沙漠尘卷风与沙尘天气形成的气象条件对比分析

Comparative Analysis of Formative Meteorological Conditions between Desert Dust Devils and Dusty weather

摘要:

摘 要：解析尘卷风与沙尘天气的异质性演变及阈值耦合机制，对干旱区生态安全、沙尘灾害防控及全球荒漠化治理具有关键科学价值。本文基于1992-2024年塔克拉玛干沙漠北缘气象观测与强化观测试验，本研究揭示了尘卷风与沙尘天气的异质性演变及热力-动力耦合机制。尘卷风日数于1994年达峰值104天后波动下降（2020年55天），沙尘天气因生态治理锐减（2024年沙尘暴20天）。月际上，尘卷风呈夏季单峰（7月达峰），受热力阈值（地气温差≥20℃、风速3.0-3.5 m/s、湿度<25%）驱动；沙尘天气表现为春季双峰（3-5月），依赖动力阈值（风速≥8m/s、湿度<35%）。过渡期（5-6月）热力增强使尘卷风日数增至11天，沙尘暴日数降至8天，反映时空竞争机制。回归模型表明：尘卷风由地气温差（+1℃频次+0.86次，R2=0.82）与风速（+1m/s频次+1.32次）协同驱动，低湿（≤25%时22次）和低压（898.6hPa）促进；沙尘天气以风速主导（≥8m/s时22.12次，R2=0.78），低湿（≤20%时20.24次）增强起沙。机制上，尘卷风作为小尺度热力-湍流现象，依赖局地热对流；沙尘天气受大尺度动力输送控制。研究结果量化了热力-动力阈值差异，可为沙尘预警、生态工程优化及气候适应策略提供多尺度调控依据，支撑区域荒漠化防治实践。

Abstract:

Abstract: Understanding the heterogeneous evolution and threshold coupling mechanisms of dust devils and sand-dust weather is of critical scientific importance for ecological security in arid regions, sand-dust disaster prevention, and global desertification control. Based on meteorological observations and intensive observation campaigns at the northern edge of the Taklimakan Desert from 1992 to 2024, this study reveals the heterogeneous evolution of dust devils and sand-dust weather, as well as their thermal-dynamic coupling mechanisms. The number of dust devil days peaked at 104 days in 1994, then fluctuated and declined (55 days in 2020), while sand-dust weather events decreased sharply due to ecological restoration (20 sandstorm days in 2024). Monthly, dust devils exhibited a single summer peak (peaking in July), driven by thermal thresholds (land-air temperature difference ≥20°C, wind speed 3.0–3.5 m/s, humidity <25%); sand-dust weather showed dual spring peaks (March–May), dependent on dynamic thresholds (wind speed ≥8 m/s, humidity <35%). During the transitional period (May–June), enhanced thermal conditions increased dust devil days to 11 days while reducing sandstorm days to 8 days, reflecting spatiotemporal competition. Regression models indicate that dust devils are synergistically driven by temperature difference (+1°C increases frequency by 0.86 times, R2=0.82-0.77) and wind speed (+1 m/s increases frequency by 1.32 times), with low humidity (≤30%: 22 events) and low pressure (898.6 hPa) as facilitators. Sand-dust weather is dominated by wind speed (≥8 m/s: 22.12 events, R2=0.69-0.78), enhanced by low humidity (≤20%: 20.24 events). Mechanistically, dust devils are small-scale thermal-turbulence phenomena relying on local thermal convection, while dusty weather is governed by large-scale dynamic transport. By quantifying thermo-dynamic threshold disparities, these findings provide multiscale regulatory insights for sand-dust early warning systems, ecological engineering optimization, and climate adaptation strategies, thereby supporting practical desertification control in arid regions.