Huei-Ping Huang

Arizona State University | ASU · Mechanical & Aerospace Engineering

The monitoring of droughts is practically important yet challenging due to the complexity of the phenomena. The occurrence of drought involves changes in meteorological conditions, vegetation coverage and soil moisture. To advance the techniques for detecting and monitoring droughts, this study explores the usage of a suite of vegetation and water...

Retrograde long waves in the higher latitudes of Northern Hemisphere can episodically attain large amplitudes and sustain coherent phase propagation for 2-3 weeks. The potential influence of such waves on extended-range weather forecast has been conjectured but not systematically quantified. Using a set of ensemble reforecast data, this study exami...

This study uses a suite of meteorological and land-surface models to quantify the changes in local climate and surface dust fluxes associated with desert urbanization. Formulas connecting friction velocity and soil moisture to dust generation are used to quantify surface fluxes for natural wind-blown dust. The models are used to conduct a series of...

This study performs an updated analysis of Northern Hemisphere retrograde disturbances that were first identified by classical observational studies as one of the dominating coherent structures in the higher latitudes on the submonthly time scale. Analyzing 8–30-day bandpass-filtered data based on reanalysis, a set of criteria on the phase and ampl...

The effect of urbanization on local climate is quantified by numerical simulations for five desert cities that represent a wide range of urban size, climate zone, and composition of land cover. Land-use land cover maps generated from Landsat data for 1985 and 2010, chosen as the start and end of a period of rapid urbanization, are used to constrain...

This study explores the impacts of the desiccation of the Aral Sea and large-scale climate change on the regional climate of Central Asia in the post-1960 era. A series of climate downscaling experiments for the 1960’s and 2000’s decades were performed using the Weather Research and Forecast model at 12-km horizontal resolution. To quantify the imp...

We quantified the spatio-temporal patterns of land cover/land use (LCLU) change to document and evaluate the daytime surface urban heat island (SUHI) for five hot subtropical desert cities (Beer Sheva, Israel; Hotan, China; Jodhpur, India; Kharga, Egypt; and Las Vegas, NV, USA). Sequential Landsat images were acquired and classified into the USGS 2...

In this study, the Weather Research and Forecasting (WRF) Model and its embedded land surface and urban canopy model are used to simulate effects of urbanization on the local climate of the Las Vegas, Nevada, metropolitan area. High-resolution simulations are performed with a 3-km horizontal resolution over the city. With identical lateral boundary...

This study examines the impact of spatial landscape configuration (e.g., clustered, dispersed) on land-surface temperatures (LST) over Phoenix, Arizona, and Las Vegas, Nevada, USA. We classified detailed land-cover types via object-based image analysis (OBIA) using Geoeye-1 at 3-m resolution (Las Vegas) and QuickBird at 2.4-m resolution (Phoenix)....

The projected changes in the downward solar radiation at the surface over North America for late 21st century are deduced from global climate model simulations with greenhouse-gas (GHG) forcing. A robust trend is found in winter over the United States, which exhibits a simple pattern of a decrease of sunlight over Northern USA. and an increase of s...

The centennial trends in the surface wind speed over North America are deduced from global climate model simulations in the Climate Model Intercomparison Project—Phase 5 (CMIP5) archive. Using the 21st century simulations under the RCP 8.5 scenario of greenhouse gas emissions, 5–10 percent increases per century in the 10 m wind speed are found over...

The twentieth-century climatology and twenty-first-century trend in precipitation P, evaporation E, and P - E for selected semiarid U.S. Southwest and Mediterranean regions are compared between ensembles from phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5). The twentieth-century simulations are validated with precipita...

We investigated the impact of assimilating microwave radiances from the Advanced Microwave Sounding Unit-A (AMSU-A) and the Microwave Humidity Sounder (MHS) into the Hurricane Weather Research and Forecasting (HWRF) model on the forecast of typhoon tracks over the western Pacific Ocean. The assimilation of MHS observations has positive impacts on t...

The climatology and trend of atmospheric angular momentum from the phase 3 and the phase 5 Climate Model Intercomparison Project (CMIP3 and CMIP5, respectively) simulations are diagnosed and validated with the Twentieth Century Reanalysis (20CR). It is found that CMIP5 models produced a significantly smaller bias in the twentieth-century climatolog...

In this presentation, we report results of a research project supported by US Civil Research and Development Foundation aimed at investigating the interplays between the Aral Sea desiccation, anthropogenic impacts, and climate change in Central Asia, and quantify principal feedbacks in the climatic system of the Aral Sea region by means of numerica...

This study performs an intercomparison of the interannual variability of atmospheric angular momentum (AAM) in eight reanalysis data sets for the post-1979 era. The AAM data are further cross validated with the independent observation of length-of-day (LOD). The intercomparison reveals a close agreement among almost all reanalysis data sets, except...

This study compares two methods of multimodel averaging for the future projection of precipitation based on the classically defined absolute and relative climate changes. In the relative change scheme, the multimodel average of the percentage changes in precipitation is multiplied by the observed present climate to form the future projection; this...

An intercomparison of the global relative angular momentum M R in five reanalysis datasets, including the Twentieth Century Reanalysis (20CR), is performed for the second half of the twentieth century. The intercomparison forms a stringent test for 20CR because the variability of M R is known to be strongly influenced by the variability of upper-tr...

This study performs regional climate simulations for Arizona, a region with complicated terrain. The dependence of simulated rainfall on model resolution is explore by climate downscaling experiments using the Weather Research and Forecasting model. The model’s horizontal resolution was refined from 12 to 6, then to 3 km. The total rainfall for win...

Using globally integrated angular momentum as a climate index, the decadal-to-interdecadal variability in CMIP5 multi-model simulations is analyzed and compared to CMIP3 and the observation of the 20th century. A particular focus of this analysis is the detection of interdecadal shifts similar to the observed 1976/77 transition from cooler to warme...

Fluid dynamical experiments using a rotating tank with an imposed radial temperature gradient provide classical examples of the realization of large-scale atmospheric circulation in a laboratory setting. The last decade has seen a revival of such experiments for research and education. Classical rotating tank experiments have adopted axially symmet...

This work assesses the effects of assimilating atmospheric infrared sounder (AIRS) observations on typhoon prediction using the three-dimensional variational data assimilation (3DVAR) and forecasting system of the weather research and forecasting (WRF) model. Two major parameters in the data assimilation scheme, the spatial decorrelation scale and...

Storm tracks play a major role in regulating the precipitation and hydrological cycle in midlatitudes. The changes in the location and amplitude of the storm tracks in response to global warming will have significant impacts on the poleward transport of heat, momentum and moisture and on the hydrological cycle. Recent studies have indicated a polew...

The advent of high accuracy satellite altimetry in the 1990's brought the first global view of ocean dynamics, which together with a global network of supporting observations brought a revolution in understanding of how the ocean works (Fu and Cazenave, 2001). At present a constellation of flying satellite missions routinely provides sea level anom...

Hindcast experiments for the tropical Atlantic sea surface temperature (SST) gradient G1, defined as tropical North Atlantic SST anomaly minus tropical South Atlantic SST anomaly, are performed using an atmospheric general circulation model coupled to a mixed layer ocean over the Atlantic to quantify the contributions of the El Niño-Southern Oscill...

This note evaluates the numerical schemes used for computing the axial component of the mountain torque from gridded global surface pressure and topography datasets. It is shown that the two formulas of the mountain torque based on (i) an integral of the product of the surface pressure and the gradient of topography, and (ii) an integral of the pro...

In this study, the Advanced Microwave Sounding Unit (AMSU) data are used to retrieve the temperature and velocity fields of typhoons and assimilate them with the three-dimensional variational data assimilation (3DVAR) routines for uses in numerical model predictions for typhoons. The authors' procedure of an end-to-end typhoon prediction using an A...

1] The degree of anisotropy is calculated for the mid-ocean currents estimated from satellite altimetry and simulated with a numerical model of the Pacific Ocean. A high resolution eddy-permitting model is used for its ability to simulate mid-ocean multiple zonal flows, crucial for the evaluation of the degree of anisotropy. Using a commonly define...

How anthropogenic climate change will affect hydroclimate in the arid regions of southwestern North America has implications for the allocation of water resources and the course of regional development. Here we show that there is a broad consensus among climate models that this region will dry in the 21st century and that the transition to a more a...

Fluid jets occur in Earth's atmosphere and oceans, and on other planets. A new theoretical view of jets has helped reveal why they form and how they interact with the surrounding fluid.

PERSPECTIVES vate TLR4, resulting in different arrangements of the TIR domain in the cytoplasmic region of TLR4. The structure of MD-2 provides clues as to how this might come about. For example, one of the true surprises of the MD-2 structure is that neither of the two lysine residues that flank its hydrophobic pocket (Lys 128 and Lys 132) bind th...

An accurate estimate of observation errors is crucial to the retrieval of atmospheric profiles from satellite data using a variational method. In practice, observation errors, both systematic and random, are often estimated from the difference between satellite observations and simulated satellite observations obtained from a radiative-transfer ope...

The Atlantic cross-equatorial SST gradient is known to influence Brazillian rainfall especially in boreal spring. An observational analysis shows that El Nino (La Nina) generally contributes to an increase (decrease) in the SST gradient. However, during about one-third of strong ENSO events, the ENSO-induced tendency is not sufficient to overturn a...

The relationship between the boreal winter El Niño SST anomaly and boreal spring tropical Atlantic SST gradient (North Atlantic minus South Atlantic) is investigated using a long, detrended SST record. For both El Niño and La Niña, concordant cases (same sign for NINO3 index and Atlantic SST gradient) slightly dominate over discordant ones, reflect...

Most major features of the interdecadal shift in boreal winter-spring precipitation over the American continents associated with the 1976–1977 transition are reproduced in atmospheric general circulation model (GCM) simulations forced with observed sea surface temperature (SST). The GCM runs forced with global and tropical Pacific SSTs produce simi...

The patterns of precipitation anomalies forced by the El Niño–Southern Oscillation during northern hemisphere winter and spring are remarkably hemispherically symmetric and, in the midlatitudes, have a prominent zonally symmetric component. Observations of global precipitation variability and the moisture budget within atmospheric reanalyses are ex...

1] Recent eddy-permitting simulations of the North Pacific Ocean have revealed robust patterns of multiple zonal jets that visually resemble the zonal jets on giant planets. We argue that this resemblance is more than just visual because the energy spectrum of the oceanic jets obeys a power law that fits spectra of zonal flows on the outer planets....

An intercomparison of the reanalysis datasets of NCEP and ECMWF is performed with respect to the response of the axial angular momentum M to the torques. While both sets satisfy the budget equations of M reasonably well (except for the time mean). this is not the case with respect to the budget equations for the difference of both sets, where the a...

The global atmospheric angular momentum (AAM) is known to increase with tropical eastern Pacific sea surface temperature (SST) anomalies during El Niño events. Using a reanalysis dataset, the ratio of the monthly AAM anomaly to El Niño SST anomaly (based on the Niño-3.4 index) is found to be approximately 1 angular momentum unit (=1025 kg m2 s1) pe...

The energy spectra of the observed zonal flows on Jupiter and Saturn are shown to obey the scaling law EZ(n)=CZ(Omega /R)^2 n^(-5) in the range of total wave numbers n not affected by large scale friction (here, Omega and R are the rotation rate and the radius of the planet, and CZ is an order-one constant). These spectra broadly resemble their cou...

The authors investigate the change of atmospheric angular momentum (AAM) in long, transient, coupled atmosphere-ocean model simulations with increasing atmospheric greenhouse gas concentration and sulfate aerosol loading. A significant increase of global AAM, on the order of 4 × 1025 kg m2 s1 for 3 × CO2-1 × CO2, was simulated by the Canadian Centr...

The anisotropiccharacteristics of small-scale forced 2D turbulence on the surface of a rotating sphere are investigated. In the absence of rotation, the Kolmogorov k −5/3 spectrum is recovered with the Kolmogorov constant C K ≈6, close to previous estimates in plane geometry. Under strong rotation, in long-term simulations without a large-scale dra...

The use of the Advanced Very High Resolution Radiometer (AVHRR) data in a one-dimensional variational scheme is examined to retrieve cloud parameters and atmospheric profiles. The variational scheme used TIROS Operational Vertical Sounder radiance data for retrieval. The AVHRR data were used in the partly cloudy and cloudy cases to provide initial...

The analysis of the zonal flows observed on Jupiter reveals that their spectrum is E(n) = CZ (Omega/R)^2 n-5, where Omega is the angular velocity, R is the radius, and n is the total wave number for the zonal mean flow. This spectrum for zonal flows was first obtained in our earlier numerical simulations of turbulent flows on the surface of a rotat...

The annual variation of global atmospheric angular momentum (AAM) is dominated by its first and second harmonic components. The first harmonic is associated with maximum global AAM in winter (December- January-February) and minimum in summer, but the second harmonic is important enough to produce a distinct secondary midwinter minimum. Locally, the...

The scale-dependent characteristics of the optimal perturbations in a zonally asymmetric barotropic model are examined. The dependence of the optimal energy growth on the initial scale is investigated through the calculations of spectrally constrained optimal perturbations. Considering an optimization time of = 3 days, and a basic state containing...

The balance of global atmospheric angular momentum is examined in a long time series of “reanalysis” data generated at the National Centers for Environmental Prediction (NCEP). A systematic negative bias of about −10 Hadleys (1018 kg m2 s−2) is obtained in the total torque in all seasons. The sum of the frictional (TF) and mountain (TM) torques con...

Differential rotation effects the large scale dynamics of small scale forced, 2D turbulence via reorganization of the spectrum from the Kolmogorov -5/3 to -5 law (Rhines, 1975). This prediction was corroborated in simulations by Sukoriansky et al. (1996) in a periodic box setting on beta-plane. It was shown that on the large scales, the energy tran...

The dynamics of two-dimensional turbulence on a rotating sphere are examined. The anisotropic Rhines scale is derived and verified in decaying turbulence simulations. Due to the anisotropic nature of the Rossby waves, the Rhines barrier is displaced toward small total wavenumber n with decreasing zonal wavenumber m. Up-scale energy transfer along t...

Understanding the dynamics of low-frequency variability in the atmosphere is crucial for the improvement of long- range climate prediction. In this study we investigate the internal dynamics of large-scale, extratropical, low- frequency variability using a global barotropic model with a zonally asymmetric basic state. A particular focus is on the s...

Branstator-Kushnir-type large-scale westward propagating waves are investigated using linear and nonlinear global barotropic models with an idealized zonally asymmetric basic state. Retrograde waves are found in the most unstable normal mode of the zonally asymmetric basic state with a jet in the Northern Hemisphere. West-ward propagating waves als...

Analyzing a suite of high-resolution ocean model simulations, it is found that the strength of the simulated horizontal temperature gradient is strongly influenced by the atmospheric forcing. Within the 5 km -300 m range in model resolution, imposing a fine-resolution forcing is far more efficient than increasing the model resolution in enhancing t...