Terrain‐Enhanced Precipitation Processes Above the Melting Layer: Results From OLYMPEX
Autor: | S. R. Brodzik, T. M. Schuldt, Lynn A. McMurdie, Joseph P. Zagrodnik, Angela K. Rowe, Robert A. Houze |
---|---|
Rok vydání: | 2018 |
Předmět: |
Atmospheric Science
010504 meteorology & atmospheric sciences 0208 environmental biotechnology Terrain Precipitation orographic enhancement of precipitation 02 engineering and technology Atmospheric sciences 01 natural sciences Aerosol and Clouds law.invention Remote Sensing Altitude law Earth and Planetary Sciences (miscellaneous) Instruments and Techniques Precipitation‐radar Radar Research Articles 0105 earth and related environmental sciences Remote Sensing and Disasters Synoptic‐scale Meteorology Atmospheric river 020801 environmental engineering precipitation processes observations Geophysics 13. Climate action Space and Planetary Science Middle latitudes Atmospheric Processes Environmental science Hydrology Global Precipitation Measurement Natural Hazards radar reflectivity Water vapor Research Article midlatitude cyclones |
Zdroj: | Journal of Geophysical Research. Atmospheres |
ISSN: | 2169-8996 2169-897X |
Popis: | Enhancement of precipitation processes aloft over complex terrain is documented using reflectivity data from an S‐band scanning radar (NPOL) that was deployed on the west coast of Washington State during the Olympic Mountains Experiment (OLYMPEX). From November 2015 through mid‐January 2016, NPOL obtained high‐resolution data within sectors over the ocean and over the windward slopes of the Olympic Mountains. Contoured Frequency by Altitude Diagrams of radar reflectivity highlight a higher frequency of occurrence of larger reflectivities for all heights between 2 and 8 km over land compared to ocean, with the largest difference in the 4‐ to 6‐km range indicating a robust signature of enhancement aloft over the windward slopes. This enhancement pattern is found to some degree under all environmental conditions considered but is especially pronounced during periods of high vapor transport, high melting level height, southwest low‐level winds, and neutral stability. These conditions are generally associated with warm sectors of midlatitude cyclones and atmospheric rivers. Past studies have postulated that a secondary enhancement in reflectivity aloft was an intrinsic part of atmospheric river type systems. However, these results show that further significant enhancement of this signature occurs as deep moist‐neutral, high water vapor content flow is lifted when it encounters a mountain range. Reflectivity data from the dual‐precipitation radar aboard the Global Precipitation Measurement satellite also documents this reflectivity increase aloft over the Olympic Mountains compared to the adjacent ocean, showing the potential for Global Precipitation Measurement to provide reliable estimates of precipitation structure over remote mountainous regions. Key Points Enhancement of precipitation processes is found in radar reflectivity data above the melting level over complex terrainEnhancement aloft is especially pronounced during periods of high vapor transport, onshore flow, and neutral low‐level static stabilitySatellite‐borne radar detects this enhancement so that reliable estimates of precipitation over remote mountain regions are possible |
Databáze: | OpenAIRE |
Externí odkaz: |