地球科学概论：Fok-Chutian-Wuhan-14.pptx

1、霍学深Fok, Hok Sum2014年12月26日楚天学子学术报告什么是地球潮汐？现有: 地球潮汐（海洋 - 海潮负荷 - 固体）地球地球地球自转地球自转月球月球/太阳太阳 引力引力 热量大气大气海洋海洋什么是地球潮汐？基础理论 -引潮位和种属)(cos),(2llleePrRrGMRU什么是地球潮汐？基础理论 -引潮位和种属HHrGMRUUemm2coscoscoscos2sin2sin)sin31)(sin31 (432222322022Hcoscoscossinsincos周日长周期半日基础理论 - 重点理论起源：理论起源：(1)牛顿均衡理论力 (Newton equilibrium

2、theory) (1600s)(2)纽康的太阳能理论 (Newcombs solar theory) (1895年)(3)布朗的月球理论 (Browns lunar theory) (1905年)海洋海潮基础理论 - 重点(1) 达尔文 (Darwin (1883) -调和分析法(2) Laplace (1775) -动态潮汐方程 (Hydrodynamic)(3) Doodsons number (1921) -潮汐频率0coscos11sin2cos1sin2vHuHRtgRutvgRvtubbeceeceekkkkkGtHt),()(cos),(),(skFpENDpChBsAt)(动量

3、方程动量方程( (水平方向) )连续方程连续方程(垂直方向)海洋海潮海洋海潮 (建模）(i) 调和分析 (Harmonic Analysis)(ii) 响应分析 (Response Analysis)(iii) Laplace (1775) 分为纯建模和同化建模0coscos11sin2cos1sin2vHuHRtgRutvgRvtubbeceeceekkkkkGtHt),()(cos),(),(202*2),(*)(Re),(mmmtwtct海洋海潮(1) 海洋海潮 (幅度范围4 - 200厘米）加快海平面上升飓风海岸侵蚀 盐水入侵 沉淀灰岩沉淀/洪水 村落红树林城市 气候变化/人为变暖Mo

4、dified from J. Kim, OSU, 12/2012GPSGRACE (海平面，水储量变化)雷达测高 （海平面和潮汐等）InSAR (沉降)验潮站沉降（泥沙负荷，构造及地下水的使用）地下水空中LIDAR (DEM与沉降)大地测量技术海洋海潮DGFI Report 79Ray (1999)Yuan et al., 2009海潮负荷 -应用海潮负荷 -应用国际科研 (论文)Stammer, D., R.D. Ray, O.B. Anderson, B.K. Arbic, W. Bosch, L. Carrere, Y. Cheng, D.S. Chinn, B.D. Dushaw, G

5、.D. Egbert, S.Y. Erofeeva, H.S. Fok, J.A.M. Green, S. Griffiths, M.A. King, F.G. Lemoine, S.B. Luthcke, F. Lyard, J. Morison, M. Muller, L. Padman, J.G. Richman, J.F. Shriver, C.K. Shum, E. Taguchi, Y. Yi (2014), Accuracy assessment of global ocean tide models, Reviews of Geophysics, SCI journal (IF

6、 =10.40)国际科研 (论文)利用大地测量和海洋实测,评估全球海潮模型.卫星(测高,相对重力,激光测距(SLR)重力仪GPS海潮流实测验潮站(深海,浅海,沿岸)国际科研 (论文) Accuracy (准确)Tide Gauge (验潮站)+ GPS+重力仪: Pelagic (深海): 0.9 1.4 cm (1.2 cm)Shelf (浅海): 5.0 7.2 cm (6.5 cm)Coastal (沿海): 6.5 18.1 cm (16 cm)Arctic (北极):5.7 8.8 cm (7.5 cm)Antarctica (南极) GPS+重力仪: 4.9 10.2 cm (8.

7、5 cm)国际科研 (论文)Deep OceanCoastal Ocean为什么在沿海地区存在大的差距？没有测高数据，近海岸数据 被 “土地污染”.国际科研 (论文)模型准确度 (Accuracy)卫星觀測 (Satellite:测高(Altimetry)：海潮模型精度相同。純建模(動力法) 和1980年的SCHWIDERSKI 模型精度一致.重力卫星(GRACE):在北极和南极地区差异更大.SLR: 差异在于土地/冰/海洋分类海潮海潮模型模型FRIS分歧分歧 (M2)单单位位: cm国际科研 (论文)模型准确度 (Accuracy)流速仪(Current Meter):所有模型都不好.原因?

8、 GOT4.8模型似乎数据拟合较好. 阅读 Ray, Inversion of oceanic tidal current from measured elevations, J. Mar. Syst., 28, 1-8, 2001 .国际科研 (论文) 为什么正演模拟精度较差?解释:海底地形和水深做得不好，因为正演需要这2个资料作输入.初始边界条件：验潮调和常数不足(因深海观测太少).结论：现今正演模拟与Schwiderski (1980, 1981)精度相同,换言之,正演模拟在过去的30年没有改善！ 国际科研 (论文)如何进一步提高海洋潮汐建模考虑地心(geocenter)变化 Desai

9、 and Ray, GRL, 2014潜在的潮汐季节性 气候变化？Ray, 2006 (验潮站观测); Kagan et al., 2008; Muller et al., 2012, 2014 (正演模建模M2); Fok et al., 2013 (测高反演建模)海洋潮汐科研发展 (理论, 观测, 验证) 海洋潮汐季节性证据 (北冰洋) - 模拟结果 - Kagan et al., 2008楚科奇海海洋潮汐科研发展 (理论, 观测, 验证) 海洋潮汐季节性证据 (北冰洋) - 数据结果 Fok et al., 2013K1潮在夏季幅度K1潮在夏季和冬季之间的幅度差K1潮在暑假相角K1潮在夏

10、季和冬季之间的相角差楚科奇海科研气候变化生命大气水和海洋冻土和冰陆面海平面上升(19852010): 2.6 0.4 mm/year After Kuo (2006)海洋潮汐科研发展全球海平面上升海洋潮汐科研发展 (理论, 观测, 验证) 海冰季节变化 (北冰洋)夏天冬天http:/nsidc.org/data/seaice_index/archives/image_select.html海洋潮汐科研发展海洋潮汐季节性证据 (北冰洋)Jason-2 数据在冬季海面高度残差较冬季大夏天冬天1米海平面上升ROWLEY, KOSTELNICK, BRAATEN, LI, MEISEL, Risk o

11、f Rising Sea Level to Population and Land Area, Eos, V 88 N 9, P 105116, FEBRUARY 2007 http:/www.cresis.ku.edu/research/data/sea_level_rise/气候变化 - 沿海风险？ROWLEY, KOSTELNICK, BRAATEN, LI, MEISEL, Risk of Rising Sea Level to Population and Land Area, Eos, V 88 N 9, P 105116, FEBRUARY 2007 http:/www.cres

12、is.ku.edu/research/data/sea_level_rise/气候变化 - 沿海风险？2米海平面上升海洋海潮 - 科研题目海潮与气候变化的相互影响海潮与气候变化的相互影响-怎样怎样解释？解释？可以用可以用GRACE做海潮吗？做海潮吗？科学科学问题:海潮能预算潮能预算(会计) : 例如如海底地形摩擦海底地形摩擦参数，参数，内波阻内波阻力力等等与海洋环流与海洋环流(正压正压和斜压运动和斜压运动之间之间的能量能量交换过程）交换过程）的的相互作用相互作用能量能量在哪消失？在哪消失？谢谢问题，建议?国际科研 (论文) How to further improve OCEAN TIDES

13、MODELING Consider geocenter variations Desai and Ray, GRL, 2014 Potential seasonality of tides ClimateRay, 2006 (tide gauge observation); Kagan et al., 2008; Muller et al., 2012, 2014 (modeling); Fok et al., 2013 (Altimetry)海潮负荷(1)海潮负荷 (假設海潮與海潮负荷相角一致(即同相),幅度7 至8.5%海潮振幅)地球地球地球自转地球自转月球月球/太阳太阳 引力引力 海洋海

14、洋海潮负荷(2)海潮负荷 (基础理论)Farrell, 1972Munk and MacDonald, 1975Accad and Pekeris,1978Hendershott, 1981Schwiderski, 1983Agnew, 1997Ray, 1998在研 (论文)(准备中)文章Estuary tidal wave Propagation海潮负荷海潮负荷 - 科研题目更好的海潮负荷模型可以提高GPS的精度吗？ 海潮负荷有季节性的变化吗？ 近海的GPS站，可用于验证近岸海潮模型的真实性吗？谢谢问题，建议?霍学深Fok, Hok Sum2014年12月 19日- 12月 27日beab

15、eabeaCrust(Far-side thicker than Near-side)MantlePermanent tideNon-permanent tide (20 cm)R(1737.4 km)1Core(Molten or Solid?)200 kmChangE-1LaserAltimetryxyzOrbiterror5065 kmForced & Free libration(1 or 500 m)100 kmxyzOrbiterrorSELENE382,667 km2Acknowledgement:Spacecraft figures from JAXA,CNSA, NASANo

16、t to scaleJin-woo Kim, OSU, 1/10 JAXA/NHK LRO50 kmMulti-beamLaserTopographyLunar Shaded Topographic MapLunar Shaded Topographic Map USGS ULCN2005 Model USGS ULCN2005 Model90o60o30o0o-30o-60o-90o90o30o60o-90o0o-30o-60oNear SideFar SideMare ImbriumMare SerenitatusMare CrisiumMare NectarisMare NubiumMa

17、re HumboldtianiumMareSmythiiOceanus ProcellarumClaviusMare MoscovienseHertzsprurgAntoniadi CraterApolloDririchlet-Jackson basinMendeleevBirkhoffMare OrientaleULCN2005 Topography (km), 1/160 resolution Archinal et al., 2007Red circle: Oceanus Procellarum study regionLunar Shaded Topographic MapLunar

18、Shaded Topographic MapChangE-1 Laser Altimeter Data ChangE-1 Laser Altimeter Data (CLTM-s01)(CLTM-s01)90o60o30o0o-30o-60o-90o90o30o60o-90o0o-30o-60oNear SideFar Side200-km polar orbit (2 month data), resolution 1/160 (3 km) Ping et al., 2008, data courtesy, J. PingLunar Shaded Topographic Map Lunar

19、Shaded Topographic Map KaguyaKaguya (SELENE) Laser Altimeter Data (SELENE) Laser Altimeter Data (LALT)(LALT)90o60o30o0o-30o-60o-90o90o30o60o-90o0o-30o-60oNear SideFar SideLALT Model Araki et al., 2008, 2009: 1/160 gridded model; 4-month altimeter time series, quaterions; 100-km altitude polar orbit,

20、 spot size = 40 m, 1-Hz, resolutions (1 m vertical)Lunar Shaded Topographic MapLunar Shaded Topographic MapNASA Lunar Reconnaissance Orbiter LOLANASA Lunar Reconnaissance Orbiter LOLA90o60o30o0o-30o-60o-90o90o30o60o-90o0o-30o-60oNear SideFar Side50-km polar orbit (14 month data), resolution 1/160 (3

21、 km) Neumann et al., 2010*Lunakhod 1 is a newly recovered reference site by LRO & lunar laser ranging Williams & Boggs, 2010, Data courtesy, Jim William, JPLUpdated Absolute Calibration of Lunar Topography (Updated from Fok et al. 2011)Observational Equation for Lunar Topography Using Altimetry T(,t

22、)OME,R(,t)(DHtce)DO(,t)geolocationVe(p1,p2,)hWhere O are orbits, H are altimetry data, are tidal heights, (p1,p2,) are libration (error 15 mas), and is the topography error. The geolocation error includes mis-pointing (e.g., up to 0.20 for SELENE) and surface topography gradient errors. O is the rad

23、ial orbit error which is primarily due to gravity and non-conservative forces (solar radiation forces, and spacecraft specific un-modeled forces, 110 m radially); is the solid body tide due to the Earth gravity (20 cm amplitude maximum for non-equilibrium tides), both and are negligible with current

24、 measurement accuracyVh2MEMMa4REM332cos2(Y(,t)tide)12 h2 can be computed from k2 Use of single-satellite and dual-satellite altimeter crossovers Shum et al., 1990 to reduce orbit errors towards improved topographyAbsolute Calibration of Lunar Topography Using Laser Retro-reflectors (Updated from Fok

25、 et al. 2011)Gridded Topography Models. T is the normalized difference (radial difference/data uncertainty), T=2.576 indicates reliability of estimate at 99% confidence ( is 31m, 50m, 300m, and 30m, respectively). RMS in bracket included Lunakhod 1 data.Reference Sites ChangE-1 Topo SELENE Topo ULCN

26、2005 Topo LRO Topo (15 months data) Combined Topography rD (m) T rD (m) T rD (m) T rD (m) T rD (m) T Lunakhod 1 (LLRR)* 3 0.11 9 0.19 6 0.02 2 0.06 1 0.03 Lunakhod 2 (LLRR) 452 14.60 98 1.96 750 2.50 85 2.84 85 2.82 Apollo 11 (LLRR) 17 0.56 14 0.29 217 0.72 3 0.11 3 0.10 Apollo 12 (ALSEP) -45 -1.45

27、-35 -0.71 74 0.25 -41 -1.35 -41 -1.36 Apollo 14 (LLRR) 24 0.77 43 0.86 -145 -0.49 26 0.88 27 0.88 Apollo 14 (ALSEP) 16 0.51 36 0.72 -153 -0.51 19 0.62 19 0.63 Apollo 15 (LLRR) 3 0.10 -83 -1.66 886 2.95 -20 -0.66 -20 -0.66 Apollo 15 (ALSEP) 2 0.05 -83 -1.66 879 2.93 -20 -0.68 -20 -0.68 Apollo 16 (ALS

28、EP) -40 -1.30 -22 -0.45 347 1.16 -22 -0.75 -23 -0.77 Apollo 17 (ALSEP) 120 3.87 -40 -0.80 511 1.70 -33 -1.09 -33 -1.11 RMS radial differences (m) 157 (150) 58 (55) 537 (510) 37 (35) 37 (35) *Lunakhod 1 is a recently recovered reference site by LRO & lunar laser ranging Williams & Boggs, 2010, data c

29、ourtesy, Jim Williams, JPL. SELENE-1 Crossover Residuals: N & S PolesSELENE-1 Crossover Residuals: N & S Poles(Dec 30, 2007 Apr 14, 2008, 4 months)(Dec 30, 2007 Apr 14, 2008, 4 months)556,759 SS crossovers, empirical adjustment (1/rev, time bias): Residuals before adjustment: RMS = 64 m Residuals af

30、ter adjustment: RMS = 55 m Limitations: geolocation errorsTopography Difference Spectrum (SELENE LALT Time Series vs. SELENE and LRO Topography Models)LALT (11 months data used)SELENE GDR LRO TopographyDual- satellite crossovers108.51 mins (1 cyc/rev)SELENE GDR SELENE TopographySingle satellite cros

31、soversTopography Difference Spectrum (CE-1 Time Series vs. SELENE and LRO Topography Models)CE-1 (2 months data used)CE-1 GDR LRO TopographyDual- satellite crossovers125 mins (1 cyc/rev)2 cyc/rev3 cyc/rev4 cyc/rev, etcCE-1 GDR SELENE TopographySingle satellite crossoversSmoothed at 3x3 degreesGeogra

32、phically-Correlated Mean Biases Between CE-1 Geographically-Correlated Mean Biases Between CE-1 and SELENE Topography Time Series (Dual-Satellite and SELENE Topography Time Series (Dual-Satellite Crossover Mean Differences) Crossover Mean Differences) Topography Height Variance Reduction Analysis fo

33、r Different ModelsData usedStdev(before)(in km)SELENE (GT)Stdev(after)(in km)CE-1(GT)Stdev(after)(in km)LRO Team (GT) 1Stdev(after)(in km)Combined(GT) 2Stdev(after)(in km)CE-1 data (2-months)2.21510.19220.06770.12120.1206SELENE data (11 months)2.20570.10760.27830.05670.0513LRO data (15 months)2.3101

34、0.17010.29480.05010.04081LRO Team (GT) is 1/160 model published on MIT website up to SM 12 with periodically updates. 2Combined topography is determined using data from all missions corrected for 1 cyc/rev, 2 cyc/rev, etc while fitting a 2nd order polynomial locally followed by iteration.Complement

35、of CE-1/SELENE data to LRO data at 1/160 x 1/160 gridded modelMissing grids when LRO data onlyComplement CE-1/SELENE data to LRO data at 1/160 x 1/160 gridded modelCE-1/SELENE data filling with missing gridsYutu & Guishu Region (Yutu & Guishu Region (Oceanus Procellarum, Oceanus Procellarum, N Nears

36、ide)earside)CE-1 ground tracks (2 months, purple) SELENE ground tracks (4 months, dark)LRO ground tracks (14 months, red)CE-1+SELENEcCE-1+SELENE+LROLocalized Power Spectra Localized Power Spectra from Lunar Topography Datafrom Lunar Topography DataUsing Spatiospectral Analysis with Slepian TaperingU

37、sing Spatiospectral Analysis with Slepian TaperingEstimate localized spectra using the Selpian tapering method Wieczorek & Simons, 2005Oceanus Procellarum Region (CE-1/SELNE/LRO Combined model) Uses Slepian function which is band-limited within the spherical cap Method operates on irregularly gridde

38、d data on a “sphere” based on a local high-degree spherical harmonics modeling, with spectral estimates obtained by tapering with a window function Method has demonstrated to have less signal leakage Wieczorek & Simons, 2005Global Power Spectra from different PlanetsCentered at (150 N, 3150E) with r

39、adius 200, Tapering (L=15) Estimated localized spectra using Selpian tapering method Wieczorek & Simons, 2005; LRO data Aug. 2011 releaseLocalized Power Spectra from Lunar topography Models Oceanus Procellarum Region (Lunar Nearside)Centered at (00 N, 2000E) with radius 200, Tapering (L=15) Estimate

40、d localized spectra using Selpian tapering method Wieczorek & Simons, 2005; LRO data Aug. 2011 releaseLocalized Power Spectra from Lunar topography Models Dririchlet-Jackson Basin Region (Lunar Farside)Topography Difference (SELENE LALT Time Series vs. SELENE and LRO Topography Models)LALT (4 months

41、 Left and 11 months data used right)SELENE GDR LRO TopographyDual- satellite crossoversSELENE GDR SELENE TopographySingle satellite crossoversStandard deviation =107.6mStandard deviation =105.5mTopography Difference (SELENE LALT Time Series vs. LRO Team and Combined Topography Models)LALT (11 months

42、 data used)SELENE GDR Combined TopographyDual- satellite crossoversStandard deviation =56.7mStandard deviation =51.3mSELENE GDR LRO Team TopographyDual- satellite crossoversTopography Difference (CE-1 Time Series vs. SELENE and LRO Topography Models)CE-1 (2 months data used)CE-1 GDR SELENE Topograph

43、ySingle satellite crossoversCE-1 GDR LRO TopographyDual- satellite crossoversStandard deviation =192.2mStandard deviation =142.2mTopography Difference (CE-1 Time Series vs. LRO Team and Combined Topography Models)CE-1 (2 months data used)CE-1 GDR LRO Team TopographySingle satellite crossoversCE-1 GD

44、R Combined TopographyDual- satellite crossoversStandard deviation =121.2mStandard deviation =120.6mLunar Geomorphology Impact CrateringResearch Topics Impact CraterSimple Crater and Complex CraterResearch Topics Impact Crater Multi-ring Crater; Jay Melosh (2011), Cambridge Press.Research Topics Impa

45、ct Crater Special CraterResearch Topics Impact Cratering Process Reference: Collins et al. (2013), ElementsResearch Topics Impact Crater Statistics+Age Reference: Head et al. (2010), ScienceResearch Topics gravity information (GRAIL, LP150q, etc)Research TopicsCrater detectionManual (Head et al. 2010; Kneissl et al. 2011, ArcGIS )Remote sensing imagery (but sparse due to Power for capturing image)Altimetry-based Digital Terrain ModelAutomaticHough TransformMorphologic constraintsMachine Learning, etc.Research TopicsCrater detection教学和科研