GSFC optical ozonesonde results during the Gap,France, intercomparisons,June 1981     

Arlin J. Krueger  Peter Simeth  Carol A. Fry  Krishna Tewari 《Planetary and Space Science》1983,31(7):749-759

A GSFC Super Loki optical ozonesonde instrument was flown as part of the ozone sensor intercomparison balloon campaign at Gap, France, in June 1981. A primary objective was to confirm biases between external absorption techniques, such as the GSFC sonde, and in situ techniques, which include ECC, Mast-Brewer, and DASIBI sondes. Ozone distributions were obtained with the GSFC sonde on three of the four ascent-descent legs of the first flight on 19 June. Ozone densities were measured redundantly over altitudes from 22 to 32 km using filters centered at 303 and 300 nm. The three profiles obtained by averaging the data from the two channels are in close agreement with an average S.E. of 1.4%. However, small but consistent differences were found between the ozone densities measured at the two wavelengths. The average difference is 5% using Vigroux cross sections and 4% using preliminary Bass cross sections. The integral ozone amount above the first ceiling altitude of 32.85 km was determined by the Langley plot method to be 45 D.U. The total ozone derived by integrating the optical ozonesonde and ECC profiles is within 2% of the Chiran Dobson Spectrophotometer observation based on a pre-campaign calibration but is 9% greater than the amount derived using a post-campaign calibration.  相似文献   

河南省肺癌空间分布格局及环境因素影响   总被引：2，自引：0，他引：2  

魏海涛  刘岩  田智慧  王晓蕾  赫晓慧  韦晶 《地理学报》2022,77(1):245-258

肺癌是最常见的恶性肿瘤之一,也是主要的肿瘤死因,河南省肺癌发病率和死亡率常年居恶性肿瘤首位,研究肺癌的空间分布格局及其与环境因子的关系对肺癌的相关防控工作意义重大。本文以2016—2018年河南省肺癌发病数据为研究对象,使用空间自相关分析方法研究河南省肺癌的空间分布格局,基于地理探测器量化各个环境因子及其两两交互作用对肺癌发病率的解释力。结果表明：空间上肺癌具有明显的集聚特征,高发区集中分布于豫中、豫东和豫南的平原和盆地地区。在所选的12种环境因子中,PM_2.5浓度、O₃浓度、年均风速、采矿业从业人员占比、人均GDP具有更高的决定力,人均GDP和医护人员占比则对多种要素的决定力均具有明显的非线性增强的作用。研究结果可以为河南省肺癌发病机理研究和相关防治工作提供科学支撑。  相似文献   

Excitation of the oxygen nightglow on the terrestrial planets     

Vladimir A. Krasnopolsky 《Planetary and Space Science》2011,59(8):754-766

A scheme of excitation, quenching, and energy transfer processes in the oxygen nightglow on the Earth, Venus, and Mars has been developed based on the observed nightglow intensities and vertical profiles, measured reaction rate coefficients, and photochemical models of the nighttime atmospheres of the Venus and Mars. The scheme involves improved radiative lifetimes of some band systems, calculated yields of the seven electronic states of O₂ in termolecular association, and rate coefficients of seven processes of electronic quenching of the Herzberg states of O₂, which are evaluated by fitting to the nightglow observations. Electronic quenching of the vibrationally excited Herzberg states by O₂ and N₂ in the Earth's nightglow is a quarter of total collisional removal of the O₂(A, A′) states and a dominant branch for the O₂(c) state. The scheme supports the conclusion by Steadman and Thrush (1994) that the green line is excited by energy transfer from the O₂(A³Σ_u⁺, v≥6) molecules, and the inferred rate coefficient of this transfer is 1.5×10⁻¹¹ cm³ s⁻¹. The O₂ bands at 762 nm and 1.27 μm are excited directly, by quenching of the Herzberg states, and by energy transfer from the O₂(⁵Π_g) state. Quenching of the O₂ band at 762 nm excites the band at 1.27 μm as well. Effective yield of the O₂(a¹Δ_g) state in termolecular association on Venus and Mars is ∼0.7. Quantitative assessments of all these processes have been made. A possible reaction of O₂(c¹Σ_u⁻)+CO is a very minor branch of recombination of CO₂ on Venus and Mars. Night airglow on Mars is calculated for typical conditions of the nighttime atmosphere. The calculated vertical intensity of the O₂ band at 1.27 μm is 13 kR, far below the recently reported detections.  相似文献   

Improved bounds on linear instability of barotropic zonal flow within the shallow water equations     

A.D. Clark  I.H. Herron 《地球物理与天体物理流体动力学》2013,107(3):328-352

Here we develop mathematical results to describe the location of linear instability of a parallel mean flow within the framework of the shallow water equations; growth estimates of near neutral modes (for disturbances subcritical with respect to gravity wave speed) in the cases of non-rotating and rotating shallow water. The bottom topography is taken to be one-dimensional and the isobaths are parallel to the mean flow. In the case of a rotating fluid, the isobaths and the mean flow are assumed to be zonal. The flow is front-like: there is a monotonic increase of mean flow velocity. Our results show that for barotropic flows the location of instabilities will be a semi-ellipse region in the complex wave velocity plane, that is based on the wave-number, Froude number, and depth of the fluid layer. We also explore the instability region for the case of spatially unbounded mean velocity profiles for non-rotating shallow water.  相似文献   

Evaluation of satellite-based precipitation estimation over Iran     

《Journal of Arid Environments》2013

Precipitation in semi-arid countries such as Iran is one of the most important elements for all aspects of human life. In areas with sparse ground-based precipitation observation networks, the reliable high spatial and temporal resolution of satellite-based precipitation estimation might be the best source for meteorological and hydrological studies. In the present study, four different satellite rainfall estimates (CMORPH, PERSIANN, adjusted PERSIANN, and TRMM-3B42 V6) are evaluated using a relatively dense Islamic Republic of Iran's Meteorological Organization (IRIMO) rain-gauge network as reference. These evaluations were done at daily and monthly time scales with a spatial resolution of 0.25° × 0.25° latitude/longitude. The topography of Iran is complicated and includes different, very diverse climates. For example, there is an extremely wet (low-elevation) Caspian Sea coastal region in the north, an arid desert in the center, and high mountainous areas in the west and north. Different rainfall regimes vary between these extremes. In order to conduct an objective intercomparison of the various satellite products, the study was designed to minimize the level of uncertainties in the evaluation process. To reduce gauge uncertainties, only the 32 pixels, which include at least five rain gauges, are considered. Evaluation results vary by different areas. The satellite products had a Probability of Detection (POD) greater than 40% in the southern part of the country and the regions of the Zagros Mountains. However, all satellite products exhibited poor performance over the Caspian Sea coastal region, where they underestimated precipitation in this relatively wet and moderate climate region. Seasonal analysis shows that spring precipitations are detected more accurately than winter precipitation, especially for the mountainous areas all over the country. Comparisons of different satellite products show that adj-PERSIANN and TRMM-3B42 V6 have better performance, and CMORPH has poor estimation, especially over the Zagros Mountains. The comparison between PERSIANN and adj-PERSIANN shows that the bias adjustment improved the POD, which is a daily scale statistic.  相似文献   

Nutrient stoichiometry and eutrophication in Indian mangroves   总被引：2，自引：2，他引：0  

M. Bala Krishna Prasad 《Environmental Earth Sciences》2012,67(1):293-299

Stoichiometry of dissolved nutrients in five important mangrove ecosystems of India (Sundarban, Bhitarkanika, Coringa, Pichavaram and Mangalavanam) was analyzed to describe the ecological and nutrient status of the inter-tidal mangroves in response to increasing human perturbations. The stoichiometric proportions of dissolved nutrients in mangroves highly deviated from the standard Redfield ratio (Si:N:P = 16:16:1), primarily because of the allochthonous nutrients derived from anthropogenic activities. In all mangroves, Si:N ratios were >1, which indicates that high silica is supplied from the terrestrial weathering to mangrove waters. Despite high phosphate loadings along with nitrogen from both point and non-point sources to mangrove waters, N:P ratios (Sundarban 11.43; Bhitarkanika 6.48; Coringa, 5.46; Pichavaram, 7.31 and Mangalavanam 4.64) demonstrate that phosphorus was a limiting nutrient in all mangrove ecosystems. The long-term nutrient analysis in Pichavaram mangrove water explains that the significant increase in dissolved nutrients since the 1980s is mainly derived from non-point sources (e.g., agriculture, aquaculture, etc.) that alter biogeochemical processes in this ecosystem. This study clearly reports that the ecological status of the Indian sub-continent mangroves is highly disturbed by anthropogenic impacts. Therefore, an appraisal of the nutrient ratios and sufficiency in mangroves facilitated an understanding of the current environmental conditions of coastal ecosystems, which further led to the proposal of the long-term observational research coupled with modeling to develop sustainable management strategies for conservation and restoration of mangroves.  相似文献   

Seasonal Variations of Hydrochemical Characteristics of Groundwater in Changping Plain,Beijing     

JIANG Tisheng  QI Junyu  WANG Mingyu  LIU Qingzhe  QU Cixiao  CHU Junyao 《资源与生态学报(英文版)》2017,8(6):655-663

Changping Plain, located in the northwest of Beijing, has become an important groundwater recharge area for the Beijing Plain and an important source for the urban water supply. In this study, groundwater samples were collected during the dry and wet seasons in 2015 from 24 monitoring wells distributed in Changping Plain. A Piper-Tri-linear diagram, a Schoeller diagram, a Gibbs diagram, and the isotope technique were used to investigate the temporal and spatial variations in the concentrations of groundwater hydrochemicals and the sources of groundwater recharge. The results indicated: 1) seasonal variations in the concentrations of HCO₃^-, Ca²⁺, and Na⁺ were significant; the spatial variations of these ions were more dramatic in the dry season than in the wet season due to the dilution effect of precipitation; 2) Most groundwater samples had a HCO₃-Ca-Mg based hydrochemical type and a few had a HCO₃-Na-K based hydrochemical type; the hydrochemical type tended to evolve from HCO₃-Ca-Mg based to HCO₃-Na-K based in some monitoring wells that showed distinct seasonal variation; 3) the groundwater in the study area originated mainly from atmospheric precipitation, and it is affected by evaporation and concentration processes.  相似文献   

A general ecosystem model for applications to primary productivity and carbon cycle studies in the global oceans     

《Ocean Modelling》2004,6(3-4):285-334

We have developed a general 1-D multi-component ecosystem model that incorporates a skillful upper ocean mixed layer model based on second moment closure of turbulence. The model is intended for eventual incorporation into coupled 3-D physical–biogeochemical ocean models with potential applications to modeling and studying primary productivity and carbon cycling in the global oceans as well as to promote the use of chlorophyll concentrations, in concert with satellite-sensed ocean color, as a diagnostic tool to delineate circulation features in numerical circulation models. The model is nitrogen-based and the design is deliberately general enough and modular to enable many of the existing ecosystem model formulations to be simulated and hence model-to-model comparisons rendered feasible. In its more general form (GEM10), the model solves for nitrate, ammonium, dissolved nitrogen, bacteria and two size categories of phytoplankton, zooplankton and detritus, in addition to solving for dissolved inorganic carbon and total alkalinity to enable estimation of the carbon dioxide flux at the air–sea interface. Dissolved oxygen is another prognostic variable enabling air–sea exchange of oxygen to be calculated. For potential applications to HNLC regions where productivity is constrained by the availability of a trace constituent such as iron, the model carries the trace constituent as an additional prognostic variable. Here we present 1-D model simulations for the Black Sea, Station PAPA and the BATS site. The Black Sea simulations assimilate seasonal monthly SST, SSS and surface chlorophyll, and the seasonal modulations compare favorably with earlier work. Station PAPA simulations for 1975–1977 with GEM5 assimilating observed SST and a plausible seasonal modulation of surface chlorophyll concentration also compare favorably with earlier work and with the limited observations on nitrate and pCO₂ available. Finally, GEM5 simulations at BATS for 1985–1997 are consistent with the available time series. The simulations suggest that while it is generally desirable to employ a comprehensive ecosystem model with a large number of components when accurate depiction of the entire ecosystem is desirable, as is the prevailing practice, a simpler formulation such as GEM5 (N²PZD model) combined with assimilation of remotely sensed SST and chlorophyll concentrations may suffice for incorporation into 3-D prediction models of primary productivity, upper ocean optical clarity and carbon cycling.  相似文献   

Indications for a long-term temperature change in the polar summer middle atmosphere     

《Journal of Atmospheric and Solar》2008,70(1):123-137

Middle atmosphere temperatures have been measured by in situ and by remote sensing instruments for several decades. Extensive temperature measurements by rocket-borne falling spheres (FS) were performed from Andøya Rocket Range in northern Norway from the late 1980s onwards. About 90 rockets were successfully launched within eight measurement campaigns and compiled to an empirical temperature statistic. About half of these measurements were in July and August. Since 1997 the Bonn University Rayleigh/Mie/Raman lidar has been operated at Esrange in northern Sweden during winter as well as during summer. One hundred and eight night mean temperature profiles were obtained for July and August from this data set and have been compared to the FS-statistics. A systematic difference could be observed, i.e. the weekly average temperatures taken from the FS-based empirical temperature statistics are up to 10 K warmer than the temperatures measured by lidar, depending on altitude. In particular comparisons during August show larger differences than comparisons with July data. Temperatures were additionally derived from the Rayleigh-scattered light of the Bonn University Na-resonance lidar which was operated during the 1980s at Andøya. No systematic differences between these measurements and the FS-data were found. Gravity waves, tides, volcanic aerosol, and the solar cycle are not likely to cause the observed differences, since their influence is minimised either by data selection (gravity waves and tides) or by measurement times (volcanic aerosol, solar cycle). Additionally to the temperature difference a change in the gravity wave activity was observed, in particular during summer 2002 and 2006. During these years also noctilucent clouds occurred rather late in the season. The latest unambiguous observation of a noctilucent cloud by the U. Bonn lidar at Esrange was on 24 August 2006. All these observations are indications of a long-term temperature change in the polar summer middle atmosphere as predicted by model calculations. While similar changes have already been observed at middle and low latitudes, temperature trend analyses for the polar atmosphere did not reveal any variation up to now.  相似文献   

Sea surface height variations in the South China Sea from satellite altimetry     

《Oceanologica Acta》1999,22(1):1-17

Sea surface elevation in the South China Sea is examined in the Topex/Poseidon altimeter data from 1992 to 1995. Sea level anomalies are smoothed along satellite tracks and in time with tidal errors reduced by harmonic analysis. The smoothed data are sampled every ten days with an along-track separation of about 40 km. The data reveal significant annual variations in sea level. In winter, low sea level is over the entire deep basin with two local lows centred off Luzon and the Sunda Shelf. In summer, sea level is high off Luzon and off the Sunda Shelf, and a low off Vietnam separates the two highs. The boundary between the Vietnam low and Sunda high coincides with the location of a jet leaving the coast of Vietnam described in earlier studies. Principal component analysis shows that the sea level variation consists mainly of two modes, corresponding well to the first two modes of the wind stress curl. Mode 1 represents the oscillation in the southern basin and shows little inter-annual variation. The mode 2 oscillation is weak in the southern basin and is strongest off central Vietnam. During the winters of 1992–1993 and 1994–1995 and the following summers, the wind stress curl is weak, and the mode 2 sea level variation in the northern basin is reduced, resulting in weaker winter and summer gyres. Weakening of the Vietnam low in summer implies diminishing of the eastward jet leaving the coast of Vietnam. The results are consistent with model simulations.  相似文献