Moisture Sources and Transport for Extreme Precipitation Over Henan in July 2021

Abstract

Frequent extreme precipitation events have resulted in severe disasters to agriculture, the economy, and human health in recent decades. Widespread concerns about extreme precipitation have been aroused among the public, the government, and the research community. Researchers have conducted numerous studies on the mechanisms responsible for extreme precipitation events (Agel et al., 2018;Collow et al., 2016). Favorable local dynamic conditions (ascending motion) and instability are critical for the occurrence of extreme precipitation. Abundant moisture supply is another indispensable condition for extreme precipitation.In recent years, many studies have focused on moisture transport and sources for precipitation, including precipitation extremes. Two main approaches are widely used in studies on moisture transport. One is in the Eulerian view by calculating water vapor transport or by identifying and tracking the variation in atmospheric rivers (Sun & Wang, 2013;Tan et al., 2021). A deficiency of the Eulerian view is that it can neither track moisture from the sources to the precipitation area nor track moisture from the target region back to its sources. The other is in the Lagrangian view by tracking the moisture of particles (or air parcels) forward or backward using Lagrangian trajectory models (Sodemann et al., 2008;Sodemann & Zubler, 2010). The Lagrangian model can provide moisture variation processes from evaporation to precipitation along the transport trajectories. Several Lagrangian trajectory models are available, such as the Lagrangian particle dispersion model FLEXPART (

The Remote Effect of Binary Typhoon Infa and Cempaka on the “21.7” Heavy Rainfall in Henan Province, China

“…Noting that the endpoints of trajectories that belongs to the west cluster are concentrated in the southern area of China. Recently, Nie and Sun (2022) demonstrated that such moisture sources are caused by local terrestrial water recycling and highlighted its important role that contributing to the formation of the “21.7” heavy rainfall event in Henan Province. In our opinion, we would rather believe such a moisture source comes from the south‐westerly monsoon flow.…”

Quantitative Stress Test of Compound Coastal‐Fluvial Floods in China's Pearl River Delta

“…This is limited by current ocean circulation models, which focus on the storm surge and neglect precipitation that falls directly into the simulation domain and the interaction between rainfall-runoff and storm surge. Ignoring these precipitation amounts may result in underestimating the compound flood in rive deltas, especially during slow-moving storms which dump an excessive amount of precipitation over a long period of time, such as Hurricane Harvey (2017) (Zhang et al, 2018), Florence (2018) (Ye et al, 2021), Ida (2021) (Flowers, 2021), and super Typhoon In-fa (2021) (Nie & Sun, 2022). Meanwhile, due to the adoption of simplified flow representation (Bates et al, 2005), hydrologic/hydrodynamic models are not feasible to simulate hydrodynamics in deep water, for example, astronomical tides, storm surges, and wind waves in offshore areas.…”

Changes in extreme rainfall over mainland China induced by landfalling tropical cyclones

“…Moreover, the WPSH is associated with ocean signals such as ENSO and the Pacific Decadal Oscillation [66][67][68], which, depending on their phase, can affect the formation pattern of TCs. In addition, large-scale circulation can transport moisture from TCs and interact with high-latitude weather systems, resulting in remote rainfall from TCs and extreme rainfall locally, such as the extreme rainfall events in July 2021 in Henan-one of the most populated provinces in China [69,70].…”