DocumentCode :
2678159
Title :
Climate, vegetation phenology and forest fires in Siberia
Author :
Balzter, Heiko ; Weedon, Graham ; Grey, Will ; Los, Sietse ; Gerard, France ; Combal, Bruno ; Bartholomé, Etienne ; Bartalev, Sergey
Author_Institution :
Univ. of Leicester, Leicester
fYear :
2007
fDate :
23-28 July 2007
Firstpage :
3843
Lastpage :
3846
Abstract :
A time series of 18 years of fAPAR (fraction of photosynthetically active radiation absorbed by the green parts of vegetation) data from the NOAA AVHRR instrument series was analyzed for interannual variations in the start, peak, end and length of the season of vegetation photosynthetic activity in Central and East Siberia. Variations in these indicators of seasonality can give important information on interactions between the biosphere and atmosphere. A second order local moving window regression model called the "camel back method" was developed to determine the dates of phenological events at subcontinental scale. The algorithm was validated by comparing the estimated dates to phenological field observations. Using spatial correlations with temperature and precipitation data and climatic oscillation indices, we postulate two geographically distinct mechanisms in the system of climatic controls of the biosphere in Siberia: Central Siberia is controlled by an "Arctic oscillation/temperature mechanism" while East Siberia is controlled by an "El Nino/precipitation mechanism". While the analysis of data from 1982 to 1991 indicates a slight increase in the length of the growing season for some land cover types due to an earlier beginning of the growing season, the overall trend from 1982 to 1999 is towards a slightly shorter season for some land cover types caused by an earlier end of season. The Arctic Oscillation tended towards a more positive phase in the Eighties leading to enhanced high pressure system prevalence but towards a less positive phase in the Nineties. We suggest that the two mechanisms also control the fire regimes in Central and East Siberia. Several extreme fire years in Central Siberia were associated with a highly positive Arctic Oscillation phase, while several years with high fire damage in East Siberia occurred in El Nino years. An analysis of remote sensing data of forest fire partially supports this hypothesis.
Keywords :
atmospheric boundary layer; atmospheric movements; atmospheric radiation; climatology; fires; forestry; remote sensing; vegetation; Arctic Oscillation; El Nino years; NOAA AVHRR instrument; Siberia; atmospheric precipitation; atmospheric temperature; biosphere-atmosphere interaction; camel back method; climate; climatic oscillation index; fAPAR; forest fires; fraction of photosynthetically active radiation; local moving window regression model; remote sensing; vegetation phenology; vegetation photosynthetic activity; Arctic; Atmosphere; Biosphere; Centralized control; Control systems; Fires; Instruments; Temperature control; Time series analysis; Vegetation; Phenology; Siberia; climate change; fire; forest; growing season;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Geoscience and Remote Sensing Symposium, 2007. IGARSS 2007. IEEE International
Conference_Location :
Barcelona
Print_ISBN :
978-1-4244-1211-2
Electronic_ISBN :
978-1-4244-1212-9
Type :
conf
DOI :
10.1109/IGARSS.2007.4423682
Filename :
4423682
Link To Document :
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