TY  - JOUR
A1  - Dommain, René
A1  - Frolking, Steve
A1  - Jeltsch-Thömmes, Aurich
A1  - Joos, Fortunat Ulrich
A1  - Couwenberg, John
A1  - Glaser, Paul H.
T1  - A radiative forcing analysis of tropical peatlands before and after their conversion to agricultural plantations
JF  - Global change biology
N2  - The tropical peat swamp forests of South-East Asia are being rapidly converted to agricultural plantations of oil palm and Acacia creating a significant global “hot-spot” for CO2 emissions. However, the effect of this major perturbation has yet to be quantified in terms of global warming potential (GWP) and the Earth's radiative budget. We used a GWP analysis and an impulse-response model of radiative forcing to quantify the climate forcing of this shift from a long-term carbon sink to a net source of greenhouse gases (CO2 and CH4). In the GWP analysis, five tropical peatlands were sinks in terms of their CO2 equivalent fluxes while they remained undisturbed. However, their drainage and conversion to oil palm and Acacia plantations produced a dramatic shift to very strong net CO2-equivalent sources. The induced losses of peat carbon are ~20× greater than the natural CO2 sequestration rates. In contrast, a radiative forcing model indicates that the magnitude of this shift from a net cooling to warming effect is ultimately related to the size of an individual peatland's carbon pool. The continuous accumulation of carbon in pristine tropical peatlands produced a progressively negative radiative forcing (i.e., cooling) that ranged from −2.1 to −6.7 nW/m2 per hectare peatland by 2010 CE, referenced to zero at the time of peat initiation. Peatland conversion to plantations leads to an immediate shift from negative to positive trend in radiative forcing (i.e., warming). If drainage persists, peak warming ranges from +3.3 to +8.7 nW/m2 per hectare of drained peatland. More importantly, this net warming impact on the Earth's radiation budget will persist for centuries to millennia after all the peat has been oxidized to CO2. This previously unreported and undesirable impact on the Earth's radiative balance provides a scientific rationale for conserving tropical peatlands in their pristine state.
KW  - Acacia plantation
KW  - CO2 emissions
KW  - drainage-based land use
KW  - global warming potential
KW  - oil palm plantation
KW  - radiative forcing
KW  - tropical peatland
Y1  - 2018
U6  - https://doi.org/10.1111/gcb.14400
SN  - 1354-1013
SN  - 1365-2486
VL  - 24
IS  - 11
SP  - 5518
EP  - 5533
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Ritter, Christoph
A1  - Ángeles Burgos, María
A1  - Böckmann, Christine
A1  - Mateos, David
A1  - Lisok, Justyna
A1  - Markowicz, Krzysztof M.
A1  - Moroni, Beatrice
A1  - Cappelletti, David
A1  - Udisti, Roberto
A1  - Maturilli, Marion
A1  - Neuber, Roland
T1  - Microphysical properties and radiative impact of an intense biomass burning aerosol event measured over Ny-angstrom lesund, Spitsbergen in July 2015
JF  - Tellus - Series B, Chemical and Physical Meteorology
N2  - In this work, an evaluation of an intense biomass burning event observed over Ny-angstrom lesund (Spitsbergen, European Arctic) in July 2015 is presented. Data from the multi-wavelengths Raman-lidar KARL, a sun photometer and radiosonde measurements are used to derive some microphysical properties of the biomass burning aerosol as size distribution, refractive index and single scattering albedo at different relative humidities. Predominantly particles in the accumulation mode have been found with a bi-modal distribution and dominance of the smaller mode. Above 80% relative humidity, hygroscopic growth in terms of an increase of particle diameter and a slight decrease of the index of refraction (real and imaginary part) has been found. Values of the single scattering albedo around 0.9 both at 355nm and 532nm indicate some absorption by the aerosol. Values of the lidar ratio are around 26sr for 355nm and around 50sr for 532nm, almost independent of the relative humidity. Further, data from the photometer and surface radiation values from the local baseline surface radiation network (BSRN) have been applied to derive the radiative impact of the biomass burning event purely from observational data by comparison with a clear background day. We found a strong cooling for the visible radiation and a slight warming in the infra-red. The net aerosol forcing, derived by comparison with a clear background day purely from observational data, obtained a value of -95 W/m(2) per unit AOD500.
KW  - aerosol
KW  - lidar
KW  - retrieval of aerosol properties
KW  - radiative forcing
KW  - Arctic aerosol
Y1  - 2018
U6  - https://doi.org/10.1080/16000889.2018.1539618
SN  - 1600-0889
VL  - 70
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  -