International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
SURFACE TEMPERATURE ESTIMATION OF GANGOTRI GLACIER USING
THERMAL REMOTE SENSING
M Anul Haq * * , Dr. Kamal Jain *, Dr K.P.R. Menon n
? Department of Civil Engineering, Indian Institute of Technology Roorkee, Roorkee, 247667, India
^ Head Data Dissemination, NRSC Balanagar, Hyderabad
*anulhaq@gmail.com
Working Group, Theme or Special Session: VIII/3: Atmosphere, Climate and Weather
KEY WORDS: DEM, Classification, Snow Ice, Multitemporal, Multispectral
ABSTRACT:
Land surface temperature (LST) is important factor in global climate change studies, for estimating radiation into heat balance
studies and as a control for climate change models. The knowledge of surface temperature is important to a range of issues and
themes in earth sciences, climate change and human interactions with environment. In this investigation an attempt has been
made to estimate surface temperature from ASTER and Landsat Thermal Band data for the Gangotri Glacier. ASTER and
Landsat Calibration had been performed to convert digital numbers to exoatmospheric radiance using published post-launch
gains and offsets. The exoatmospheric radiance is then converted to surface radiance by applying the Emissivity Normalization
method, assuming the emissivity of the Investigation area is constant (0.97, the emissivity of glacier ice). The surface temperature
is then extracted from the surface radiance. Based on images from Oct 1990, 2001 and 2010 mean temperatures of 15.763,
15.893 and 17.154 respectively, are inferred. The extracted temperature data were compared to observed temperatures and
showed a good correlation, with differences of 1-20c.The variability of these retrieved Land surface Temperatures has been
investigated with respect snout point, ELA and highest point of Gangotri Glacier determined from the Landsat visible bands and
ASTER DEM. The emissivity per pixel is retrieved directly from satellite data and has been estimated as narrow band emissivity
at the satellite sensor channel in order to minimize the errors in the land surface temperature estimation of study area.
1. INTRODUCTION
Land surface temperature can provide important
information about the surface physical properties and
climate which plays a role in many environmental
processes (Dousset & Gourmelon 2003; Weng, Lu &
Schubring 2004). Many studies have estimated the
relative warmth of cities by measuring the air
temperature, using land based observation stations.
Some studies used measurements of temperature
using temperature sensors mounted on car, along
various routes (Yamashita 1996). This method can be
both expensive and time consuming and lead to
problems in spatial interpolation. Remote sensing
might be a better alternative to the aforesaid methods.
The advantages of using remotely sensed data are the
availability of high resolution, consistent and
repetitive coverage and capability of measurements
of earth surface conditions (Owen, Carlson & Gillies
1998). In remote sensing, Thermal infrared (TIR)
sensors can obtain quantitative information of surface
temperature across the LU/LC categories.
Himalayan region glaciers are distributed in different
climatic zones. The mean daily air temperature is low
in the month of January and rises during the pre-
monsoon period (February to May), with maximum
average daily temperatures during late May and early
June, while during the post monsoon (October to
January) season, mean daily air temperature
decreases. The Himalaya cause changes in the air
masses crossing the region, resulting in a special
microclimate in the region. The southern plains
possess sub-tropical climate with the middle hills
having a temperate climate and an alpine climate in
the high mountain ranges.
Surface temperature is one of the most important
parameters for estimating the effect of climatic
change on glaciers. Unfortunately, estimating surface
temperature using traditional weather-station based
meteorological observations is not a feasible solution
for Snout, ELA and Max altitude of Glacier.
Therefore, through remote sensing studies, a synoptic
view of the Himalayan region can be established and
used for regional climatologically studies.
