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Ravan Ahmadov

Affiliation/Employer
CIRES
Partner Affiliation
gsl
Publon ID

Publications

Corresponding Articles: 38

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...

Ravan Ahmadov
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 system

Ravan Ahmadov
Institution 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...

Ravan Ahmadov

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) ...

Ravan Ahmadov
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 ...

Ravan Ahmadov
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...

Ravan Ahmadov
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...

Ravan Ahmadov
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...

Ravan Ahmadov
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...

Ravan Ahmadov
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...

Ravan Ahmadov
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)...

Ravan Ahmadov
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...

Ravan Ahmadov

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...

Ravan Ahmadov
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...

Ravan Ahmadov

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...

Ravan Ahmadov
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...

Ravan Ahmadov
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...

Ravan Ahmadov

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...

Ravan Ahmadov

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...

Ravan Ahmadov
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...

Ravan Ahmadov

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...

Ravan Ahmadov
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...

Ravan Ahmadov
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...

Ravan Ahmadov
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 ...

Ravan Ahmadov
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...

Ravan Ahmadov

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...

Ravan Ahmadov
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 ...

Ravan Ahmadov
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...

Ravan Ahmadov
Institutions Earth System Research Laboratory - ESRL National Oceanic and Atmospheric Administration - NOAA

Were Wildfires Responsible for the Unusually High Surface Ozone in 2 Colorado during 2021?

Ground-level ozone (O3) was unusually high in northern Colorado in the summer of 2021 with maximum daily 8-hr average (MDA8) concentrations 6 to 8 parts-per-billion by volume (ppbv) higher than in 2019, 2020, or 2022. One or more of the monitors on the Colorado Front Range exceeded the 2015 U.S. National Ambient Air Quality Standard (NAAQS) of 7...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

Assimilation of Aerosol Optical Depth Into the Warn-on-Forecast System for Smoke (WoFS-Smoke)

This research extends the Warn-on-Forecast System for Smoke (WoFS-Smoke) by adding the capability to assimilate aerosol optical depth (AOD) retrievals from the Geostationary Operational Environmental Satellite Series-R (GOES-R) satellites. The WoFS is a rapidly cycling, ensemble-based analysis and forecasting system designed to generate short te...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

Landscape Fire, Smoke, and Health: Linking Biomass Burning Emissions to Human Well‐Being: Profiles of Operational and Research Forecasting of Smoke and Air Quality Around the World (Pages: 149-191)

Where and when wildfires occur, what pollutants they emit, how the chemistry of smoke changes in the atmosphere, and what impact this air pollution has on human health and well-being are questions explored across different scientific disciplines. Landscape Fire, Smoke, and Health: Linking Biomass Burning Emissions to Human Well-Being is desig...

Ravan Ahmadov

Population co-exposure to extreme heat and wildfire smoke pollution in California during 2020

Excessive warming from climate change has increased the total wildfire burned area over the past several decades in California. This has increased population exposure to both hazardous concentrations of air pollutants from fires such as fine particulate matter (smoke PM2.5) and extreme heat events. Exposure to PM2.5 and extreme heat are individu...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

Heat flux assumptions contribute to overestimation of wildfire smoke injection into the free troposphere

Injections of wildfire smoke plumes into the free troposphere impact air quality, yet model forecasts of injections are poor. Here, we use aircraft observations obtained during the 2019 western US wildfires (FIREX-AQ) to evaluate a commonly used smoke plume rise parameterization in two atmospheric chemistry-transport models (WRF-Chem and HRRR-Sm...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

Exposure of agricultural workers in California to wildfire smoke under past and future climate conditions

Wildfire activity in the western U.S. has increased in frequency and severity in recent decades. Wildfire smoke emissions contribute to elevated fine particulate matter (PM2.5) concentrations that are dangerous to public health. Due to the outdoor and physically demanding nature of their work, agricultural workers are particularly vulnerable to ...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

A simple and realistic aerosol emission approach for use in the Thompson-Eidhammer microphysics sscheme in the NOAA UFS Weather Model (version GSL global-24Feb 2022)

A physics suite under development at NOAA's Global Systems Laboratory (GSL) includes the aerosol-aware double-moment Thompson–Eidhammer microphysics (TH-E MP) scheme. This microphysics scheme uses two aerosol variables (concentrations of water-friendly aerosol (WFA) and ice-friendly aerosol (IFA) numbers) to include interactions with some of the...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

Ingesting GOES-16 fire radiative power retrievals into Warn-on-Forecast System for Smoke

Background The record number of wildfires in the United States in recent years has led to an increased focus on developing tools to accurately forecast their impacts at high spatial and temporal resolutions. Aims The Warn-on-Forecast System for Smoke (WoFS-Smoke) was developed to improve these forecasts using wildfire properties retrieved f...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

A Case Study Featuring the Time Evolution of a Fire-Induced Plume Jet Over the Rum Creek Fire: Mechanisms, Processes, and Dynamical Interplay

Results are presented from the Rum Creek fire during the California Fire Dynamics Experiment (CalFiDE). An instrumented payload aboard the NOAA Twin Otter (TO) aircraft, which included a scanning micro-pulsed Doppler lidar (DL) and in situ chemistry packages, was used to address the evolution of a buoyant plume jet (BPJ) and transport dynamics o...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA

A better representation of VOC chemistry in WRF-Chem and its impact on ozone over Los Angeles

The declining trend in vehicle emissions has underscored the growing significance of Volatile Organic Compound (VOC) emissions from Volatile Chemical Products (VCP). However, accurately representing VOC chemistry in simplified chemical mechanisms remains challenging due to its chemical complexity including speciation and reactivity. Previous stu...

Ravan Ahmadov
Institution National Oceanic and Atmospheric Administration - NOAA