Article
Geosciences, Multidisciplinary
Maximilien Bolot, Stephan Fueglistaler
Summary: A recent study found that convective ice flux near the tropical tropopause plays a crucial role in moisture transport, but due to challenging observation conditions and computational limitations, the quantification of these storms' effects remains limited.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
Jacqueline M. Nugent, Christopher S. Bretherton
Summary: Tropical convection that overshoots the cold point tropopause can directly impact the climate by affecting water vapor, temperatures, and thin cirrus in the upper troposphere-lower stratosphere region. The distribution of these overshoots between land and ocean can determine their influence in a changing climate. Cold point-overshooting convection occurs more frequently over convectively active land areas than over warm oceans. This proxy method can evaluate the accuracy of simulated cold point overshoots. Cold point overshoots have an influence on the temperature structure and water vapor in the lower stratosphere.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Geosciences, Multidisciplinary
I. Reinares Martinez, S. Evan, F. G. Wienhold, J. Brioude, E. J. Jensen, T. D. Thornberry, D. Heron, B. Verreyken, S. Korner, H. Vomel, J. -M. Metzger, F. Posny
Summary: A nascent in situ cirrus was observed on January 11, 2019 in the tropical tropopause layer over the southwestern Indian Ocean. Data from balloon-borne instruments were used to characterize the cirrus and its environment. Optical modeling was employed to estimate the cirrus microphysical properties, indicating that the formation may have been triggered by a high-frequency gravity wave.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Astronomy & Astrophysics
J. M. Nugent, S. M. Turbeville, C. S. Bretherton, P. N. Blossey, T. P. Ackerman
Summary: Pervasive cirrus clouds in the upper troposphere and tropical tropopause layer influence climate by altering radiation balance and water vapor budget. Global storm-resolving models can better simulate deep convection and cirrus with further improvements. Fine-grid models show good agreement but also differences in representing ice and snow formation.
EARTH AND SPACE SCIENCE
(2022)
Article
Geosciences, Multidisciplinary
Matthias Rothlisberger, Lukas Papritz
Summary: Kinematic backward trajectories are used to globally quantify the contributions of different processes to near-surface temperature anomalies. Diabatic cooling dominates in the coldest regions, while advection is the main factor in most ocean areas. TN1day anomalies over extratropical land masses arise from a combination of both processes. The mean age and formation distance of TN1day anomalies vary strongly in space. Five distinct types of TN1day events are identified based on physical and spatio-temporal characteristics.
GEOPHYSICAL RESEARCH LETTERS
(2023)
Article
Multidisciplinary Sciences
E. Larour, E. Rignot, M. Poinelli, B. Scheuchl
Summary: Research has shown that ice shelf thinning does not reactivate rifts, but rather heals them; on the other hand, thinning of the ice melange encasing preexisting rifts controls the opening rate of the rift, with an above-linear dependence on thinning.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Meteorology & Atmospheric Sciences
Zhenquan Wang, Jinming Ge, Jialin Yan, Wenxue Li, Xuan Yang, Meihua Wang, Xiaoyu Hu
Summary: This research focuses on the diurnal cycles and radiative effects of tropical oceanic high clouds above the 300 hPa level. The study finds that the diurnal cycle of these clouds significantly impacts their radiative effects, with the shifting of the diurnal centroid from midnight towards noon correlating with a decrease in net cloud radiative effects. The strength of convection and cold point temperature are identified as major factors influencing the diurnal-cycle centroid of these clouds. Additionally, observations show a correlation between the diurnal-cycle centroid of these clouds and the global mean temperature, with a 2-hour shift towards noon for every 1 degree Celsius increase in global mean temperature.
Article
Environmental Sciences
Jing Feng, Yi Huang
Summary: The study found that tropical cyclone events significantly increase the occurrence frequency of TTL clouds, mainly contributed by overshooting deep convection. Using a synergistic method with satellite observations, a vertically oscillating pattern of temperature anomalies above tropical cyclones was discovered.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Astronomy & Astrophysics
S. M. Turbeville, J. M. Nugent, T. P. Ackerman, C. S. Bretherton, P. N. Blossey
Summary: This study investigates the representation of tropical cirrus in global storm-resolving models, which have higher resolution and explicit convection. Model differences in cirrus populations dominate over regional differences, likely driven by subgrid processes. Understanding these model differences is essential in predicting future climates accurately.
EARTH AND SPACE SCIENCE
(2022)
Article
Environmental Sciences
Chandrika Dhanapalan Aju, Rajesh Reghunath, Ashokan Laila Achu, Ambujendran Rajaneesh
Summary: The study on the hydrogeochemistry of groundwater in the Kallada River Basin in South India revealed rock-water interaction processes and major ion concentration changes, providing significant insights into the hydrogeochemical processes in KRB. The dominant groundwater types and geochemical associations varied spatially and temporally, highlighting the complex hydrogeochemical characteristics of the region. The pre-monsoon water types were Ca2+-Mg2+-Cl- while post-monsoon saw a shift to Na+-Cl-, with deeper wells showing a consistent Na+-Cl- water type throughout the seasons.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Andries Jan de Vries, Franziska Aemisegger, Stephan Pfahl, Heini Wernli
Summary: The study investigates the formation of tropical ice clouds related to deep convection in the West African monsoon using stable water isotopes as tracers. The findings demonstrate that isotopes can be useful in understanding the processes involved in the formation of ice clouds and their impact on climate.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Environmental Sciences
Yuxin Zhao, Jiming Li, Lijie Zhang, Cong Deng, Yarong Li, Bida Jian, Jianping Huang
Summary: This study investigates the diurnal variations in cloud cover and cloud vertical distribution over the Tibetan Plateau. The results show that total cloud cover peaks in the morning and varies spatially and temporally. The study also reveals the dominant presence of opaque cirrus clouds over the plateau, which exhibit significant diurnal variations.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2023)
Article
Environmental Sciences
Julia Schneider, Kristina Hohler, Robert Wagner, Harald Saathoff, Martin Schnaiter, Tobias Schorr, Isabelle Steinke, Stefan Benz, Manuel Baumgartner, Christian Rolf, Martina Kramer, Thomas Leisner, Ottmar Mohler
Summary: Homogeneous freezing of aqueous sulfuric acid aerosol particles was studied through laboratory experiments at the AIDA cloud simulation chamber. The results showed deviations from the water activity criterion-based predictions at lower temperatures, but agreement at higher temperatures. The ice saturation ratios of sulfuric acid aerosol particles increased with decreasing temperatures, impacting model predictions of cirrus cloud occurrence.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Engineering, Environmental
Zhikun Chen, Maria Elektorowicz, Chunjiang An, Xuelin Tian
Summary: Sea ice can act as a temporary sink and transport medium for microplastics, and the entrainment and enrichment of microplastics in ice are influenced by various properties and environmental characteristics. High rotation speed in freshwater enhances the entrainment of hydrophobic microplastics, while high turbulence in saline water inhibits the entrainment of all microplastic types. This study highlights the critical pathways of microplastics' fate in cold regions.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Environmental Sciences
Sara Bacer, Sylvia C. Sullivan, Odran Sourdeval, Holger Tost, Jos Lelieveld, Andrea Pozzer
Summary: This study quantifies and investigates the ICNC rates of cold cloud microphysical processes using the chemistry-climate model EMAC, finding that the model ICNCs are generally consistent with satellite observations in terms of spatial distribution but are overestimated. Ice crystal rates are dominated by freezing of cloud droplets and convective detrainment over tropical land masses as sources, while aggregation and accretion act as the largest sinks, with all processes exhibiting highly skewed distributions. Sensitivity studies on different ice nucleation parameterizations and a future global warming scenario show only slight changes in the hierarchy of ice crystal sources and an upward shift in altitude and increase in rates towards the end of the 21st century.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)