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Based on non-radiance-calibrated DMSP/OLS nighttime light imagery from 1992 to 2003, urban land area statistical data, meteorological data and land surface temperature data retrieved by MODIS and NOAA/AVHRR data, the influence of urbanization on regional climatic trend of temperature in the Yangtze River Delta (YRD) was analyzed. Conclusions are as follows: 1) There is a significant urbanization process from 1992 to 2003 in the YRD. Four city clusters of Nanjing-Zhenjiang-Yangzhou, Suzhou-Wuxi-Changzhou, Shanghai and Hangzhou Bay form a zigzag city belt. The increase rate of annual mean air temperature in city-belt is 0.28-0.44℃/10a from 1991 to 2005, which is far larger than that of non-city-belt. 2) The urban heat island (UHI) effect on regional mean air temperature in different seasons is summer>autumn>spring>winter.3) The UHI intensity and the urban total population logarithm are creditably correlated. 4) The UHI effect made the regional annual mean air temperature increased 0.072℃ from 1961 to 2005, of which 0.047℃ from 1991 to 2005, and the annual maximum air temperature increased 0.162℃, of which 0.083℃ from 1991 to 2005. All these indicating that the urban expansion in the YRD from 1991 to 2005 may be regarded as a serious climate signal.

A large shock-induced melt vein in L6 ordinary chondrite Roosevelt County 106 contains abundant high-pressure minerals, including olivine, enstatite, and plagioclase fragments that have been transformed to polycrystalline ringwoodite, majorite, lingunite, and jadeite. The host chondrite at the melt-vein margins contains olivines that are partially transformed to ringwoodite. The quenched silicate melt in the shock veins consists of majoritic garnets, up to 25 lm in size, magnetite, maghemite, and phyllosilicates. The magnetite, maghemite, and phyllosilicates are the terrestrial alteration products of magnesiow€ ustite and quenched glass. This assemblage indicates crystallization of the silicate melt at approximately 20-25 GPa and 2000°C. Coarse majorite garnets in the centers of shock veins grade into increasingly finer grained dendritic garnets toward the vein margins, indicating increasing quench rates toward the margins as a result of thermal conduction to the surrounding chondrite host. Nanocrystalline boundary zones, that contain wadsleyite, ringwoodite, majorite, and magnesiow€ ustite, occur along shock-vein margins. These zones represent rapid quench of a boundary melt that contains less metal-sulfide than the bulk shock vein. One-dimensional finite element heat-flow calculations were performed to estimate a quench time of 750-1900 ms for a 1.6-mm thick shock vein. Because the vein crystallized as a single high-pressure assemblage, the shock pulse duration was at least as long as the quench time and therefore the sample remained at 20-25 GPa for at least 750 ms. This relatively long shock pulse, combined with a modest shock pressure, implies that this sample came from deep in the L chondrite parent body during a collision with a large impacting body, such as the impact event that disrupted the L chondrite parent body 470 Myr ago.

a zonally oriented north-south tropospheric temperature dipole is induced. While the tropospheric warming in the tropics arises from El Nino like heating, the tropospheric cooling in the mid-latitudes arises possibly from the local SSTA forcing. For the positive phase of the second mode, the upper-tropospheric anticyclonic vorticity anomaly in the east pole arises from local SSTA forcing in North Pacific, whereas the cyclonic anomaly in the west pole results from southeastward Rossby wave energy emanation from North Atlantic to East Asia.

) and stishovite crystallized from a FeO-SiO 2 -rich zone in the melt vein, which formed by shock melting of FeO-SiO 2 -rich material that had been altered and metasomatized before shock. Based on the pressure stabilities of the high-pressure minerals, ringwoodite, akimotoite, and Ca-clinopyroxene, the melt vein crystallized at approximately 18 GPa. The Fe 2 SiO 4 -spinel + stishovite assemblage in the FeO-SiO 2 -rich melts is consistent with crystallization of the melt vein matrix at the pressure up to 18 GPa. The crystallization pressure of ∼18 GPa is much lower than the 45-90 GPa pressure one would conclude from the S6 shock effects in melt veins (Stˆffler et al. 1991) and somewhat less than the 25-30 GPa inferred from S5 shock effects (Schmitt 2000) found in the bulk rock.

Abstract-Here we report the transmission electron microscopy (TEM) observations of the mineral assemblages and textures in shock-induced melt veins from seven L chondrites of shock stages ranging from S3 to S6. The mineral assemblages combined with phase equilibrium data are used to constrain the crystallization pressures, which can be used to constrain shock pressure in some cases. Thick melt veins in the Tenham L6 chondrite contain majorite and magnesiowüstite in the center, and ringwoodite, akimotoite, vitrified silicate-perovskite, and majorite in the edge of the vein, indicating crystallization pressure of ~25 GPa. However, very thin melt veins (5-30 μm wide) in Tenham contain glass, olivine, clinopyroxene, and ringwoodite, suggesting crystallization during transient low-pressure excursions as the shock pressure equilibrated to a continuum level. Melt veins of Umbarger include ringwoodite, akimotoite, and clinopyroxene in the vein matrix, and Fe 2 SiO 4 -spinel and stishovite in SiO 2 -FeO-rich melt, indicating a crystallization pressure of ~18 GPa. The silicate melt veins in Roy contain majorite plus ringwoodite, indicating pressure of ~20 GPa. Melt veins of Ramsdorf and Nakhon Pathon contain olivine and clinoenstatite, indicating pressure of less than 15 GPa. Melt veins of Kunashak and La Lande include albite and olivine, indicating crystallization at less than 2.5 GPa. Based upon the assemblages observed, crystallization of shock veins can occur before, during, or after pressure release. When the assemblage consists of high-pressure minerals and that assemblage is constant across a larger melt vein or pocket, the crystallization pressure represents the equilibrium shock pressure.

Acid rain has been recognized as a serious environmental problem in China since the 1980s, but little is known about the effects of the climatic change in regional precipitation on the temporal and spatial variability of severe acid rain. We present the effects of the regional precipitation trend change on the area and intensity of severe acid rain in southern China, and the spatio-temporal distribution characteristics of SO 2 and NO 2 concentrations are analyzed on the basis of SO 2 and NO 2 column concentration data. The results are as follows.