Measured and simulated latent and sensible heat fluxes at two marine sitesin the Baltic Sea

Citation
A. Rutgersson et al., Measured and simulated latent and sensible heat fluxes at two marine sitesin the Baltic Sea, BOUND-LAY M, 99(1), 2001, pp. 53-84
Citations number
48
Categorie Soggetti
Earth Sciences
Journal title
BOUNDARY-LAYER METEOROLOGY
ISSN journal
00068314 → ACNP
Volume
99
Issue
1
Year of publication
2001
Pages
53 - 84
Database
ISI
SICI code
0006-8314(200104)99:1<53:MASLAS>2.0.ZU;2-I
Abstract
In this study, turbulent heat flux data from two sites within the Baltic Se a are compared with estimates from two models. The main focus is on the lat ent heat flux. The measuring sites are located on small islands close to th e islands of Bornholm and Gotland. Both sites have a wide wind direction se ctor with undisturbed over-water fetch. Mean parameters and direct fluxes w ere measured on masts during May to December 1998. The two models used in this study are the regional-scale atmospheric model HIRLAM and the ocean model PROBE-Baltic. It is shown that both models overe stimate the sensible and latent heat fluxes. The overestimation can, to a l arge extent, be explained by errors in the air-water temperature and humidi ty differences. From comparing observed and modelled data, the estimated 8- month mean errors in temperature and humidity are up to 1 degreesC and 1 g kg(-1),respectively. The mean errors in the sensible and latent heat fluxes for the same period are approximately 15 and 30 W m(-2), respectively. Bulk transfer coefficients used for calculating heat and humidity fluxes at the surface were shown to agree rather well with the measurements, at leas t for the unstable data. For stable stratification, the scatter in data is generally large, and it appears that the bulk formulation chosen overestima tes turbulent heat fluxes.