Bivariate and Partial Wavelet Coherence for Revealing the Remote Impacts of Large-Scale Ocean-Atmosphere Oscillations on Drought Variations in Xinjiang, China

Water, Journal Year: 2025, Volume and Issue: 17(7), P. 957 - 957

Published: March 25, 2025

Xinjiang, an arid area located in the central part of Eurasian continent with high evaporation and low precipitation, experiences frequent droughts. This study builds on previous research by incorporating five key ocean-atmosphere oscillations using one-month SPEI as a meteorological drought indicator. Monthly time series precipitation temperature from 53 stations are utilized to calculate monthly series, seasonal Kendall test analyzes trends. Despite increased conditions Xinjiang worsened due temperatures, especially south, during 1961–2017. The clustered agglomerative hierarchical method, basically reflecting Xinjiang’s topographical climatic diversity. However, classical correlation methods show weak or negligible overall between large-scale oscillators. Therefore, partial wavelet coherence (PWC) method was used detect scale-specific correlations. Both bivariate (BWC) PWC detected significant correlations oscillators at some specific scales. Our analyses indicate that southern droughts more influenced Pacific Indian Ocean oscillators, while northern affected Atlantic Arctic climate variations.

Language: Английский

Delayed Response of Soil Moisture and Hydrological Droughts to Meteorological Drought Over East Asia

International Journal of Climatology, Journal Year: 2025, Volume and Issue: unknown

Published: April 26, 2025

ABSTRACT The frequency and severity of meteorological drought across Eastern Asia (EA) are observed projected to increase with ongoing global climate change. However, the temporal spatial responses land surface elements including soil moisture runoff remain insufficiently understood characterised, especially in terms quantifying differentiated lag time hydrological responses. In this study, we investigate spatiotemporal response droughts EA, using Standardised Precipitation Index (SPI; a measure precipitation deficit), Soil Moisture Drought (SSMDI; anomalies) Streamflow (SSI; assessing streamflow deviations) at short‐ (1–3), medium‐ (6–9) long‐scales (12–24 months). results show that northern indicate weak negative correlations 1–6 month scales, while southern regions, stronger positive 9–24 scales. Hydrological exhibit consistently strong all regions EA. Northern longer times up 8 months drought, whereas rapid (1 month). EA have delayed extending 10 months. As change use changes may amplify impacts, long‐term forecasting adaptive management essential mitigate water shortages ecological stress region.

Language: Английский

Assessing teleconnection influences on the spatial and temporal patterns of meteorological drought in Northwest China

Big Earth Data, Journal Year: 2024, Volume and Issue: 8(4), P. 703 - 731

Published: Aug. 23, 2024

This study delves into the complex relationship between teleconnection patterns and meteorological drought in Northwest China, highlighting crucial influence of global circulation indices on regional dynamics. By analyzing precipitation temperature data from 1962 to 2022 using CN05.1 datasets incorporating various indices, employs Standardized Precipitation Evapotranspiration Index (SPEI) delineate conditions. Utilizing Modified Mann-Kendall test segmented models for trend change point detection, along with cross wavelet transforms (XWT) coherence (WTC) analysis examine impact 15 uncovers significant spatial temporal climatic variations. Findings indicate a increase precipitation, March-April-May (MAM) season showing pronounced severity mainly due rise value 0.0420 °C/year. Change reveals pivotal shifts climate, region's susceptibility climate change. The identified strong correlations occurrences like Artic Oscillation (AO), Atlantic Multidecadal (AMO), Pacific Decadal (PDO) Southern (SOI), especially within 4–8 year timeframe, pointing role teleconnections affecting local These insights are vital formulating effective management adaptation strategies arid semi-arid regions, offering valuable guidance policymakers researchers focused improving water resource enhancing resilience such vulnerable environments.

Language: Английский