基于1951—2019年NCEP/NCAR再分析资料、Hadley环流中心海温、海冰密集度资料,通过合成分析和诊断温度异常方程,研究不同类型ENSO对初冬北极海冰的影响。结果表明,EP La Niña发展年初冬(11—12月),巴伦支—喀拉海海冰异常减少;CP L...基于1951—2019年NCEP/NCAR再分析资料、Hadley环流中心海温、海冰密集度资料,通过合成分析和诊断温度异常方程,研究不同类型ENSO对初冬北极海冰的影响。结果表明,EP La Niña发展年初冬(11—12月),巴伦支—喀拉海海冰异常减少;CP La Niña发展初冬,巴伦支—喀拉海海冰异常增加。EP和CP型El Ni1o对初冬北极海冰的影响类似:格陵兰海海冰异常减少,而哈德逊—巴芬湾海冰异常增加。不同类型ENSO对初冬北极海冰的影响主要通过产生不同的大气遥相关,引起同期和前期的海表气温异常而实现。展开更多
Eastern oyster (Crassostrea virginica) abundance has declined severely over the past century along the Atlantic and Gulf coasts of the United States. For varied reasons, overfishing among the foremost, bivalves no lon...Eastern oyster (Crassostrea virginica) abundance has declined severely over the past century along the Atlantic and Gulf coasts of the United States. For varied reasons, overfishing among the foremost, bivalves no longer make up considerable reefs as was common. While discourse continues on oyster restoration and augmentation, gaps in knowledge of C. virginica and regional environmental interactions remain. Our primary aim was to examine the C. virginica filter feeding of phytoplankton in the Hudson River Estuary, New York City. Secondarily, this study examined the filtration of these oysters in relation to environmental attributes. Chlorophyll-a, the predominant photosynthesizing pigment in red and green algae, is an indicator of phytoplankton productivity in aquatic settings. Crassostrea virginica consumes first-tier plankton from the water column’s seston;thus analysis of chlorophyll-a content allows estimating phytoplankton concentrations, from which oyster filtration efficiency (FE) was quantified. Water conditions (temperature, dissolved oxygen, pH, salinity, turbidity, tide and flow rate) also were recorded. Spectrophotometric determination of chlorophyll-a concentration methodology was derived from the Standard Methods text favored by the US EPA. This project compared real-time Hudson River Estuary (HRE) water samples prior to passing through a contained oyster reef and samples of water post-filtration. This sampling scenario was unique as the contained reef used was fed by HRE water. Most studies on oyster filtration have been laboratory-based, and few assessed oysters in the field. This study took place at Pier 40, the River Project Wetlab, lower Hudson River along Manhattan. The FE of this reef was calculated for two months during various environmental states which can be the basis of future investigations. Statistically significant differences were found between pre- and post-filtration water samples (Z = 4.620, p < 0.001). This study provides a glimpse at how the oysters fare in the HRE environment and expands upon known oyster ecological services and environmental interactions.展开更多
The main objective of this study is to examine the NARR (North American Regional Reanalysis Model) high-resolution dataset to understand the last two decades dramatic climate changes in Hudson Bay associated with the ...The main objective of this study is to examine the NARR (North American Regional Reanalysis Model) high-resolution dataset to understand the last two decades dramatic climate changes in Hudson Bay associated with the atmospheric keys by synoptically analysis. The anomalies of the near-surface meteorological parameters such as air temperature, humidity, mean sea level pressure, wind vectors along with cloudiness, precipitation, surface albedo and downward longwave radiation at surface in seasonally based changes have been analysed. The increase in low-level thermal structure leads to changing the near-surface humidity, evaporation, cloudiness, precipitation and downward longwave radiation at the surface. Also, winds have been accelerated associated with anticyclonic curvature development. The results show significant atmospheric changes during the last two decades in Hudson Bay with the highest values mostly during winter and fall seasons in the north, east boundaries and James Bay area. Using the statistical analysis for mean low-level temperature, surface albedo, low-level clouds and evaporation at the surface during nearly recent 2 decades (1998-2018) rather than the normal climatology mean (1981-2010) have revealed the meaningful significant difference for mentioned parameters. The statistical analysis results show that during spring there is a significant positive correlation between low clouds anomaly and 2 m air temperature anomaly rather than other seasons. So, the recent atmospheric changes in the study area as a region located in the Arctic and sub-Arctic can contribute to extra-local and global warming.展开更多
This study was designed to evaluate antimicrobial and antioxidant activities of the essential oil and methanol extract from Mentha longifolia L. hudson. Antioxidant activity was evaluated through 2,2-diphenyl-l-picryl...This study was designed to evaluate antimicrobial and antioxidant activities of the essential oil and methanol extract from Mentha longifolia L. hudson. Antioxidant activity was evaluated through 2,2-diphenyl-l-picrylhydrazyl （DPPH） assay and β-carotene/linoleic acid assay. The essential oil and methanol extract were individually tested [disc-diffusion assay and evaluating minimum inhibition concentration （MIC）] against a number of bacteria. The essential oil showed strong antimicrobial activity against bacteria tested whereas the methanol extract almost remained inactive. In contrast, the extract showed much better activity than the essential oil in antioxidant activity assays employed, e.g. in the inhibition of free radical DPPH and β-carotene/linolcic acid systems. In the former, the extract was able to reduce the stable free radical DPPH with an IC50 of 55.3μg/mL while that of the oils were 10,630μg/mL. When compared to BHT （butylated hydroxytoluene）, a synthetic antioxidant, both showed weaker antioxidative potential. Similarly, in β-carotene/linoleic acid assay, these samples were not effectively able to inhibit the linoleic acid oxidation; exhibiting only 24% and 36% inhibitions at 2 mg/mL, respectively; both were far below than that of BHT. Total phenolic constituent of the extract was approximately 4.5 g/100 g as gallic acid equivalent. Gas chromatography-mass spectroscopy （GC-MS） analysis of the oil resulted in the identification of 45 constituents, ei^-piperitone epoxide, pulegone and piperitenone oxide being the main components. The results indicate that essential oil and extract ofM. longifolia L. hudson may be used as natural preservative in food against the agents of foodborne diseases and food spoilage.展开更多
The meteorological mechanisms causing the recent increase in winter wind speed on Hudson Bay are investigated by examining the NARR dataset (The North American Regional Reanalysis Model) for the past several decades. ...The meteorological mechanisms causing the recent increase in winter wind speed on Hudson Bay are investigated by examining the NARR dataset (The North American Regional Reanalysis Model) for the past several decades. Winter seasonal changes for atmospheric variables are examined and their interconnections are studied. Yearly mean near-surface temperatures are analyzed from 1948 to denote a rapid warming over Hudson Bay from late 1998 onwards. The surface albedo, air temperatures, mean sea level pressure and wind vector anomalies from 1998 to 2015 have also been studied. The comparison of the 1000 hPa wind vector mean and departures from 1981-2010 (normal period) averages have shown an intensification of anti-cyclonic anomaly pattern over most parts of Hudson Bay. The structure of the wind vector anomalies has revealed a contrast between cyclonic and anti-cyclonic local wind circulations mostly in the east, north and north-west regions along with wind speed increasing at 10 m, increases in near-surface air temperature and decreasing of the surface albedo. The anomalies of the wind vector analysing at different pressure levels show the change in wind direction mostly from northwesterly (zonal wind weakening) to south and easterlies. The polar jet wind vectors at 200 mb during anomaly time (1998-2015) have revealed the changes in magnitude and position. During winter anomaly time, the polar jet at 200 mb has been shifted mostly from rather mean colder north westerly currents to the rather warmer south and easterly anomaly currents over Hudson Bay areas. The yearly historical total accumulated Hudson Bay ice coverage during 1980-2015, using Canadian Ice Service data has shown a slight reduction in the north, north-west and eastern Hudson Bay. The linear regressions of the winter temperature anomaly at 2 m against albedo anomaly, alongside the wind speed anomaly at 10 m against air temperature at 2 m, have shown a relationship between these variables. Also, there is a statistically meaningful relation between decreased albedo and increased evaporation.展开更多
PhD, Emeritus Professor, Imperial College, UKPast-President, International Society for Rock Mechanics （ISRM）Tel： ＋44-1707-322819E-mail： john.a.hudson@gmail.com John A Hudson obtained his BSc degree in.
文摘基于1951—2019年NCEP/NCAR再分析资料、Hadley环流中心海温、海冰密集度资料,通过合成分析和诊断温度异常方程,研究不同类型ENSO对初冬北极海冰的影响。结果表明,EP La Niña发展年初冬(11—12月),巴伦支—喀拉海海冰异常减少;CP La Niña发展初冬,巴伦支—喀拉海海冰异常增加。EP和CP型El Ni1o对初冬北极海冰的影响类似:格陵兰海海冰异常减少,而哈德逊—巴芬湾海冰异常增加。不同类型ENSO对初冬北极海冰的影响主要通过产生不同的大气遥相关,引起同期和前期的海表气温异常而实现。
文摘Eastern oyster (Crassostrea virginica) abundance has declined severely over the past century along the Atlantic and Gulf coasts of the United States. For varied reasons, overfishing among the foremost, bivalves no longer make up considerable reefs as was common. While discourse continues on oyster restoration and augmentation, gaps in knowledge of C. virginica and regional environmental interactions remain. Our primary aim was to examine the C. virginica filter feeding of phytoplankton in the Hudson River Estuary, New York City. Secondarily, this study examined the filtration of these oysters in relation to environmental attributes. Chlorophyll-a, the predominant photosynthesizing pigment in red and green algae, is an indicator of phytoplankton productivity in aquatic settings. Crassostrea virginica consumes first-tier plankton from the water column’s seston;thus analysis of chlorophyll-a content allows estimating phytoplankton concentrations, from which oyster filtration efficiency (FE) was quantified. Water conditions (temperature, dissolved oxygen, pH, salinity, turbidity, tide and flow rate) also were recorded. Spectrophotometric determination of chlorophyll-a concentration methodology was derived from the Standard Methods text favored by the US EPA. This project compared real-time Hudson River Estuary (HRE) water samples prior to passing through a contained oyster reef and samples of water post-filtration. This sampling scenario was unique as the contained reef used was fed by HRE water. Most studies on oyster filtration have been laboratory-based, and few assessed oysters in the field. This study took place at Pier 40, the River Project Wetlab, lower Hudson River along Manhattan. The FE of this reef was calculated for two months during various environmental states which can be the basis of future investigations. Statistically significant differences were found between pre- and post-filtration water samples (Z = 4.620, p < 0.001). This study provides a glimpse at how the oysters fare in the HRE environment and expands upon known oyster ecological services and environmental interactions.
文摘The main objective of this study is to examine the NARR (North American Regional Reanalysis Model) high-resolution dataset to understand the last two decades dramatic climate changes in Hudson Bay associated with the atmospheric keys by synoptically analysis. The anomalies of the near-surface meteorological parameters such as air temperature, humidity, mean sea level pressure, wind vectors along with cloudiness, precipitation, surface albedo and downward longwave radiation at surface in seasonally based changes have been analysed. The increase in low-level thermal structure leads to changing the near-surface humidity, evaporation, cloudiness, precipitation and downward longwave radiation at the surface. Also, winds have been accelerated associated with anticyclonic curvature development. The results show significant atmospheric changes during the last two decades in Hudson Bay with the highest values mostly during winter and fall seasons in the north, east boundaries and James Bay area. Using the statistical analysis for mean low-level temperature, surface albedo, low-level clouds and evaporation at the surface during nearly recent 2 decades (1998-2018) rather than the normal climatology mean (1981-2010) have revealed the meaningful significant difference for mentioned parameters. The statistical analysis results show that during spring there is a significant positive correlation between low clouds anomaly and 2 m air temperature anomaly rather than other seasons. So, the recent atmospheric changes in the study area as a region located in the Arctic and sub-Arctic can contribute to extra-local and global warming.
文摘This study was designed to evaluate antimicrobial and antioxidant activities of the essential oil and methanol extract from Mentha longifolia L. hudson. Antioxidant activity was evaluated through 2,2-diphenyl-l-picrylhydrazyl （DPPH） assay and β-carotene/linoleic acid assay. The essential oil and methanol extract were individually tested [disc-diffusion assay and evaluating minimum inhibition concentration （MIC）] against a number of bacteria. The essential oil showed strong antimicrobial activity against bacteria tested whereas the methanol extract almost remained inactive. In contrast, the extract showed much better activity than the essential oil in antioxidant activity assays employed, e.g. in the inhibition of free radical DPPH and β-carotene/linolcic acid systems. In the former, the extract was able to reduce the stable free radical DPPH with an IC50 of 55.3μg/mL while that of the oils were 10,630μg/mL. When compared to BHT （butylated hydroxytoluene）, a synthetic antioxidant, both showed weaker antioxidative potential. Similarly, in β-carotene/linoleic acid assay, these samples were not effectively able to inhibit the linoleic acid oxidation; exhibiting only 24% and 36% inhibitions at 2 mg/mL, respectively; both were far below than that of BHT. Total phenolic constituent of the extract was approximately 4.5 g/100 g as gallic acid equivalent. Gas chromatography-mass spectroscopy （GC-MS） analysis of the oil resulted in the identification of 45 constituents, ei^-piperitone epoxide, pulegone and piperitenone oxide being the main components. The results indicate that essential oil and extract ofM. longifolia L. hudson may be used as natural preservative in food against the agents of foodborne diseases and food spoilage.
文摘The meteorological mechanisms causing the recent increase in winter wind speed on Hudson Bay are investigated by examining the NARR dataset (The North American Regional Reanalysis Model) for the past several decades. Winter seasonal changes for atmospheric variables are examined and their interconnections are studied. Yearly mean near-surface temperatures are analyzed from 1948 to denote a rapid warming over Hudson Bay from late 1998 onwards. The surface albedo, air temperatures, mean sea level pressure and wind vector anomalies from 1998 to 2015 have also been studied. The comparison of the 1000 hPa wind vector mean and departures from 1981-2010 (normal period) averages have shown an intensification of anti-cyclonic anomaly pattern over most parts of Hudson Bay. The structure of the wind vector anomalies has revealed a contrast between cyclonic and anti-cyclonic local wind circulations mostly in the east, north and north-west regions along with wind speed increasing at 10 m, increases in near-surface air temperature and decreasing of the surface albedo. The anomalies of the wind vector analysing at different pressure levels show the change in wind direction mostly from northwesterly (zonal wind weakening) to south and easterlies. The polar jet wind vectors at 200 mb during anomaly time (1998-2015) have revealed the changes in magnitude and position. During winter anomaly time, the polar jet at 200 mb has been shifted mostly from rather mean colder north westerly currents to the rather warmer south and easterly anomaly currents over Hudson Bay areas. The yearly historical total accumulated Hudson Bay ice coverage during 1980-2015, using Canadian Ice Service data has shown a slight reduction in the north, north-west and eastern Hudson Bay. The linear regressions of the winter temperature anomaly at 2 m against albedo anomaly, alongside the wind speed anomaly at 10 m against air temperature at 2 m, have shown a relationship between these variables. Also, there is a statistically meaningful relation between decreased albedo and increased evaporation.
文摘PhD, Emeritus Professor, Imperial College, UKPast-President, International Society for Rock Mechanics （ISRM）Tel： ＋44-1707-322819E-mail： john.a.hudson@gmail.com John A Hudson obtained his BSc degree in.
