Convective Mass-Flux From Long Term Radar Reflectivities Over Darwin, Australia
| Autor: | Christian Jakob, Alessandro C. M. Savazzi, A. Pier Siebesma |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Convection
Mass flux Atmospheric Science Scale (ratio) Polarimetry Magnitude (mathematics) Atmospheric sciences law.invention Geophysics Space and Planetary Science law Skewness Earth and Planetary Sciences (miscellaneous) Radar Constant (mathematics) Geology Physics::Atmospheric and Oceanic Physics |
| Zdroj: | Journal Of Geophysical Research-Atmospheres, 126(19) |
| ISSN: | 2169-897X |
| Popis: | Most cumulus parametrizations today make use of a simple conceptual model of convection, called the mass-flux approach. This approach depicts convection as an ensemble of updrafts and downdrafts occurring within a model grid-box. The aim of this study is to determine convective mass-fluxes and their constituents on the scale of a 100 km GCM grid-box from a C-band polarimetric radar and thereafter investigate the relative role of area fraction and vertical velocity in determining the shape and magnitude of bulk mass-flux profiles. We make use of observational estimates of these quantities spanning 13 wet seasons in the tropical region of Darwin. Following a bulk approach, the results show that the distribution of mass-flux is positively skewed and its mean profile peaks at 4 km. This is the result of constant area fractions and increasing vertical velocities below that level. Above 4 km, in-cloud vertical velocity plays a marginal role compared to the convective area fraction in controlling mass-flux profiles. |
| Databáze: | OpenAIRE |
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