs. Altitude of the Andes barrier jet shows only a weak relationship with the OPG. Significant storms with positive OPGs are typically linked with an austral blocking of the westerlies and an equatorward migration of the midlatitude storm track. For negative OPGs, either a cutoff low or the northern edge of a surface migratory cyclone reaches the Elqui Valley in such a way that significant rainfall only occurs in the near-coastal region without major snowfall accumulation over the Andes.en_US
dc.publisherAmerican Meteorological Societyen_US
dc.subjectCutoff lowsen_US
dc.subjectOrographic effectsen_US
dc.subjectSynoptic climatologyen_US
dc.subjectCold Frontsen_US
dc.subjectPrecipitationen_US
dc.subjectValley/mountain flowsen_US
dc.titleMeteorological Interpretation of Orographic Precipitation Gradients along an Andes West SLope Basin at 30°S (Elqui Valley, Chile)en_US
dc.typeArticleen_US
kusw.kuauthorRahn, David
kusw.kudepartmentGeography and Atmospheric Scienceen_US
dc.identifier.doi10.1175/JHM-D-16-0073.1en_US
kusw.oaversionScholarly/refereed, publisher versionen_US
kusw.oapolicyThis item meets KU Open Access policy criteria.en_US
dc.rights.accessrightsopenAccessen_US


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