DOI: 10.5194/tc-8-25-2014
Scopus记录号: 2-s2.0-84891885387
论文题名: A wavelet melt detection algorithm applied to enhanced-resolution scatterometer data over Antarctica (2000-2009)
作者: Steiner N ; , Tedesco M
刊名: Cryosphere
ISSN: 19940416
出版年: 2014
卷: 8, 期: 1 起始页码: 25
结束页码: 40
语种: 英语
英文关键词: algorithm
; brightness temperature
; melting
; QuickBird
; SeaWinds
; spatial resolution
; spatiotemporal analysis
; wavelet
; weather station
英文摘要: Melting is mapped over Antarctica at a high spatial resolution using a novel melt detection algorithm based on wavelets and multiscale analysis. The method is applied to Ku-band (13.4 GHz) normalized backscattering measured by SeaWinds onboard the satellite QuikSCAT and spatially enhanced on a 5 km grid over the operational life of the sensor (1999-2009). Wavelet-based estimates of melt spatial extent and duration are compared with those obtained by means of threshold-based detection methods, where melting is detected when the measured backscattering is 3 dB below the preceding winter mean value. Results from both methods are assessed by means of automatic weather station (AWS) air surface temperature records. The yearly melting index, the product of melted area and melting duration, found using a fixed threshold and wavelet-based melt algorithm are found to have a relative difference within 7% for all years. Most of the difference between melting records determined from QuikSCAT is related to short-duration backscatter changes identified as melting using the threshold methodology but not the wavelet-based method. The ability to classify melting based on relative persistence is a critical aspect of the wavelet-based algorithm. Compared with AWS airerature records, both methods show a relative agreement to within 10% based on estimated melt conditions, although the fixed threshold generally finds a greater agreement with AWS. Melting maps obtained with the wavelet-based approach are also compared with those obtained from spaceborne brightness temperatures recorded by the Special Sensor Microwave/Image (SSM/I). With respect to passive microwave records, we find a higher degree of agreement (9% relative difference) for the melting index using the wavelet-based approach than threshold-based methods (11% relative difference).© Author(s) 2014. CC Attribution 3.0 License. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/74905
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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作者单位: City College of New York, City University of New York, New York, United States
Recommended Citation:
Steiner N,, Tedesco M. A wavelet melt detection algorithm applied to enhanced-resolution scatterometer data over Antarctica (2000-2009)[J]. Cryosphere,2014-01-01,8(1)