中国南京与美国德克萨斯稻田甲烷排放的比较(英文)

稻田甲烷排放试验分别在南京与德克萨斯水稻生长季实施，观测期内测定甲烷排放通量、上壤温度和水稻生物量。结果表明：南京稻田土镶温度的季节性变幅为１５．３℃，甲烷排放通量与土壤温度成非线性正相关而与水稻生物量无关；德克萨斯稻田土壤温度的季节性变幅为的２．９℃，甲烷排放通量与土壤温度无关而与水稻生物量成线性正相关。由此得出结论：在持续淹水和无外源有机碳施加的条件下，土壤温度变幅大的地区驱动稻田甲烷排放季节性变化的关键因子为土壤温度，土壤温度变幅小的地区其关键驱动因子则为水稻的生长量。     

A record of palynomorphs from the Waterstones (Triassic) of Liverpool

A rich microflora from the Waterstones of St. James' Cemetery, Liverpool, is noted. The age of this assemblage and of others recorded from the Waterstones Formation and associated strata is discussed.     

Integrated garnet and zircon–titanite geochronology constrains the evolution of ultra‐high–pressure terranes: An example from the Sulu orogen

Dating ultra‐high–pressure (UHP) metamorphic rocks provides important timing constraints on deep subduction zone processes. Eclogites, deeply subducted rocks now exposed at the surface, undergo a wide range of metamorphic conditions (i.e. deep subduction and exhumation) and their mineralogy can preserve a detailed record of chronologic information of these dynamic processes. Here, we present an approach that integrates multiple radiogenic isotope systems in the same sample to provide a more complete timeline for the subduction–collision–exhumation processes, based on eclogites from the Dabie–Sulu orogenic belt in eastern China, one of the largest UHP terranes on Earth. In this study, we integrate garnet Lu–Hf and Sm–Nd ages with zircon and titanite U–Pb ages for three eclogite samples from the Sulu UHP terrane. We combine this age information with Zr‐in‐rutile temperature estimates, and relate these multiple chronometers to different P–T conditions. Two types of rutile, one present as inclusions in garnet and the other in the matrix, record the temperatures of UHP conditions and a hotter stage, subsequent to the peak pressure (‘hot exhumation') respectively. Garnet Lu–Hf ages (c. 238–235 Ma) record the initial prograde growth of garnet, while coupled Sm–Nd ages (c. 219–213 Ma) reflect cooling following hot exhumation. The maximum duration of UHP conditions is constrained by the age difference of these two systems in garnet (c. 235–220 Ma). Complementary zircon and titanite U–Pb ages of c. 235–230 Ma and c. 216–206 Ma provide further constraints on the timing of prograde metamorphism and the ‘cold exhumation' respectively. We demonstrate that timing of various metamorphic stages can thus be determined by employing complementary chronometers from the same samples. These age results, combined with published data from adjacent areas, show lateral diachroneity in the Dabie–Sulu orogeny. Three sub‐blocks are thus defined by progressively younger garnet ages: western Dabie (243–238 Ma), eastern Dabie–northern Sulu (238–235 Ma) and southern Sulu terranes (225–220 Ma), which possibly correlate to different crustal slices in the recently proposed subduction channel model. These observed lateral chronologic variations in a large UHP terrane can possibly be extended to other suture zones.     

FORESHORE DEPOSITIONAL PATTERNS ALONG THE RHODE ISLAND SOUTHSHORE

An application of polynomial curve fitting to sediment cumulative frequency distributions is presented to delineate the foreshore depositional patterns along the barrier beaches of the Rhode Island southshore. The analysis is based on 92 sampled stations where data for beach geometry, tidal stage, and sediment size were collected. Using the size-frequency classes obtained from sieving the foreshore sediment samples at 0.25 O intervals and fitting third-degree polynomial equations to these data, over 94% of the variation within the sediment cumulative frequency distributions is explained. The four curve coefficients (a, b, c, d) derived from the predicted third-degree equation are used in a discriminant function analysis to test the relationship between the curve shape and sediment source. Comparison of the discriminant scores with the respective station locations suggests that a series of Pleistocene headlands which occur as discrete points along the beach are serving as independent sources of sediment for the system.     

Sequential Coronal Mass Ejections from AR8038 in May 1997

Three homologous coronal mass ejections (CMEs) occurred on 5, 12 and 16 May 1997 from the single magnetic polarity inversion line (PIL) of AR8038. The three events together provide STEREO-like quadrature views of the 12 May 1997 CME and EIT double dimming. The recurrent CMEs with the nearly identical post-CME potential state and the ‘sigmoid to arcade to sigmoid’ transformations indicate a repeatable store?–?release?–?restore process of the free energy. How was the free magnetic energy re-introduced to the potential state corona after each release in this decaying active region? Making use of the known time interval bounded by the adjacent homologous CMEs, we made the following measures. The unsigned magnetic flux of AR8038, Φ_AR, decreased by approximately 18% during 66 h, while the unsigned flux, Φ_PIL, in a Gaussian-weighted PIL-region containing the flare site increased by about 50% during 36 hrs prior to the C1.3 flare on 12 May 1997. The significant increase of Φ_PIL demonstrates the magnetic gradient increase and the build-up of free energy in the PIL-region during the time leading to the eruption. Fourier local correlation tracking (FLCT) flow speed in AR8038 ranges from 0 to 292.8 m?s^?1 with a mean value of 63.2 m?s^?1. The flow field contains a persistent converging flow towards the flaring PIL and an effective shear flow distributed in the AR. Minor angular motions were found. An integrated proxy Poynting flux S _h estimates the energy input to the corona to be on the order of 1.15×10³² erg during the 66 hrs before the C1.3 flare. It suggests that sufficient energy for a flare/CME can be introduced to the corona on the order of several days by the flows deduced from photospheric magnetic field motions in this small decaying active region.     

Measuring water availability with limited ground data: assessing the feasibility of an entirely remote‐sensing‐based hydrologic budget of the Rufiji Basin,Tanzania, using TRMM,GRACE, MODIS,SRB, and AIRS

This study explores the feasibility of an entirely satellite remote sensing (RS)‐based hydrologic budget model for a ground data‐constrained basin, the Rufiji basin in Tanzania, from the balance of runoff (Q), precipitation (P), storage change (ΔS), and evapotranspiration (ET). P was determined from the Tropical Rainfall Measuring Mission, ΔS from the Gravity Recovery and Climate Experiment, and ET from the Moderate Resolution Imaging Spectroradiometer, the surface radiation budget, and the Atmosphere Infrared Radiation Sounder. Q was estimated as a residual of the water balance and tested against measured Q for a sub‐basin of the Rufiji (the Usangu basin) where ground measurements were available (R² = 0.58, slope = 1.9, root mean square error = 29 mm/month, bias = 14%). We also tested a geographical information system (GIS)‐driven (ArcCN‐runoff) runoff model (R² = 0.64, slope = 0.43, root mean square error = 39 mm/month). We conducted an error propagation analysis from each of the model's hydrologic components (P, ET, and ΔS). We find that the RS‐based model amplitude is most sensitive to ET and slightly less so to P, whereas the model's seasonal trends are most sensitive to ?S. Although RS–GIS‐driven models are becoming increasingly used, our results indicate that long‐term water resource assessment policy and management may be more appropriate than ‘instantaneous’ or short‐term water resource assessment. However, our analyses help develop a series of tools and techniques to progress our understanding of RS–GIS in water resource management of data‐constrained basins at the level of a water resource manager. Copyright © 2012 John Wiley & Sons, Ltd.     

Promises and Perils of Decentralized Forest Governance: The Case of Indonesia's Forest Management Units in Reducing Emission from Deforestation and Forest Degradation (REDD+)

Indonesia's forest management unit (Kesatuan Pengelolaan Hutan or KPH) system can be a promising mechanism for balancing international and national interests for global carbon mitigation initiatives with local interests in project implementation. We discuss the potential role of the KPH system in implementing REDD+ (Reducing Emission from Deforestation and Forest Degradation) projects and improving decentralized forest governance. Substantial financial gains from international initiatives like REDD+ and others can provide appropriate motivation for the central government to ensure successful decentralization of forest management. Development and implementation of REDD+ activities can also support the KPHs in performing their basic functions: conducting forest inventory, developing and implementing forest management plans, and strengthening communication and coordination with local communities. However, engaging indigenous peoples and local communities, which is a legal mandate for the system, will require building some measure of democratic process that can hold the KPHs accountable to local people.     

Observational Indicators of Formation Excitation of H2

Theoretical predictions by Farebrother et al. and Meijer et al. of rovibrational excitation probabilities in H₂ arising from formation by Eley-Rideal processes on a graphite surface are incorporated into a model of the chemistry and excitation of interstellar H₂. The model includes the usual radiative and collisional pumping of H₂ rotational and vibrational states, in addition to the formation processes. Predictions are made for HH₂ rovibrational emission line intensities for representative points in diffuse and in dark interstellar clouds. We find that – if all the interstellar HH₂ is formed by this Eley-Rideal process – then the consequences of formation pumping, as distinct from collisional and radiative pumping, should be clearly evident in both cases. In particular, we predict a clear spectral signature of this direct HH₂ formation process on graphite, distinct from radiative and collisional pumping; this signature should be evident in both diffuse and dark clouds; but the emissivity for dark clouds is predicted to be some 500 times greater than that in diffuse clouds in which the dense material may be embedded. An observational search for this signature in two dark cloud sources was made, but a preliminary analysis of the data did not yield a detection. The implications of and possible reasons for this preliminary conclusion are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.