Ravan Ahmadov authored and/or contributed to the following articles/publications.
CO2 Transport, Variability, and Budget over the Southern California Air Basin Using the High-Resolution WRF-VPRM Model during the CalNex 2010 Campaign
To study regional-scale carbon dioxide (CO2) transport, temporal variability, and budget over the Southern California Air Basin (SoCAB) during the California Research at the Nexus of Air Quality and Climate Change (CalNex) 2010 campaign period, a model that couples the Weather Research and Forecasting (WRF) Model with the Vegetation Photosynthes...Institution National Oceanic and Atmospheric Administration - NOAA
Using VIIRS fire radiative power data to simulate biomass burning emissions, plume rise and smoke transport in a real-time air quality modeling systemInstitution National Oceanic and Atmospheric Administration - NOAA
Use of VIIRS Aerosol Optical Depth Information at NOAA GSL to Improve Smoke, Visibility, and Weather Forecasts in the Experimental High Resolution Rapid Refresh
Recent wildfires in the U.S. and abroad have underscored the far-reaching effects that smoke from wildfires has on lives and industries, impacting air quality, aviation, solar energy generation, and more. As a result, demand has increased for reliable and accurate forecasts of smoke emanating from wildfires. To a...
Inline Coupling of Simple and Complex Chemistry Modules within the Global Weather Forecast model FIM (FIM-Chem v1)
The global Flow-following finite-volume Icosahedral Model (FIM), which was developed in the Global Systems Laboratory of NOAA/ESRL, has been coupled inline with aerosol and gas-phase chemistry schemes of different complexity using the chemistry and aerosol packages from WRF-Chem v3.7, named as FIM-Chem v1. The three chemistry schemes include 1) ...Institutions National Oceanic and Atmospheric Administration - NOAA Earth System Research Laboratory - ESRL
How does a Pinatubo‐size Volcanic Cloud Reach the Middle Stratosphere?
Volcanic explosions are the most critical replenishing mechanism of the stratospheric aerosol Junge layer. A fresh volcanic cloud comprises mostly sulfur‐bearing gases, volcanic ash, and water vapor. It is commonly assumed that only sulfate aerosols remain in an aged volcanic cloud. Accurate simulation of the initial evolution of multicomponent ...Institution National Oceanic and Atmospheric Administration - NOAA
Evaluation and intercomparison of wildfire smoke forecasts from multiple modeling systems for the 2019 Williams Flats fire
Wildfire smoke is one of the most significant concerns of human and environmental health, associated with its substantial impacts on air quality, weather, and climate. However, biomass burning emissions and smoke remain among the largest sources of uncertainties in air quality forecasts. In this study, we evaluate the smoke emissions and plume f...Institution National Oceanic and Atmospheric Administration - NOAA
A fast visible-wavelength 3D radiative transfer model for numerical weather prediction visualization and forward modeling
Solar radiation is the ultimate source of energy flowing through the atmosphere; it fuels all atmospheric motions. The visible-wavelength range of solar radiation represents a significant contribution to the earth's energy budget, and visible light is a vital indicator for the composition and thermodynamic processes of the atmosphere from the sm...Institution National Oceanic and Atmospheric Administration - NOAA
Combined impacts of nitrous acid and nitryl chloride on lower-tropospheric ozone: new module development in WRF-Chem and application to China
Nitrous acid (HONO) and nitryl chloride (ClNO2) – through their photolysis – can have profound effects on the nitrogen cycle and oxidation capacity of the lower troposphere. Previous numerical studies have separately considered and investigated the sources/processes of these compounds and their roles in the fate of reactive nitrogen and the prod...Institution National Oceanic and Atmospheric Administration - NOAA
Improving dust simulations in WRF-Chem v4.1.3 coupled with the GOCART aerosol module
In this paper, we rectify inconsistencies that emerge in the Weather Research and Forecasting model with chemistry (WRF-Chem) v3.2 code when using the Goddard Chemistry Aerosol Radiation and Transport (GOCART) aerosol module. These inconsistencies have been reported, and corrections have been implemented in WRF-Chem v4.1.3. Here, we use a WRF-Ch...Institution National Oceanic and Atmospheric Administration - NOAA
The impacts of transported wildfire smoke aerosols on surface air quality in New York State: A case study in summer 2018
Wildfire smoke aerosols, once emitted, can transport over long distances and affect surface air quality in downwind regions. In New York State (NYS), fine particulate matter (PM2.5) concentration continues to decrease due to anthropogenic emission reductions and regulatory initiatives in recent years. Smoke aerosols, however, are projected to in...Institution National Oceanic and Atmospheric Administration - NOAA
Sources and characteristics of summertime organic aerosol in the Colorado Front Range: perspective from measurements and WRF-Chem modeling
The evolution of organic aerosols (OAs) and their precursors in the boundary layer (BL) of the Colorado Front Range during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ, July–August 2014) was analyzed by in situ measurements and chemical transport modeling. Measurements indicated significant production of secondary OA (SOA)...Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Development of a Fuel-Based Oil and Gas Inventory of Nitrogen Oxides Emissions
In this study, we develop an alternative Fuel-based Oil and Gas inventory (FOG) of nitrogen oxides (NOx) from oil and gas production using publicly available fuel use records and emission factors reported in the literature. FOG is compared with the Environmental Protection Agency’s 2014 National Emissions Inventory (NEI) and with new top-down es...
Modeling Ozone in the Eastern U.S. using a Fuel-Based Mobile Source Emissions Inventory
Recent studies suggest overestimates in current U.S. emission inventories of nitrogen oxides (NOx = NO + NO2). Here, we expand a previously developed fuel-based inventory of motor-vehicle emissions (FIVE) to the continental U.S. for the year 2013, and evaluate our estimates of mobile source emissions with the U.S. Environmental Protection Agency...Institution National Oceanic and Atmospheric Administration - NOAA
Nitrous acid formation in a snow-free wintertime polluted rural area
Nitrous acid (HONO) photolysis is an important source of hydroxyl radicals (OH) in the lower atmosphere, in particular in winter when other OH sources are less efficient. The nighttime formation of HONO and its photolysis in the early morning have long been recognized as an important contributor to the OH budget in polluted environments. Over th...
The Weather Research and Forecasting Model: Overview, System Efforts, and Future Directions
Since its initial release in 2000, the Weather Research and Forecasting (WRF) Model has become one of the world’s most widely-used numerical weather prediction models. Designed to serve both research and operational needs, it has grown to offer a spectrum of options and capabilities for a wide range of applications. In addition, it underlies a n...Institutions National Center for Atmospheric Research - NCAR National Oceanic and Atmospheric Administration - NOAA
Diagnostic fields developed for hourly updated NOAA weather models
This document describes methods for diagnosing non-prognostic variables from explicit prognostic variables from hourly updated NOAA models. Many of these diagnostics have been developed for specific forecast applications for downstream forecast users over the years; these variables have been output from the Rapid Update Cycle (RUC) model prior t...Institution National Oceanic and Atmospheric Administration - NOAA
Megafires and thick smoke portend big problems for migratory birds
In 2020, the fire season affecting the western United States reached unprecedented levels. The 116 fires active in September consumed nearly 20,822 km2 (https://inciweb.nwcg.gov/accessible-view/ Accessed 2020-09-29) with 80% of this footprint (16,567 km2) from 68 fires occurring within California, Oregon, and Washington. Although the 2020 fire s...
Quantifying Carbon Monoxide Emissions on the Scale of Large Wildfires
The University of Colorado Airborne Solar Occultation Flux (CU AirSOF) instrument conducted the first suborbital carbon monoxide (CO) mass flux measurements on the scale of large wildfires, showing that the destructive fires in northern California in October 2017 emitted 2040 ± 316 tonnes CO hr−1. Pyrogenic estimates from 7 satellite-based emiss...
High-resolution smoke forecasting for the 2018 Camp Fire in California
Smoke from the 2018 Camp Fire in Northern California blanketed a large part of the region for two weeks, creating poor air quality in the “unhealthy” range for millions of people. The NOAA Global System Laboratory’s HRRR-Smoke model was operating experimentally in real time during the Camp Fire. Here, output from the HRRR-Smoke model is compared...Institution National Oceanic and Atmospheric Administration - NOAA
Impacts of heterogeneous uptake of dinitrogen pentoxide and chlorine activation on ozone and reactive nitrogen partitioning: improvement and application of the WRF-Chem model in southern China
The uptake of dinitrogen pentoxide (N2O5) on aerosol surfaces and the subsequent production of nitryl chloride (ClNO2) can have a significant impact on the oxidising capability and thus on secondary pollutants such as ozone. The range of such an impact, however, has not been well quantified in different geographical regions. In this study, we ap...
Understanding high wintertime ozone pollution events in an oil- and natural gas-producing region of the western US
Recent increases in oil and natural gas (NG) production throughout the western US have come with scientific and public interest in emission rates, air quality and climate impacts related to this industry. This study uses a regional-scale air quality model (WRF-Chem) to simulate high ozone (O3) episodes during the winter of 2013 over the Uinta Ba...Institution Earth System Research Laboratory - ESRL
WRF-Chem Version 3.8.1 Users Guide
The WRF-Chem User's Guide is designed to provide the reader with information specific to the chemistry part of the WRF model and its potential applications. It will provide the user a description of the WRF-Chem model and discuss specific issues related to generating a forecast that includes chemical constituents beyond what is typically used by...Institutions National Center for Atmospheric Research - NCAR National Oceanic and Atmospheric Administration - NOAA
The High-Resolution Rapid Refresh (HRRR): An Hourly Updating Convection-Allowing Forecast Model. Part 1: Motivation and System Description
The High-Resolution Rapid Refresh (HRRR) is a convection-allowing implementation of the Weather Research and Forecasting model (WRF-ARW) with hourly data assimilation that covers the conterminous United States and Alaska and runs in real time at the NOAA National Centers for Environmental Prediction. Implemented operationally at NOAA/NCEP in 201...Institution National Oceanic and Atmospheric Administration - NOAA
Prototype of a Warn-on-Forecast System for Smoke (WoFS-Smoke)
This research begins the process of creating an ensemble-based forecast system for smoke aerosols generated from wildfires using a modified version of the National Severe Storms Laboratory (NSSL) Warn-on-Forecast System (WoFS). The existing WoFS has proven effective in generating short-term (0–3 h) probabilistic forecasts of high-impact weather ...Institution National Oceanic and Atmospheric Administration - NOAA
Airborne Emission Rate Measurements Validate Remote Sensing Observations and Emission Inventories of Western U.S. Wildfires
Abstract Image Carbonaceous emissions from wildfires are a dynamic mixture of gases and particles that have important impacts on air quality and climate. Emissions that feed atmospheric models are estimated using burned area and fire radiative power (FRP) methods that rely on satellite products. These approaches show wide variability and have l...
Development and evaluation of the Aerosol Forecast Member in the National Center for Environment Prediction (NCEP)'s Global Ensemble Forecast System (GEFS-Aerosols v1)
The National Oceanic and Atmospheric Administration (NOAA)'s National Weather Service (NWS) is on its way to deploying various operational prediction applications using the Unified Forecast System (https://ufscommunity.org/, last access: 18 June 2022), a community-based coupled, comprehensive Earth modeling system. An aerosol model component dev...Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA
Impacts of estimated plume rise on PM2.5 exceedance prediction during extreme wildfire events: A comparison of three schemes (Briggs, Freitas, and Sofiev)
Plume height plays a vital role in wildfire smoke dispersion and the subsequent effects on air quality and human health. In this study, we assess the impact of different plume rise schemes on predicting the dispersion of wildfire air pollution, and the exceedances of the National Ambient Air Quality Standards (NAAQS) for fine particulate matter ...Institution National Oceanic and Atmospheric Administration - NOAA
Simulating wildfire emissions and plume rise using geostationary satellite fire radiative power measurements: a case study of the 2019 Williams Flats fire
We use the Weather Research and Forecasting with Chemistry (WRF-Chem) model with new implementations of GOES-16 wildfire emissions and plume rise based on fire radiative power (FRP) to interpret aerosol observations during the 2019 NASA-NOAA FIREX-AQ field campaign and perform model evaluations. We compare simulated aerosol concentrations and op...Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA