Xiaocen Shen

University of Reading · Department of Meteorology

It is widely accepted that Arctic Amplification (AA) - enhanced Arctic warming relative to global warming - will increasingly moderate cold-air outbreaks to the midlatitudes. Yet, some recent studies also argue that AA over the last three decades to the rest of the present century may potentially contribute to more frequent severe winter weather in...

Teleconnections are crucial in shaping climate variability and regional climate change. The fidelity of teleconnections in climate models is important for reliable climate projections. As the observed sample size is limited, scientific judgment is required when models disagree with observed teleconnections. We illustrate this using the example of t...

Based on the JRA-55 reanalysis data, the persistent downward impacts of the weak stratospheric polar vortex (WPV) events are examined. The WPV events with persistent tropospheric impacts are selected and classified into two groups according to whether there is a phase switch of the surface Arctic Oscillation (AO) around the onset day of the cases....

During the recent four decades since 1980, a series of modern climate satellites were launched, allowing for the measurement and record-keeping of multiple climate parameters, especially over the polar regions where traditional observations are difficult to obtain. China has been actively engaging in polar expeditions. Many observations were conduc...

Sudden-stratospheric-warming (SSW) events are often followed by significant weather and climate impacts at the surface. By affecting the North Atlantic Oscillation (NAO), SSWs can lead to periods of extreme cold in parts of Europe and North America. Previous studies have used observations and free-running climate models to try to identify features...

Changes in the stratospheric polar vortex (SPV) can remarkably impact tropospheric circulation. Based on the diagnosis of reanalysis data, this study finds that the location shift rather than the strength change dominates the intraseasonal variability of SPV. Further analysis suggests that it couples well with the tropospheric circulation, forming...

Sudden stratospheric warming events (SSWs) are often followed by significant weather and climate impacts at the surface. By affecting the North Atlantic Oscillation (NAO), SSWs can lead to periods of extreme cold in parts of Europe and North America. Previous studies have used observations and free-running climate models to try to identify features...

Based on observation and reanalysis datasets, numerical experiments with a simple dynamical model, and climate model outputs, this study investigates the second leading waveguide teleconnection along the summer polar front jet (PFJ) over Eurasia on the interannual time scale, the British–Okhotsk Corridor (BOC) pattern. The BOC pattern explains 20.8...

Motivated by the strong Antarctic sudden stratospheric warming (SSW) in 2019, a survey on the similar Antarctic weak polar vortex events (WPVs) is presented, including their life cycle, dynamics, seasonality, and climatic impacts. The Antarctic WPVs have a frequency of about four events per decade, with the 2002 event being the only major SSW. They...

The strongest and most persistent upward propagation of zonal wavenumber 1 (WN1) Rossby waves from the troposphere on record led to the rare Antarctic sudden stratospheric warming (SSW) in September 2019. The dynamical contribution from instantaneous anomalous WN1 and its linear interference with the climatological WN1 contributed equally to the ev...