Inhomogeneities in the daily mean/maximum/ minimum temperature （Tm/Tmax/Tmin） series from 1960- 2008 at 549 National Standard Stations （NSSs） in China were analyzed by using the Multiple Analysis of Series for Hom...Inhomogeneities in the daily mean/maximum/ minimum temperature （Tm/Tmax/Tmin） series from 1960- 2008 at 549 National Standard Stations （NSSs） in China were analyzed by using the Multiple Analysis of Series for Homogenization （MASH） software package. Typical biases in the dataset were illustrated via the cases of Beijing （B J）, Wutaishan （WT）, Urumqi （UR） and Henan （HN） stations. The homogenized dataset shows a mean warming trend of 0.261/0.193/0.344℃/decade for the annual series of Tm/Tmax/Tmin, slightly smaller than that of the original dataset by 0.006/0.009/0.007℃/decade. However, considerable differences between the adjusted and original datasets were found at the local scale. The adjusted Tmin series shows a significant warming trend almost everywhere for all seasons, while there are a number of stations with an insignificant trend in the original dataset. The adjusted Tm data exhibit significant warming trends annually as well as for the autumn and winter seasons in northern China, and cooling trends only for the summer in the middle reaches of the Yangtze River and parts of central China and for the spring in southwestern China, while the original data show cooling trends at several stations for the annual and seasonal scales in the Qinghai, Shanxi, Hebei, and Xinjiang provinces. The adjusted Tmax data exhibit cooling trends for summers at a number of stations in the mid-lower reaches of the Yangtze and Yellow Rivers and for springs and winters at a few stations in southwestern China, while the original data show cooling trends at three/four stations for the annual/autumn periods in the Qinghai and Yunnan provinces. In general, the number of stations with a cooling trend was much smaller in the adjusted Tm and Tmax dataset than in the original dataset. The cooling trend for summers is mainly due to cooling in August. The results of homogenization using MASH appear to be robust; in particular, different groups of stations with consideration of elevation led to minor effects i展开更多
Homogenization of climate observations remains a challenge to climate change researchers, especially in cases where metadata （e.g., probable dates of break points） are not always available. To examine the inffuence ...Homogenization of climate observations remains a challenge to climate change researchers, especially in cases where metadata （e.g., probable dates of break points） are not always available. To examine the inffuence of metadata on homogenizing climate data, the authors applied the recently developed Multiple Analysis of Series for Homogenization （MASH） method to the Beijing （BJ） daily temperature series for 1960- 2006 in three cases with different references： （1） 13M-considering metadata at BJ and 12 nearby stations; （2） 13NOM-considering the same 13 stations without metadata; and （3） 21NOM-considering 20 further stations and BJ without metadata. The estimated mean annual, seasonal, and monthly inhomogeneities are similar between the 13M and 13NOM cases, while those in the 21NOM case are slightly different. The detected biases in the BJ series corresponding to the documented relocation dates are as low as -0.71~0C, -0.79~0C, and -0.5~0C for the annual mean in the 3 cases, respectively. Other biases, including those undocumented in metadata, are minor. The results suggest that any major inhomogeneity could be detected via MASH, albeit with minor differences in estimating inhomogeneities based on the different references. The adjusted annual series showed a warming trend of 0.337, 0.316, and 0.365~0C （10 yr）^（-1） for the three cases, respectively, smaller than the estimate of 0.453~0C （10 yr）^（-1） in the original series, mainly due to the relocation-induced biases. The impact of the MASH-type homogenization on estimates of climate extremes in the daily temperature series is also discussed.展开更多
Two homogenized datasets of daily maximum temperature （Tmax）, mean temperature （Tm）, and min- imum temperature （Tmin） series in China have recently been developed. One is CHTM3.0, based on the Multiple Analysis ...Two homogenized datasets of daily maximum temperature （Tmax）, mean temperature （Tm）, and min- imum temperature （Tmin） series in China have recently been developed. One is CHTM3.0, based on the Multiple Analysis of Series for Homogenization （MASH） method, and includes 753 stations for the period 1960-2013. The other is CHHTD1.0, based on the Relative Homogenization test （RHtest）, and includes 2419 stations over the period 1951-2011. The daily Tmax/Tm/Tmin series at 751 stations, which are in both datasets, are chosen and compared against the raw dataset, with regard to the number of breakpoints, long-term climate trends, and their geographical patterns. The results indicate that some robust break points associated with relocations can be detected, the inhomogeneities are removed by both the MASH and RHtest method, and the data quality is improved in both homogenized datasets. However, the differences between CHTM3.0 and CHHTD1.0 are notable. By and large, in CHHTD1.0, the break points detected are fewer, but the adjustments for inhomogeneities and the resultant changes of linear trend estimates are larger. In contrast, CHTM3.0 provides more reasonable geographical patterns of long-term climate trends over the region. The reasons for the differences between the datasets include： （1） different algorithms for creating reference series for adjusting the candidate series--more neighboring stations used in MASH and hence larger-scale regional signals retained; （2） different algorithms for cMculating the adjustments--larger adjustments in RHtest in general, partly due to the individual local reference information used; and （3） different rules for judging inhomogeneity--all detected break points are adjusted in CHTM3.0, based on MASH, while a number of break points detected via RHtest but without supporting metadata are overlooked in CHHTD1.0. The present results suggest that CHTM3.0 is more suitable for analyses of large-scale climate change in China, while CHHTD1.0 contains more origina展开更多
Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based ...Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based on analysis of empirical cumulative density function（ECDF） regarding climate extremes.The cumulative density functions of daily precipitation series,the trends of annual and seasonal precipitation,and summer extreme events during 1960–2012 in the original and final adjusted series at Beijing station were comparatively analyzed to show the necessity and efficiency of the new method.Results indicate that the ECDF adjustments can improve the homogeneity of high-order moments of daily series and the estimation of climate trends in extremes.The linear trends of the regional-mean annual and seasonal（spring,summer,autumn,and winter）precipitation series are-10.16,4.97,-20.04,5.02,and-0.11 mm（10 yr）-1,respectively.The trends over the BMR increase consistently for spring/autumn and decrease for the whole year/summer; however,the trends for winter decrease in southern parts and increase in northern parts.Urbanization affects local trends of precipitation amount,frequency,and intensity and their geographical patterns.For the urban-influenced sites,urbanization tends to slow down the magnitude of decrease in the precipitation and extreme amount series by approximately-10.4% and-6.0%,respectively; enhance the magnitude of decrease in precipitation frequency series by approximately 5.7%; reduce that of extremes by approximately-8.9%; and promote the decreasing trends in the summer intensity series of both precipitation and extremes by approximately 6.8% and51.5%,respectively.展开更多
This study was conducted to compare effects of 3 physical forms of feed including mash(diet 1), pellet(diet 2) and complete feed block(CFB; diet 3) on digestion, fermentation and performance of lambs.Twenty-one lambs ...This study was conducted to compare effects of 3 physical forms of feed including mash(diet 1), pellet(diet 2) and complete feed block(CFB; diet 3) on digestion, fermentation and performance of lambs.Twenty-one lambs with an initial average body weight of 26 ± 2.5 kg and 6 ± 1.5 months of age were assigned through a completely randomized design to 3 treatments and 7 replicates. The experimental treatments had the same formulation. The results of present experiment showed that CFB significantly increased feed intake and nutrient digestibility(P < 0.05). There was no significant difference among the diets for rumen fluid pH, blood glucose, concentration of volatile fatty acids(P > 0.05), except acetic acid(P < 0.05). The rumen ammonia nitrogen(NH3-N), mixed rumen protozoa population(RPP), Entodiniums spp., Epidiniums spp., blood urea nitrogen(BUN) concentration, rumination time adjusted for dry matter(DM), neutral detergent fiber(NDF), acid detergent fiber(ADF) intake, and total body weight gain of lambs in CFB diet were the highest among all diets(P < 0.05). Feed conversion ratio at days 31 to 45 and whole experimental period were better in CFB than in other diets(P < 0.05). Overall, according to the findings of the present study, among 3 physical forms of the diets, CFB had the best efficiency due to improvement of nutrient digestibility, rumen fermentation and performance of lambs. Therefore, the CFB diet offers the best result in lambs compared with mash and pellet diets.展开更多
基金supported by the National Basic Research Program of China 2009CB421401 and 2006CB400503
文摘Inhomogeneities in the daily mean/maximum/ minimum temperature （Tm/Tmax/Tmin） series from 1960- 2008 at 549 National Standard Stations （NSSs） in China were analyzed by using the Multiple Analysis of Series for Homogenization （MASH） software package. Typical biases in the dataset were illustrated via the cases of Beijing （B J）, Wutaishan （WT）, Urumqi （UR） and Henan （HN） stations. The homogenized dataset shows a mean warming trend of 0.261/0.193/0.344℃/decade for the annual series of Tm/Tmax/Tmin, slightly smaller than that of the original dataset by 0.006/0.009/0.007℃/decade. However, considerable differences between the adjusted and original datasets were found at the local scale. The adjusted Tmin series shows a significant warming trend almost everywhere for all seasons, while there are a number of stations with an insignificant trend in the original dataset. The adjusted Tm data exhibit significant warming trends annually as well as for the autumn and winter seasons in northern China, and cooling trends only for the summer in the middle reaches of the Yangtze River and parts of central China and for the spring in southwestern China, while the original data show cooling trends at several stations for the annual and seasonal scales in the Qinghai, Shanxi, Hebei, and Xinjiang provinces. The adjusted Tmax data exhibit cooling trends for summers at a number of stations in the mid-lower reaches of the Yangtze and Yellow Rivers and for springs and winters at a few stations in southwestern China, while the original data show cooling trends at three/four stations for the annual/autumn periods in the Qinghai and Yunnan provinces. In general, the number of stations with a cooling trend was much smaller in the adjusted Tm and Tmax dataset than in the original dataset. The cooling trend for summers is mainly due to cooling in August. The results of homogenization using MASH appear to be robust; in particular, different groups of stations with consideration of elevation led to minor effects i
基金supported by grants from the National Basic Research Program of China(2009CB421401/2006CB400503)China Meteorological Administration (GYHY200706001)
文摘Homogenization of climate observations remains a challenge to climate change researchers, especially in cases where metadata （e.g., probable dates of break points） are not always available. To examine the inffuence of metadata on homogenizing climate data, the authors applied the recently developed Multiple Analysis of Series for Homogenization （MASH） method to the Beijing （BJ） daily temperature series for 1960- 2006 in three cases with different references： （1） 13M-considering metadata at BJ and 12 nearby stations; （2） 13NOM-considering the same 13 stations without metadata; and （3） 21NOM-considering 20 further stations and BJ without metadata. The estimated mean annual, seasonal, and monthly inhomogeneities are similar between the 13M and 13NOM cases, while those in the 21NOM case are slightly different. The detected biases in the BJ series corresponding to the documented relocation dates are as low as -0.71~0C, -0.79~0C, and -0.5~0C for the annual mean in the 3 cases, respectively. Other biases, including those undocumented in metadata, are minor. The results suggest that any major inhomogeneity could be detected via MASH, albeit with minor differences in estimating inhomogeneities based on the different references. The adjusted annual series showed a warming trend of 0.337, 0.316, and 0.365~0C （10 yr）^（-1） for the three cases, respectively, smaller than the estimate of 0.453~0C （10 yr）^（-1） in the original series, mainly due to the relocation-induced biases. The impact of the MASH-type homogenization on estimates of climate extremes in the daily temperature series is also discussed.
基金Supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA05090100)National Science and Technology Support Program of China(2012BAC22B04)+1 种基金China Meteorological Administration Special Public Welfare Research Fund(GYHY201206013)National Natural Science Foundation of China(41505071)
文摘Two homogenized datasets of daily maximum temperature （Tmax）, mean temperature （Tm）, and min- imum temperature （Tmin） series in China have recently been developed. One is CHTM3.0, based on the Multiple Analysis of Series for Homogenization （MASH） method, and includes 753 stations for the period 1960-2013. The other is CHHTD1.0, based on the Relative Homogenization test （RHtest）, and includes 2419 stations over the period 1951-2011. The daily Tmax/Tm/Tmin series at 751 stations, which are in both datasets, are chosen and compared against the raw dataset, with regard to the number of breakpoints, long-term climate trends, and their geographical patterns. The results indicate that some robust break points associated with relocations can be detected, the inhomogeneities are removed by both the MASH and RHtest method, and the data quality is improved in both homogenized datasets. However, the differences between CHTM3.0 and CHHTD1.0 are notable. By and large, in CHHTD1.0, the break points detected are fewer, but the adjustments for inhomogeneities and the resultant changes of linear trend estimates are larger. In contrast, CHTM3.0 provides more reasonable geographical patterns of long-term climate trends over the region. The reasons for the differences between the datasets include： （1） different algorithms for creating reference series for adjusting the candidate series--more neighboring stations used in MASH and hence larger-scale regional signals retained; （2） different algorithms for cMculating the adjustments--larger adjustments in RHtest in general, partly due to the individual local reference information used; and （3） different rules for judging inhomogeneity--all detected break points are adjusted in CHTM3.0, based on MASH, while a number of break points detected via RHtest but without supporting metadata are overlooked in CHHTD1.0. The present results suggest that CHTM3.0 is more suitable for analyses of large-scale climate change in China, while CHHTD1.0 contains more origina
基金supported by the State Programs of Science and Technology Development(Grant No.2012BAC22B04)the National Natural Science Foundation of China(Grant No.41475078)+1 种基金the National Department Public Benefit Research Foundation of China(Grant No.GYHY201206013)the Science and Technology program of the Institute of Urban Meteorology(Grant No.IUMKY201302PP0102)
文摘Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based on analysis of empirical cumulative density function（ECDF） regarding climate extremes.The cumulative density functions of daily precipitation series,the trends of annual and seasonal precipitation,and summer extreme events during 1960–2012 in the original and final adjusted series at Beijing station were comparatively analyzed to show the necessity and efficiency of the new method.Results indicate that the ECDF adjustments can improve the homogeneity of high-order moments of daily series and the estimation of climate trends in extremes.The linear trends of the regional-mean annual and seasonal（spring,summer,autumn,and winter）precipitation series are-10.16,4.97,-20.04,5.02,and-0.11 mm（10 yr）-1,respectively.The trends over the BMR increase consistently for spring/autumn and decrease for the whole year/summer; however,the trends for winter decrease in southern parts and increase in northern parts.Urbanization affects local trends of precipitation amount,frequency,and intensity and their geographical patterns.For the urban-influenced sites,urbanization tends to slow down the magnitude of decrease in the precipitation and extreme amount series by approximately-10.4% and-6.0%,respectively; enhance the magnitude of decrease in precipitation frequency series by approximately 5.7%; reduce that of extremes by approximately-8.9%; and promote the decreasing trends in the summer intensity series of both precipitation and extremes by approximately 6.8% and51.5%,respectively.
基金Ramin Agriculture and Natural Resources University of Khuzestan for financial support
文摘This study was conducted to compare effects of 3 physical forms of feed including mash(diet 1), pellet(diet 2) and complete feed block(CFB; diet 3) on digestion, fermentation and performance of lambs.Twenty-one lambs with an initial average body weight of 26 ± 2.5 kg and 6 ± 1.5 months of age were assigned through a completely randomized design to 3 treatments and 7 replicates. The experimental treatments had the same formulation. The results of present experiment showed that CFB significantly increased feed intake and nutrient digestibility(P < 0.05). There was no significant difference among the diets for rumen fluid pH, blood glucose, concentration of volatile fatty acids(P > 0.05), except acetic acid(P < 0.05). The rumen ammonia nitrogen(NH3-N), mixed rumen protozoa population(RPP), Entodiniums spp., Epidiniums spp., blood urea nitrogen(BUN) concentration, rumination time adjusted for dry matter(DM), neutral detergent fiber(NDF), acid detergent fiber(ADF) intake, and total body weight gain of lambs in CFB diet were the highest among all diets(P < 0.05). Feed conversion ratio at days 31 to 45 and whole experimental period were better in CFB than in other diets(P < 0.05). Overall, according to the findings of the present study, among 3 physical forms of the diets, CFB had the best efficiency due to improvement of nutrient digestibility, rumen fermentation and performance of lambs. Therefore, the CFB diet offers the best result in lambs compared with mash and pellet diets.
