Development of a REgion‐Specific Ecosystem Feedback Fire (RESFire) Model in the Community Earth System Model

Wang

et al. 2019

Preprint

Self Cite

Abstract. Carbonaceous aerosols significantly affect global radiative forcing and climate through absorption and scattering of sunlight. Black carbon (BC) and brown carbon (BrC) are light-absorbing carbonaceous aerosols. The direct radiative effect (DRE) of BrC is uncertain. A recent study suggests that BrC absorption is comparable to BC in the upper troposphere over biomass burning regions and that the resulting radiative heating tends to stabilize the atmosphere. Yet current climate models do not include proper physical and chemical treatments of BrC. In this study, we derived a BrC global biomass burning emission inventory on the basis of the Global Fire Emissions Database 4 (GFED4), developed a BrC module in the Community Atmosphere Model version 5 (CAM5) of Community Earth System Model (CESM) model, and investigated the photo-bleaching effect and convective transport of BrC on the basis of Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) and Deep Convective Clouds and Chemistry Project (DC-3) measurements. The model simulations of BC were also evaluated using HIAPER (High-Performance Instrumented Airborne Platform for Environmental Research) Pole-to-Pole Observations (HIPPO) measurements. We found that globally BrC is a significant absorber, the DRE of which is 0.10&#8201;W/m2, more than 25&#8201;% of BC DRE (+0.39&#8201;W/m2). Most significantly, model results indicated that BrC atmospheric heating in the tropical mid and upper troposphere is larger than that of BC. The source of tropical BrC is mainly from wildfires, which are more prevalent in the tropical regions than higher latitudes and release much more BrC relative to BC than industrial sources. While BC atmospheric heating is skewed towards northern mid-latitude lower atmosphere, BrC heating is more centered in the tropical free troposphere. The contribution of BrC heating to the Hadley circulation and latitudinal expansion of the tropics is comparable to BC heating.

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Modeling global radiative effect of brown carbon: A larger heating source in the tropical free troposphere than black carbon

Wang

et al. 2019

Preprint

Self Cite

“…This study set out to simulate the climatology of fires, and not individual fire events. Like only a few other fire models [Zou et al, 2019], pyrE was developed with consideration of regional behavior.…”

Section: Discussionmentioning

confidence: 99%

“…The modeling approach presented in this paper provides a good reproduction of the seasonality compared to satellite retrievals (see Results section). However, the simulated magnitude of fire count and burned area was too small compared to satellite retrievals and required the use of a scaling factor, a common practice among other fire models [Pfeifer et al, 2013;Knorr et al, 2014;Hantson et al, 2016;Zou et al, 2019]. To calibrate the global modeled fire count to MODIS retrievals, we used a global scaling factor of 30 for all fire count.…”

Section: Implementation Within Modelementioning

confidence: 99%

“…Traditionally, fires are included in climate models using emission inventories [Lamarque et al, 2010;van der Werf et al, 2010van der Werf et al, , 2017van Marle et al, 2017]. Some models have the ability to simulate BB emissions interactively with a varying level of complexity [Thonicke et al, 2001;Arora and Boer, 2005;Pechony and Shindell, 2009;Li et al, 2012;Lasslop et al, 2014;Hantson et al, 2016;Rabin et al, 2017;Zou et al, 2019]. On the one end of the spectrum, there are statistically-based models, and on the other end there are detailed empirical and physical process-based models.…”

mentioning

confidence: 99%

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The interactive global fire module pyrE

Mezuman

Tsigaridis

Faluvegi

et al. 2019

Preprint

Abstract. Fires affect the composition of the atmosphere and Earth’s radiation balance by emitting a suite of reactive gases and particles. An interactive fire module in an Earth System Model (ESM) allows us to study the natural and anthropogenic drivers, feedbacks, and interactions of open fires. To do so, we have developed pyrE, the NASA GISS interactive fire emissions module. The pyrE module is driven by environmental variables like flammability and cloud-to-ground lightning, calculated by the GISS ModelE ESM, and parameterized anthropogenic impacts based on population density data. Fire emissions are generated from the actual flaming phase in pyrE (fire count), not the scar left behind (burned area), as is commonly done in other interactive fire modules. Using pyrE, we examine fire behavior, regional fire suppression, burned area, fire emissions, and how it all affects atmospheric composition. To do so, we evaluate pyrE by comparing it to satellite-based datasets of fire count, burned area, fire emissions, and aerosol optical depth (AOD). We demonstrate pyrE’s ability to simulate the daily and seasonal cycles of open fires and resulting emissions. Our results indicate that interactive fire emissions are bias low by 32–42 %, depending on emitted species, compared to the GFED4s inventory. The bias in emissions drives underestimation in column densities, which is diluted by natural and anthropogenic emissions sources and production and loss mechanisms. Yet, in terms of AOD, a simulation with interactive fire emissions performs just as well as a simulation with prescribed fire emissions.

Wildland Fire Smoke in the United States

Smoke Plume Dynamics

Liu

Heilman

Potter

et al. 2022

Smoke plume dynamic science focuses on understanding the various smoke processes that control the movement and mixing of smoke. A current challenge facing this research is providing timely and accurate smoke information for the increasing area burned by wildfires in the western USA. This chapter synthesizes smoke plume research from the past decade to evaluate the current state of science and identify future research needs. Major advances have been achieved in measurements and modeling of smoke plume rise, dispersion, transport, and superfog; interactions with fire, atmosphere, and canopy; and applications to smoke management. The biggest remaining gaps are the lack of high-resolution coupled fire, smoke, and atmospheric modeling systems, and simultaneous measurements of these components. The science of smoke plume dynamics is likely to improve through development and implementation of: improved observational capabilities and computational power; new approaches and tools for data integration; varied levels of observations, partnerships, and projects focused on field campaigns and operational management; and new efforts to implement fire and stewardship strategies and transition research on smoke dynamics into operational tools. Recent research on a number of key smoke plume dynamics has improved our understanding of coupled smoke modeling systems, modeling tools that use field campaign data, real-time smoke modeling and prediction, and smoke from duff burning. This new research will lead to better predictions of smoke production and transport, including the influence of a warmer climate on smoke.