Spatial patterns of precipitation and topography in the Himalaya

Spatial variability in precipitation has received little attention in the study of connections between climate, erosion, and tectonics. However, long-term precipitation patterns show large variations over spatial scales of ~10 km and are strongly controlled by topography. We use precipitation rate estimates from Tropical Rainfall Measuring Mission (TRMM) satellite radar data to approximate annual precipitation over the Himalaya at a spatial resolution of 10 km. The resulting precipitation pattern shows gradients across the range, and from east to west along the range, and fivefold differences between major valleys and their adjacent ridges. Basin-wide average precipitation estimates correlate well with available measured mean runoff for Himalayan rivers. Estimated errors of 15%–50% in TRMM-derived annual precipitation are much smaller than the spatial variability in predicted totals across the study area. A simple model of orographic precipitation predicts a positive relationship between precipitation and two topographically derived factors: the saturation vapor pressure at the surface and this pressure times the slope. This model captures significant features of the pattern of precipitation, including the gradient across the range and the ridge-valley difference, but fails to predict the east-west gradient and the highest totals. Model results indicate that the spatial pattern of precipitation is strongly related to topography and therefore must co-evolve with the topography, and suggest that our model may be useful for investigation of the relationships among the coupled climate-erosion-tectonic system.

[1]  A. Barros,et al.  Probing orographic controls in the Himalayas during the monsoon using satellite imagery , 2004 .

[2]  D. Montgomery,et al.  Coupled spatial variations in precipitation and long-term erosion rates across the Washington Cascades , 2003, Nature.

[3]  David R. Montgomery,et al.  Modeling large-scale fluvial erosion in geographic information systems , 2003 .

[4]  A. Barros,et al.  Monitoring the Monsoon in the Himalayas: Observations in Central Nepal, June 2001 , 2003 .

[5]  David R. Montgomery,et al.  Orographic precipitation and the relief of mountain ranges , 2003 .

[6]  A. Barros,et al.  Winter storms in the central Himalayas , 2003 .

[7]  C. Daly,et al.  A knowledge-based approach to the statistical mapping of climate , 2002 .

[8]  A. Barros,et al.  An Investigation of the Onsets of the 1999 and 2000 Monsoons in Central Nepal , 2002 .

[9]  David R. Montgomery,et al.  Spatial coincidence of rapid inferred erosion with young metamorphic massifs in the Himalayas , 2002 .

[10]  J. Tomkin,et al.  The influence of alpine glaciation on the relief of tectonically active mountain belts , 2002 .

[11]  D. Montgomery,et al.  Effects of orographic precipitation variations on the concavity of steady-state river profiles , 2002 .

[12]  David R. Montgomery,et al.  Climate, tectonics, and the morphology of the Andes , 2001 .

[13]  Katsuhiko Nishikawa,et al.  Development of precipitation radar onboard the Tropical Rainfall Measuring Mission (TRMM) satellite , 2001, IEEE Trans. Geosci. Remote. Sens..

[14]  Jeffrey A. Jones,et al.  Use of the Surface Reference Technique for Path Attenuation Estimates from the TRMM Precipitation Radar , 2000 .

[15]  M. L. Shrestha.  Interannual variation of summer monsoon rainfall over Nepal and its relation to Southern Oscillation Index , 2000 .

[16]  A. Barros,et al.  A study of the 1999 monsoon rainfall in a mountainous region in central Nepal using TRMM products and rain gauge observations , 2000 .

[17]  S. P. Anderson,et al.  "Numerical Simulations of Glacial-valley Longitudinal Profile Evolution: Reply." , 2000 .

[18]  Thomas L. Bell,et al.  Dependence of Satellite Sampling Error on Monthly Averaged Rain Rates:Comparison of Simple Models and Recent Studies , 2000 .

[19]  Sean D. Willett,et al.  Orogeny and orography: The effects of erosion on the structure of mountain belts , 1999 .

[20]  Brian A. Colle,et al.  Evaluation of MM5 and Eta-10 Precipitation Forecasts over the Pacific Northwest during the Cool Season , 1999 .

[21]  Michael Manga,et al.  Gravity Currents in the Environment and the Laboratory, by John E. Simpson , 1999 .

[22]  C. Schär,et al.  A PRECIPITATION CLIMATOLOGY OF THE ALPS FROM HIGH-RESOLUTION RAIN-GAUGE OBSERVATIONS , 1998 .

[23]  D. Wratt,et al.  Factors Affecting the Distribution and Spillover of Precipitation in the Southern Alps of New Zealand—A Case Study , 1997 .

[24]  K. Ramasastri,et al.  Topographical Influence on Precipitation Distribution in Different Ranges of Western Himalayas , 1995 .

[25]  Dennis P. Lettenmaier,et al.  Dynamic modeling of orographically induced precipitation , 1994 .

[26]  David R. Legates,et al.  The Accuracy of United States Precipitation Data , 1994 .

[27]  M. Goodchild,et al.  Environmental Modeling with GIS , 1994 .

[28]  Dennis P. Lettenmaier,et al.  Dynamic Modeling of the Spatial Distribution of Precipitation in Remote Mountainous Areas , 1993 .

[29]  J. Grotzinger,et al.  Orographic precipitation, erosional unloading, and tectonic style , 1993 .

[30]  Philippe Fullsack,et al.  Erosional control of active compressional orogens , 1992 .

[31]  W. Cramer,et al.  The IIASA database for mean monthly values of temperature , 1991 .

[32]  P. O. Koons,et al.  The topographic evolution of collisional mountain belts; a numerical look at the Southern Alps, New Zealand , 1989 .

[33]  W. Cotton,et al.  Numerical Study of an Observed Orogenic Mesoscale Convective System. Part 1: Simulated Genesis and Comparison with Observations , 1989 .

[34]  W. Rockwell Geyer,et al.  Gravity currents: In the environment and the laboratory , 1989 .

[35]  Gerald R. North,et al.  Sampling Error Study for Rainfall Estimate by Satellite Using a Stochastic Model , 1988 .

[36]  Thomas L. Bell,et al.  A space‐time stochastic model of rainfall for satellite remote‐sensing studies , 1987 .

[37]  P. Rakhecha,et al.  Monsoon dynamics: The effect of elevation on monsoon rainfall distribution in the central Himalayas , 1981 .

[38]  Ronald B. Smith.  The Influence of Mountains on the Atmosphere , 1979 .