77c840a59c7ea151880291e780ecaca8 remotesensing_a2020v12n22p3738.pdf 345da238024e0883a19491a02a69b0973f58ca9d remotesensing_a2020v12n22p3738.pdf c74dbb61d38b129097996828b033f58db8fc0bb746d416697be06fe0e9948759 remotesensing_a2020v12n22p3738.pdf Title: Improved Estimates of Arctic Land Surface Phenology Using Sentinel-2 Time Series Subject: The high spatial resolution and revisit time of Sentinel-2A/B tandem satellites allow a potentially improved retrieval of land surface phenology (LSP). The biome and regional characteristics, however, greatly constrain the design of the LSP algorithms. In the Arctic, such biome-specific characteristics include prolonged periods of snow cover, persistent cloud cover, and shortness of the growing season. Here, we evaluate the feasibility of Sentinel-2 for deriving high-resolution LSP maps of the Arctic. We extracted the timing of the start and end of season (SoS and EoS, respectively) for the years 2019 and 2020 with a simple implementation of the threshold method in Google Earth Engine (GEE). We found a high level of similarity between Sentinel-2 and PhenoCam metrics; the best results were observed with Sentinel-2 enhanced vegetation index (EVI) (root mean squared error (RMSE) and mean error (ME) of 3.0 d and -0.3 d for the SoS, and 6.5 d and -3.8 d for the EoS, respectively), although other vegetation indices presented similar performances. The phenological maps of Sentinel-2 EVI compared well with the same maps extracted from the Moderate Resolution Imaging Spectroradiometer (MODIS) in homogeneous landscapes (RMSE and ME of 9.2 d and 2.9 d for the SoS, and 6.4 and -0.9 d for the EoS, respectively). Unreliable LSP estimates were filtered and a quality flag indicator was activated when the Sentinel-2 time series presented a long period (>40 d) of missing data; discontinuities were lower in spring and early summer (9.2%) than in late summer and autumn (39.4%). The Sentinel-2 high-resolution LSP maps and the GEE phenological extraction method will support vegetation monitoring and contribute to improving the representation of Artic vegetation phenology in land surface models. Keywords: land surface phenology; vegetation monitoring; Sentinel-2; arctic; cloud computing; Google Earth Engine Author: Adrià Descals, Aleixandre Verger, Gaofei Yin and Josep Peñuelas Creator: LaTeX with hyperref package Producer: pdfTeX-1.40.18 CreationDate: Fri Nov 13 13:15:07 2020 CET ModDate: Fri Nov 13 13:15:07 2020 CET Custom Metadata: yes Metadata Stream: no Tagged: no UserProperties: no Suspects: no Form: none JavaScript: no Pages: 13 Encrypted: no Page size: 595.276 x 841.89 pts (A4) Page rot: 0 File size: 8584794 bytes Optimized: no PDF version: 1.5 name type encoding emb sub uni object ID ------------------------------------ ----------------- ---------------- --- --- --- --------- CAHJRE+URWPalladioL-Ital Type 1 Custom yes yes no 85 0 CEGSSE+URWPalladioL-Bold Type 1 Custom yes yes no 86 0 WNWTFR+VnURWPalladioL-Bold Type 1 Custom yes yes no 87 0 IHTPWC+URWPalladioL-Roma Type 1 Custom yes yes no 88 0 YXWRXG+VnURWPalladioL Type 1 Custom yes yes no 89 0 OFLXAT+Rpxr Type 1 Builtin yes yes no 90 0 WKQIZL+Pxsy Type 1 Builtin yes yes no 91 0 ZKJPJD+TimesNewRomanPS-BoldItalicMT Type 1C WinAnsi yes yes no 96 0 MCBCCI+SourceSansRoman-Regular Type 1C Custom yes yes no 113 0 MCBCCM+SourceSansRoman.613wght Type 1C Custom yes yes no 114 0 MCBCCO+SourceSansRoman-Bold Type 1C Custom yes yes no 115 0 JMKEHF+PalatinoLinotype CID TrueType Identity-H yes yes yes 183 0 JMKEIG+PalatinoLinotype TrueType WinAnsi yes yes no 184 0 JMKELH+PalatinoLinotype,Italic TrueType WinAnsi yes yes no 185 0 JMKEMJ+PalatinoLinotype,Bold TrueType WinAnsi yes yes no 186 0 JMKFFG+TimesNewRoman CID TrueType Identity-H yes yes yes 187 0 JMKFNE+Arial CID TrueType Identity-H yes yes yes 188 0 GIGFZE+CMR10 Type 1 Builtin yes yes no 228 0 JMKEIG+PalatinoLinotype TrueType WinAnsi yes yes no 245 0 JMKELH+PalatinoLinotype,Italic TrueType WinAnsi yes yes no 246 0 JMKEMJ+PalatinoLinotype,Bold TrueType WinAnsi yes yes no 247 0 JMKFFG+TimesNewRoman CID TrueType Identity-H yes yes yes 248 0 JMKEIG+PalatinoLinotype TrueType WinAnsi yes yes no 290 0 JMKELH+PalatinoLinotype,Italic TrueType WinAnsi yes yes no 291 0 JMKEMJ+PalatinoLinotype,Bold TrueType WinAnsi yes yes no 292 0 JMKFFG+TimesNewRoman CID TrueType Identity-H yes yes yes 293 0 JMKEIG+PalatinoLinotype TrueType WinAnsi yes yes no 309 0 JMKELH+PalatinoLinotype,Italic TrueType WinAnsi yes yes no 310 0 JMKEMJ+PalatinoLinotype,Bold TrueType WinAnsi yes yes no 311 0 JMKFFG+TimesNewRoman CID TrueType Identity-H yes yes yes 312 0 JMKEIG+PalatinoLinotype TrueType WinAnsi yes yes no 340 0 JMKELH+PalatinoLinotype,Italic TrueType WinAnsi yes yes no 341 0 JMKEMJ+PalatinoLinotype,Bold TrueType WinAnsi yes yes no 342 0 JMKFFG+TimesNewRoman CID TrueType Identity-H yes yes yes 343 0 JMKEIG+PalatinoLinotype TrueType WinAnsi yes yes no 369 0 JMKELH+PalatinoLinotype,Italic TrueType WinAnsi yes yes no 370 0 JMKEMJ+PalatinoLinotype,Bold TrueType WinAnsi yes yes no 371 0 JMKFFG+TimesNewRoman CID TrueType Identity-H yes yes yes 372 0 JMKEIG+PalatinoLinotype TrueType WinAnsi yes yes no 388 0 JMKELH+PalatinoLinotype,Italic TrueType WinAnsi yes yes no 389 0 JMKEMJ+PalatinoLinotype,Bold TrueType WinAnsi yes yes no 390 0 JMKFFG+TimesNewRoman CID TrueType Identity-H yes yes yes 391 0 VSHNAE+Rpcxr Type 1 Builtin yes yes no 470 0 Jhove (Rel. 1.28.0, 2023-05-18) Date: 2024-10-02 04:24:38 CEST RepresentationInformation: remotesensing_a2020v12n22p3738.pdf ReportingModule: PDF-hul, Rel. 1.12.4 (2023-03-16) LastModified: 2023-03-31 11:39:38 CEST Size: 8584794 Format: PDF Version: 1.5 Status: Well-Formed and valid SignatureMatches: PDF-hul MIMEtype: application/pdf PDFMetadata: Objects: 0 FreeObjects: 1 IncrementalUpdates: 0 DocumentCatalog: ViewerPreferences: HideToolbar: false HideMenubar: false HideWindowUI: false FitWindow: true CenterWindow: false DisplayDocTitle: false NonFullScreenPageMode: UseNone Direction: L2R ViewArea: CropBox ViewClip: CropBox PrintArea: CropBox PageClip: CropBox PageLayout: SinglePage PageMode: UseNone Outlines: Item: Title: ぉのぴひはつふっぴどはの〠 Item: Title: きちぴづひどちぬび〠ちのつ〠きづぴとはつび〠 Children: Item: Title: こぴふつべ〠ぁひづち〠 Item: Title: いちぴち〠 Item: Title: ぐとづのはぬはでべ〠ぅへぴひちっぴどはの〠 Item: Title: こづのぴどのづぬ〭〲〠ざづでづぴちぴどはの〠ぉのつどっづび〠 Item: Title: ぉねばぬづねづのぴちぴどはの〠はて〠がちのつ〠こふひてちっづ〠ぐとづのはぬはでべ〠ぁぬではひどぴとねび〠どの〠ぇははでぬづ〠ぅちひぴと〠ぅのでどのづ〠 Item: Title: ざちぬどつちぴどはの〠ぷどぴと〠ぐとづのはぃちね〠 Item: Title: ぃはねばちひどびはの〠ぷどぴと〠ぴとづ〠きはつづひちぴづ〠げづびはぬふぴどはの〠ぉねちでどので〠こばづっぴひはひちつどはねづぴづひ〠〨きくいぉこ〩〠がちのつ〠こふひてちっづ〠ぐとづのはぬはでべ〠 Item: Title: げづびふぬぴび〠 Item: Title: いどびっふびびどはの〠 Item: Title: ぃはのっぬふびどはのび〠 Item: Title: げづてづひづのっづび Filters: FilterPipeline: FlateDecode Fonts: Type1: Font: BaseFont: GIGFZE+CMR10 FontSubset: true FirstChar: 40 LastChar: 61 FontDescriptor: FontName: GIGFZE+CMR10 Flags: Symbolic FontBBox: -40, -250, 1009, 750 FontFile: true Font: BaseFont: CAHJRE+URWPalladioL-Ital FontSubset: true FirstChar: 40 LastChar: 121 FontDescriptor: FontName: CAHJRE+URWPalladioL-Ital Flags: Symbolic FontBBox: -170, -305, 1010, 941 FontFile: true EncodingDictionary: Differences: true Font: BaseFont: CEGSSE+URWPalladioL-Bold FontSubset: true FirstChar: 3 LastChar: 241 FontDescriptor: FontName: CEGSSE+URWPalladioL-Bold Flags: Symbolic FontBBox: -152, -301, 1000, 935 FontFile: true EncodingDictionary: Differences: true Font: BaseFont: VSHNAE+Rpcxr FontSubset: true FirstChar: 169 LastChar: 169 FontDescriptor: FontName: VSHNAE+Rpcxr Flags: Symbolic FontBBox: -212, -286, 1344, 973 FontFile: true Font: BaseFont: WNWTFR+VnURWPalladioL-Bold FontSubset: true FirstChar: 160 LastChar: 160 FontDescriptor: FontName: WNWTFR+VnURWPalladioL-Bold Flags: Symbolic FontBBox: -152, -301, 1000, 935 FontFile: true EncodingDictionary: Differences: true Font: BaseFont: IHTPWC+URWPalladioL-Roma FontSubset: true FirstChar: 2 LastChar: 248 FontDescriptor: FontName: IHTPWC+URWPalladioL-Roma Flags: Symbolic FontBBox: -166, -283, 1021, 943 FontFile: true EncodingDictionary: Differences: true Font: BaseFont: YXWRXG+VnURWPalladioL FontSubset: true FirstChar: 161 LastChar: 226 FontDescriptor: FontName: YXWRXG+VnURWPalladioL Flags: Symbolic FontBBox: -166, -283, 1021, 943 FontFile: true EncodingDictionary: Differences: true Font: BaseFont: OFLXAT+Rpxr FontSubset: true FirstChar: 11 LastChar: 62 FontDescriptor: FontName: OFLXAT+Rpxr Flags: Symbolic FontBBox: -40, -283, 904, 728 FontFile: true Font: BaseFont: WKQIZL+Pxsy FontSubset: true FirstChar: 0 LastChar: 14 FontDescriptor: FontName: WKQIZL+Pxsy Flags: Symbolic FontBBox: -21, -994, 1292, 912 FontFile: true Pages: Page: Sequence: 1 Annotations: Annotation: Subtype: Link Rect: 75, 757, 248, 793 Annotation: Subtype: Link Rect: 474, 757, 519, 793 Annotation: Subtype: Link Rect: 158, 660, 169, 674 Annotation: Subtype: Link Rect: 269, 660, 280, 674 Annotation: Subtype: Link Rect: 456, 660, 467, 674 Annotation: Subtype: Link Rect: 466, 558, 518, 577 Annotation: Subtype: Link Rect: 119, 153, 126, 162 ActionDest: 432 Annotation: Subtype: Link Rect: 468, 153, 475, 162 ActionDest: 432 Annotation: Subtype: Link Rect: 476, 153, 483, 162 ActionDest: 432 Annotation: Subtype: Link Rect: 252, 126, 259, 135 ActionDest: 432 Annotation: Subtype: Link Rect: 260, 126, 267, 135 ActionDest: 432 Annotation: Subtype: Link Rect: 508, 126, 515, 135 ActionDest: 432 Annotation: Subtype: Link Rect: 359, 99, 366, 108 ActionDest: 432 Annotation: Subtype: Link Rect: 112, 72, 119, 81 ActionDest: 432 Annotation: Subtype: Link Rect: 185, 38, 254, 50 Annotation: Subtype: Link Rect: 379, 38, 519, 50 Page: Sequence: 2 Annotations: Annotation: Subtype: Link Rect: 239, 715, 246, 725 ActionDest: 432 Annotation: Subtype: Link Rect: 144, 688, 151, 698 ActionDest: 432 Annotation: Subtype: Link Rect: 390, 675, 402, 684 ActionDest: 457 Annotation: Subtype: Link Rect: 244, 634, 251, 644 ActionDest: 432 Annotation: Subtype: Link Rect: 252, 634, 259, 644 ActionDest: 432 Annotation: Subtype: Link Rect: 138, 621, 150, 630 ActionDest: 457 Annotation: Subtype: Link Rect: 334, 553, 346, 562 ActionDest: 457 Annotation: Subtype: Link Rect: 347, 553, 358, 562 ActionDest: 457 Annotation: Subtype: Link Rect: 127, 513, 134, 522 ActionDest: 432 Annotation: Subtype: Link Rect: 346, 472, 358, 481 ActionDest: 457 Annotation: Subtype: Link Rect: 107, 445, 118, 454 ActionDest: 457 Annotation: Subtype: Link Rect: 472, 445, 484, 454 ActionDest: 457 Annotation: Subtype: Link Rect: 485, 445, 497, 454 ActionDest: 457 Annotation: Subtype: Link Rect: 133, 285, 145, 294 ActionDest: 457 Annotation: Subtype: Link Rect: 312, 131, 319, 143 ActionDest: 174 Annotation: Subtype: Link Rect: 462, 120, 474, 130 ActionDest: 457 Page: Sequence: 3 Annotations: Annotation: Subtype: Link Rect: 221, 726, 228, 738 ActionDest: 174 Annotation: Subtype: Link Rect: 302, 452, 314, 461 ActionDest: 457 Annotation: Subtype: Link Rect: 315, 452, 327, 461 ActionDest: 457 Annotation: Subtype: Link Rect: 327, 452, 339, 461 ActionDest: 457 Annotation: Subtype: Link Rect: 230, 425, 242, 434 ActionDest: 457 Annotation: Subtype: Link Rect: 364, 321, 376, 331 ActionDest: 457 Annotation: Subtype: Link Rect: 148, 231, 155, 243 ActionDest: 240 Annotation: Subtype: Link Rect: 207, 176, 214, 188 ActionDest: 240 Annotation: Subtype: Link Rect: 256, 165, 268, 175 ActionDest: 457 Annotation: Subtype: Link Rect: 407, 109, 414, 121 ActionDest: 240 Page: Sequence: 4 Annotations: Annotation: Subtype: Link Rect: 175, 673, 187, 682 ActionDest: 457 Annotation: Subtype: Link Rect: 380, 673, 392, 682 ActionDest: 457 Annotation: Subtype: Link Rect: 250, 659, 262, 668 ActionDest: 457 Annotation: Subtype: Link Rect: 312, 470, 324, 479 ActionDest: 457 Annotation: Subtype: Link Rect: 457, 372, 464, 384 ActionDest: 240 Annotation: Subtype: Link Rect: 254, 307, 266, 317 ActionDest: 457 Annotation: Subtype: Link Rect: 267, 308, 279, 317 ActionDest: 457 Page: Sequence: 5 Annotations: Annotation: Subtype: Link Rect: 150, 259, 162, 269 ActionDest: 457 Annotation: Subtype: Link Rect: 353, 109, 365, 118 ActionDest: 457 Page: Sequence: 6 Annotations: Annotation: Subtype: Link Rect: 301, 688, 313, 698 ActionDest: 457 Annotation: Subtype: Link Rect: 369, 648, 381, 657 ActionDest: 457 Annotation: Subtype: Link Rect: 144, 268, 156, 277 ActionDest: 457 Annotation: Subtype: Link Rect: 419, 254, 431, 263 ActionDest: 457 Annotation: Subtype: Link Rect: 281, 154, 288, 166 ActionDest: 283 Page: Sequence: 7 Annotations: Annotation: Subtype: Link Rect: 319, 503, 326, 515 ActionDest: 283 Annotation: Subtype: Link Rect: 319, 463, 326, 474 ActionDest: 335 Annotation: Subtype: Link Rect: 470, 436, 477, 447 ActionDest: 335 Annotation: Subtype: Link Rect: 344, 422, 351, 434 ActionDest: 335 Annotation: Subtype: Link Rect: 247, 395, 254, 407 ActionDest: 335 Annotation: Subtype: Link Rect: 327, 368, 334, 380 ActionDest: 335 Page: Sequence: 8 Annotations: Annotation: Subtype: Link Rect: 508, 293, 515, 306 ActionDest: 364 Annotation: Subtype: Link Rect: 244, 279, 251, 291 ActionDest: 364 Annotation: Subtype: Link Rect: 283, 117, 290, 129 ActionDest: 364 Annotation: Subtype: Link Rect: 261, 103, 268, 115 ActionDest: 174 Page: Sequence: 9 Annotations: Annotation: Subtype: Link Rect: 104, 170, 116, 179 ActionDest: 457 Annotation: Subtype: Link Rect: 370, 102, 382, 111 ActionDest: 457 Annotation: Subtype: Link Rect: 349, 75, 361, 84 ActionDest: 457 Page: Sequence: 10 Annotations: Annotation: Subtype: Link Rect: 93, 715, 105, 725 ActionDest: 457 Annotation: Subtype: Link Rect: 453, 715, 465, 725 ActionDest: 457 Annotation: Subtype: Link Rect: 475, 526, 482, 535 ActionDest: 432 Annotation: Subtype: Link Rect: 361, 513, 373, 522 ActionDest: 457 Annotation: Subtype: Link Rect: 161, 499, 173, 508 ActionDest: 467 Annotation: Subtype: Link Rect: 305, 499, 317, 508 ActionDest: 467 Annotation: Subtype: Link Rect: 411, 445, 423, 454 ActionDest: 457 Annotation: Subtype: Link Rect: 404, 418, 416, 427 ActionDest: 467 Page: Sequence: 11 Annotations: Annotation: Subtype: Link Rect: 331, 610, 518, 621 Annotation: Subtype: Link Rect: 100, 329, 137, 339 Annotation: Subtype: Link Rect: 367, 290, 405, 301 Annotation: Subtype: Link Rect: 316, 265, 354, 275 Annotation: Subtype: Link Rect: 136, 226, 174, 236 Annotation: Subtype: Link Rect: 455, 212, 492, 223 Annotation: Subtype: Link Rect: 446, 186, 483, 197 Annotation: Subtype: Link Rect: 136, 149, 173, 159 Annotation: Subtype: Link Rect: 136, 123, 174, 133 Annotation: Subtype: Link Rect: 136, 97, 174, 107 Page: Sequence: 12 Annotations: Annotation: Subtype: Link Rect: 273, 714, 311, 725 Annotation: Subtype: Link Rect: 122, 676, 160, 686 Annotation: Subtype: Link Rect: 234, 651, 271, 661 Annotation: Subtype: Link Rect: 100, 612, 137, 622 Annotation: Subtype: Link Rect: 449, 585, 487, 596 Annotation: Subtype: Link Rect: 177, 547, 214, 557 Annotation: Subtype: Link Rect: 284, 521, 321, 531 Annotation: Subtype: Link Rect: 172, 483, 210, 493 Annotation: Subtype: Link Rect: 210, 456, 390, 467 Annotation: Subtype: Link Rect: 207, 430, 519, 441 Annotation: Subtype: Link Rect: 454, 391, 491, 402 Annotation: Subtype: Link Rect: 441, 366, 478, 376 Annotation: Subtype: Link Rect: 257, 327, 295, 338 Annotation: Subtype: Link Rect: 100, 289, 137, 299 Annotation: Subtype: Link Rect: 232, 250, 270, 260 Annotation: Subtype: Link Rect: 291, 224, 328, 234 Annotation: Subtype: Link Rect: 379, 185, 417, 196 Annotation: Subtype: Link Rect: 423, 185, 459, 196 Annotation: Subtype: Link Rect: 280, 159, 457, 170 Annotation: Subtype: Link Rect: 479, 120, 516, 131 Annotation: Subtype: Link Rect: 254, 95, 291, 105 Page: Sequence: 13 Annotations: Annotation: Subtype: Link Rect: 317, 714, 354, 725 Annotation: Subtype: Link Rect: 468, 675, 505, 686 Annotation: Subtype: Link Rect: 334, 637, 371, 648 Annotation: Subtype: Link Rect: 76, 565, 166, 596 Annotation: Subtype: Link Rect: 234, 559, 407, 570 Checksum: 22df5767 Type: CRC32 Checksum: 77c840a59c7ea151880291e780ecaca8 Type: MD5 Checksum: 345da238024e0883a19491a02a69b0973f58ca9d Type: SHA-1 Checksum: c74dbb61d38b129097996828b033f58db8fc0bb746d416697be06fe0e9948759 Type: SHA-256