The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.
The site is secure.
The
https://
ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.
Chungu Lu authored and/or contributed to the following articles/publications.
Using the daily maximum air temperature and mean humidity observations at 394 surface weather stations across China, the changes in the annual number of days of high temperature weather (HTW), high humidity weather (HHW), and sultry weather (STW) in China over the period 1961–2004 are studied. The results indicate that there were considerable sp...
The Tibetan Plateau is the largest and highest plateau in the world. Because of its unique geographic feature, the Tibetan Plateau plays important roles in global weather and climate systems. In particular, due to its elevated land surface and strong radiative heating, the Tibetan Plateau becomes a favorable place for initiating a large number ...
In the winter of 2008, China experienced once-in-50-yr (or once in 100 yr for some regions) snow and ice storms. These storms brought huge socio economical impacts upon the Chinese people and government. Al- though the storms had been predicted, their severity and persistence were largely underestimated. In this study, these cases were revisited...
Two-dimensional continuous wavelet analysis and its application to meteorological data
The two-dimensional continuous wavelet transform (2D CWT) has become an important tool to examine and diagnose nonstationary datasets on the plane. Compared with traditional spectral analysis methods, the 2D CWT provides localized spectral information of the analyzed dataset. It also has the advantage over the 2D discrete wavelet transform (DWT)...
Large-scale topography of China: A factor for the seasonal progression of the Meiyu rainband?
Monsoon rainfall has been the major precipitation source for many East Asian countries, particularly China. This rainfall typically forms as a band with a distinctive northwestward movement from early spring to midsummer and is known as the Meiyu front. Meiyu rainfall constitutes a part of the East Asian monsoon. As spring transitions into summe...
Generalized Moist Potential Vorticity and its Application in the Analysis of Atmospheric Flows
Potential vorticity (PV) serves as an important dynamic tracer for large-scale motions in the atmosphere and oceans. Significant progress has been made on the understanding and application of PV since the work of Hoskins et al., who introduced an “IPV thinking” of a dynamical system in a purely dry atmosphere. In particular, there has been a sub...
World water tower: An atmospheric perspective
A large amount of water is stored in the world's highest and largest plateau, the Tibetan Plateau, in the forms of glaciers, snowpacks, lakes, and rivers. It is vital to understand where these waters come from and whether the supply to these water resources has been experiencing any changes during recent global warming. Here we show the maintena...
Because it is the largest and highest plateau in the world, the Tibetan Plateau plays an important role in the global atmospheric energy and water cycles. The large water resource stored in this region and its downstream transports support nearly 40% of the world population, including China, India, and many Southeast and East Asian countries. Th...
High-resolution (3 km) time-lagged (initialized every 3 h) multimodel ensembles were produced in support of the Hydrometeorological Testbed (HMT)-West-2006 campaign in northern California, covering the American River basin (ARB). Multiple mesoscale models were used, including the Weather Research and Forecasting (WRF) model, Regional Atmospheric...
Rossby wave ray tracing in a barotropic divergent atmosphere
The effects of divergence on low-frequency Rossby wave propagation are examined by using the twodimensional Wentzel–Kramers–Brillouin (WKB) method and ray tracing in the framework of a linear barotropic dynamic system. The WKB analysis shows that the divergent wind decreases Rossby wave frequency (for wave propagation northward in the Northern H...
Since December 2005, the NCEP (National Centers for Environmental Prediction) short-range ensemble forecasting (SREF) system has been updated by constructing new ensemble components (Du et al. 2006). This system contains perturbed initial/boundary conditions, multiple physics, and multimodel. It covers the North American continent and the adjace...
Turbulence and gravity waves in a dynamically unbalanced upper-level jet-frontal system
Comparison of cold season QPF and PQPF from time-lagged and multiple model ensembles
Methods of generating NWP ensemble QPF include using alternative initial conditions, multiple models, or a combination of both. We examine an approximation to the method of alternative initial conditions that involves reinitializing a forecast model after a short time period, during which the initial state has evolved. This is known as a time-la...
Turbulence generation by gravity waves within upper-level jet-front systems
The cascade of energy from gravity-inertia waves generated by unbalanced jet streak dynamics to turbulent eddies has been simulated and observed. This energy cascade process is studied with an idealized model of a baroclinic three-dimensional jet streak initialized by inverting a specified potential vorticity field, multi-scale numerical weather...
Three- dimensional variational data assimilation (3DVAR) analysis is an important method used at operational and research institutes in meteorology, for example, the National Centers for Environmental (NCEP) and the European Centre for Medium-Range Weather Forecasts (ECMWF). In 3DVAR analysis, forms of cost functions and constraints (e. g., g...