tom breider, loretta mickley, daniel jacob, cui ge, jun wang, melissa payer, betty croft, david...
DESCRIPTION
15 SO 2 BC Tg S yr -1 Tg C yr -1 NORTH AMERICA 15 SO 2 BC Tg S yr -1 Tg C yr -1 EUROPE 25 SO 2 BC Tg S yr -1 Tg C yr -1 EAST ASIA 20 SO 2 BC Tg S yr -1 Tg C yr -1 RUSSIA 15 SO 2 BC Emissions Source: MACCcity Inventory (Granier et al., 2011) 1980–2010: Dynamic Anthropogenic Emission Trends Emissions have decreased in N.America & Europe and increased in East Asia Image Source : NASA Earth ObservatoryTRANSCRIPT
Tom Breider, Loretta Mickley, Daniel Jacob, Cui Ge, Jun Wang, Melissa Payer, Betty Croft, David Ridley, Sangeeta Sharma, Kostas
Eleftheriadis, Joe McConnell, Henrik Skov, Lee Husain
Arctic Climate Response to Decadal Changes in Radiative Forcing from Aerosols
Source : NASA
Arctic – “A region in transition”
60-90N
Source: Shindell et al., 20091880 1900 1920 1940 1960 1980 2000
0.500.00
1.00
1.50
2.50
2.00
SAT
anom
aly
(°C)Arctic surface air
temperatures are increasing (2x global average)
What processes are driving the observed trends?
1980 1990 2000 2010
Mas
s Con
c, u
g S
m-3
0.6
0.9
0.3
0.0
At high Arctic sites sulfate and BC concentrations decreased by 2-3% per year
between 1980 and 2010
Spring sulfate mass Ny-Alesund
15
SO2
BC
0.6
0
0
Tg S
yr-1
Tg C
yr-1
NORTH AMERICA15
SO2
BC
0.6
0
0
1980 2010
Tg S
yr-1
Tg C
yr-1
EUROPE25
SO2
BC
0.8
0
0
1980 2010
Tg S
yr-1
Tg C
yr-1
EAST ASIA20 SO2
BC3.0
0
0
1980 2010
Tg S
yr-1
Tg C
yr-1
RUSSIA15
SO2
BC
0.8
0
0
1980 2010
Emissions Source: MACCcity Inventory (Granier et al., 2011)
1980–2010: Dynamic Anthropogenic Emission Trends
Emissions have decreased in N.America & Europe and increased in East Asia
Image Source : NASA Earth Observatory
GEOS-Chem v9.01.03 driven by MERRA meteorology at 4x5 degrees for the period 1980-2010
1980 --> 2000ACCMIP (Lamarque et al., 2010)
2005 -> 2010RCPs / regional
inventories
Anthropogenic Emissions = MACCcity (Granier et al., 2011)
1980 --> 1996Duncan et al., 2002
1997 -> 2010GFED3 (van der Werf et al., 2010) + GFAS corrections (Kaiser et al., 2012)
Update precipitable water in low-level precipitating Arctic clouds in summer to 1x10-7 g m-3
Scale annual SOx ems to match Smith et al., 2011 and BC ems to
match Cohan and Wang, 2014Retain spatial and seasonal emissions
Updates
Observed trends in Arctic surface sulfate and BC
are reproduced to within 30% in all seasons
Spring sulfate Ny-Alesund
Steep drop after 1988 = collapse of the former Soviet Union
Arctic AERONET AOD observations are
underestimated by 20%
9% Spring; 28% Summer; 34% Fall
Season R2
Spring 0.37
Summer 0.29
Fall 0.0
Annual 0.38
1980 1990 2000 2010
0.6
0.9
0.3
0.0
Mas
s Con
c, u
g S
m-3
0.14
0.10
0.08
0.06
0.04
0.12
0.02
0.00-90 -60 -30 0
Latitude30 60 90
GEOS-Chem Arctic sulfate AOD in 2006 is towards the higher end of AEROCOM phase II simulations
Source: Myhre et al., 2013
Sulfate 550nm AOD
AEROCOM modelsOptical Depth, dimensionless
This simulation
*Forcing does not include BC on snow
Net all-sky surface
aerosol RF,W m-2
DJF MAM SONJJA
Early 1980s = 1980-1982Mid 2000s = 2004-2007
Arctic surface aerosol radiative forcing decreased between the early
1980s and mid 2000s
Early 1980s Mid 2000s
Net Forcing
Net Arctic surface aerosol radiative forcing is largest in spring and summer and is mainly sulfate (75%)
*Net forcing does not include BC on snow
Net all-sky surface
aerosol RF,W m-2
Sulfate
OC
BC
DJF MAM SONJJANet Arctic aerosol forcing of +0.1 W m-2 between early 1980s and mid 2000s
Summary
Surface trends in spring Arctic sulfate and BC are captured to within 30%.
We find a smaller total surface aerosol forcing compared to Quinn et al., 2008 in spring (-0.48 W m-2 vs -0.72 W m-2) and summer (-0.26 W m-2 vs -0.93 W m-2)
Net Arctic surface aerosol RF between the early 1980s and mid 2000s is +0.1 W m-2, largest in summer and spring, and is mainly sulfate (75%)
Net Arctic surface forcing driven by emissions decreases in Russia (+0.04 W m-2), FSU+EBLOC (+0.04 W m-2),Europe (+0.03 W m-2), North America (+0.01 W m-2)
Net all-sky surface
RF,W m-2
RussiaEuropeFSU+EBLOCNorth America
Net surface forcing mainly from Russia, FSU and Europe
Net all-sky surface
RF,W m-2
The sum of the regional net Arctic surface forcing is larger than the net surface forcing
Net Forcing
RussiaEuropeFSU+EBLOCNorth America
15
SO2
BC
0.6
0
0
Tg S
yr-1
Tg C
yr-1
NORTH AMERICA15
SO2
BC
0.6
0
0
1980 2010
Tg S
yr-1
Tg C
yr-1
EUROPE25
SO2
BC
0.8
0
0
1980 2010
Tg S
yr-1
Tg C
yr-1
EAST ASIA20 SO2
BC3.0
0
0
1980 2010
Tg S
yr-1
Tg C
yr-1
RUSSIA15
SO2
BC
0.8
0
0
1980 2010
Emissions Source: MACCcity Inventory (Granier et al., 2011)
1980–2010: Dynamic Anthropogenic Emission Trends
Image Source : NASA Earth Observatory
Net forcing from emissions increases in China and other regions reduces the net forcing from emissions decrease in spring by 36%
Net all-sky surface
RF,W m-2
RussiaFSU+EBLOCEuropeNorth AmericaChinaOther
Summary
Surface trends in spring Arctic sulfate and BC are captured to within 30%.
We find a smaller total surface aerosol forcing compared to Quinn et al., 2008 in spring (-0.48 W m-2 vs -0.72 W m-2) and summer (-0.26 W m-2 vs -0.93 W m-2)
Net Arctic surface aerosol RF between the early 1980s and mid 2000s is +0.1 W m-2, largest in summer and spring, and is mainly sulfate (75%)
Net Arctic surface forcing driven by emissions decreases in Russia (+0.04 W m-2), FSU+EBLOC (+0.04 W m-2),Europe (+0.03 W m-2), North America (+0.01 W m-2)
