Abstract Snow drought, characterized by an anomalous reduction in snowpack, exerts profound hydrological and socioeconomic impacts cold regions. Despite its significance, the influence of diverse snow drought types, including warm, dry, warm‐and‐dry variants, on streamflow remains inadequately understood. Here we present first hemispheric‐scale, observation‐based assessment patterns seasonal annual ( Q ) across 3049 northern catchments over 1950–2020. Our findings reveal that with a lower...

Abstract It has long been assumed that over a sufficiently period of time, changes in catchment water storage (Δ S ) are relatively minor term compared to other fluxes and can be neglected the balance equation. However, validity this fundamental assumption rarely tested, associated uncertainties calculations remain unknown. Here, we use long‐term (1982–2011) observations monthly streamflow ( Q precipitation P for 1,057 global unimpaired catchments, combined with four independent...

Abstract. Land evapotranspiration (ET) plays a crucial role in Earth's water–carbon cycle, and accurately estimating global land ET is vital for advancing our understanding of land–atmosphere interactions. Despite the development numerous products recent decades, widely used still possess inherent uncertainties arising from using different forcing inputs imperfect model parameterizations. Furthermore, lack sufficient situ observations makes direct evaluation impractical, impeding their...

Abstract It has been found that a decreased fraction of precipitation falling as snow in warmer climate significantly affects streamflow. Here, based on observations from 631 catchments over the contiguous United States, we proposed framework to investigate first‐order and second‐order hydro‐climatic relationships between annual streamflow snowfall fraction. Results show addition mean streamflow, interannual variability will also decrease with lower context warming. The positive relationship...

Abstract Understanding the evolving relationships between snow and streamflow dynamics with variations in climate drivers is crucial for hydrologic predictions sustainability of water‐energy supply systems cold regions. However, comprehensive hemisphere‐scale assessments are lacking. Using extensive observations from approximately 850 catchments reanalysis data sets spanning 1950–2020, here we reveal a widespread transition cold‐season precipitation to temperature as dominant control...

Abstract Meteorological droughts can reverberate through the water cycle, impacting resources, ecosystems, agriculture, and socio‐economic sectors. Despite this, there remains a scarcity of studies delving into transition from meteorological to hydrological influencing factors operating at event level. Using long‐term observations spanning nominally 1979 2017, we identified matched based on standardized drought indices across 1089 catchments globally, examined characteristics propagation...

Abstract Ongoing climate change is modifying snow dynamics, further altering streamflow ( Q ) in cold regions. Despite extensive research over the past decades, impact of changes on mean annual remains debated, and underlying mechanisms driving these responses are still unclear. In this study, we employ Budyko framework to establish multivariate relationships between a model parameter several variables, including snowfall fraction f s ), across 931 carefully selected snow‐influenced...

Abstract Understanding the spatio-temporal evolution of drought propagation is crucial for improving our monitoring and prediction droughts. However, impact changing snow dynamics on time (tP) has rarely been assessed. Utilizing observed streamflow reanalyzed climate data from ~900 northern snow-affected catchments, here we provide a comprehensive investigation temporal changes in tP underlying mechanisms context diminishing snow. Results show that catchments with higher fraction...

Climate warming reduces snow cover in cold regions, altering snowmelt flood regimes with significant hydrological and ecological consequences. Existing evidence indicates that as climate warms, tends to begin earlier the season, leading floods. Here we show timing of floods can be either advanced or delayed under warming. Using streamflow observations from 1950-2020 an event-based analysis distinguishes flood-generating mechanisms across 2339 Northern Hemisphere, snow-affected catchments,...

Transpiration (T) is pivotal in the global water cycle, responding to soil moisture, atmospheric stress, climate changes, and human impacts. Therefore, establishing a reliable transpiration dataset essential. Collocation analysis methods have been proven effective for assessing errors these products, which can subsequently be used multisource fusion. However, previous results did not consider error cross-correlation, rendering less reliable. In this study, we employ collocation analysis,...

Abstract. Land evapotranspiration (ET) plays a crucial role in Earth's water-carbon cycle, and accurately estimating global land ET is vital for advancing our understanding of land-atmosphere interactions. Despite the development numerous products recent decades, widely used still possess inherent uncertainties arising from using different forcing inputs imperfect model parameterizations. Furthermore, lack sufficient in-situ observations makes direct evaluation impractical, impeding their...

With the ongoing climate warming, changes in intra-annual distribution, annual volume, and their inter-annual variability of streamflow have been key research topics ever-increasing interest. For settling question how changing shapes dynamics, here, we used long-term (1950-2010) observations monthly (Q) for 2960 global unimpaired catchments, combined with snowfall (SF) precipitation (P) estimates from ERA5-Land to provide a assessment effect on variability. Results showed that was main...

With persistent global warming, more precipitation will land on the earth's surface as rainfall instead of snowfall. Here, based observations from hundreds catchments, we proposed a framework (the second-order Budyko framework) to investigate hydro-climatic relationships between annual streamflow and snowfall fraction. Results show that in addition mean streamflow, inter-annual variability also decrease with lower fraction context warming. The positive relationship may result asymmetric...

FIGURE.S1 Global distribution of absolute error variances (𝜎 𝜀 𝑖2 ) ERA5L andPMLv2 using IVD at a resolution 0.

Transpiration (T) is pivotal in the global water cycle, responding to soil moisture, atmospheric stress, climate changes, and human impacts. Therefore, establishing a reliable transpiration dataset essential. Different products exhibit significant differences, necessitating evaluation of errors. Collocation analysis methods have been proven effective for assessing errors these products, which can subsequently be used multisource fusion. However, previous results did not consider error...