Revealing climate dynamics through topsoil magnetic properties on the Chinese Loess Plateau

The Chinese Loess Plateau (CLP), with its extensive deposits of eolian dust and interbedded paleosols, provides a unique archive for reconstructing climate variability, particularly precipitation and monsoonal dynamics. This study examines the magnetic properties of 106 modern topsoil samples from the CLP to explore their spatial distribution and relationship with climate factors, provides a systematic, publication-quality comparison of CLP magnetic climofunctions from 1994 to the present day. Our results showed that topsoils were primarily composed of magnetite and maghemite, with grain sizes ranging from superparamagnetic (SP) to single domain (SD) and pseudo-single domain (PSD). Magnetic properties such as low-field magnetic susceptibility (χ lf ), anhysteretic remanent magnetization (χ ARM ), and frequency-dependent susceptibility (χ fd %) demonstrated a clear spatial trend, increasing from northwest to southeast in parallel with higher mean annual precipitation (MAP) and temperature (MAT). These findings highlight precipitation as a critical driver of magnetic enhancement through pedogenic processes, particularly during wet and dry cycles. Both MAP and MAT showed positive correlations with χ ARM /SIRM and χfd%, while correlations with χ lf were weaker, reflecting the complexity of climate and soil interactions. We established new climofunctions linking MAP and MAT with χ ARM /SIRM and χfd%, and place these in the context of previous transfer functions for the CLP, underscoring the potential of magnetic proxies for high-resolution climatic reconstructions in monsoon-dominated regions.