Assessing and Forecasting Atmospheric Outflow of α-HCH from China on Intra-, Inter-, and Decadal Time Scales

Abstract

Atmospheric outflow of α-HCH from China from 1952 to 2009 was investigated using Chinese Gridded Pesticide Emission and Residue Model (ChnGPERM). The model results show that the outflows via the northeast boundary (NEB, longitude 115−135°E along 55°N and latitude 37−55°N along 135°E) and the mid-south boundary (MSB, longitude 100−120°E along 17°N) of China account for 47% and 35% of the total outflow, respectively. Two climate indices based on the statistical association between the time series of modeled α-HCH outflow and atmospheric sealevel pressure were developed to predict the outflow on different time scales. The first index explains 70/83% and 10/ 46% of the intra-annual variability of the outflow via the NEB and MSB during the periods of 1952−1984 and 1985−2009, respectively. The second index explains 16% and 19% of the interannual and longer time scale variability in the outflow through the NEB during June−August and via the MSB during October−December for 1991−2009, respectively. Results also revealed that climate warming may potentially result in stronger outflow via the NEB than the MSB. The linkage between the outflow with large scale atmospheric circulation patterns and climate warming trend over China was also discussed.

Influence of monsoon system on α‐HCH fate in Asia: A model study from 1948 to 2008

“…[9] [10] A fugacity method developed by Harner et al [Harner et al, 2001;Tian et al, 2012] was used to assess the response of a-HCH degradation, deposition, and reemission to environmental factors.…”

Air–Seawater Exchange of Organochlorine Pesticides along the Sediment Plume of a Large Contaminated River

“…18 Many studies have focused on the effect of declining air concentrations on the re-emission of OCPs from soils directly to the atmosphere. 19,20 Less is known about lateral remobilization from contaminated soils through superficial and diffuse runoff and riverine transport toward marine coastal environments. In the context of global climate and land use change, soil erosion and riverine transport of contaminated sediments might represent a relevant component of OCP remobilization on local or possibly regional scales.…”

“…A global ban resulted in a general and significant decline in atmospheric concentrations. − Under conditions of declining primary sources, secondary sources become increasingly influential . Many studies have focused on the effect of declining air concentrations on the re-emission of OCPs from soils directly to the atmosphere. , Less is known about lateral remobilization from contaminated soils through superficial and diffuse runoff and riverine transport toward marine coastal environments. In the context of global climate and land use change, soil erosion and riverine transport of contaminated sediments might represent a relevant component of OCP remobilization on local or possibly regional scales. − Suspended sediment-bound OCPs in estuaries undergo both incorporation into the sediment bed by particle sedimentation and redistribution between the water and suspended particles, driven by hydrological and physical/chemical conditions.…”

Assessing Environmental Fate of β-HCH in Asian Soil and Association with Environmental Factors

“…Model and Model Input. The ChnGPERM employed in this investigation has been used in previous numerical studies of α-HCH budget 16 and atmospheric outflow 17 from China. Briefly, the model consists of transfer and transport modules.…”