Determination of snow water equivalent over eastern part of Turkey using passive microwave data

Download

index.pdf

Date

2011

Author

Beşer, Özgür

Metadata

Show full item record

Item Usage Stats

167
views

110
downloads

The assimilation process to produce daily Snow Water Equivalent (SWE) maps is modified by using Helsinki University of Technology (HUT) snow emission model and AMSR-E passive microwave data. The characteristics of HUT emission model is analyzed in-depth and discussed with respects to the extinction coefficient function. A new extinction coefficient function for the HUT model is proposed for snow over mountainous areas. Performance of the modified model is checked against original and other modified cases against ground truth data covering 2003-2007 winter periods. A new approach to calculate grain size and density is integrated inside the developed data assimilation process. An extensive validation is successfully carried out by means of snow data measured at ground stations during 2008-2010 winter periods. Validation results were less satisfactory for SWE smaller than 75.0 mm and greater than 200.0 mm. Overestimation is especially observed for stations located below 1750.0 m elevation where SWE is less than 75.0 mm. Applied methodology is fine tuned to improve its performance for shallow snow depths observed below 1750 m elevation using a relationship that integrates 10.7 GHz channel data. But an underestimation for SWE greater than 150 mm could not beresolved due to microwave signal saturation that is expected in dense snowpack.

Subject Keywords

Snow

URI

http://etd.lib.metu.edu.tr/upload/12613620/index.pdf
https://hdl.handle.net/11511/20758

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Determination of snow water equivalent over the eastern part of Turkey using passive microwave data Sorman, A. Unal; Beser, Ozgur (2013-07-01) Information on regional snow water equivalent (SWE) is required for the management of water generated from snowmelt. Modeling of SWE in the mountainous regions of eastern Turkey, one of the major headwaters of Euphrates-Tigris basin, has significant importance in forecasting snowmelt discharge, especially for optimum water usage. An assimilation process to produce daily SWE maps is developed based on Helsinki University of Technology (HUT) model and AMSR-E passive microwave data. The characteristics of the ...
Analysis of future climate change impacts on snow distribution over mountainous watersheds in Northern California by means of a physically-based snow distribution model Ishida, K.; Ercan, Ali; Trinh, T.; Kavvas, M. L.; Ohara, N.; Carr, K.; Anderson, M. L. (2018-12-01) The impacts of climate change on snow distribution through the 21st century were investigated over three mountainous watersheds in Northern California by means of a physically-based snow distribution model. The future climate conditions during a 90-year future period from water year 2010 to 2100 were obtained from 13 future climate projection realizations from two GCMs (ECHAM5 and CCSM3) based on four SRES scenarios (A1B, A1FI, A2, and B1). The 13 future climate projection realizations were dynamically down...
Cross-Country Assessment of H-SAF Snow Products by Sentinel-2 Imagery Validated against In-Situ Observations and Webcam Photography Piazzi, Gaia; Tanis, Cemal Melih; KUTER, SEMİH; Simsek, Burak; Puca, Silvia; Toniazzo, Alexander; Takala, Matias; Akyürek, Sevda Zuhal; Gabellani, Simone; Arslan, Ali Nadir (2019-03-15) Information on snow properties is of critical relevance for a wide range of scientific studies and operational applications, mainly for hydrological purposes. However, the ground-based monitoring of snow dynamics is a challenging task, especially over complex topography and under harsh environmental conditions. Remote sensing is a powerful resource providing snow observations at a large scale. This study addresses the potential of using Sentinel-2 high-resolution imagery to assess moderate-resolution snow p...
Real time snow recognition from msg satellite for mountainous areas Surer, S.; Gokdemir, O.; Beser, O.; Akyürek, Sevda Zuhal; Sorman, A. U.; Erturk, A. G. (2008-06-05) In Hydrology Satellite Application Facilities (HydroSAF) Project which is a financially supported project by EUMETSAT, the use of snow products retrieved from satellite images in hydrological applications and to observe the impact of the products are key issues. Turkey is a part of the HydroSAF project, both in developing satellite derived snow products (snow recognition, effective snow cover, and snow water equivalent) for mountainous areas, cal/val of satellite-derived snow products with ground observatio...
Impacts of climate change on snow accumulation and melting processes over mountainous regions in Northern California during the 21st century Ishida, K.; Ohara, N.; Ercan, Ali; Jang, S.; Trinh, T.; Kavvas, M. L.; Carr, K.; Anderson, M. L. (2019-10-01) A point-location-based analysis of future climate change impacts on snow accumulation and melting processes was conducted over three study watersheds in Northern California during a 90-year future period by means of snow regime projections. The snow regime projections were obtained by means of a physically-based snow model with dynamically downscaled future climate projections. Then, atmospheric and snow-related variables, and their interrelations during the 21st century were investigated to reveal future c...

Citation Formats

Ö. Beşer, “Determination of snow water equivalent over eastern part of Turkey using passive microwave data,” Ph.D. - Doctoral Program, Middle East Technical University, 2011.