Julian Wang

• PhD
• Senior Researcher at National Oceanic and Atmospheric Administration

Windblown dust events, including dust storms and smaller blowing dust events, pose severe risks to public health and transportation safety. In the United States, the statistics of fatalities caused by dust events remains elusive. We developed a new dataset by merging dust fatality data from NOAA Storm Events Database and the Department of Transport...

We discuss several issues raised by Comrie (2021), which uses a crowdsourced dataset to study dust storms and coccidioidomycosis (Valley fever). There is inconsistency in the term “dust storm” used by science communities. The dust data from NOAA Storm Events Database are from diverse sources, unsuitable for assessing dust-coccidioidomycosis relatio...

Although air quality in the United States has improved remarkably in the past decades, ground-level ozone (O3) often rises in exceedance of the national ambient air quality standard in nonattainment areas, including the Long Island Sound (LIS) and its surrounding areas. Accurate prediction of high-ozone episodes is needed to assist government agenc...

Although air quality in the United States improved remarkably in the past decades, ground-level ozone (O3) rises often in exceedance of the national ambient air quality standard in nonattainment areas, including the Long Island Sound (LIS) and its surrounding areas. Accurate prediction of high ozone episodes is needed to assist government agencies...

From the perspectives of remote sensing and climatic factors like surface meteorological parameters, large‐scale atmospheric circulations, and external forcing factors (EFFs), the authors synthesize and review spatiotemporal variations of PM2.5 over North China and how climate anomalies affect autumn and winter haze variability in North China accor...

Analogous to the circumstances in wintertime, the increasing severity of autumnal haze pollution over the Beijing–Tianjin–Hebei (BTH) region may also lead to impairment of the socioeconomic development and human health in this region. Despite man-made aerosol emissions, the interannual variability of autumnal (September–October–November) haze days...

Analogous to the circumstances in wintertime, the increasing severity of autumnal haze pollution over the Beijing–Tianjin–Hebei (BTH) region may also lead to impairment of the socioeconomic development and human health in this region. Despite manmade aerosol emissions, the interannual variability of autumnal (September–October–November) haze days (...

In this study, water temperature and meteorological data in Lake Taihu from June 11 to July 6, 2013, are collected to calibrate and verify the unstructured grid finite-volume community ocean model (FVCOM) coupled with a heat exchange module. The spatial and temporal variations of potential energy anomalies (PEA) in the lake, simulated by the calibr...

In contrast with the considerable number of studies on the variability of winter haze pollution over eastern China, there have been few studies of autumnal haze in this region. The interannual variability of autumnal (September–November) haze days in the Beijing–Tianjin–Hebei region (AHDBTH) is significantly correlated with the Scandinavia–central...

In a warming world there is a fair amount of uncertainty with respect to projections of tropical cyclone (TC) activity, which is strongly dependent on the climatic background state. To reduce that uncertainty and identify the sensitivity of global warming impacts to the background state, we classify the global oceans into three sub-regions: (1) hig...

In this study, 44 profiles of gross primary productivity (GPP) and sunlight, along with water temperature, Chlorophyll-a (Chla) and nutrients, were observed in Meiliang Bay of Taihu Lake, China, in the spring, summer, and fall seasons. Effects of water temperature, light, and nutrient concentration were examined in relation to the GPP-unit-Chla (GP...

Supporting Information S1

Climate models have consistently projected a drying trend in the southwestern United States, aiding speculation of increasing dust storms in this region. Long-term climatology is essential to documenting the dust trend and its response to climate variability. We have reconstructed long-term dust climatology in the western United States, based on a...

In the northern hemisphere, there are six permanent or semi-permanent atmospheric activity centers, namely the Icelandic Low, Aleutian Low, India Low, Mongolia High, North Pacific High, and North Atlantic High. The first four are semi-permanent action centers and the last two are permanent circulation systems. The India Low exists only during the s...

In order to construct climate quality long-term dust storm dataset, merged dust storm climatology in Phoenix is developed based on three data sources: regular meteorological records, in situ air quality measurements, and satellite remote sensing observations. The result presented in this paper takes into account the advantages of each dataset and i...

Dust aerosols affect human life, ecosystems, atmospheric chemistry and climate in various aspects. Some studies have revealed intensified dust activity in the western US during the past decades despite the weaker dust activity in non-US regions. It is important to extend the historical dust records, to better understand their temporal changes, and...

The representation of transient air-sea interactions is critical to the prediction of the sea surface temperature diurnal cycle and daily variability. This study develops a multi-level upper ocean model to more realistically resolve these interactions. The model is based on the one-dimensional turbulence kinetic energy closure developed by Noh et a...

Dust aerosols affect human life, ecosystems, atmospheric chemistry and climate in various aspects. Studies have revealed intensified dust activity in the western US during the past decades despite the weaker dust activity in non-US regions. It is important to extend the historical dust records, to better understand their temporal changes, and use s...

Dust storms, as extreme environmental events, are one of the Earth’s major natural hazards. Their impact on socio-economics can range from local urban to (trans-) continental and from minutes to decades, such as the dust bowl of the 1930s in the United States. Research on dust storms can be traced back for several decades as a meteorological extens...

This study investigates the refined simulation skill that results when the regional Climate extension of the Weather Research and Forecasting (CWRF) model is nested in the ECMWF Hamburg version 4.5 (ECHAM) atmospheric general circulation model over the United States during 1980-2009, where observed sea surface temperatures are used in both models....

A hybrid seasonal forecasting approach was generated by the National Centers for Environmental Prediction operational Climate Forecast System (CFS) and its nesting Climate extension of Weather Research and Forecasting (CWRF) model to improve forecasting skill over the United States. Skills for the three summers of 2011-2013 were evaluated regarding...

To improve dust storm identification over the western United States, historical dust events measured by air quality and satellite observations are analyzed based on their characteristics in data sets of regular meteorology, satellite based aerosol optical depth (AOD), and air quality measurements. Based on the prevailing weather conditions associat...

http://www.ncdc.noaa.gov/societal-impacts/air-stagnation

As precursors for tropospheric ozone and nitrate aerosols, Nitrogen oxides (NOx) in present atmosphere and its transformation in responding to emission and climate perturbations are studied by CAM-Chem model and air quality measurements including National Emission Inventory (NEI), Clean Air Status and Trends Network (CASTNET) and Environmental Prot...

In order to better understand the characteristics of dust storm processes over the western United States, available dust storm events reported by media or recorded by NASA earth observatory are classified into four types based on the prevailing weather systems. Then these four types of dust storm events related to cold fronts, downbursts, tropical...

The global numerical weather prediction model GRAPES at the National Meteorological Center of the China Meteorological Administration is subject to substantial systematic discrepancies from satellite-retrieved cloud cover, cloud water contents, and radiative fluxes. In particular, GRAPES produces insufficient total cloud cover and liquid water amou...

In this study, a group of indices were defined regarding intensity (P), area (S) and central position (λ c, ϕ c) of the Aleutian low (AL) in the Northern Hemisphere in winter, using seasonal and monthly mean height field at 1000-hPa. These indices were calculated over 60 winter seasons from 1948/1949 to 2007/2008 using reanalysis data. Climatic and...

The CWRF is developed as a climate extension of the Weather Research and Forecasting model (WRF) by incorporating numerous improvements in the representation of physical processes and integration of external (top, surface, lateral) forcings that are crucial to climate scales, including interactions between land, atmosphere, and ocean; convection an...

This study develops fine temporal (seasonal, day-of-week, diurnal) and vertical allocations of anthropogenic emissions for the TRACE-P inventory and evaluates their impacts on the East Asian air quality prediction using WRF-Chem simulations in July 2001 at 30-km grid spacing against available surface measurements from EANET and NEMCC. For NO2 and S...

The U.S. air quality is impacted by emissions both within and outside the United States. The latter impact is manifested as long-range transport (LRT) of pollutants across the U.S. borders, which can be simulated by lateral boundary conditions (LBC) into a regional modeling system. This system consists of a regional air quality model (RAQM) that in...

This study uses the most recent simulations from all available fully coupled atmosphere–ocean general circulation models (CGCMs) to investigate whether the North American monsoon (NAM) precipitation seasonal–interannual variations are simulated and, if so, whether the key underlying physical mechanisms are correctly represented. This is facilitated...

A suite of eighteen simulations over the U.S. and Mexico, representing combinations of two mesoscale regional climate models (RCMs), two driving global general circulation models (GCMs), and the historical and four future anthropogenic forcings were intercompared. The RCMs' downscaling reduces significantly driving GCMs' present-climate biases and...

A linear, spectral, tidal model for middle atmosphere thermal tides has been developed. the spectral model is based on horizontal vorticity and divergence equations, and the vertical structure equation for the geopotential is solved with appropriate boundary conditions. Such an approach yields a stable temperature field and a consistent velocity fi...

Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976–77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affect...

Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976-77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality and accessibility of prey, which in turn may have affecte...

1] A mesoscale model (MM5)–based regional climate model (CMM5) integration driven by the Parallel Climate Model (PCM), a fully coupled atmosphere-ocean-land-ice general circulation model (GCM), for the present (1986–1995) summer season climate is first compared with observations to study the CMM5's downscaling skill and uncertainty over the United...

This paper utilizes the best available quality data from multiple sources to develop consistent surface boundary conditions (SBCs) for mesoscale regional climate model (RCM) applications. The primary SBCs include 1) fields of soil characteristic (bedrock depth, and sand and clay fraction profiles), which for the first time have been consistently in...

Illinois State Water Survey published or submitted for publication is peer reviewed

The fifth-generation PSU NCAR Mesoscale Model (MM5)-based regional climate model (CMM5) capability in simulating the U.S. precipitation annual cycle is evaluated with a 1982 2002 continuous baseline integration driven by the NCEP DOE second Atmospheric Model Intercomparison Project (AMIP II) reanalysis. The causes for major model biases (difference...

Declines of Steller sea lion (Eumetopias jubatus) populations in the Aleutian Islands and Gulf of Alaska could be a consequence of physical oceanographic changes associated with the 1976--77 climate regime shift. Changes in ocean climate are hypothesized to have affected the quantity, quality, and accessibility of prey, which in turn may have affec...

A new North Atlantic Oscillation (NAO) index, the NAOI, is defined as the differences of normalized sea level pressures regionally zonal-averaged over a broad range of longitudes 80°W-30°E. A comprehensive comparison of six NAO indices indicates that the new NAOI provides a more faithful representation of the spatial-temporal variability associated...

1] A modified zonal index (ZI) for the Northern Hemisphere (NH) general circulation is defined as the normalized difference in zonal-averaged sea level pressure anomalies between 35°N and 65°N. The ZI is a measure of hemispheric-wide fluctuations in air mass between two annular belts of action (ABAs) over middle and high latitudes, centered near 35...

Dynamical links of the Northern Hemisphere stratosphere and troposphere are studied, with an emphasis on whether stratospheric changes have a direct effect on tropospheric weather and climate. In particular, downward propagation of stratospheric anomalies of polar temperature in the winter-spring season is examined based upon 22 years of NCEP-NCAR...

Trends of NAO and AO are shown, along with trends of various stratospheric fields and dynamical processes, including geopotential height, temperature and zonal wind, as well as EP flux and its divergence, based upon 30 years (1968-1997) of NCEP/NCAR Reanalysis data. Monthly trends are estimated by using linear regression. The NAO trends are similar...

In the past half century, the mean summertime temperature in China has increased, with nights warming more than days. Using surface station observations, we show that the frequency of extreme heat-stress events in China, caused by extremely hot and humid days as well as by heatwaves lasting for a few days, has increased over the period from 1951 to...

Climatological surface temperature and humidity variables for China are presented based on 6-hourly data from 196 stations for the period of 1961-90. Seasonal and annual means for daytime, nighttime, and the full day are shown. The seasonal cycle of moisture is primarily controlled by the east Asia monsoon system, with dominant factors of temperatu...

We compared the temporal variability of the heat content of the world ocean, of the global atmosphere, and of components of Earth's cryosphere during the latter half of the 20th century. Each component has increased its heat content (the atmosphere and the ocean) or exhibited melting (the cryosphere). The estimated increase of observed global ocean...

It has been observed that major air pollution episodes are usually related to the presence of stagnating anticyclones. Such anticyclones may linger over an area for a protracted period (4 days or more). During this period, surface wind speeds can fall to very low values. The near surface circulation is therefore insufficient to disperse accumulated...

Key features of the U.S. summer precipitation regime are examined within the context of the evolving North American monsoon system. The focus is on the antecedent and subsequent atmospheric conditions over the conterminous United States relative to the onset of monsoon precipitation over the southwestern United States, which typically begins in ear...

Climate simulations and forecast experiments of increasingly large ensemble size are being performed to assess the predictive skill of a dynamic model on seasonal and longer timescales. Especially in the cases of ensemble climate simulation or forecast forced by observed or predicted sea surface temperatures, the model is expected to maximize poten...

A series of climate ensemble experiments using the climate model from National Centers for Environmental Prediction (NCEP) were performed to exam impact of sea surface temperature (SST) on dynamics of El-Nino / Southern Oscillation (ENSO). A specific question addressed in this paper is how important the mean stationary wave influences anomalous Ros...

The NCEP and NCAR are cooperating in a project (denoted "reanalysis") to produce a 40-year record of global analyses of atmospheric fields in support of the needs of the research and climate monitoring communities. This effort involves the recovery of land surface, ship, rawinsonde, pibal, aircraft, satellite, and other data; quality controlling an...

Secular changes in the spatial and temporal structures of the El Nino/Southern Oscillation (ENSO) cycle using four different versions of global sea surface temperature (SST) analysis are examined. This study substantiates a conceptual framework that views the multidecadal, low-frequency variations as a varying climate "base state' upon which ENSO-s...

The sensitivity of the systematic error of extended-range forecasts to sea surface temperature (SST) anomalies is investigated. General circulation model (GCM) experiments were performed to quantify error patterns for warm, normal, and cold SST anomalies in the equatorial central Pacific. The model underestimates the strength of tropical convection...

The impact of satellite data is smaller than that obtained in previous impact studies during the First GARP (Global Atmospheric Research Program) Global Experiment (FGGE) that took place in 1979, reflecting the effect of improvements that have been implemented in the global analysis scheme and the model. In the Northern Hemisphere (NH), there are n...

In the tropical Pacific, the annual variation of sea surface temperature (SST) consists of two distinct components with respect to the equation, 1) an antisymmetric extratropical annual cycle and 2) a symmetric equatorial annual cycle (SEAC). The former, explaining abut 70% of SST variance on average, is primarily a delayed response to the solar ra...

The June-August 1992 (JJA 1992) season featured a weakening of the 1991-1992 El Nino-Southern Oscillation (ENSO) warm episode and a return toward normal conditions in the tropical Pacific. In the Northern Hemisphere, below-normal temperatures dominated the landmass regions in midlatitudes except in Europe where above-normal temperatures persisted t...

The impact of the sea surface temperature (SST) anomalies on predictions in the extratropics has been studied by comparing circulation changes in general circulation model experiments generated with observed and climatological sea surface temperatures for warm and cold South Oscillation events. As the atmosphere responds to the warm (cold) tropical...

Tropospheric biennial variability in several components of the Southern Oscillation (SO) is defined and described through analysis of observational data from the Comprehensive Ocean-Atmosphere Data Set (COADS), as well as through investigation of several SO index time series. The analysis suggests that the temporal behavior of the SO can be describ...

Using surface marine wind and sea surface temperature data from the period 1950–1987, together with sea surface temperature and sea level pressure data from several stations in the Pacific, we have identified two dominant time scales of El Niño-Southern Oscillation (ENSO) variability. One is a biennial mode, with periods near 24 months, the other a...

The longitude-time cross section of outgoing longwave radiation and zonal winds at the equator indicates a regular eastward propagation of interannual time-scale perturbations all the way from the Indian Ocean, across the maritime continent, to as far east as the eastern Pacific during the 5 years of 1979–83. These interannual perturbations also ex...

Typescript. Thesis (Ph. D.)--University of Hawaii at Manoa, 1988. Bibliography: leaves 147-154. Microfilm. xx, 154 leaves, bound ill. 29 cm

Relationships between midlatitude cold surges and tropical convections are investigated utilizing 30-60 day filtered 850mb meridional winds and outgoing longwave radiation (OLR) data during the three Northern Hemisphere winters of 1980-83. The 30-60 day southerly surges over the eastern Indian Ocean off the west Australian coast act as the trigger...