Development of a land surface model including cloud water deposition on vegetation

Katata G, Nagai H, Wrzesinsky T, Klemm O, Eugster W, Burkard R

Research article (journal)

Abstract

A land surface model including cloud ( fog) water deposition on vegetation was developed to better predict the heat and water exchanges between the biosphere and atmosphere. A new scheme to calculate cloud water deposition on vegetation was implemented in this model. High performance of the model was confirmed by comparison of calculated heat and cloud water flux over a forest with measurements. The new model provided a better prediction of measured turbulent and gravitational fluxes of cloud water over the canopy than the commonly used cloud water deposition model. In addition, simple linear relationships between wind speed over the canopy (|U|) and deposition velocity of cloud water (V-dep) were found both in measurements and in the calculations. Numerical experiments using the model were performed to study the influences of two types of leaves (needle and broad leaves) and canopy structure parameters ( total leaf area index and canopy height) on Vdep. When the size of broad leaves is small, they can capture larger amounts of cloud water than needle leaves with the same canopy structure. The relationship between aerodynamic and canopy conductances for cloud water at a given total leaf area density ( LAD) strongly influenced V-dep. From this, it was found that trees whose LAD approximate to 0.1 m(2) m(-3) are the most efficient structures for cloud water deposition. A simple expression for the slope of V-dep plotted against LAD obtained from the experiments can be useful for predicting total cloud water deposition to forests on large spatial scales.

Details about the publication

JournalJournal of Applied Meteorology and Climatology
Volume47
Issue8
Page range2129-2146
StatusPublished
Release year2008 (31/08/2008)
Language in which the publication is writtenEnglish
DOI10.1175/2008JAMC1758.1
Keywordsdry deposition sensitivity-analysis fog deposition spruce forest balsam fir canopy fluxes soil rain site

Authors from the University of Münster

Klemm, Otto
Professur für Klimatologie (Prof. Klemm)