Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectr...Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectrum density） of each band of gPhone gravimetric gauges in different surrounding environments were analyzed and compared with Peterson＇s NLNM（new low-noise model） which is derived from the envelope at the power spectrum density of 75 seismograph stations around the world. The results showed that： the influence of station type on the noise magnitude of gPhone gravimeter is very small; The seismic band noise magnitude（hereinafter referred to as SNM） and the sub-seismic band noise magnitude（hereinafter referred to as SSNM） in the coastal gPhone gravimeter are higher than those of inland stations. Although the local hydrological change has a great influence on the gravity observation, the rainfall is not directly relative to the noise magnitude of the instrument. Except 3 coastal stations, the eight stations which had the highest amplitudes in the SNM were located near the seismic belt. This indicates that the SNM of the gPhone Gravimeter may reflect some seismic information.Compared with the NLNM model, the PSD of the gPhone gravimeter is lower than the NLNM model in the long period band（〈3×10^（-5）Hz）, indicating that the gPhone gravimeter is more suitable for detecting long-period signals（〉10 h） than the seismometer.展开更多
In-situ measurement of atmospheric CO_2 was made at the top of the Waliguan Mountain(36°17′N,100°54′E,3816 m asl).where the air is not directly affected by the local anthropogenic and natural sources,by us...In-situ measurement of atmospheric CO_2 was made at the top of the Waliguan Mountain(36°17′N,100°54′E,3816 m asl).where the air is not directly affected by the local anthropogenic and natural sources,by using a nondispersive infrared(NDIR)analyzer and following the procedures proposed by WMO.The CO_2 in the flask samples collected on the mountain was also analyzed in a laboratory.The measurements uncover the daily,monthly and seasonal variabilities and the baseline level of the CO_2 in the air over the“clean”area of Chinese hinterland.Results suggest that the CO_2 concentration over the East Asia continent has evident periodical variation,similar to that of global distribution.In 1992,an annual mean baseline CO_2 concentration of 356.4 ppm over the continent was obtained.The annual mean val- ue was 357.2 ppm for 1993.Some relationships between the CO_2 concentration at Waliguan and the weather conditions, especially,wind speed and direction are found through the observation.展开更多
The comprehensive impact of atmospheric dry deposition and wet deposition and the pollution sources of farmlands,mining areas,and towns along the Baihe River on the water quality of Miyun reservoir is investigated fro...The comprehensive impact of atmospheric dry deposition and wet deposition and the pollution sources of farmlands,mining areas,and towns along the Baihe River on the water quality of Miyun reservoir is investigated from the angle of the complex sources of air-soil-water pollution processes,in the context of the 1990-2001 precipitation chemical data at Shangdianzi station-a WMO regional background air pollution monitoring station 15 km far from the Miyun reservoir,in conjunction with the atmospheric dry deposition and wet deposition data of the 2002-2003 Beijing City Air Pollution Observation Field Experiment(BECAPEX).Analysis results suggest that the major ions in precipitation in the Miyun reservoir region in this period were SO 42-,NO 3-,NH4+and Ca2+;wet acid deposition quantity of Miyun reservoir in the summer half year(April to September)was greater than the quantity in the winter half year(October to March),and the annual wet acid deposition in the reservoir exhibited a rising trend with the mean 1038.45 t,the maximum 1766.31 t occurred in 1996,and the minimum 604.02 t in 1994;the long-term averaged pH of atmospheric precipitation in the Miyun reservoir region was 5.20,i.e.weakly acidic,and the interannual variation of pH values displayed a falling trend.pH values of water body at various depths in the Miyun reservoir were all greater than 7.0,but they exhibited vertical and horizontal nonhomogeneity,and at the same region pH decreased vertically with depth;the 2002 and 2003 annual dustfalls in the Miyun reservoir were 13513.08 t and 3577.64 t,respectively,and the spring dustfall was the number one in a year,accounting for the 61.91%and 44.56%of the annual totals of 2002 and 2003,respectively.Because the atmospheric dry deposition and wet depositions contain multiple types heavy metal elements and harmful elements,they to some extent exacerbated the eutrophication,acidification and potential heavy metal pollution of the reservoir water.The above comprehensive analysis results reveal the complex source characters of the air-soil-water pollution process and the multi-sphere interaction effect.Besides,summer(rainy season)is a season when local soil pollutants enter the water system of reservoir after being washed out by torrential rain or heavy precipitation,which starts the air-soil-water chaining pollution processes,and results in the water pollution of rivers and reservoirs.It is found from the statistical analysis in this paper that the water pollution of Miyun reservoir was correlated with the rain wash-out and confluent flow in the peripheral and upstream local region of the reservoir,and the pollutant concentration of the reservoir water was significantly correlated with the upstream local region precipitation.Those correlation characters reveal the effect of the air-soil-water multi-spheric interaction of reservoir water pollution process.This paper presents the point of view of the complex source analysis of reservoir water pollution and a technical approach for tracing the spatial distribution of the upstream pollution source of the water systems of reservoir.展开更多
基金supported by key task project in Sicence for earthquake resilience No.XH17053the National Key Scientific Instrument and Equipment Development Projects of China(Grant No.2012YQ10022506)
文摘Based on the observations of 36 gPhone gravimeters in 2015, the background noise levels in the seismic frequency band（200-600 s） and sub-seismic band（1-6 h） are calculated. The differences in the PSD（power spectrum density） of each band of gPhone gravimetric gauges in different surrounding environments were analyzed and compared with Peterson＇s NLNM（new low-noise model） which is derived from the envelope at the power spectrum density of 75 seismograph stations around the world. The results showed that： the influence of station type on the noise magnitude of gPhone gravimeter is very small; The seismic band noise magnitude（hereinafter referred to as SNM） and the sub-seismic band noise magnitude（hereinafter referred to as SSNM） in the coastal gPhone gravimeter are higher than those of inland stations. Although the local hydrological change has a great influence on the gravity observation, the rainfall is not directly relative to the noise magnitude of the instrument. Except 3 coastal stations, the eight stations which had the highest amplitudes in the SNM were located near the seismic belt. This indicates that the SNM of the gPhone Gravimeter may reflect some seismic information.Compared with the NLNM model, the PSD of the gPhone gravimeter is lower than the NLNM model in the long period band（〈3×10^（-5）Hz）, indicating that the gPhone gravimeter is more suitable for detecting long-period signals（〉10 h） than the seismometer.
基金This study is supported by the National Science and Technology Commission of China.
文摘In-situ measurement of atmospheric CO_2 was made at the top of the Waliguan Mountain(36°17′N,100°54′E,3816 m asl).where the air is not directly affected by the local anthropogenic and natural sources,by using a nondispersive infrared(NDIR)analyzer and following the procedures proposed by WMO.The CO_2 in the flask samples collected on the mountain was also analyzed in a laboratory.The measurements uncover the daily,monthly and seasonal variabilities and the baseline level of the CO_2 in the air over the“clean”area of Chinese hinterland.Results suggest that the CO_2 concentration over the East Asia continent has evident periodical variation,similar to that of global distribution.In 1992,an annual mean baseline CO_2 concentration of 356.4 ppm over the continent was obtained.The annual mean val- ue was 357.2 ppm for 1993.Some relationships between the CO_2 concentration at Waliguan and the weather conditions, especially,wind speed and direction are found through the observation.
基金supported by the Major State Bas ic Research Development Program“973”Project(Grant No.TG1999045700)the International Sci-Tech Cooperat ive Project of China Sci-Tech Department(Grant No.2004DFA06100).
文摘The comprehensive impact of atmospheric dry deposition and wet deposition and the pollution sources of farmlands,mining areas,and towns along the Baihe River on the water quality of Miyun reservoir is investigated from the angle of the complex sources of air-soil-water pollution processes,in the context of the 1990-2001 precipitation chemical data at Shangdianzi station-a WMO regional background air pollution monitoring station 15 km far from the Miyun reservoir,in conjunction with the atmospheric dry deposition and wet deposition data of the 2002-2003 Beijing City Air Pollution Observation Field Experiment(BECAPEX).Analysis results suggest that the major ions in precipitation in the Miyun reservoir region in this period were SO 42-,NO 3-,NH4+and Ca2+;wet acid deposition quantity of Miyun reservoir in the summer half year(April to September)was greater than the quantity in the winter half year(October to March),and the annual wet acid deposition in the reservoir exhibited a rising trend with the mean 1038.45 t,the maximum 1766.31 t occurred in 1996,and the minimum 604.02 t in 1994;the long-term averaged pH of atmospheric precipitation in the Miyun reservoir region was 5.20,i.e.weakly acidic,and the interannual variation of pH values displayed a falling trend.pH values of water body at various depths in the Miyun reservoir were all greater than 7.0,but they exhibited vertical and horizontal nonhomogeneity,and at the same region pH decreased vertically with depth;the 2002 and 2003 annual dustfalls in the Miyun reservoir were 13513.08 t and 3577.64 t,respectively,and the spring dustfall was the number one in a year,accounting for the 61.91%and 44.56%of the annual totals of 2002 and 2003,respectively.Because the atmospheric dry deposition and wet depositions contain multiple types heavy metal elements and harmful elements,they to some extent exacerbated the eutrophication,acidification and potential heavy metal pollution of the reservoir water.The above comprehensive analysis results reveal the complex source characters of the air-soil-water pollution process and the multi-sphere interaction effect.Besides,summer(rainy season)is a season when local soil pollutants enter the water system of reservoir after being washed out by torrential rain or heavy precipitation,which starts the air-soil-water chaining pollution processes,and results in the water pollution of rivers and reservoirs.It is found from the statistical analysis in this paper that the water pollution of Miyun reservoir was correlated with the rain wash-out and confluent flow in the peripheral and upstream local region of the reservoir,and the pollutant concentration of the reservoir water was significantly correlated with the upstream local region precipitation.Those correlation characters reveal the effect of the air-soil-water multi-spheric interaction of reservoir water pollution process.This paper presents the point of view of the complex source analysis of reservoir water pollution and a technical approach for tracing the spatial distribution of the upstream pollution source of the water systems of reservoir.
