[1] Measurements of surface ozone (O 3 ), carbon monoxide (CO), nitric oxide (NO), and total reactive nitrogen (NO y ) were made, in conjunction with other trace gases and fine aerosols, at Mount Waliguan (WLG, 36.28°N, 100.90°E, 3816 m above sea level) in the late spring and summer of 2003 in order to better understand the source(s) of ozone and other chemically active gases over the remote highlands of western China. The average mixing ratio (plus or minus standard deviation) was 58 (±9) ppbv for O 3 , 155 (±41) ppbv for CO, and 3.83 (±1.46) ppbv for NO y in the spring phase, compared to a summer average value of 54 (±11) ppbv for O 3 , 125 (±36) ppbv for CO, and 3.60 (±1.13) ppbv for NO y . The daytime (0800-1759 local time) average NO mixing ratios were 72 (±79) pptv and 47 (±32) pptv in the spring and summer, respectively. The ozone mixing ratios exhibited a minimum in late morning, while CO (and NO y in spring) showed enhanced concentrations at night. The latter is in contrast to the diurnal behaviors observed in many remote mountain sites. Analysis of 10-day back trajectories using output from FifthGeneration National Center for Atmospheric Research/Penn State University Mesoscale Model (MM5) simulations shows that air masses from the remote western regions contained the lowest level of CO (121-129 ppbv) but had the highest O 3 (60 ppbv), compared to the other three air mass groups that were impacted by anthropogenic emissions in eastern/southern China and in the Indian subcontinent. Ozone correlated negatively with CO (and water vapor content), particularly during summer in air originating in the west, suggesting that the high-ozone events were mostly derived from the downward transport of the upper tropospheric air and not from anthropogenic pollution. An examination of in situ chemical measurements (CO-NO y correlation, ethyne/ propane, and benzene/propane) as well as Measurements of Pollution in the Troposphere (MOPITT) and Moderate-Resolution Imaging Spectroradiometer (MODIS) remotesensing data revealed some impacts from forest fires in central Asia in the late spring of 2003 on the background concentrations of trace gases over western China. While the O 3 and CO levels at WLG are comparable to those at remote continental sites in Europe and North America, the NO y concentrations were substantially higher at WLG. The possible reasons for the abnormally high NO y levels are discussed. While more studies are needed to pin down these sources/causes, including a possible contribution from long-range transport, we believe that microbial processes in soils and animal wastes associated with animal grazing were an important cause of the elevated NO y . The observed daytime NO concentrations imply a net photochemical production of O 3 at WLG, suggesting a positive contribution of photochemistry to the ozone budget.

As part of ABC-EAREX2005 experiment, numerous trace gases were measured at Gosan on Jeju Island, South Korea in March 2005 to characterize the impact of recent outflow from the Asian continent and to inter-compare measurement techniques used by participating groups. Here we present measurements of O 3 , CO, and whole air samples of methane, C 2-C 8 non-methane hydrocarbons (NMHCs) and C 1-C 2 halocarbons obtained during the study. The large temporal variations in the measured trace gas concentrations at Gosan were due to the transport of background marine air and of regional pollution mainly from the Chinese subcontinent. Average mixing ratios (AE s.d.) were 54.6 ðAE9:0Þ ppbv and 283 ðAE100Þ ppbv for O 3 and CO, respectively. CO showed good correlations (r 2 ¼ 0:62-0.81) with combustion tracers such as ethyne and benzene but poorly correlated (r 2 ¼ 0:11-0.29) with light alkanes, suggesting that the latter were contributed by non-combustion source(s). Back trajectory analysis showed that air masses mainly originated from the North China Plains and northeastern China, which together accounted for 64% of the total trajectories. The highest mean mixing ratios of O 3 and combustion-derived species were found in air masses from eastern China and Korea, indicating the significant impact of emissions from these regions. Interestingly, air masses from northeast China contained elevated levels of light alkanes and the smallest ratios of ethyne/propane and benzene/propane among the air-mass groups, suggesting contribution from natural gas leakage in the upwind region, possibly from Siberia.

Experimental study of the formation and propagation of three-dimensional (3D) faults is of great significance in the understanding of the propagation process developing from initial natural faults. In the study described in this paper, experimental investigations of 3D propagation processes of a type of surface fault are carried out under biaxial compression. The strain field near the surface fault is dynamically measured and fully analyzed with a high-density Multi-Channel Digital Strain Gauge (MCDSG) and Digital Speckle Correlation Method (DSCM) based on the white-light image analysis. Simultaneously the micro-fracture process involved in fault formation is observed by a 3D acoustic emission (AE) location system with a set of multi-channel whole-wave record equipment. The experimental results show that the 3D propagation process of surface fault differs greatly from that of the two-dimensional (2D) state and that a new more complicated type of 3D morphological characters and deformation mechanisms are produced. The 3D propagation process of surface faults may be divided into three stages: 1) the first stage of crack propagation initiated by wing cracks; 2) the conversion stage propagated by petal cracks; and 3) the second stage of crack propagation formed by shell-shaped fracture surface. The primary propagation patterns of the three stages are different. The corresponding deformation fields and micro-fracture distributions are likewise different. The fracture activities from petal cracks especially are of vital importance during surface fault propagation. This is also a key conversion state and marks an intrinsic difference between 2D-like and the 3D state in fault development.surface fault, 3D propagation, strain field, digital speckle, acoustic emission Faults are one of the most common tectonic conformations. A fault formation mechanism and mutual action relationship, affected by fault shape, movement type and relative composition [1,2] , are the most challenging theoretical issues in tectonic geology, and are consequently of important practical significance in the understanding of some fracture phenomena associated with fault activities.The classical theory of fracture mechanics is commonly used to explain and predict the spatial type and growth pattern of a fault. Early in the progress of this study field, a natural fault was abstracted as a twodimensional (2D) fault (penetrative fault) kept in a continuous uniform medium which may induce many new cracks (tensile, shear and twisting cracks, etc.) under external loading. These new cracks were used to illustrate and describe common occurrences of natural faults. The 2D morphology approach can only explain the distribution patterns of some sub-faults. However, the formation and evolution of faults is basically three-dimensional (3D), and the results from 2D analysis are difficult to transfer to the 3D case. More recently, some researchers have tried to describe the 3D types of crack growth using a mixed fracture mode (including Mode I, Mode II, and Mode III)...