Lake-effect snowfall(LES)occurs when cold air moves across open lakes.LES is expected to occur more frequently over the TP,due to the intensified lake expansion caused by intensified global warming.Thus,there is an ur...Lake-effect snowfall(LES)occurs when cold air moves across open lakes.LES is expected to occur more frequently over the TP,due to the intensified lake expansion caused by intensified global warming.Thus,there is an urgent need to comprehensively assess the LES over the TP.Here,we revealed that the LES is triggered by westerly southward shift leading to the drop in air temperature and is positively correlated with lake area,wind speed and longitude across 12 large lakes(>300 km^(2))based on satellite observations and reanalysis data.Using a sensitivity model simulation,we determined that large lakes in the southern TP contributed to more than 50%of the snowfall in the downwind area in 2013.Projections indicate that the westerly-triggered LES will increase under the future RCP4.5 climate warming scenario,highlighting the importance of developing adaptive policies to address the growing risks associated with future LES.展开更多
In this study, high-resolution weather research and forecasting(WRF) simulations are used to explore the sensitivity of lake-effect convection over Poyang Lake(PL) to the change of lake surface temperature(LST). A con...In this study, high-resolution weather research and forecasting(WRF) simulations are used to explore the sensitivity of lake-effect convection over Poyang Lake(PL) to the change of lake surface temperature(LST). A control experiment(CTR) with climate mean LST(303 K) is compared with six sensitivity experiments(CTR-1/2/3K and CTR+1/2/3K) in which the LSTs are set based on the mean LST difference of 6 K between the maximum and minimum. The results show that the CTR experiment reasonably reproduces the lake-effect convection, and the lake-effect convection in sensitivity experiments is significantly influenced by the LST. With the increase of LST, the initiation time of the lake-effect convection is advanced gradually, while the initiation location moves PL from its shore.The lake-effect convection strengthens(weakens) in the increase-temperature CTR+1/2/3K(decrease-temperature CTR-1/2/3K) experiments, but the lake-effect convection does not monotonically strengthen with the LST, for the strongest one occurring in the CTR+1K experiment. The corresponding diagnostic analysis shows that the upward sensible heat flux and latent heat flux over PL increase with the LST, resulting in the enhancement of the lake-land breeze and the enlargement of the convective available potential energy(CAPE). This is the main reason for the changes in the initiation time and location, as well as the intensity of lake-effect convection in different experiments.In addition, the non-monotonous variation of the level of free convection, which is mainly induced by the non-monotonous variation of the lifting condensation level, is responsible for the non-monotonous variation of the lake-effect convection intensity with the LST.展开更多
基金supported by the Youth Innovation Promotion Association of Chinese Academy of Sciences(CAS2022067)the Basic Science Center for Tibetan Plateau Earth System(41988101)。
文摘Lake-effect snowfall(LES)occurs when cold air moves across open lakes.LES is expected to occur more frequently over the TP,due to the intensified lake expansion caused by intensified global warming.Thus,there is an urgent need to comprehensively assess the LES over the TP.Here,we revealed that the LES is triggered by westerly southward shift leading to the drop in air temperature and is positively correlated with lake area,wind speed and longitude across 12 large lakes(>300 km^(2))based on satellite observations and reanalysis data.Using a sensitivity model simulation,we determined that large lakes in the southern TP contributed to more than 50%of the snowfall in the downwind area in 2013.Projections indicate that the westerly-triggered LES will increase under the future RCP4.5 climate warming scenario,highlighting the importance of developing adaptive policies to address the growing risks associated with future LES.
基金Supported by the National Natural Science Foundation of China (41865003)Key Lab of Poyang Lake Wetland and Watershed Research of Ministry of Eduction (Jiangxi Normal University)(PK2022005)。
文摘In this study, high-resolution weather research and forecasting(WRF) simulations are used to explore the sensitivity of lake-effect convection over Poyang Lake(PL) to the change of lake surface temperature(LST). A control experiment(CTR) with climate mean LST(303 K) is compared with six sensitivity experiments(CTR-1/2/3K and CTR+1/2/3K) in which the LSTs are set based on the mean LST difference of 6 K between the maximum and minimum. The results show that the CTR experiment reasonably reproduces the lake-effect convection, and the lake-effect convection in sensitivity experiments is significantly influenced by the LST. With the increase of LST, the initiation time of the lake-effect convection is advanced gradually, while the initiation location moves PL from its shore.The lake-effect convection strengthens(weakens) in the increase-temperature CTR+1/2/3K(decrease-temperature CTR-1/2/3K) experiments, but the lake-effect convection does not monotonically strengthen with the LST, for the strongest one occurring in the CTR+1K experiment. The corresponding diagnostic analysis shows that the upward sensible heat flux and latent heat flux over PL increase with the LST, resulting in the enhancement of the lake-land breeze and the enlargement of the convective available potential energy(CAPE). This is the main reason for the changes in the initiation time and location, as well as the intensity of lake-effect convection in different experiments.In addition, the non-monotonous variation of the level of free convection, which is mainly induced by the non-monotonous variation of the lifting condensation level, is responsible for the non-monotonous variation of the lake-effect convection intensity with the LST.
文摘白洋淀是雄安新区核心生态功能区,其水生态安全备受关注。本研究采集白洋淀代表性点位的表层沉积物,以青海弧菌Q67(Vibrio qinghaiensis Q67)为受试生物进行急性毒性筛查,以河蚬(Corbicula fluminea)为模型生物开展毒性效应机制解析,典型污染物筛查完成污染物风险评估。通过整合Q67急性毒性分级,河蚬CAT、SOD、AChE、P450、GST活性、MDA含量等生物标志物和掘穴率和虹吸速率个体行为学差异性指标,以及污染物风险分级等4条证据链(lines of evidence,LoE),构建了加权证据法(weight of evidence,WoE)框架,实现对沉积物质量综合评价。结果显示,点位S4(大田庄村)、S7(南刘庄村)和S8(枣林庄村)沉积物对Q67表现急性毒性效应;河蚬转录组分析表明,差异表达基因显著富集于神经信号通路、代谢通路及氧化损伤等相关通路;6项生物标志物指标进一步证实了上述亚致死效应,S6(圈头村)、S7(南刘庄村)和S8(枣林庄村)的综合生物标志物响应指数分别达11.68、15.99和11.13,高于其他点位;行为学指标上,S2(北河庄村)、S4(大田庄村)、S5(端村)、S7(南刘庄村)的掘穴率和虹吸速率均发生显著改变。化学筛查中48种高关注新污染物(含精神类药物、抗生素等)与6种重金属(Cr、Mn、Zn、Cu、Cd、Pb)检测显示,克林霉素(N.D.~43.15μg·kg^(-1))(以干质量dw计,下同)和Cd(0.10~0.68 mg·kg^(-1))存在中度及以上生态风险,为主要风险因子。WoE整合评价表明,邻近城镇的S4(大田庄村)、S6(圈头村)、S7(南刘庄村)点位WoE值较高,沉积物质量相对较差。本研究通过多证据链整合明确了白洋淀沉积物污染特征与关键风险因子,为沉积物污染防控及雄安新区生态安全保障提供数据基础。
