Probing orographic controls in the Himalayas during the monsoon using satellite imagery
TLDR
The linkages between the space-time variability of observed clouds, rainfall, large-circulation patterns and topography in northern India and the Himalayas were investigated using remote sensing data as discussed by the authors.Abstract:
The linkages between the space-time variability of observed clouds, rainfall, large-circulation patterns and topography in northern India and the Himalayas were investigated using remote sensing data The research purpose was to test the hypothesis that cloudiness patterns are dynamic tracers of rainstorms, and therefore their temporal and spatial evolution can be used as a proxy of the spatial and temporal organization of precipitation and precipitation processes in the Himalayan range during the monsoon The results suggest that the space-time distribution of precipitation, the spatial variability of the diurnal cycle of convective activity, and the terrain (landform and altitudinal gradients) are intertwined at spatial scales ranging from the order of a few kms (1–5km) up to the continental-scale Furthermore, this relationship is equally strong in the time domain with respect to the onset and intra-seasonal variability of the monsoon Infrared and microwave imagery of cloud fields were analyzed to characterize the spatial and temporal evolution of mesoscale convective weather systems and short-lived convection in Northern India, the Himalayan range, and in the Tibetan Plateau during three monsoon seasons (1999, 2000 and 2001) The life cycle of convective systems suggests landform and orographic controls consistent with a convergence zone constrained to the valley of the Ganges and the Himalayan range, bounded in the west by the Aravalli range and the Garhwal mountains and in the East by the Khasi Hills and the Bay of Bengal, which we call the Northern India Convergence Zone (NICZ) The NICZ exhibits strong night-time activity along the south-facing slopes of the Himalayan range, which is characterized by the development of short-lived convection (1–3h) aligned with protruding ridges between 1:00 and 3:00 AM The intra-annual and inter-annual variability of convective activity in the NICZ were assessed with respect to large-scale synoptic conditions, monsoon activity in the Bay of Bengal, and the modulating role of orography Empirical orthogonal function (EOF) and canonical correlation (CC) analysis suggest that joint modes of variability of monsoon weather and topography, which we call orographic land-atmosphere interactions, modulate the space-time variability of cloudiness in the region Finally, scaling analysis of cloudiness suggests three different scaling regimes of orographic land-atmosphere interactions: 1) a synoptic-scale regime (≥70-80km); 2) an orographic meso–β regime (30–70km) associated with the succession of wide valleys and bulky terrain features; and 3) an orographic meso–α regime (≤30km) associated with the complex succession of protruding south-facing ridges and narrow valleys that characterize the Himalayan foothills between altitudes of 3000 and 5000m elevationsread more
Citations
More filters
Journal ArticleDOI
Toward a complete Himalayan hydrological budget: Spatiotemporal distribution of snowmelt and rainfall and their impact on river discharge
TL;DR: In this article, a combination of validated remotely-sensed climate parameters was used to characterize the spatiotemporal distribution of rainfall, snowfall, and evapotranspiration in order to quantify their relative contribution to mean river discharge.
Journal ArticleDOI
Orographic effects on precipitating clouds
TL;DR: In this article, it was shown that mesoscale convective systems are triggered by nocturnal downslope flows and by diurnally triggered disturbances propagating away from mountain ranges.
Journal ArticleDOI
Response of debris-covered glaciers in the Mount Everest region to recent warming, and implications for outburst flood hazards
Douglas I. Benn,Douglas I. Benn,Tobias Bolch,Tobias Bolch,K. A. Hands,Jason Gulley,Jason Gulley,Adrian Luckman,Lindsey Nicholson,Duncan J. Quincey,Sarah Thompson,Sarah Thompson,R Toumi,S. Wiseman +13 more
TL;DR: In this article, an integrated view of debris-covered glacier response to climate change is presented, which helps provide a long-term perspective on evolving glacier lake outburst floods (GLOFs).
Journal ArticleDOI
Elevation dependency of recent and future minimum surface air temperature trends in the Tibetan Plateau and its surroundings
TL;DR: In this paper, the authors examined the temporal trends in monthly mean minimum temperatures from 116 weather stations in the eastern Tibetan Plateau and its vicinity during 1961-2006, and also analyzed projected climate changes in the entire Tibetan plateau and its surroundings from two sets of modeling experiments under future global warming conditions.
Journal ArticleDOI
Monsoon convection in the Himalayan region as seen by the TRMM Precipitation Radar
TL;DR: In this article, the three-dimensional structure of summer monsoon convection in the Himalayan region and its overall variability are examined by analyzing data from the Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar over the June-September seasons of 2002 and 2003.
References
More filters
Journal ArticleDOI
A Practical Guide to Wavelet Analysis.
TL;DR: In this article, a step-by-step guide to wavelet analysis is given, with examples taken from time series of the El Nino-Southern Oscillation (ENSO).
Journal ArticleDOI
Statistical Analysis in Climate Research
Journal ArticleDOI
Monsoons: Processes, predictability, and the prospects for prediction
Peter J. Webster,V. O. Magaña,Tim Palmer,Jagadish Shukla,Robert A. Tomas,M. Yanai,Tetsuzo Yasunari +6 more
TL;DR: In this article, a thorough description of observed monsoon variability and the physical processes that are thought to be important is presented, and some strategies that may help achieve improvement are discussed.
Journal ArticleDOI
Monsoons and the dynamics of deserts
Mark J. Rodwell,Brian J. Hoskins +1 more
TL;DR: In this paper, the authors proposed a monsoon-desert mechanism for desertification whereby remote diabatic heating in the Asian monsoon region can induce a Rossby-wave pattern to the west.
Journal ArticleDOI
The Role of Mountains in the South Asian Monsoon Circulation
Douglas G. Hahn,Syukuro Manabe +1 more
TL;DR: An 11-level numerical model of the atmospheric circulation which has a prescribed seasonal variation of insulation and sea surface temperatures is integrated with respect to time for approximately three model years as discussed by the authors.