Aircraft Observations Reveal the Relationship Between Cumulus Entrainment Rate and Aerosol Loading

Geophysical Research Letters, Год журнала: 2024, Номер 51(19)

Опубликована: Окт. 1, 2024

Abstract The influence of entrainment, a key process characterized by the entrainment rate in cumulus parameterization, on aerosol‐cloud interactions has been widely recognized. However, despite qualitative links established between and aerosol loading, quantitative relationship based observational evidence remains elusive. This study utilizes aircraft observations clouds during two field campaigns to determine loading. In both campaigns, is negatively correlated with It speculated that increased loading enhances cloud edge droplet evaporation, which leads buoyancy vertical velocity within cloud, thereby reducing rate. Further analysis shows response perturbations more significant smaller weak less pronounced under opposite conditions. These findings shed new light improving description parameterizations.

Язык: Английский

---

Development and Application of a New Convective Entrainment Rate Parameterization for Improving Precipitation Simulation Over the Tibetan Plateau and Its Surrounding Areas

Journal of Advances in Modeling Earth Systems, Год журнала: 2025, Номер 17(1)

Опубликована: Янв. 1, 2025

Abstract The Tibetan Plateau (TP) significantly impacts the global climate. TP's unique geographical conditions make it one of areas with largest precipitation biases in numerical models. overestimation and distribution models are closely related to parameterization convection processes over TP. In light this, a new deep convective entrainment rate suitable for region is developed based on observational data applied Grell‐Freitas Ensemble Scheme Weather Research Forecasting Model. scheme reduces simulated TP, decreasing from 29.4% default 11.8%. physical mechanism behind improved simulation results as follows: first, closer observed results. Second, terms cloud macrophysics, increases rate, top height depth clouds, decreases number grids updrafts vertical layers surface. Third, microphysics, increased water content weakens intensity precipitation. All these mechanisms ultimately reduce accumulated amount, providing an optimized modeling tool weather climate research which also aids better assessing cycle resource reserves “Asian Water Tower.”

Язык: Английский

---

Reconciling observed and predicted droplet concentration at the Indian summer monsoon cloud base

The Science of The Total Environment, Год журнала: 2025, Номер 973, С. 179077 - 179077

Опубликована: Март 22, 2025

Язык: Английский

---

Implementation and Evaluation of Physics‐Driven Dynamic Entrainment‐Mixing Parameterization in a Climate Model and Its Impact on Low‐Cloud Simulation

Journal of Geophysical Research Atmospheres, Год журнала: 2025, Номер 130(6)

Опубликована: Март 25, 2025

Abstract The turbulent entrainment‐mixing process in the Community Earth System Model version 1.2 (CESM1.2) is assumed to follow extremely inhomogeneous entrainment‐mixing. However, different scenarios can occur real clouds. To address this deficiency, a unifying parameterization that represents processes implemented and evaluated CESM1.2. results indicate homogeneous mixing degree values simulated by new CESM1.2 are predominantly greater than 50%, suggesting tendency toward mixing. Compared mechanism, increases cloud droplet number concentration ( N c ). More importantly, improves low‐cloud fraction (CLDLOW) simulation Northwest Pacific (NWP) Southeast (SEP) regions, with relative improvements of 2.95% 4.17%, respectively. Furthermore, reach up 44.6% 16.2% NWP SEP respectively, when considering relationship between CLDLOW. Further analysis reveals enhances optical depth, longwave radiative cooling effect, net condensation rate, water ratio, lower‐troposphere stability, CLDLOW increasing . These underscore importance improving climate models.

Язык: Английский

---

Detection and Spatiotemporal Distribution Analysis of Vertically Developing Convective Clouds over the Tibetan Plateau and East Asia Using GEO-KOMPSAT-2A Observations

Remote Sensing, Год журнала: 2025, Номер 17(8), С. 1427 - 1427

Опубликована: Апрель 17, 2025

Vertically developing convective clouds (VDCCs), characterized by cloud-top ascent and cooling, are critical precursors to severe weather due their association with intense updrafts. However, existing studies constrained limited spatiotemporal resolution of data tracking methodologies, hindering real-time pixel-level capture VDCC evolution. Furthermore, large-scale statistical analyses distribution remain scarce compared mature systems, particularly in topographically complex regions like the Tibetan Plateau (TP). To address these challenges, we integrated an optical flow algorithm (for dense atmospheric motion vector (AMV) retrieval) cooling rates (CTCRs, as indicators vertical development), leveraging high multispectral capabilities GEO-KOMPSAT-2A (GK2A) satellite. This approach achieved detection at 10 min intervals across diurnal cycles, enabling comprehensive analysis. Based on this technical foundation, most important finding study was distinct over TP East Asia (EA) analyzing three summers (2021–2023). Specifically, peaks preceded precipitation 2–3 h, confirming precursor roles both regions. Regional comparisons revealed that topographic thermal forcing strongly influenced patterns. The exhibited earlier more frequent daytime convection middle-to-low levels than EA, driven forcing, yet development moisture scarcity. In contrast, EA’s monsoonal sustained deeper convection, VDCCs penetrating upper troposphere. offer new insights into processes surrounding regions, offering potential improvements monitoring early warning systems.

Язык: Английский

---

AS-SOMTF: A novel Multi-task Learning Model for Water Level Prediction by Satellite Remoting

Digital Communications and Networks, Год журнала: 2025, Номер unknown

Опубликована: Май 1, 2025

Язык: Английский

---

Revisiting the dry-to-wet shift of summer precipitation over the Three-River Headwaters region, hinterland of the Tibetan Plateau: a perspective of moisture sources changes

Climate Dynamics, Год журнала: 2024, Номер 62(9), С. 8827 - 8847

Опубликована: Июль 30, 2024

Язык: Английский

---

Quantifying the Turbulent Entrainment‐Mixing Processes Based on Z‐LWC Relationships of Cloud Droplets

Geophysical Research Letters, Год журнала: 2024, Номер 52(1)

Опубликована: Дек. 27, 2024

Abstract Turbulent entrainment‐mixing processes profoundly influence the relationship between radar reflectivity factor and liquid water content ( Z ‐LWC) of cloud droplets. However, quantification mechanisms based on ‐LWC is still lacking. To address this gap, 12,218 cases are simulated using Explicit Mixing Parcel Model. We examine variations parameters in power‐law = a LWC b , parameter homogeneous mixing degree ψ ), measure quantifying processes. The results indicate that distributes within range 1–2, with positive correlation . ‐ fitted, which connects for various types. suggest potential employing remote sensing approach to investigate non‐precipitating small cumulus/stratocumulus clouds, thereby overcoming limitations traditional observational studies rely solely aircraft observations.

Язык: Английский

---

Vertical structures and microphysical mechanisms of winter precipitation over the southwestern mountainous area of China

Atmospheric Research, Год журнала: 2024, Номер 303, С. 107346 - 107346

Опубликована: Март 15, 2024

Язык: Английский

---