Madden Julian Oscillations in Total Column Ozone, Air Temperature and Surface Pressure Measured over Cochin during Summer Monsoon 2015

The intra-seasonal variability plays a major role in the inter-annual variability of weather parameters such as rainfall, temperature and pressure which lead to extreme weather events in certain years. The active (more rainy days) and break (less rainy days) periods of Indian summer monsoon heavily depend on the intra-seasonal variability of weather parameters such as wind, pressure and temperature oscillations during the monsoon season. In the present analysis daily total column ozone, surface temperature and surface pressure measured over Cochin using Microtop II Ozonometer (sun Photometer) were used to study the Intra-Seasonal Variations (ISV) of the above parameters during the monsoon season, 2015. The dominant and significant intra-seasonal oscillations (ISOs) were identified using an advanced statistical method called the Discrete Mayer’s Wavelet (DMW) analysis. Two major ISOs such as Madden Julian Oscillations (MJO, 30 - 60 days) and quasi-bi weekly (12 - 16 days) oscillations were found in TCO, surface temperature and pressure. In TCO an additional mode of ISO with quasi tri-weekly periodicity was also found (16 - 22 day). It is observed that MJO mode is the dominant among all other modes and its positive and negative phases correlate with positive and negative anomalies of the above parameters. The ISO mode in the surface pressure shows an out of phase relation with the Indian summer monsoon rainfall which indicates the active and break periods of Indian summer monsoon. The contribution of MJO mode is dominant in the tropical atmosphere, which modulates the intra-seasonal variability. It is found that for the year 2015 total column ozone, surface pressure and surface temperature show an annual range of 30 DU, 4 hPa and 1°C, respectively.

Investigating Contributions of Total Column Ozone Variation on Some Meteorological Parameters in Nigeria

The relationship between some meteorological parameters and variation of total column ozone (TCO) concentration in Nigeria is studied from 1998-2012. The results using a descriptive analysis revealed a seasonal ozone variation having the same trend in all the stations during the period of study. High variability of TCO occurred between December and March coinciding with the period of dry season and low variability of TCO was observed in August coinciding with the period of rainy season. The observed trends in all the stations show that the TCO variation in Nigeria is mostly caused by natural occurrences. Calabar and Port Harcourt stations showed a high percent of TCO variability, while Kano and Maiduguri indicated a low percentage of TCO variability. Using Spearman correlation analysis, TCO concentration has a strong negative correlation with temperature in some stations with correlation coefficient (r) (-0.8392, -0.8531, -0.7832, -8881 and -0.7902) for Calabar, Port Harcourt, Makurdi, Lagos and Ilorin respectively. Kano and Maiduguri showed a weak positive correlation coefficient (r) 0.4965 and 0.3776 respectively. Positive correlation observed in Kano and Maiduguri could be as a result of high dehydration of water vapour in these stations due to seasonal harmattan and latitudinal effects. Probably, some of the substances that could deplete ozone such as HCl, aerosol are soluble in water thereby being washed off by rain during wet season leading to maximum TCO concentration during rainy season. Consequently, the observed phenomenon is through transportation of ozone content through the influence of Brewer-Dobson circulation. Again, during wet season, there is the mechanism of low pressure and lower tropopause height phenomenon, therefore, total ozone enhancement. Interestingly, variation in TCO is part of symbolic tools for tropospheric meteorology alteration and this invariably leads to climate change.

Temporal Distribution of Total Column Ozone over Cochin—A Study Based on in Situ Measurements and ECMWF Reanalysis

The variability of Atmospheric ozone is very important to understand the radiative balance of the earth-atmospheric system and climate change. In order to understand the temporal variability of total column ozone (TCO) over the coastal station Cochin (9.95°N, 76.27°E), we used the ECMWF (European Centre for Medium-Range Weather Forecasts) reanalysis TCO and ground based measurements using Microtop II Sun Photometer (Ozonometer). The trend, seasonal changes and diurnal variation of ozone concentration have been studied in detail for the period 1981-2014. Cochin is a tropical coastal station with tropical monsoon climate and hence we examined the variability of TCO during pre-monsoon (March-May), monsoon (June-September) and post monsoon (October-December) seasons. Significant variations are noted in the TCO for the different seasons during the period of study. Based on the measurements and analysis, it is observed that TCO is maximum during monsoon and minimum during pre- and post-monsoon. We computed the TCO climatology for pre-monsoon (262.0 DU), monsoon (275 DU) and post-monsoon (253 DU) seasons and found that TCO shows a decadal trend (solar cycle). During monsoon season TCO varies with an increase of approximately 14 DU from the pre-monsoon value and a decrease of 22 DU from the post-monsoon value. The increase in TCO concentration during monsoon may be attributed to the monsoonal wind circulations and organized convection. The validation of ECMWF TCO with in situ measurements using Microtop II Ozonometer has been carried out for the year 2015 and found that the values are positively correlated. The diurnal variability of TCO was examined for vernal and autumnal equinox days and noticed the change in variability.

Effects of Sudden Stratospheric Warming Events on the Distribution of Total Column Ozone over Polar and Middle Latitude Regions

In winter the polar stratosphere is extremely cold. During the Sudden Stratospheric Warming events, the polar stratospheric temperature rises concurrently zonal-mean zonal flow weakens over a short period of time. As the zonal flow weakens, the stratospheric circulation becomes highly asymmetrical and the stratospheric polar vortex is displaced off the pole. The polar stratospheric temperature rises by 50°C and the stratospheric circumpolar flow reverses direction in a span of just few days. Sudden Stratospheric Warming (SSW) leads to significant changes in the rate of several chemical reactions which occur in the polar stratosphere. During such events, the dynamical fields in the polar stratosphere completely altered and columnar ozone changed. This study concentrated on the variability of winter polar vortex, meridional temperature gradient and associated changes in the Total Column Ozone (TCO) over the polar and middle latitude regions. It is found that changes in the amount of column ozone are positively correlated with polar lower stratospheric temperature with colder (warmer) temperature correlating with less (high) amount column ozone. But in the middle latitude region we observed negative correlations between ozone concentration and stratospheric temperature. In almost all cases there is sudden increase of ozone concentration over the pole and after few days the value is reduced when the warming effect is weak. During SSW events there observed an increase of 30 DU in TCO from the average value over the pole and if the SSW is strong TCO is found to rise by 50 DU. But in the middle latitude approximately 10 DU increase is noted. From the above results it may be concluded that variability of column ozone depends on dynamic and stratospheric chemistry over the poles and in middle latitude the variability can be attributed to the dynamical aspects. Anomaly of column ozone is higher during sudden stratospheric warming events over both polar and middle latitude region. The meridional temperature gradient reverses first and after two days polar vortex changes its direction or weakens followed by an increase of column ozone over the polar region. An increase of 30° Kelvin in the average temperature value noted over the polar region during sudden stratospheric warming events.

Global and Hemispherical Interannual Variation of Total Column Ozone from TOMS and OMI Data

Daily Total Column Ozone (TCO) measurements compiled from Total Ozone Mapping Spectrometer (TOMS) and Ozone Monitoring Instruments (OMI) were used to analyze the global and hemispherical TCO interannual variations. Two periods of TCO measurements were analyzed separately covering full years. For the 1978-1994 period, the TCO showed a global decade decrease rate of 13.45 DU (about -4.3%). For the Northern Hemisphere(NH) the decade decrease rate was of 12.96 DU (-4.0%), while in the Southern Hemisphere (SH) was of 13.57 DU (-4.5%). These decreases in ozone trends, using the totality of TOMS and OMI satellite measurements, are greater than those reported in literature. The 1998-2014 period global TCO decade decrease rate was of 1.56 DU, corresponding 0.94 DU and 0.138 DU for the NH and SH, respectively. The global TCO variations must show a double annual periodicity, the first one with maxima in March due to the Northern Hemisphere (NH) and the second one during September due to the Southern Hemisphere (SH). However, the maxima due to SH TCO interannual variations have gradually vanished. A disturbance in the SH TCO interannual variations has appeared since 1980;graphically the periodicity brakes down and transforms to a double peak from 1985 and on. This effect can be attributed to the hemispheric impact of the ozone hole at the South Pole. Between October 1, 2004 and December 14, 2005 TOMS and OMI have recorded this disturbance unequivocally. We conclude that the disturbance in SH TCO has an irreversible character.

Spatial and Temporal Variability of Total Column Ozone over the Indian Subcontinent: A Study Based on Nimbus-7 TOMS Satellite

The distribution and variability of ozone is very important to the atmospheric thermal structures, and it can exert their greater influence on climate. Present study is based on Nimbus-7 TOMS overpass column ozone for a period of 14 years (1979-1992) over twelve selected Indian stations from south to north latitude and it explores the spatial and temporal variability of Total Column Ozone (TCO). For this investigation an advanced statistical methods such as Factor Analysis and Morlet wavelet transform are employed. Total column ozone variability over these stations is grouped into two clusters (Eigen value greater than 1) by the Multivariate Factor analysis. It is found that the Group I stations shows the same nature of variability mainly due the first factor as the primarily loading and whereas as the Group II stations shows the same nature of variability due to second factor as the primary loading. The correlation value of TCO decreases from 0.9 to 0.32 as we move from south to north stations (lower latitude to higher latitude). The total column ozone over tropical stations is maximum during monsoon season with peak in the month of June and that for the higher latitude stations is during the pre-monsoon season. Annual average of TCO for tropical stations is about 265 DU and that for subtropical stations is about 280 DU and a difference of 15 DU is noted in the annual average of TCO between tropical and subtropical stations. A large reduction in TCO is noted over the Indian subcontinent in the year 1985, the same year in which the ozone hole over Antarctica was discovered. It is also found that two prominent oscillations are present in total column ozone one with a periodicity of 16 to18 months and other with 28 to 32 months (QBO periodicity) apart from the annual oscillations. These oscillations are found to be significant at above 95% level of confidence when tested with Power Spectrum method. Tropical TCO shows high concentration during the westerly phase and low concentration during the easterly phase of the equatorial stratospheric quasi-biennial oscillation.

A Comparative Study of Intra-Seasonal Variability of Total Column Ozone Measured over the Tropical Maritime and Coastal Stations Using Microtop II Ozonometer

The study of temporal and spatial distribution of ozone is very important for understanding the atmospheric chemistry and thereby its impact on environment, weather and climate. The intra-seasonal variability plays a major role in the inter-annual variability of weather parameters such as rainfall, temperature, pressure and atmospheric trace gas constituents such as atmospheric ozone. The strength of monsoon circulation and deep convection greatly modifies the atmospheric compositions and meteorological parameters such as rainfall amount, distributions of atmospheric trace gas concentrations and other weather parameters over the summer monsoon region. The daily total column ozone (TCO) measured over maritime station (Lakshadweep Island— 10°10'N & 73°30'E) and coastal station (Cochin—9°55'N and 76°16'E) using Microtop II Ozonometer were considered for the comparative study of seasonal and intra-seasonal variability for the year 2015. The annual average of total column ozone over Lakshadweep Islands and Cochin was 290 DU and 280 DU respectively for the year 2015. The greater concentrations in daily TCO measurements over Lakshadweep Islands for all seasons compared to Cochin lead to the speculations that, the surface ozone concentration is more because of pollution from the diesel burning emissions, since the whole Island’s population completely depends on diesel generator for the power supply. During winter season maritime station shows a decrease of ~30 DU in TCO over Lak-shadweep Island compared to coastal station Cochin (~18 DU) from the annual mean in the month of December. During pre-monsoon season TCO concentration is high over both locations. There is gradual increase of TCO concentration over Cochin from pre-monsoon to monsoon season and peak in the month of September, but decreasing TCO concentrations measured over Lakshadweep during July to August. In the analysis it was found that Intra-Seasonal Variability (ISV) in total column ozone over Lakshadweep Islands and Cochin during summer monsoon season was modulated by the monsoon dynamics and convection, thereby changes in the photochemistry of ozone production and distributions over the monsoon region. Two significant intra-seasonal oscillations (ISOs) such as Madden Julian Oscillation (MJO) and Quasi-Biweekly Oscillations (QBW) were identified in the TCO during monsoon season. The MJO shows higher periodicity (~54 days) over Lakshadweep Islands compared to the coastal station, Cochin (~48 days). Intra-seasonal variability of TCO over the maritime and coastal stations varies with geographic locations, marine boundary layer characteristics and also with seasons. The intra-seasonal variability or ISOs controls the interannual variability of TCO over a region. Hence deeper knowledge of ISOs in trace gases such as ozone helps us to understand more about the regional climate and air quality.

Preliminary Investigation of Total Ozone Column and Its Relationship with Atmospheric Variables

This study attempts to investigate the interaction between lower and upper atmosphere, employing daily data of Total Ozone Column (TOC) and atmospheric parameter (cloud cover) over Nigeria from 1998-2012;in order to study the dynamic effect of ozone on climate and vice versa. This is due to the fact that ozone and climate influence each other and the understanding of the dynamic effect of the interconnectivity is still an open research area. Monthly mean daily TOC and cloud cover data were obtained from the Earth Probe Total Ozone Mass Spectroscopy (EPTOMS) and the International Satellite Cloud Climatology Project (ISCCP)-D2 datasets respectively. Bivariate analysis and Mann Kendall trend tests were used in data analysis. MATLAB and ArcGIS software were employed in analyzing the data. Results reveal that TOC increased spatially from the coastal region to the north eastern region of the country. Seasonally, the highest value of TOC was observed at the peak of rainy season when cloud activity is very high, while the lowest value was recorded in dry season. These variations were attributed to rain producing mechanisms and atmospheric phenomena which influence the transport and distribution of ozone. Furthermore, the statistical analysis reveals significant relationship between TOC and low and middle cloud covers in contrast to high cloud cover. This relationship is consistent with previous studies using other atmospheric variables. This study has given scientific insight which is useful in understanding the coupling of the lower and upper atmosphere.

Impact of 4DVAR Assimilation of AIRS Total Column Ozone Observations on the Simulation of Hurricane Earl

The Atmospheric Infrared Sounder（AIRS） provides twice-daily global observations of brightness temperature, which can be used to retrieve the total column ozone with high spatial and temporal resolution.In order to apply the AIRS ozone data to numerical prediction of tropical cyclones, a four-dimensional variational（4DVAR） assimilation scheme on selected model levels is adopted and implemented in the mesoscale non-hydrostatic model MM5. Based on the correlation between total column ozone and potential vorticity（PV）, the observation operator of each level is established and five levels with highest correlation coefficients are selected for the 4DVAR assimilation of the AIRS total column ozone observations. The results from the numerical experiments using the proposed assimilation scheme for Hurricane Earl show that the ozone data assimilation affects the PV distributions with more mesoscale information at high levels first and then influences those at middle and low levels through the so-called asymmetric penetration of PV anomalies.With the AIRS ozone data being assimilated, the warm core of Hurricane Earl is intensified, resulting in the improvement of other fields near the hurricane center. The track prediction is improved mainly due to adjustment of the steering flows in the assimilation experiment.

Quality control of AIRS total column ozone data within tropical cyclones

The Atmospheric Infrared Sounder （AIRS） provides infrared radiance observations twice daily, which can be used to retrieve total column ozone with high spatial resolution. However, it was found that almost all of the ozone data within typhoons and hurricanes were flagged to be of bad quality by the AIRS original quality control （QC） scheme. This determination was based on the ratio of total precipitable water （TPW） error divided by TPW value, where TPW was an AIRS retrieval product. It was found that the difficulty in finding total column ozone data that could pass AIRS QC was related to the low TPW employed in the AIRS QC algorithm. In this paper, a new two-step QC scheme for AIRS total column ozone is developed. A new ratio is defined which replaces the AIRS TPW with the zonal mean TPW retrieved from the Advanced Microwave Sounding Unit. outliers when the new The first QC step is to remove ratio exceeds 33%. Linear regression models between total column ozone and mean potential vorticity are subsequently developed with daily updates, which are required for future applications of the proposed total ozone QC algorithm to vortex initialization and assimilation of AIRS data. In the second QC step, observations that significantly deviate from the models are further removed using a biweighting algorithm. Numerical results for two typhoon cases and two hurricane cases show that a large amount of good quality AIRS total ozone data is kept within Tropical Cyclones after implementing the proposed QC algorithm.

Estimation of the Total Dust Column and Dry Deposition Flux over the Yellow Sea,China Based on Shipboard Sun Photometer Measurements:Case Study

The total dust column and the dry deposition flux were calculated based on the optical properties that were measured by a shipboard sun photometer POM-01 MK II in a cloud-free and nonfrontal dust condition on 24 April 2006. The total dust column was calculated by using an integration method of the particle size distribution; the mean value was 1.42±0.30 g m 2. A linear correlation between the total dust column and the aerosol optical depth （AOD） with a linear factor of 2.7 g m 2 over the Sahara was applied to calculate the total dust column in this study; the results were lower than these calculated by the integration method. A reasonable factor of 3.2 g m^-2 was achieved by minimizing the standard deviation （SD） of the two methods. The two layers model, which includes the deposition processes of turbulent transfer, Brownian diffusion, impaction and gravitational settling over the sea＇s surface, was used to calculate the dry deposition flux; the mean value was 5.05±2.49 μg m^-2 s^-1. A correlation among the total dust column, dry deposition flux, AOD, and effective radius was discussed. The correlation between the total better than that between dust column and the AOD was the total dust column and the effective radius; however, the correlation between the dry deposition flux and the effective radius was better than that between the dry deposition flux and the AOD.

Prediction of the trend of total column ozone over the Tibetan Plateau

By using 2-D chemical model, the trend of total column ozone over the Tibetan Plateau is simulated. The results show that from 1980 to 1993, the total column ozone over the Tibetan Plateau decreases; after 1995, it starts to recover. But until 2050, it will not still reach the level of 1980 total column ozone. Under Tibetan special circulation, its total column ozone recovers more rapidly than zonal mean. Therefore, the Tibetan special meridional circulation is not a main reason why the total column ozone over the Tibetan Plateau decreases more strongly than zonal mean.

Unique influences of reboiler inventory control on the operation of totally reboiled reactive distillation columns

In this work,the dynamics and operation of the totally reboiled reactive distillation columns are visualized in terms of transfer function based process models.This kind of processes is found to be characterized by underdamped step responses due to the special topological configuration and the intricate interplay between the reaction operation and the separation operation involved.The under-dampness can be substantially alleviated through the tight inventory control of bottom reboiler and this presents beneficial effects to process dynamics and operation.Two totally reboiled reactive distillation columns,separating,respectively,a hypothetical synthesis reaction from reactants A and B to product C,and a real decomposition reaction from 1,4-butanediol to tetrahydrofuran and water,are employed to demonstrate these uncommon behaviors.The results obtained give full support to the above qualitative interpretation.Despite the strong influences of reaction kinetics and thermodynamic properties of the reacting mixtures,the totally reboiled reactive distillation columns are generally considered to present such unique behaviors and require tight inventory control of bottom reboiler to facilitate their control system development.

杭州地区大气臭氧浓度垂直分布

利用国产双池型电化学反应臭氧探空仪在杭州开展为期1年(2021年12月~2022年11月)观测,分析了该地区臭氧廓线垂直分布、臭氧柱总量以及对流层臭氧柱含量特征,并评估AIRS和MLS反演的臭氧廓线产品以及AIRS、OMIDOAS和TROPOMI反演的臭氧柱总量产品.结果表明,臭氧探空仪与地面原位臭氧分析仪观测结果具有高一致性.杭州地区臭氧垂直结构呈显著月变化特征,5月在上对流层-下平流层区域(12~16km高度范围)呈现高浓度臭氧的下传结构.4~9月在边界层附近1.5km高度以下观测到高浓度臭氧含量层.边界层内臭氧含量夏季最高,垂直变化不明显;其次是春季、秋季和冬季,均表现为随高度增加而增大.臭氧探空廓线与卫星反演臭氧垂直廓线吻合较好,在对比高度范围内相对偏差大多<10%.杭州地区臭氧柱总量和对流层柱含量平均值分别为302.1DU和40.5DU,呈明显季节变化特征.臭氧柱总量和对流层柱含量最高的季节分别为春季和夏季,5月对流层臭氧柱含量最高.臭氧探空柱总量与AIRS、OMI DOAS和TROPOMI反演臭氧柱总量一致性较好,相关系数分别为0.78、0.88和0.76.

AQC柱前衍生高效液相色谱方法测定康复新液中游离氨基酸和总肽的含量

目的应用6-氨基喹啉基-N-羟基琥珀酰亚氨基氨基甲酸酯(AQC)柱前衍生化技术,建立康复新液中游离氨基酸和总肽的高效液相色谱(HPLC)含量测定方法,并以总肽含量为指标对市售样品进行检测。方法以十八烷基硅烷键合硅胶为填充剂(Kromasil 100-5 C18色谱柱);60%乙腈(A)-0.14 mol·L^(-1)三水合乙酸钠溶液,用磷酸调节pH值至5.0(B)为流动相,梯度洗脱;柱温:39℃;流速:1.0 mL·min^(-1),检测波长:248 nm。结果14种氨基酸均能达到良好的分离效果;门冬氨酸、谷氨酸、丝氨酸、组氨酸、甘氨酸、精氨酸、苏氨酸、丙氨酸、脯氨酸、缬氨酸、赖氨酸、异亮氨酸、亮氨酸和苯丙氨酸分别在2.0~99.7、3.4~168.5、2.8~139.6、4.0~201.4、4.8~238.1、6.7~336.9、3.3~167.5、9.7~487.3、4.1~202.5、4.4~221.6、5.4~270.5、3.3~166.8、4.8~240.8、4.7~236.6μg·mL^(-1)范围内呈现良好的线性关系(r=0.9995~1.0000);游离氨基酸的平均加样回收率(n=6)为86.8%~108.1%,RSD为2.8%~4.4%,总肽酸水解氨基酸的平均加样回收率(n=6)为83.2%~102.7%,RSD为0.1%~3.1%;仪器精密度、重复性、稳定性实验的RSD均小于5.0%。结论该方法与现行质量标准的紫外分光光度法比较,二者测定的总氨基酸含量结果基本一致,但前者的专属性、重现性更优;以具有生物活性的总肽为质控指标,针对性更强,可为康复新液的质量评价提供更科学、合理的方法。

Comparison between ozonesonde measurements and satellite retrievals over Beijing,China

从2013年开始,作者团队使用自主研发电化学原理臭氧探空仪在华北平原北京地区进行每周一次观测.本研究首次使用2013-2019年期间北京地区臭氧探空数据评估Aqua卫星搭载大气红外探测仪(AIRS)和Aura卫星搭载微波临边探测器(MLS)反演垂直臭氧廓线,并对比臭氧探空,AIRS和Aura卫星搭载臭氧监测仪(OMI)臭氧柱总量结果.尽管臭氧探空与卫星反演垂直臭氧廓线在局部高度处差异较大,但整体来说两者较为接近(相对偏差大多<10%).臭氧探空,AIRS和OMI三种仪器测量臭氧柱总量的年变化特征较为一致,其年均臭氧柱总量分别为351.8±18.4 DU,348.8±19.5 DU和336.9±14.2 DU.后续对国内多站点观测数据分析将有助于进一步理解臭氧探空与卫星反演臭氧资料在不同区域的一致性.

2022年9月福建邵武边界层臭氧异常升高的气象成因

【目的】为揭示边界层O_(3)异常升高及大气热力、动力条件对其影响的机理。【方法】该文基于多源观测资料,采用天气分型、统计合成和物理量诊断等方法,探究了2022年9月福建邵武(国家级气象探空站、O_(3)探空观测科学试验基地)出现边界层O_(3)异常升高的特征及大气热动力的综合作用。【结果】2022年9月邵武近地层O_(3-8h)异常正距平最高达125.4%;在非光化学时段(21时—次日07时)O_(3-1h)较多年平均值增长137.1%;边界层O_(3)体积混合比(OVMR)明显高于不同季节的平均状态,21日O_(3)探空观测到边界层O_(3)总量为全年同层探空观测的极大值。O_(3)异常升高是副热带高压和3个台风外围下沉气流共同影响的结果,导致全月较30 a气候态平均呈现:太阳辐射偏强、低云量偏少、地面气温升高,相对湿度偏低、降水量偏少,偏北风持续时间长且风速偏大;7日和21日边界层O_(3)总量高值日的气象探空廓线呈现大气层结稳定、空气干燥、湿层薄,同时下沉对流有效位能DCAPE值较高,在200~800 J·kg^(-1)之间,即存在明显的下沉气流;低层主导风为偏东风,风速在4~8 m·s^(-1)之间。【结论】气象要素配置与大气的热力、动力条件一方面有利于O_(3)光化学生成,另一方面有利于上风向高浓度O_(3)水平输送和边界层高浓度O_(3)垂直下沉侵入,而后者是O_(3)异常升高的主要来源。

参玫五味粉中总皂苷与多糖的提取及其体外活性研究

试验旨在探究参玫五味粉中总皂苷与多糖联合提取的最佳工艺条件及其体外活性。试验以参玫五味粉总皂苷与多糖的提取质量分数为考察指标,通过对提取溶剂浓度和浸泡时间的优化确定最佳提取工艺,测定参玫五味粉总皂苷提取物与多糖提取物对羟基自由基的清除率及对亚硝酸盐的抑制率,探索其体外抗氧化和抗肿瘤活性。结果显示:在最佳提取工艺条件下,联合提取4根层析柱中总皂苷的提取率依次为92.65%、98.99%、102.68%、104.31%,出膏率为10.00%,干浸膏中总皂苷含量为34.99 mg/g;多糖的提取率依次为93.57%、98.20%、100.77%、101.27%,出膏率为12.55%,干浸膏中多糖含量为19.20 mg/g。参玫五味粉总皂苷与多糖提取物清除羟基自由基的IC_(50) 值均大于对照VC,表明两者具有体外抗氧化活性,且具有一定的亚硝酸盐抑制作用。研究表明,柱层析联合提取法同时提取参玫五味粉总皂苷与多糖,提取率高且操作简便易行,可为畜牧业饲料添加剂的发展提供参考价值。

2023年8月6日德州地震地-气耦合响应分析

为探究2023年8月6日德州5.5级地震与大气参数之间的相关性,利用NCEP/NCAR再分析资料、多普勒测风激光雷达以及Sentinel-5P卫星遥感资料对地震前后地表潜热通量、气溶胶光学厚度和CO柱浓度进行研究.结果发现:①地震前3d地表潜热通量(SLHF)出现一个高峰,峰值接近2018—2022年SLHF的平均值与标准差之和.②德州地震前3h内大气气溶胶的状态极不稳定,气溶胶光学厚度(AOD)变化异常显著,地震的影响逐渐消除后,恢复至震前水平.③与地震前相比,CO柱浓度在地震后明显增加,升高趋势出现在地震的前两天.这些大气参数的异常特征表明,德州地震发生前后岩石圈和大气层之间有相互耦合的联系.

南极臭氧柱总量的时空变化特性与影响因素分析

利用大气本底站监测数据验证了大气红外探测仪(AIRS)反演数据(2003年3月―2021年2月),在此基础上基于AIRS数据分析了南极臭氧柱总量时空分布以及变化特性,并进而利用线性回归、相关性分析、小波分析等方法,结合平流层温度和海冰数据,分析了南极臭氧柱总量变化特征的影响因素。结果表明:AIRS反演数据与大气本底站监测数据的相关系数均在0.945以上,具有较高的准确度和平稳性。南极臭氧柱总量的时间变化具有很强的周期性,谷值与谷值交替约为12个月。通过小波时-频结合分析发现,南极臭氧柱总量明显存在时间尺度为2、4、6、8~10、13年的周期,其中震荡最剧烈的第一主周期13年又以10年为周期变化,第二主周期6年又以4年为周期变化,2003―2021年内第一主周期经历了2次高-低变化期,第二主周期经历了4次高-低变化期。臭氧柱总量随季节变化明显,春季是南极臭氧柱总量最高的季节,冬季、夏季、秋季依次次之。南极臭氧的空间分布特征差异较大,总体来看纬度越高,臭氧柱总量越低,并在85°S附近达到最低值。南极洲大部分区域平流层温度与臭氧柱总量呈显著正相关,统计结果显示当平流层温度小于189K时会出现臭氧洞;南极海冰范围与南极臭氧柱总量变化基本一致,两者皆存在2、6~8、12~14年的变化周期,但海冰范围变化要早一个月。