Surface-sensible and latent heat fluxes over the Tibetan Plateau from ground measurements, reanalysis, and satellite data

Abstract

Abstract. Estimations from meteorological stations over the Tibetan Plateau (TP) indicate that since the 1980s the surface-sensible heat flux has been decreasing continuously, and modeling studies suggest that such changes are likely linked to the weakening of the East Asian Monsoon through exciting Rossby wave trains. However, the spatial and temporal variations in the surface-sensible and latent heat fluxes over the entire TP remain unknown. This study aims to characterize the spatial and seasonal variability of the surfacesensible and latent heat fluxes at 0.5 • over the TP from 1984 to 2007 by synthesizing multiple data sources including ground measurements, reanalysis products, and remotesensing products. The root mean square errors (RMSEs) from cross validation are 14.3 Wm −2 and 10.3 Wm −2 for the monthly fused sensible and latent heat fluxes, respectively. The fused sensible and latent heat-flux anomalies are consistent with those estimated from meteorological stations, and the uncertainties of the fused data are also discussed. The associations among the fused sensible and latent heat fluxes and the related surface anomalies such as mean temperature, temperature range, snow cover, and normalized difference vegetation index (NDVI) in addition to atmospheric anomalies such as cloud cover and water vapor show seasonal dependence, suggest that the land-biosphere-atmosphere interactions over the TP could display nonuniform feedbacks to the climate changes. It would be interesting to disentangle the drivers and responses of the surface-sensible and latent heat-flux anomalies over the TP in future research from evidences of modeling results.

Comparison of satellite-based evapotranspiration estimates over the Tibetan Plateau

“…The LandFlux-EVAL benchmark product was found to agree well with observation-based precipitation, in situ measurementsvalidated radiation (Shi and Liang, 2013a), and in situ measurements-validated LE product (Shi and Liang, 2014). From this point of view, it can be served as the reference dataset.…”

“…Besides precipitation, the radiation is another important driver for LE. Compared to the published studies, the LandFlux-EVAL LE also corresponds well with the merged net radiation and LE datasets, which were developed and validated over the TP by Shi and Liang (2013a, b) and Shi and Liang (2014). The spatial distribution of annual mean net radiation and LE can be found in study of Shi and Liang (2013a) and Shi and Liang (2014).…”

“…Compared to the published studies, the LandFlux-EVAL LE also corresponds well with the merged net radiation and LE datasets, which were developed and validated over the TP by Shi and Liang (2013a, b) and Shi and Liang (2014). The spatial distribution of annual mean net radiation and LE can be found in study of Shi and Liang (2013a) and Shi and Liang (2014). Although the LandFlux-EVAL has not been validated against in situ measurements over the TP, the similar spatial patterns between LE and both observation-based precipitation and validated radiation to some extent demonstrate the validity of LandFlux-EVAL over the TP.…”

“…The TP has strong impacts on weather and climate at the regional to global scale and controls climatic and environmental changes in Asia and elsewhere in the Northern Hemisphere (Ma et al, 2008). The knowledge of ET is essential for the study of land-atmosphere interactions, and assessment of the impacts of and feedbacks to the global change (Shi and Liang, 2014). In order to characterise the distribution of ET over the TP, different methods using micrometeorological measurements (Yang et al, 2003;Lee et al, 2012;Chen et al, 2013b;Zhang et al, 2007), remote sensing products (Ma et al, , 2006Chen et al, 2013a) and the combined use of both data sources (Ma et al, 2003(Ma et al, , 2011You et al, 2014) have been investigated over the last decades.…”

Simulated annual changes in plant functional types and their responses to climate change on the northern Tibetan Plateau

“…On the NTP, decreased (increased) vegetation growth in the northwest (southwest and northeast) will result in reduction (enhancement) in roughness length and increase (decrease) in albedo, changes in stomatal resistance, etc. These changes in biogeophysical properties over the region will feed back into the momentum and carbon exchange, water, and energy balances and will undoubtedly affect large scale circulations such as the onset and intensity of South Asia and East Asia monsoons (Wu et al, 2007;Shi and Liang, 2014;Cui et al, 2015;He et al, 2015), thereby affecting the regional and global climate.…”