@article{fdi:010064959,
  title = {{B}lack carbon in snow in the upper {H}imalayan {K}humbu {V}alley, {N}epal : observations and modeling of the impact on snow albedo, melting, and radiative forcing},
  author = {{J}acobi, {H}. {W}. and {L}im, {S}. and {M}enegoz, {M}. and {G}inot, {P}atrick and {L}aj, {P}. and {B}onasoni, {P}. and {S}tocchi, {P}. and {M}arinoni, {A}. and {A}rnaud, {Y}ves},
  editor = {},
  language = {{ENG}},
  abstract = {{B}lack carbon ({BC}) in snow in the {H}imalayas has recently attracted considerable interest due to its impact on snow albedo, snow and glacier melting, regional climate and water resources. {A} single particle soot photometer ({SP}2) instrument was used to measure refractory {BC} (r{BC}) in a series of surface snow samples collected in the upper {K}humbu {V}alley, {N}epal between {N}ovember 2009 and {F}ebruary 2012. {T}he obtained time series indicates annual cycles with maximum r{BC} concentrations before the onset of the monsoon season and fast decreases during the monsoon period. {D}etected concentrations ranged from a few up to 70 ppb with rather large uncertainties due to the handling of the samples. {D}etailed modeling of the snowpack, including the detected range and an estimated upper limit of {BC} concentrations, was performed to study the role of {BC} in the seasonal snowpack. {S}imulations were performed for three winter seasons with the snowpack model {C}rocus, including a detailed description of the radiative transfer inside the snowpack. {W}hile the standard {C}rocus model strongly overestimates the height and the duration of the seasonal snowpack, a better calculation of the snow albedo with the new radiative transfer scheme enhanced the representation of the snow. {H}owever, the period with snow on the ground without {BC} in the snow was still overestimated between 37 and 66 days, which was further diminished by 8 to 15% and more than 40% in the presence of 100 or 300 ppb of {BC}. {C}ompared to snow without {BC}, the albedo is reduced on average by 0.027 and 0.060 in the presence of 100 and 300 ppb {BC}. {W}hile the impact of increasing {BC} in the snow on the albedo was largest for clean snow, the impact on the local radiative forcing is the opposite. {H}ere, increasing {BC} caused an even larger impact at higher {BC} concentrations. {T}his effect is related to an accelerated melting of the snowpack caused by a more efficient metamorphism of the snow due to an increasing size of the snow grains with increasing {BC} concentrations. {T}he melting of the winter snowpack was shifted by 3 to 10 and 17 to 27 days during the three winter seasons in the presence of 100 and 300 ppb {BC} compared to clean snow, while the simulated annual local radiative forcing corresponds to 3 to 4.5 and 10.5 to 13.0 {W} m(-2). {A}n increased sublimation or evaporation of the snow reduces the simulated radiative forcing, leading to a net forcing that is lower by 0.5 to 1.5 {W} m(-2), while the addition of 10 ppm dust causes an increase of the radiative forcing between 2.5 and 3 {W} m(-2). {A}ccording to the simulations, 7.5 ppm of dust has an effect equivalent to 100 ppb of {BC} concerning the impact on the melting of the snowpack and the local radiative forcing.},
  keywords = {{NEPAL} ; {HIMALAYA}},
  booktitle = {},
  journal = {{C}ryosphere},
  volume = {9},
  numero = {4},
  pages = {1685--1699},
  ISSN = {1994-0416},
  year = {2015},
  DOI = {10.5194/tc-9-1685-2015},
  URL = {https://www.documentation.ird.fr/hor/fdi:010064959},
}