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Lin Y.,Liaoning Province Public Meteoro logical Service Center | Li Q.,Shenyang Regional Climate Center | Wang H.-B.,Institute of Atmospheric Environment | Ji R.-P.,Institute of Atmospheric Environment | And 6 more authors.
Chinese Journal of Ecology | Year: 2016

Using the data observed with ASD FieldSpec Pro FR spectroradiometer based on a trial with various levels of drought stress during different growth periods of maize in Jinzhou, Liaoning Province, the variation characteristics of maize canopy hyperspectral reflectance were investigated and inversion models on soil water content considering spectral parameters were established. The results showed that, after drought stress during the period from seven leaves to jointing, the spectral reflectance within spectral bands of 750 to 1400 nm, the amplitude and the area of red edge decreased and the time of their response to drought stress was shorter, and differed from those un-der well-watered condition, while the reflectance within the spectral bands from 350 to 750 nm and from 1400 to 2300 nm demonstrated an increasing trend. As far as inversion methods, the inversion error of soil water content with regression method based on hyperspectral reflectance was smaller than that of first derivative spectra. Moreover, the inversion accuracy of soil water content at the 10 cm depth was higher than that at the depth of 30 cm. © 2016, editorial Board of Chinese Journal of Ecology. All Rights Reserved.


Jia Q.-Y.,Institute of Atmospheric Environment | Zhou G.-S.,China Academy Meteorological science | Zhou G.-S.,CAS Institute of Botany | Wang Y.,CAS Institute of Botany | Liu X.-M.,Shenyang Regional Climate Center
Huanjing Kexue/Environmental Science | Year: 2010

Urban areas were significant contributors to global carbon dioxide emissions. The eddy covariance (EC) was used to measure carbon dioxide (CO2) concentration and flux data at urban area in Shenyang. This research analyzed the characteristics of atmospheric CO2 concentration and flux in October 2008 to November 2008 period before and in the heating period. The results showed that the daily variation of CO2 concentration was two-peak curve. The first peak time appeared as same as sunrise time, while the second peak time impacted by vehicles and heating. The result of CO2 flux showed that urban atmospheric CO2 was net emissions, vegetation photosynthesis absorbed CO2 of traffic, the CO2 flux peak appeared at 17:15-18:15 in the heating period, CO2 emission increased 29.37 g · (m2 · d)-1 in the heating period than that before the heating period; there was corresponding relationship between CO2 flux and the time when temperature peak and sensible heating flux (Hc) turn positive. The results also indicated that atmospheric CO2 concentration and its flux were affected seriously by both wind direction and carbon sources.


Zhang X.,Chinese Academy of Meteorological Sciences | Zhou X.,Shenyang Regional Climate Center | Zhang H.,Chinese Academy of Meteorological Sciences
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2015

Based on the surface observation data, this study established the time series of aerosol optical depth (AOD) of Huangshi city in Hubei Province in recent 60 years by using climate trend analysis and correlation analysis. The relationship between AOD and precipitation was investigated. The results showed that AOD increased significantly in Huangshi city in recent 60 years, with the maximum in 1991. The numbers of precipitation days and light rain days showed obvious decrease, while the numbers of moderate and heavy rain days increased and the change of rainstorm days was not significant. Light rain precipitation decreased with the significant increase of AOD, while the change trend of moderate precipitation and above was not obvious. In summary, the increase of AOD in Huangshi city in recent 60 years had impact on number of rainy days and precipitation, while the correlation remained to be further studied. ©, 2015, Science Press. All right reserved.


Liu N.,Institute of Atmospheric Environment | Ma Y.,Institute of Atmospheric Environment | Liu X.,Shenyang Regional Climate Center | Zhang Y.,Institute of Atmospheric Environment | And 2 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2011

In order to study the temporal variation of haze and fog in Shenyang, haze and fog times were determined from the hourly visibility, particle concentration, relative humidity and weather patterns, observed for one whole year from 1 June 2009 to 31 May 2010. Based on the experimental criteria and definitions, the haze times account for 53.9% of the total observations; far higher than the fog proportion of 8.4%. Considering the temporal variation, haze occurs most frequently in winter and fog reaches a peak in summer. They both appear comparatively frequently in autumn, while rarely in spring. The seasonal variation of particles is the same as that of haze, which means that haze is closely associated with air pollution and visibility. Haze is definitely an indicator of the city air quality. Haze times from mild to severe grade account for 72.1%, 18.2%, 6.5% and 3.2% of the total observational times. The proportion of medium and severe grade haze times is rather low. It can be seen that human health has not been affected seriously in Shenyang, but everyone should take health precautions in autumn and winter.


Cui Y.,Shenyang Regional Climate Center | Zhao C.,Shenyang Regional Climate Center | Wang T.,Shenyang Regional Climate Center | Wang Y.,Shenyang Regional Climate Center | And 6 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae | Year: 2015

Temporal and spatial characteristics of haze days with varied intensity and the possible climatic factors have been analyzed by applying meteorological data from 52 surface weather stations in Liaoning Province between 1961 and 2013. In terms of spatial distribution, there is a high-value center located in Shenyang City and two sub-high-value centers in the southwest of Jinzhou City and in the east of Chaoyang City, where annual total haze events generally exceed 50 days. The number of haze days in the western and northeastern mountainous areas is the lowest with less than 10 days a year. Haze events are more frequently observed in winter and autumn, accounting for over 60% of annual total, followed by summer and least frequently in spring. Averaged number of annual haze days in Liaoning Province have a significant increasing trend of 3.5 d/decade during 1961-2013. Days with slight, mild and moderate haze increase significantly, but the days with severe haze have no significant change. Unfavorable climate conditions exacerbated the occurrence of haze events. Significantly negative correlation is found between haze days and precipitation days, and the precipitation days show an obvious decreasing trend in the province, probably reducing the wet-depositing capacity of atmospheric pollutants. On the other hand, the reduced mean wind speed and strong wind days lead to the reduction of pollutants diffusion capacity. ©, 2015, Science Press. All right reserved.


Li L.-G.,Institute of Atmospheric Environment | Liu X.-M.,Shenyang Regional Climate Center | Zhao X.-L.,Institute of Atmospheric Environment | Wang H.-B.,Institute of Atmospheric Environment | And 2 more authors.
Chinese Journal of Applied Ecology | Year: 2010

The monthly, annual, and inter-decade variations of heat island effect in inner and outer suburbs of Shenyang and their relationships with urbanization were analyzed, based on the air temperature data from 1961 to 2008. It was indicated that the monthly and annual heat island effect was higher in inner suburb than in outer suburb, and decreased from inner suburb to outer suburb. The variation trend of monthly heat island effect in inner and outer suburbs was similar from March to November, but in contrary from December to next February, possibly due to the effects of heating in winter. The annual heat island effect in both inner and outer suburbs had an increasing trend before 2000 but a decreasing trend after 2000, and was significantly positively correlated with the green land area, population, and established construction area before 2000 (P<0. 05), but significantly negatively correlated with them after 2000 (P<0. 05), the correlation degree being 0. 43, 0. 52, and 0. 26, respectively.


Feng C.,Liaoning Academy of Agricultural science | Zheng J.-M.,Liaoning Academy of Agricultural science | Feng L.-S.,Liaoning Academy of Agricultural science | Yu X.-J.,Shenyang regional climate center | And 3 more authors.
Applied Mechanics and Materials | Year: 2014

In this study, the soil column experiment was adopted to investigated the release characteristic of P from soil by citric acid leaching. The results showed that the P release characteristics were different from each other under various citrate concentrations. At high concentration (50 mM) treatment, P concentration of effluents increased rapidly with effluent volume at the beginning, reached the maximum value after approximately 150 ml solution had passed through the columns. For the column treated with 5 mM of citric acid, the P in leachates was increased gradually to the maximum concentration, and then approached a relatively stable level during the 1000-3050 ml effluent volume. For low concentration (0.5 mM) treatment, the level of P in the effluents has always been very low, though a small peak was observed during the leaching. ©(2014) Trans Tech Publications, Switzerland.


Gong Q.,Shenyang Regional Climate Center | Wang H.-Y.,Institute of Atmospheric Environment | Zhang Y.-F.,Shenyang Regional Climate Center | Wang Y.,Shenyang Regional Climate Center | And 3 more authors.
Chinese Journal of Ecology | Year: 2013

Based on the 1961-2010 climate data from 55 meteorological stations, and by using linear regression and the comparison of different standard climate periods, this paper analyzed the changes in climate factors and their impacts on the extreme climate events in Liaoning Province. In recent 50 years, the mean annual air temperature in the Province had a significant increase, with an increment of 0. 30°C per decade. The increasing rate of the mean daily minimum air temperature (0. 48 °C per decade) was over twice of that of the mean daily maximum air temperature (0. 20 °C per decade). As compared with those in the first standard climate period (1961-1990), the mean annual air temperature in the nearest 30-year standard climate period (1981-2010) increased by 0. 5°C, the annual sunshine duration reduced by nearly 100 h, but the precipitation had no obvious change trend. Under the background of climate warming, the summer chilling damage and the extreme cold events still occurred. Extreme precipitation had no significant change trend, but the interannual fluctuation of the maximum daily precipitation and of the process maximum precipitation was greater than the linear trend. The extreme precipitation showed signs of expansion from eastern Liaoning to the whole province. No significant change was observed on the snow cover depth, but the top two ranks of the maximum snow depth all occurred after 2000. The frozen soil depth had a significantly decreased trend. Under the background of climate warming, the precaution against extreme climate events should not be ignored.


Cui Y.,Shenyang Regional Climate Center | Zhao C.-Y.,Shenyang Regional Climate Center | Zhou X.-Y.,Shenyang Regional Climate Center | Ao X.,Shenyang Regional Climate Center | And 4 more authors.
Zhongguo Huanjing Kexue/China Environmental Science | Year: 2016

Based on the surface meteorological data from 194 weather stations located in the Northeast of China during 1961~2013, temporal and spatial characteristics of haze days and haze with varied intensity have been analyzed. In terms of spatial distribution, there are two high-value centers located in the central Liaoning Province and north central Heilongjiang Province respectively, where annual total haze events generally exceed 50days. The least haze events occur in the west of Jilin Province with less than 2days per year.Furthermore, the spatial distribution of varied intensity (slight, mild, moderate and severe) haze days is approximately consistent with that of the total haze days.Haze events are more frequently observed in winter (57.9%), followed by autumn and they are least frequently in springs. Average number of annual haze days in study area has a significant increasing trend of 2.9d/decade during 1961~2013 with greatest increase occurring during 1980~2000. Days with slight,mild, moderate and severe haze have also increased, but mild, moderate and severe haze days reduced slightly in the 21st century compared with the 1980s. © 2016, Editorial Board of China Environmental Science. All right reserved.

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