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521.
The formation mechanism of the nocturnal urban boundary layer (UBL), especially in the winter nighttime, was investigated based on the extensive field observations conducted during November 1984 in Sapporo, Japan. A strong, elevated inversion formed over the Sapporo urban area and the inversion base height was approximately twice the average building height. Velocity fluctuations
u, w and Reynolds stress % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaaca% WG1bWaaWbaaSqabeaacaaIXaaaaGGaaOGae8hiaaIaam4DamaaCaaa% leqabaGaaGymaaaaaaaaaa!3A9C!\[\overline {u^1 w^1 } \] had nearly uniform profiles within the nocturnal UBL and decreased with height above the UBL. On the other hand, temperature fluctuations
t
, and heat fluxes % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaaca% WG1bWaaWbaaSqabeaacaaIXaaaaGGaaOGae8hiaaIaeqiUde3aaWba% aSqabeaacaaIXaaaaaaaaaa!3B56!\[\overline {u^1 \theta ^1 } \] and % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaaca% WG3bWaaWbaaSqabeaacaaIXaaaaGGaaOGae8hiaaIaeqiUde3aaWba% aSqabeaacaaIXaaaaaaaaaa!3B58!\[\overline {w^1 \theta ^1 } \] had peaks at the inversion base and small values within the nocturnal UBL. The turbulent kinetic energy budget showed that the turbulent transport term and shear generation from urban canopy elements are important in the nocturnal UBL development; the role of the buoyancy term is small. The turbulence data analysis and application of a simple advective model showed that the mechanism of UBL formation may be controlled by the downward transport of sensible heat from the elevated inversion caused by mechanically-generated turbulence.Nomenclature
g
accelaration due to gravity, m s-2
-
k
turbulent kinetic energy, m2 s-1
-
K
m
eddy viscosity, m2 s-1
-
L
Monin-Obukhov lenght, m
-
p
pressure, Kg m-2
-
U, V, W
mean wind speed in the downwind, crosswind, and vertical directions, respectively, m s-1
-
u
1, w
1
wind speed fluctuation in the downwind and vertical direction, respectively, m s-1
-
u
1
friction velocity, m s-1
- % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaaca% WG1bWaaWbaaSqabeaacaaIXaaaaGGaaOGae8hiaaIaam4DamaaCaaa% leqabaGaaGymaaaaaaaaaa!3A9C!\[\overline {u^1 w^1 } \]
momentum flux, m2s-2
- % MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaaca% WG1bWaaWbaaSqabeaacaaIXaaaaGGaaOGae8hiaaIaam4DamaaCaaa% leqabaGaaGymaaaaaaaaaa!3A9C!\[\overline {u^1 \theta^1 } \]
sensible heat flux, m2s-1°C
-
WD
wind direction, deg
-
WS
wind speed, m s-1
-
z
altitude, m
-
Z
h
inversion base height, m
-
Z
j
wind maximum height, m
-
Z
t
inversion top height, m
-
T
u-r
heat island intensity, °C
-
temperature lapse rate at rural site, °C m-1
-
energy dissipation rate, m2s-3
-
1
Potential temperature fluctuation, °C
-
*
scaling temperature, (=-% MathType!MTEF!2!1!+-% feaafeart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaa0aaaeaaca% WG1bWaaWbaaSqabeaacaaIXaaaaGGaaOGae8hiaaIaeqiUde3aaWba% aSqabeaacaaIXaaaaaaaaaa!3B56!\[\overline {u^1 \theta ^1 } \]/u*) °C
-
mean potential temperature fluctuation, K
-
density of air, Kgm-3
-
K
von Kármán constant (=0.4)
- u, v, w
standard deviation of wind speed in the downwind, crosswind, and vertical directions, respectively, m s-1
-
standard diviation of temperature, °C 相似文献
522.
Nobutaka Shimada Tomoki Nakamura Yasuo Morinaga Yoshihito Shikama 《Resource Geology》2005,55(2):91-100
Abstract. The presence of invisible gold was confirmed in arsenian pyrite from the Hishikari epithermal gold deposit, Kagoshima, Japan, by means of EPMA and SIMS analyses. The relative concentration of invisible gold may be positively correlated with As contents (0.01 to 10.37 wt%) of fine-grained arsenian pyrite which commonly occurs in the auriferous quartz veins. Although arsenian pyrite occurs widely in any mineralization stage with electrum and other sulfide, sulfosalts, selenide or telluride minerals, arsenian pyrites having higher As contents accompanied by invisible gold occur dominantly in the middle stage of fine-adularia-quartz and in the late stage of coarse-quartz rather than in the early stage of columnar-adularia. 相似文献
523.
P. L. Tikhomirov V. Yu. Prokof’ev I. A. Kal’ko A. V. Apletalin Yu. N. Nikolaev K. Kobayashi E. Nakamura 《Geotectonics》2017,51(2):131-151
The paper presents new data on the isotopic age and chemical composition of volcanic rocks from the Tytyl’veem and Mangazeika basins of western Chukotka superposed on Mesozoides of the Verkhoyansk–Chukotka Tectonic Region. The results of SIMS U–Pb zircon dating (121.4 ± 2.8 and 118.0 ± 2.0 Ma) corroborate the Aptian age of the Tytyl’veem Formation. This age, in turn, indicates its formation after closure of the South Anyui ocean (Neocomian), but before origination of the Okhotsk–Chukotka Belt (Albian–Campanian). Post-collisional Aptian igneous rocks are widespread in the northern Verkhoyansk–Chukotka Tectonic Region; the legth of the corresponding igneous province is no less than 1400 km. In geochemical characteristics, the post-collisional volcanic rocks occurring in Western Chukotka are similar with the rocks from Andean-type igneous belts. 相似文献
524.
Characterization of drying-induced deformation behaviour of Opalinus Clay and tuff in no-stress regime 总被引:1,自引:0,他引:1
Aung Ko Ko Soe Masahiko Osada Manabu Takahashi Tai Sasaki 《Environmental Geology》2009,58(6):1215-1225
The drying-induced deformation behaviour of Opalinus Clay and tuff, which are being investigated under international and local
collaborative projects for nuclear waste disposal in Switzerland and Japan, was investigated under a no-stress condition in
the laboratory to evaluate their generic susceptibility to the formation of excavation damaged zone. The cylindrical core
samples of Opalinus Clay and tuff were prepared to a one-dimensional drying condition and submitted to an uncontrolled laboratory
environment. The strain evolution, evaporative water loss and environmental entities, such as temperature and relative humidity,
were recorded simultaneously and quasi-continuously. It was observed that the drying phase induced significant strain magnitude
and damage in Opalinus Clay samples, which was evidenced by the formation of hairy cracks on the surface parallel to the bedding.
On the contrary, the strain occurrences in tuff samples were relatively insignificant, and no tendency of cracking was observed.
In addition, the quasi-continuous availability of volumetric strains was further used in poroelastic relation for the estimation
of capillary suction evolution. The calculated results were validated with pore size distributions obtained from mercury intrusion
porosimetry. 相似文献
525.
Spatial variability and correlation of environmental proxies during the past 18,000 years among multiple cores from Lake Pumoyum Co,Tibet, China 总被引:3,自引:0,他引:3
Junbo Wang Liping Zhu Mitsugu Nishimura Toshio Nakamura Jianting Ju Manping Xie Watanabe Takahiro Matsunaka Testsuya 《Journal of Paleolimnology》2009,42(3):303-315
Multiple cores from Lake Pumoyum Co, southern Tibet, provide an improved understanding of the spatial distribution of lake
sediments, and how well they represent the paleo-climate. Comparative study of these cores using AMS 14C dating and environmental proxies clarified their relationships with environmental changes. Our work focused on understanding
the spatial similarities among cores covering different time scales, and evaluating variations in sedimentary processes across
sites. The four studied cores demonstrate different sedimentation rates, but environmental proxies help synchronize the timing
of environmental variations. Sediment variables such as total organic carbon (TOC), inorganic carbon (IC), and grain size
in different cores correlate well and corroborate changing trends over the past 10,000 cal years. Differences in sedimentation
rates and facies among core sites probably result largely from differences in water depth. The core from the deepest site
displays the highest average sedimentation rates and the highest accumulation rates of TOC, but lowest content of IC. Two
cores from somewhat shallower sites have plant residues in their lower sections and record similar variations in both the
number of layers and their depositional ages. Our results do not indicate any significant variation in sedimentation pattern
or its related factors among the three sites. A single core from the deepest site could adequately represent the total lake
environment over the time span covered. But cores from somewhat shallower sites might reveal important shifts in the environment
over a longer time period. 相似文献