A 12-year high-resolution climatology of atmospheric water transport over the Tibetan Plateau

Abstract

Abstract. The Tibetan Plateau (TP) plays a key role in the water cycle of high Asia and its downstream regions. The respective influence of the Indian and East Asian summer monsoon on TP precipitation and regional water resources, together with the detection of moisture transport pathways and source regions are the subject of recent research. In this study, we present a 12-year high-resolution climatology of the atmospheric water transport (AWT) over and towards the TP using a new data set, the High Asia Refined analysis (HAR), which better represents the complex topography of the TP and surrounding high mountain ranges than coarse-resolution data sets. We focus on spatiotemporal patterns, vertical distribution and transport through the TP boundaries. The results show that the mid-latitude westerlies have a higher share in summertime AWT over the TP than assumed so far. Water vapour (WV) transport constitutes the main part, whereby transport of water as cloud particles (CP) also plays a role in winter in the Karakoram and western Himalayan regions. High mountain valleys in the Himalayas facilitate AWT from the south, whereas the high mountain regions inhibit AWT to a large extent and limit the influence of the Indian summer monsoon. No transport from the East Asian monsoon to the TP could be detected. Our results show that 36.8 ± 6.3 % of the atmospheric moisture needed for precipitation comes from outside the TP, while the remaining 63.2 % is provided by local moisture recycling.

The neglected Indo‐Gangetic Plains low‐level jet and its importance for moisture transport and precipitation during the peak summer monsoon

“…It is evident that vigorous moisture transport over the IGP exists in global and regional high-resolution reanalysis simulations during peak monsoon season [Curio et al, 2015], which suggests that there is a crucial flow that is understudied in the region. The influx of moisture from the BOB into the IGP has long been recognized as a part of easterly propagating tropical depressions associated with advancement and retreat of monsoon trough [Goswami et al, 2003;Krishnamurthy and Ajayamohan, 2010;Rajeevan et al, 2010;Wang et al, 2013;Dong et al, 2016;Karmacharya et al, 2016].…”

“…Since the monsoon field has placed little emphasis on elucidating the phenomenology and dynamics of the northeastern IAM branch [Curio et al, 2015], we demonstrate the existence of an easterly low-level jet (LLJ) over the IGP (referred to as the IG LLJ) during peak monsoon season. The reanalysis products, model experiments and diagnostics used for the study are described in section 2.…”

Controls on Deuterium Excess across Asia

“…Recycling of continental moisture also has an effect on the isotopic composition of both vapor and precipitation (e.g., [5,23,24]), and was shown to make up to 80% of precipitation in parts of Central Asia and the Tibetan Plateau [25][26][27][28]. The effect of local continental recycling is less predictable as it integrates the isotopic composition of surface water, which can be highly variable.…”

Annual Glacier-Wide Mass Balance (2000–2016) of the Interior Tibetan Plateau Reconstructed from MODIS Albedo Products

“…The data comprises two datasets of 30 km and 10 km resolution, including pressure, geopotential height, temperature, and wind direction and speed. This re-analysis product with a 10 km spatial resolution has been widely used for various geo-biophysical applications in climatic, hydrological, and glaciological studies [49][50][51] and can be accessed for free at http://www.klima.tu-berlin.de/HAR.…”