Spatial variability of the surface energy balance of Lake Kasumigaura and implications for flux measurements

Spatial variability of lake surface energy balance and its causes are not understood well.90-m resolution energy balance maps of Lake Kasumigaura (172 km2) in Japan　obtained by interpolating stations’ data and bulk equations allowed investigation ofthese issues. Due to lake-scale variation in meteorological variables and small-scale fluctuations of surface temperature Ts, surface heat fluxes were found differed horizontally at two distinctive scales while radiative fluxes were more uniform. The key variable Ts to surface fluxes was only homogenous for directions with a longer fetch or under calm wind conditions. Using these findings, the suitability of flux station locations, one at the center of the lake and another within a cove, were considered.Although both locations satisfied the fetch requirements, Ts was not always found to be homogeneous in the cove, making this location less suitable for flux measurements, an issue that has been overlooked in scientific communities

Variance methods to estimate regional heat fluxes with aircraft measurements in the convective boundary layer

Turbulence data obtained by aircraft observations in the convective boundary layer (CBL) were analyzed to estimate the regional surface heat fluxes through application of the variance methods. Several heights within and above the CBL were flown repeatedly above the flux observation site in a homogeneous steppe region in Mongolia. The vertical profiles of the second moment about the mean, i.e., the variance, of temperature were found to follow in general the functional forms proposed in previous studies. These variance statistics were applied to the variance formulations to estimate surface sensible heat fluxes. First, the flux estimation was made with these equations and the constant parameters as proposed in previous studies. Then, the constants were re-calibrated with the current data set and used for flux estimation. In addition, a new simpler formulation was proposed and also calibrated with the current data set. Finally, additional variables, which represent the large scale atmospheric conditions namely baroclinity and advection, were considered for possible improvement of the flux estimation. The resulting rms difference of the estimated sensible heat flux and ground based measurements was reduced from about 40–100 W m−2 for the results obtained with the original constants and formulations, to 30 W m−2 or less for those obtained with locally calibrated constants and introduction of four additional variables. All formulations including the new simple equation performed equally well

〈資料〉北東アジア植生変遷域の水循環と生物・大気圏の相互作用の解明:RAISE Projectの概要

In the northeastern Asia, a climatic shift from humid condition in the northern part to and condition in the southern part can be found in a relatively narrow, boundary zone. As a consequence of the steep gradient in climatic conditions, a distinct "ecotone" (i.e., forest-grassland-desert) is formed in the northeastern Asia. Such a ecotone is sensitive to changes in external environment even though those changes are very small. The main focus of RAISE Project is the evaluation of the effects of these changes on the rangeland ecosystem with emphasis on the role of hydrologic cycle m northeastern Asia. The strategy of the project includes field observations for the understanding of the current status of the ecosystem and the modeling of the atmosphere, hydrosphere and biosphere in this area. The models to be produced and optimized for the area will then be used for the prediction of the possible changes of the area in response to likely scenarios of future climate and land use changes

Tests and applications of self-consistent cranking in the interacting boson model

The self-consistent cranking method is tested by comparing the cranking calculations in the interacting boson model with the exact results obtained from the SU(3) and O(6) dynamical symmetries and from numerical diagonalization. The method is used to study the spin dependence of shape variables in the $sd$ and $sdg$ boson models. When realistic sets of parameters are used, both models lead to similar results: axial shape is retained with increasing cranking frequency while fluctuations in the shape variable $\gamma$ are slightly reduced.Comment: 9 pages, 3 ps figures, Revte