In order to investigate the dew amounts and analysis formation conditions of dew by examining the correlations between dew amounts and meteorological factors in Carex lasiocarpa marsh in the Sanjiang Plain,the dew amo...In order to investigate the dew amounts and analysis formation conditions of dew by examining the correlations between dew amounts and meteorological factors in Carex lasiocarpa marsh in the Sanjiang Plain,the dew amounts and several meteorological factors were monitored during the growing season from June to September in 2005 and 2008 at the Sanjiang Mire Wetland Experimental Station,Chinese Academy of Sciences.Dew was collected by woodstick made by poplar tree in Carex lasiocarpa marsh and the amounts were estimated by subtraction method.The results indicated that average daily accumulated dew amounts reached the peak in August.The highest dew amounts in Carex lasiocarpa marsh were 0.201 mm/d,and the most frequent dew volume ranged from 0.08 mm/d to 0.14 mm/d.The amounts correlated positively with relative humidity,dew point temperature,and water vapor pressure.Whereas it correlated negatively with wind speed.The dew production in Carex lasiocarpa marsh more frequently occurred under the conditions of wind speed around 2.0 m/s,the water vapor pressure above 9 hPa;the relative humidity between 90% and 95% and dew point temperature above 6 ℃.展开更多
Dew is an essential water resource for the survival and reproduction of organisms in arid and semi-arid regions.Yet estimating the dew amount and quantifying its long-term variation are challenging.In this study,we el...Dew is an essential water resource for the survival and reproduction of organisms in arid and semi-arid regions.Yet estimating the dew amount and quantifying its long-term variation are challenging.In this study,we elucidate the dew amount and its long-term variation in the Kunes River Valley,Northwest China,based on the measured daily dew amount and reconstructed values(using meteorological data from 1980 to 2021),respectively.Four key results were found:(1)the daily mean dew amount was 0.05 mm during the observation period(4 July-12 August and 13 September-7 October of 2021).In 35 d of the observation period(i.e.,73%of the observation period),the daily dew amount exceeded the threshold(>0.03 mm/d)for microorganisms;(2)air temperature,relative humidity,and wind speed had significant impacts on the daily dew amount based on the relationships between the measured dew amount and meteorological variables;(3)for estimating the daily dew amount,random forest(RF)model outperformed multiple linear regression(MLR)model given its larger R^(2) and lower MAE and RMSE;and(4)the dew amount during June-October and in each month did not vary significantly from 1980 to the beginning of the 21^(st) century.It then significantly decreased for about a decade,after it increased slightly from 2013 to 2021.For the whole meteorological period of 1980-2021,the dew amount decreased significantly during June-October and in July and September,and there was no significant variation in June,August,and October.Variation in the dew amount in the Kunes River Valley was mainly driven by relative humidity.This study illustrates that RF model can be used to reconstruct long-term variation in the dew amount,which provides valuable information for us to better understand the dew amount and its relationship with climate change.展开更多
基金Under the auspices of National Natural Science Foundation of China(40771035)the Knowledge Innovation Project,Chinese Academy of Sciences(KZCX2-YW-Q06-03)
文摘In order to investigate the dew amounts and analysis formation conditions of dew by examining the correlations between dew amounts and meteorological factors in Carex lasiocarpa marsh in the Sanjiang Plain,the dew amounts and several meteorological factors were monitored during the growing season from June to September in 2005 and 2008 at the Sanjiang Mire Wetland Experimental Station,Chinese Academy of Sciences.Dew was collected by woodstick made by poplar tree in Carex lasiocarpa marsh and the amounts were estimated by subtraction method.The results indicated that average daily accumulated dew amounts reached the peak in August.The highest dew amounts in Carex lasiocarpa marsh were 0.201 mm/d,and the most frequent dew volume ranged from 0.08 mm/d to 0.14 mm/d.The amounts correlated positively with relative humidity,dew point temperature,and water vapor pressure.Whereas it correlated negatively with wind speed.The dew production in Carex lasiocarpa marsh more frequently occurred under the conditions of wind speed around 2.0 m/s,the water vapor pressure above 9 hPa;the relative humidity between 90% and 95% and dew point temperature above 6 ℃.
基金supported by the National Natural Science Foundation of China (41901048)the Project of State Key Laboratory of Desert and Oasis Ecology,Xinjiang Institute of Ecology and Geography,Chinese Academy of Sciences (E151030101)+1 种基金the Project of National Cryosphere Desert Data Center of China (2021kf02)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (2021438)
文摘Dew is an essential water resource for the survival and reproduction of organisms in arid and semi-arid regions.Yet estimating the dew amount and quantifying its long-term variation are challenging.In this study,we elucidate the dew amount and its long-term variation in the Kunes River Valley,Northwest China,based on the measured daily dew amount and reconstructed values(using meteorological data from 1980 to 2021),respectively.Four key results were found:(1)the daily mean dew amount was 0.05 mm during the observation period(4 July-12 August and 13 September-7 October of 2021).In 35 d of the observation period(i.e.,73%of the observation period),the daily dew amount exceeded the threshold(>0.03 mm/d)for microorganisms;(2)air temperature,relative humidity,and wind speed had significant impacts on the daily dew amount based on the relationships between the measured dew amount and meteorological variables;(3)for estimating the daily dew amount,random forest(RF)model outperformed multiple linear regression(MLR)model given its larger R^(2) and lower MAE and RMSE;and(4)the dew amount during June-October and in each month did not vary significantly from 1980 to the beginning of the 21^(st) century.It then significantly decreased for about a decade,after it increased slightly from 2013 to 2021.For the whole meteorological period of 1980-2021,the dew amount decreased significantly during June-October and in July and September,and there was no significant variation in June,August,and October.Variation in the dew amount in the Kunes River Valley was mainly driven by relative humidity.This study illustrates that RF model can be used to reconstruct long-term variation in the dew amount,which provides valuable information for us to better understand the dew amount and its relationship with climate change.
