Temporal relations of column water vapor and tropical precipitation

Holloway, C. E. ORCID: https://orcid.org/0000-0001-9903-8989 and Neelin, J. D. (2010) Temporal relations of column water vapor and tropical precipitation. Journal of the Atmospheric Sciences, 67 (4). pp. 1091-1105. ISSN 1520-0469 doi: 10.1175/2009JAS3284.1

Abstract/Summary

Empirical studies using satellite data and radiosondes have shown that precipitation increases with column water vapor (CWV) in the tropics, and that this increase is much steeper above some critical CWV value. Here, eight years of 1-min-resolution microwave radiometer and optical gauge data at Nauru Island are analyzed to better understand the relationships among CWV, column liquid water (CLW), and precipitation at small time scales. CWV is found to have large autocorrelation times compared with CLW and precipitation. Before precipitation events, CWV increases on both a synoptic-scale time period and a subsequent shorter time period consistent with mesoscale convective activity; the latter period is associated with the highest CWV levels. Probabilities of precipitation increase greatly with CWV. Given initial high CWV, this increased probability of precipitation persists at least 10–12 h. Even in periods of high CWV, however, probabilities of initial precipitation in a 5-min period remain low enough that there tends to be a lag before the start of the next precipitation event. This is consistent with precipitation occurring stochastically within environments containing high CWV, with the latter being established by a combination of synoptic-scale and mesoscale forcing.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/19579
Item Type	Article
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology Science > School of Mathematical, Physical and Computational Sciences > NCAS
Publisher	American Meteorological Society
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