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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Components of near-surface energy balance derived from satellite soundings - Part 2
T2 - Noontime latent heat flux
AU - Mallick, K.
AU - Jarvis, A.
AU - Wohlfahrt, G.
AU - Kiely, G.
AU - Hirano, T.
AU - Miyata, A.
AU - Yamamoto, S.
AU - Hoffmann, L.
PY - 2014/12/22
Y1 - 2014/12/22
N2 - This paper introduces a relatively simple method for recovering global fields of latent heat flux. The method focuses on specifying Bowen ratio estimates through exploiting air temperature and vapour pressure measurements obtained from infrared soundings of the AIRS (Atmospheric Infrared Sounder) sensor onboard NASA's Aqua platform. Through combining these Bowen ratio retrievals with satellite surface net available energy data, we have specified estimates of global noontime surface latent heat flux at the 1 degrees x 1 degrees scale. These estimates were provisionally evaluated against data from 30 terrestrial tower flux sites covering a broad spectrum of biomes. Taking monthly average 13: 30 data for 2003, this revealed promising agreement between the satellite and tower measurements of latent heat flux, with a pooled root-mean-square deviation of 79Wm(-2), and no significant bias. However, this success partly arose as a product of the underspecification of the AIRS Bowen ratio compensating for the underspecification of the AIRS net available energy, suggesting further refinement of the approach is required. The error analysis suggested that the landscape level variability in enhanced vegetation index (EVI) and land surface temperature contributed significantly to the statistical metric of the predicted latent heat fluxes.
AB - This paper introduces a relatively simple method for recovering global fields of latent heat flux. The method focuses on specifying Bowen ratio estimates through exploiting air temperature and vapour pressure measurements obtained from infrared soundings of the AIRS (Atmospheric Infrared Sounder) sensor onboard NASA's Aqua platform. Through combining these Bowen ratio retrievals with satellite surface net available energy data, we have specified estimates of global noontime surface latent heat flux at the 1 degrees x 1 degrees scale. These estimates were provisionally evaluated against data from 30 terrestrial tower flux sites covering a broad spectrum of biomes. Taking monthly average 13: 30 data for 2003, this revealed promising agreement between the satellite and tower measurements of latent heat flux, with a pooled root-mean-square deviation of 79Wm(-2), and no significant bias. However, this success partly arose as a product of the underspecification of the AIRS Bowen ratio compensating for the underspecification of the AIRS net available energy, suggesting further refinement of the approach is required. The error analysis suggested that the landscape level variability in enhanced vegetation index (EVI) and land surface temperature contributed significantly to the statistical metric of the predicted latent heat fluxes.
KW - REMOTE-SENSING DATA
KW - CONVECTIVE BOUNDARY-LAYER
KW - SOUTHERN GREAT-PLAINS
KW - CLEAR-SKY DAYS
KW - SOIL-MOISTURE
KW - WATER-VAPOR
KW - CARBON-DIOXIDE
KW - BOWEN-RATIO
KW - EVAPOTRANSPIRATION ALGORITHM
KW - CLOSURE PROBLEM
U2 - 10.5194/bg-11-7369-2014
DO - 10.5194/bg-11-7369-2014
M3 - Journal article
VL - 11
SP - 7369
EP - 7382
JO - Biogeosciences
JF - Biogeosciences
SN - 1726-4170
IS - 24
ER -