Data and code for JC paper: Fire aerosols slow down the global water

1. Model platform and Experimental design

    We used Earth system model CESM as the model platform. It is comprised of the Community Atmosphere Model, version 5.3 (CAM5.3), the Community Land Model, version 4 (CLM4); the Slab Ocean Model (SOM); and the Community Ice Code, version 4 (CICE4).

    Two simulations were performed: Fire and NOFIRE. The setup of the two simulations is identical but using different prescribed fire aerosol emissions. The FIRE simulation used daily fire BC, POM, and sulfur dioxide (SO₂) emissions from 2003 to 2011 (9 years). The fire emissions (Jiang et al. 2016) were based on daily satellite-based Global Fire Emissions Database version 3.1 (GFED 3.1) (van der Werf et al. 2010; Mu et al. 2011) and the vertical distribution of emissions in the AeroCom protocol (Dentener et al. 2006). In NOFIRE, fire aerosol emissions were set to zero.

    The two simulations were run for 99 years with the fire emissions data cycling 11 times. The last 27 years of each simulation were analyzed. Both simulations used 0.9° (latitude) ×1.25° (longitude) horizontal resolution for the land and atmosphere (30 atmospheric levels), while the ocean and sea-ice components used a gx1v6 displaced pole grid. The model time step was 30 minutes. Input data except for fire aerosol emissions were the default (without any change) inputs provided with the CESM.

2. Introduction of files

-fire and -nofire: simulations with and without fire aerosols

Longitude (lon) and latitude (lat) are already included in each file

grid.nc:

area: grid cell area (km²)

landfrac: land fraction (0 to 1)

landmask: land mask (0 for ocean and 1 for land)

 

Aerosol* files:

BC: BC vertically integrated concentration

POM: POM vertically integrated concentration

SO4: SO₄ vertically integrated concentration

AOD: AOD

 

PrE* files:

Pr: precipitation (mm/s)

E: ocean evaporation and land evapotranspiration (mm/s)

 

ETcomp* files:

ce: canopy evaporation (mm/s)

ct: canopy transpiration (mm/s

ge: ground evaporation (mm/s)

 

runoffs* files:

runoff: total runoff (mm/s)

srfr: surface runoff (mm/s)

dr: drainage (mm/s)

other: other runoffs (mm/s)

 

landhyd* files:

ci: canopy interception (mm/s)

thr: throughfall (mm/s)

iflt: infiltration (mm/s)

ssm: surface soil moisture (mm³/mm³)

rzsm: root-zone soil moisture (mm³/mm³)

 

snow-rad* files:

smlt: snow melt (mm/s)

snow: snowfall (mm/s)

fsnow: surface forcing of BC in snow (W/m²)

svsr: surface visible solar radiation (W/m²)

scf: snow coverage fraction

 

T-atmwater-seaice* files:

tas: surface air temperature (K)

icef: sea ice coverage fraction

wv: atmospheric water vapor (kg/m²)

 

cwp: cloud water path (kg/m²)

cdc: vertically-integrated droplet concentration (1/m²)

 

UVRH850hPa* files:

U850: Zonal wind at 850hPa (m/s)

V850: Meridional wind at 850hPa (m/s)

RH850: Relative humidity at 850hPa (%)

 

code.tar: code and model setup