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Title: Exact Expression for the Lifting Condensation Level

  1. Department of Earth and Planetary Science, University of California, Berkeley, and Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
OSTI Identifier:
Grant/Contract Number:
Atmospheric System Research
Resource Type:
Journal Article: Published Article
Journal Name:
Journal of the Atmospheric Sciences
Additional Journal Information:
Journal Volume: 74; Journal Issue: 12; Related Information: CHORUS Timestamp: 2017-11-27 12:12:51; Journal ID: ISSN 0022-4928
American Meteorological Society
Country of Publication:
United States

Citation Formats

Romps, David M. Exact Expression for the Lifting Condensation Level. United States: N. p., 2017. Web. doi:10.1175/JAS-D-17-0102.1.
Romps, David M. Exact Expression for the Lifting Condensation Level. United States. doi:10.1175/JAS-D-17-0102.1.
Romps, David M. 2017. "Exact Expression for the Lifting Condensation Level". United States. doi:10.1175/JAS-D-17-0102.1.
title = {Exact Expression for the Lifting Condensation Level},
author = {Romps, David M.},
abstractNote = {},
doi = {10.1175/JAS-D-17-0102.1},
journal = {Journal of the Atmospheric Sciences},
number = 12,
volume = 74,
place = {United States},
year = 2017,
month =

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on November 22, 2018
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  • Onset and coverage of small cumulus clouds depend on the relative abundance of surface-layer air parcels possessing favorable buoyancy and moisture - two variables that are coupled through the surface energy budget. This abundance is described using a joint frequency distribution (JFD) as a function of virtual potential temperature {theta}{sub v} and height of the lifting condensation level z{sub LCL}. It is shown analytically that the shape and spread of this JFD depends on the ranges of Bowen ratios and solar forcings (albedoes, cloud shading, etc.) that exist within a domain of heterogeneous land use. To sample the character ofmore » such JFDs in the real atmosphere, a case study is presented using turbulence data gathered by aircraft flying in the surface layer of southwest France. This case study includes 4 days of clear skies during the Hydrologic Atmospheric Pilot Experiment (HAPEX) of 1986. The full flight track during HAPEX overflew a wide range of land use including evergreen forest, corn, vineyards, pastures, and irrigated fields over varied topography. The JFDs from these full tracks are found to be quite complex, being frequently multimodal with a convoluted perimeter. However, when a full track is broken into segments, each over a subdomain of quasi-homogeneous land use, the resulting segment JFDs are mono-modal with simpler topology. Such a characterization of JFDs provides guidance toward eventual subgrid cumulus parameterization in large-scale forecast models, with associated impacts in aviation forecasting, pollutant venting and chemical reactions, verticle dispersion and turbulence modulation, and radiation balance in climate-change models. 48 refs., 17 figs., 7 tabs.« less
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  • Premature chromosome condensation (PCC) in Chinese hamster ovary (CHO) cells following exposure to 300-kVp x rays was first detected in the mitosis that followed the second postirradiation S phase. Thus, cells irradiated in G1 first expressed PCC at the second postirradiation mitosis while cells irradiated in G2 did not express PCC until the third postirradiation mitosis. Cells irradiated in the S phase expressed PCC at the second postirradiation mitosis with a frequency that was related to the position of the cells in the S phase at the time of exposure, cells in the first half of the S phase (atmore » the time of exposure) showing a higher frequency than cells positioned in the second half. Thus, DNA replication during the first postirradiation S phase may be involved in the processing of lesions that eventually give rise to PCC. For cells in G1 at the time of exposure, the D/sub o/ for PCC expression at the second postirradiation mitosis was around 825 rad, indicating that PCC may play only a minor role in x-ray-induced cell killing. Autoradiographic analysis indicated approximately 50% of the PCC patches scored were replicating DNA at the time condensation was attempted. Daughter cells derived from such cells would suffer loss of genetic material.« less