Numerical simulation of "an American haboob"

Abstract

Abstract.A dust storm of fearful proportions hit Phoenix in the early evening hours of 5 July 2011. This storm, an American haboob, was predicted hours in advance because numerical, land-atmosphere modeling, computing power and remote sensing of dust events have improved greatly over the past decade. High-resolution numerical models are required for accurate simulation of the small scales of the haboob process, with high velocity surface winds produced by strong convection and severe downbursts. Dust productive areas in this region consist mainly of agricultural fields, with soil surfaces disturbed by plowing and tracks of land in the high Sonoran Desert laid barren by ongoing draught.Model simulation of the 5 July 2011 dust storm uses the coupled atmospheric-dust model NMME-DREAM (Nonhydrostatic Mesoscale Model on E grid, Janjic et al., 2001; Dust REgional Atmospheric Model, Nickovic et al., 2001;Pérez et al., 2006) with 4 km horizontal resolution. A mask of the potentially dust productive regions is obtained from the land cover and the normalized difference vegetation index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS). The scope of this paper is validation of the dust model performance, and not use of the model as a tool to investigate mechanisms related to the storm. Results demonstrate the potential technical capacity and availability of the relevant data to build an operational system for dust storm forecasting as a part of a warning system. Model results are compared with radar and other satellitebased images and surface meteorological and PM 10 observations. The atmospheric model successfully hindcasted the position of the front in space and time, with about 1 h late arrival in Phoenix. The dust model predicted the rapid uptake of dust and high values of dust concentration in the ensuing storm. South of Phoenix, over the closest source regions (∼25 km), the model PM 10 surface dust concentration reached ∼2500 µg m −3 , but underestimated the values measured by the PM 10 stations within the city. Model results are also validated by the MODIS aerosol optical depth (AOD), employing deep blue (DB) algorithms for aerosol loadings. Model validation included Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), equipped with the lidar instrument, to disclose the vertical structure of dust aerosols as well as aerosol subtypes. Promising results encourage further research and application of high-resolution modeling and satellite-based remote sensing to warn of approaching severe dust events and reduce risks for safety and health.

Development of a dynamic dust source map for NMME-DREAM v1.0 model based on MODIS Normalized Difference Vegetation Index (NDVI) over the Arabian Peninsula

“…Similarly, Spyrou et al (2010) used a 30 s global land use/cover database, classified according to the 24 category U.S. Geological Survey (USGS) land use/cover system (Anderson et al, 1976) to define active areas in the SKIRON dust model. Solomos et al (2011) used the LEAF soil and vegetation sub-model of the Regional Atmospheric Modeling System (RAMS) (Walko et al, 2000) to identify the active dust sources in the RAMS-ICLAMS model. However, the abovementioned methodologies have some significant drawbacks.…”

Polarimetric radar observations of dust storms at C- and S-band

“…In Arizona, outflow from convective storms associated with the active phase of the southwestern monsoon often initiates dust storms (Raman et al 2014). Thunderstorms commonly develop over the mountains and gradually move out into surrounding areas during the mid-and lateafternoon, with convective outflows often raising dust (Vukovic et al 2014). Microbursts associated with this activity may have considerable fine-scale structure, recently resolved using radar observations (Vasiloff and Howard 2009).…”

“…Given the importance of these events to aviation, human health (e.g., Sprigg et al 2014), and air quality (e.g., Draxler et al 2001;Raman et al 2014)-along with the growing interest in using modeling approaches to nowcast these events (e.g., Vukovic et al 2014;Huang et al 2015)-further understanding of radar signatures within dust storms is warranted. Therefore, here we present the first detailed polarimetric radar observations, at C-band and S-band, of several dust storm events from areas prone to this phenomenon.…”

Analysis of aerosol absorption properties and transport over North Africa and the Middle East using AERONET data

“…For instance, particle absorption characteristics are used in assessing aerosol emission sources, types, and interaction phases . Aerosol categorization also helps identify dominant aerosol types over a certain geographic location, while climatology effects due to aerosols' spatial and temporal distribution is carried out by examining aerosol sizes along with their absorption characteristics using modeling, satellites, and ground-based measurements (El-Askary, 2006;Kaskaoutis et al, 2012;Aboel Fetouh et al, 2013;Vukovic et al, 2014;Sprigg et al, 2014). It is noteworthy that Figure 1.…”