Desert Encroachment in Central Asia - Quantification of soil biogenic Nitric Oxide emissions by ground- and satellite-based methodologies (DEQNO)

中国西北部的新疆省是中亚大沙漠的一部分，目前正经历着快速的经济增长，这与土地利用的实质性（和快速）变化有着内在的联系，从沙漠/草原到灌溉和肥料灌溉的绿洲农业。新疆绿洲一氧化氮（NO;一种间接温室气体）的大量生物源排放被认为并预计在不久的将来会增加。然而，任何测量数据的土壤生物NO排放量是完全缺乏从这个偏远地区。我们建议提供量化的NO通量（和蒸散）地块，绿洲和区域尺度的估计。这将通过以下方式实现：（1）对代表性土壤样品进行实验室培养测量，建立地表植被大气传输模型，并基于GIS进行放大，（2）基于差分光学吸收光谱法，根据卫星反演确定NO2和H2O的垂直柱密度，以及（3）地面微气象原位测量。以及浓度和通量的拉格朗日弥散模型。重点是验证（通过一套现场测量）的两个估计，这些将获得的实验室/SVAT/GIS放大的方法，以及来自卫星观测。这将明确地进行昼夜以及地块和绿洲规模。

The north-western Chinese province Xinjiang, part of the great deserts of Central Asia, currently experiences fast economic growth, intrinsically tied to substantial (and rapid) changes of land use, from desert/grassland to irrigation and fertilizer fed oasis agriculture. Substantial biogenic emissions of nitric oxide (NO; an indirect greenhouse gas) from Xinjiang s oases are supposed and expected to increase in near future. However, any measured data of soil biogenic NO emissions are entirely lacking from this remote region. We propose to deliver quantified estimates of NO fluxes (and evapotranspiration) plot, oasis, and regional scale. This will be achieved by (1) laboratory incubation measurements on representative soil samples, surface-vegetation-atmosphere-transport (SVAT) modeling, and GIS based up-scaling, (2) differential optical absorption spectroscopy based determination of vertical column densities of NO2 and H2O from satellite retrievals, and (3) ground based micrometeorological in-situ measurements, as well as Lagrangian dispersion modelling of concentrations and fluxes. Emphasis is given on validation (by a suite of in-situ field measurements) of both estimates, those which will be obtained by the laboratory/SVAT/GIS up-scaling approach, as well as those derived from satellite observations. This will be explicitly performed on diel as well as on plot and oasis scales.