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contributor authorMercer, Amanda
contributor authorChang, Rachel
contributor authorFolkins, Ian
date accessioned2019-09-19T10:04:12Z
date available2019-09-19T10:04:12Z
date copyright2/1/2018 12:00:00 AM
date issued2018
identifier othermwr-d-17-0189.1.pdf
identifier urihttp://yetl.yabesh.ir/yetl1/handle/yetl/4261190
description abstractAbstractMeasurements from the Aircraft Communications, Addressing, and Reporting System (ACARS) dataset between 2005 and 2014 are used to construct diurnal vertical cross sections of relative humidity in the lower troposphere at six airports in the U.S. Midwest. In summer, relative humidity maxima occur between 2 and 3 km during the overnight hours of 0300?0900 local solar time (LST). These maxima coincide with negative anomalies in temperature and positive anomalies in specific humidity. Vertical winds from the Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2), reanalysis dataset show that the height and diurnal timing of these positive relative humidity anomalies are consistent with the regional diurnal pattern of vertical motion. During the day, there is rising motion over the Rocky Mountains and subsidence over the Midwest, while conversely at night, there is sinking motion over the mountains and rising motion over the Midwest. The nocturnal relative humidity maxima over the Midwest are the strongest direct observational evidence to date of this mountain?plains solenoidal circulation, and provide a useful diagnostic for testing the strength of this circulation in climate and reanalysis models. There is significant interannual variability in the strength of the nocturnal relative humidity maxima. In 2011, the relative humidity maxima are very pronounced. In 2014, however, they are almost nonexistent. Finally, the relative humidity maxima are discussed in relation to the low-level jet (LLJ). The LLJ appears to be too low to directly contribute to the nocturnal relative humidity maxima.
publisherAmerican Meteorological Society
titleNocturnal Relative Humidity Maxima above the Boundary Layer in the U.S. Midwest: A Diagnostic for the Mountain–Plains Solenoidal Circulation
typeJournal Paper
journal volume146
journal issue2
journal titleMonthly Weather Review
identifier doi10.1175/MWR-D-17-0189.1
journal fristpage641
journal lastpage658
treeMonthly Weather Review:;2018:;volume 146:;issue 002
contenttypeFulltext


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