Stratiform Cloud—Inversion Characterization During the Arctic Melt Season
2009 (English)In: Boundary-layer Meteorology, ISSN 0006-8314, E-ISSN 1573-1472, Vol. 132, no 3, 455-474 p.Article in journal (Refereed) Published
Data collected during July and August from the Arctic Ocean Experiment 2001illustrated a common occurrence of specific-humidity (q) inversions, where moistureincreases with height, coinciding with temperature inversions in the central Arctic boundarylayer and lower troposphere. Low-level stratiform clouds and their relationship to temperatureinversions are examined using radiosonde data and data from a suite of remote sensinginstrumentation. Two low-level cloud regimes are identified: the canonical case of stratiformclouds, where the cloud tops are capped by the temperature inversion base (CCI—CloudsCapped by Inversion) and clouds where the cloud tops were found well inside the inversion(CII—Clouds Inside Inversion). The latter case was found to occur more than twiceas frequently than the former. The characteristic of the temperature inversion is shown tohave an influence on the cloud regime that was supported. Statistical analyses of the cloudregimes using remote sensing instruments suggest that CCI cases tend to be dominated bysingle-phase liquid cloud droplets; radiative cooling at the cloud top limits the vertical extentof such clouds to the inversion base height. The CII cases, on the other hand, display characteristicsthat can be divided into two situations—(1) clouds that only slightly penetrate thetemperature inversion and exhibit a microphysical signal similar to CCI cases, or (2) cloudsthat extend higher into the inversion and show evidence of a mixed-phase cloud structure.An important interplay between the mixed-phase structure and an increased potential for turbulentmixing across the inversion base appears to support the lifetime of CII cases existingwithin the inversion layer.
Place, publisher, year, edition, pages
2009. Vol. 132, no 3, 455-474 p.
Meteorology and Atmospheric Sciences
IdentifiersURN: urn:nbn:se:su:diva-32472DOI: 10.1007/s10546-009-9407-1ISI: 000270129600006OAI: oai:DiVA.org:su-32472DiVA: diva2:280628