GRACE Technical Note 07 TITLE: Monthly estimates of C20 from 5 SLR satellites based on GRACE RL05 models. UPDATE HISTORY: Created January 12, 2018 - last month reported is November 2017. NOTE: This will be the final update to TN07 for RL05; Next update will be re-issued based on RL06 models. SPECIAL NOTES: Please use these estimates to replace the C20 values from the GSM files of the GRACE RL05 products only. These estimates should not be used with the GRACE RL04 or earlier products. In particular, a rate for C20 has not been modeled for RL05, whereas a rate was modeled for RL04. 1) The GRACE gravity solution from CSR for 'November 2011' actually spans October 17, 2011 to November 16, 2011, due to the lack of useful accelerometer data in the latter half of November. A replacement value of C20 is provided for this special solution (denoted by *) as well as for the full calendar month of November 2011. 2) The GRACE gravity solution from CSR for 'December 2011' actually spans December 12, 2011 to January 11, 2012, due to the lack of useful accelerometer data in the first half of December. A replacement value of C20 is provided for this special solution (denoted by *) as well as for the full calendar month of December 2011. 3) The GRACE gravity solution from CSR for 'April 2012' actually spans March 20, 2012 to April 19, 2012, due to the lack of useful accelerometer data in the latter half of April. A replacement value of C20 is provided for this special solution (denoted by *). 4) The estimates from June 2013 through June 2014 have been updated. The previous values were biased due to an error in the AOD1B model, which has been corrected. The updated values are consistent with the re-released RL05 solutions for these months. 5) The GRACE gravity solution from CSR for 'May 2015' actually spans April 12, 2015 to May 11, 2015, due to the lack of useful data in the latter half of May. A replacement value is provided for this special solution (denoted by *). 6) The 'monthly' RL05 solutions from December 2015 onward will not necessarily be based on GRACE data from just one month. The epoch of the C20 replacement will be indicated by the same epoch of the data in the RL05 solution. As before, these special cases will by denoted by *. The regular monthly solutions will still be be provided in addition to these special solutions. AUTHORS: M. Cheng & J. Ries Center for Space Research The University of Texas at Austin Email: grace@podaac.jpl.nasa.gov DESCRIPTION: As a convenience to users who wish to use a replacement value for C20, a monthly C20 estimate time series is provided. These estimates are obtained from the analysis of Satellite Laser Ranging (SLR) data to five geodetic satellites: LAGEOS-1 and 2, Starlette, Stella and Ajisai. The background gravity model used in the SLR analysis is consistent with the GRACE Release-05 processing, including the use of the same Atmosphere-Ocean De-aliasing product. Each estimate is valid for the month whose STARTING MJD is provided in the first column. The product value for the C20 harmonic from the GSM-2 file may be replaced by the C20 value given in Column 3 below. This series may be cited as: Cheng, M.K., B. D. Tapley, and J. C. Ries, "Deceleration in the Earth's oblateness", Jour. Geophys. Res., V118, 1-8, doi:10.1002/jgrb.50058, 2013. This file will be regularly updated. FORMAT: Column 1: MJD of BEGINNING of solution data span Column 2: Year and fraction of year of BEGINNING of solution data span Column 3: Replacement C20 (Use this value instead of value in GSM-2 file) Column 4: Replacement C20 - mean C20 (1.0E-10) Column 5: C20 Sigma (1.0E-10) Mean C20: -0.4841694723127E-03 All values are normalized in the same sense as the GSM product conventions FORMAT(F7.1,F10.4,E22.13,2F8.4) PRODUCT: 51910.0 2001.0000 -0.4841695371845E-03 -0.6487 0.4842 51941.0 2001.0849 -0.4841694860033E-03 -0.1369 0.5040 51969.0 2001.1615 -0.4841694572985E-03 0.1501 0.3876 52000.0 2001.2464 -0.4841694094025E-03 0.6291 0.4277 52030.0 2001.3285 -0.4841694065999E-03 0.6571 0.3489 52061.0 2001.4134 -0.4841694272552E-03 0.4506 0.3521 52091.0 2001.4956 -0.4841695207290E-03 -0.4842 0.3355 52122.0 2001.5804 -0.4841695884243E-03 -1.1611 0.3316 52153.0 2001.6653 -0.4841695712313E-03 -0.9892 0.3841 52183.0 2001.7474 -0.4841695337336E-03 -0.6142 0.3735 52214.0 2001.8323 -0.4841695299978E-03 -0.5769 0.3957 52244.0 2001.9144 -0.4841694583184E-03 0.1399 0.3749 52275.0 2002.0000 -0.4841694691120E-03 0.0320 0.3576 52306.0 2002.0849 -0.4841694371123E-03 0.3520 0.3262 52334.0 2002.1615 -0.4841694091465E-03 0.6317 0.3071 52365.0 2002.2464 -0.4841693593721E-03 1.1294 0.3913 52395.0 2002.3285 -0.4841693910629E-03 0.8125 0.3283 52426.0 2002.4134 -0.4841694251921E-03 0.4712 0.3571 52456.0 2002.4956 -0.4841695504017E-03 -0.7809 0.3514 52487.0 2002.5804 -0.4841695881911E-03 -1.1588 0.3355 52518.0 2002.6653 -0.4841695497460E-03 -0.7743 0.3917 52548.0 2002.7474 -0.4841695314961E-03 -0.5918 0.3402 52579.0 2002.8323 -0.4841695079343E-03 -0.3562 0.3789 52609.0 2002.9144 -0.4841694306711E-03 0.4164 0.3961 52640.0 2003.0000 -0.4841694315266E-03 0.4079 0.3833 52671.0 2003.0849 -0.4841694348913E-03 0.3742 0.3388 52699.0 2003.1615 -0.4841693832727E-03 0.8904 0.3016 52730.0 2003.2464 -0.4841693934308E-03 0.7888 0.3793 52760.0 2003.3285 -0.4841693950251E-03 0.7729 0.3420 52791.0 2003.4134 -0.4841694180029E-03 0.5431 0.3151 52821.0 2003.4956 -0.4841695528889E-03 -0.8058 0.3537 52852.0 2003.5804 -0.4841695964474E-03 -1.2413 0.2898 52883.0 2003.6653 -0.4841695439730E-03 -0.7166 0.3051 52913.0 2003.7474 -0.4841695585708E-03 -0.8626 0.3524 52944.0 2003.8323 -0.4841695042388E-03 -0.3193 0.3869 52974.0 2003.9144 -0.4841694625399E-03 0.0977 0.3547 53005.0 2004.0000 -0.4841694606067E-03 0.1171 0.3509 53036.0 2004.0849 -0.4841694345624E-03 0.3775 0.3533 53065.0 2004.1643 -0.4841694178212E-03 0.5449 0.3643 53096.0 2004.2491 -0.4841694165320E-03 0.5578 0.4253 53126.0 2004.3313 -0.4841693916295E-03 0.8068 0.3592 53157.0 2004.4162 -0.4841694278420E-03 0.4447 0.4204 53187.0 2004.4983 -0.4841695232318E-03 -0.5092 0.4279 53218.0 2004.5832 -0.4841695518672E-03 -0.7955 0.3294 53249.0 2004.6680 -0.4841695214177E-03 -0.4910 0.3976 53279.0 2004.7502 -0.4841694719957E-03 0.0032 0.3923 53310.0 2004.8350 -0.4841694908907E-03 -0.1858 0.3763 53340.0 2004.9172 -0.4841694050067E-03 0.6731 0.4176 53371.0 2005.0000 -0.4841694319562E-03 0.4036 0.3182 53402.0 2005.0849 -0.4841693913962E-03 0.8092 0.4180 53430.0 2005.1615 -0.4841693363121E-03 1.3600 0.4120 53461.0 2005.2464 -0.4841693320825E-03 1.4023 0.3558 53491.0 2005.3285 -0.4841693526806E-03 1.1963 0.3329 53522.0 2005.4134 -0.4841693773771E-03 0.9494 0.3384 53552.0 2005.4956 -0.4841694784173E-03 -0.0610 0.3237 53583.0 2005.5804 -0.4841695063346E-03 -0.3402 0.3254 53614.0 2005.6653 -0.4841695259264E-03 -0.5361 0.3438 53644.0 2005.7474 -0.4841694970874E-03 -0.2477 0.3296 53675.0 2005.8323 -0.4841694999082E-03 -0.2760 0.3842 53705.0 2005.9144 -0.4841694483084E-03 0.2400 0.3703 53736.0 2006.0000 -0.4841694495810E-03 0.2273 0.3508 53767.0 2006.0849 -0.4841694207157E-03 0.5160 0.3838 53795.0 2006.1615 -0.4841694118505E-03 0.6046 0.3856 53826.0 2006.2464 -0.4841694194808E-03 0.5283 0.3705 53856.0 2006.3285 -0.4841693986983E-03 0.7361 0.3401 53887.0 2006.4134 -0.4841693884009E-03 0.8391 0.2972 53917.0 2006.4956 -0.4841695162079E-03 -0.4390 0.2796 53948.0 2006.5804 -0.4841695136424E-03 -0.4133 0.2964 53979.0 2006.6653 -0.4841695171566E-03 -0.4484 0.3095 54009.0 2006.7474 -0.4841694976465E-03 -0.2533 0.3054 54040.0 2006.8323 -0.4841694372646E-03 0.3505 0.3348 54070.0 2006.9144 -0.4841693958592E-03 0.7645 0.3300 54101.0 2007.0000 -0.4841694763799E-03 -0.0407 0.3278 54132.0 2007.0849 -0.4841693800409E-03 0.9227 0.3933 54160.0 2007.1615 -0.4841693690423E-03 1.0327 0.2974 54191.0 2007.2464 -0.4841694039056E-03 0.6841 0.3218 54221.0 2007.3285 -0.4841693831858E-03 0.8913 0.2983 54252.0 2007.4134 -0.4841694091547E-03 0.6316 0.3073 54282.0 2007.4956 -0.4841695181558E-03 -0.4584 0.3278 54313.0 2007.5804 -0.4841695411735E-03 -0.6886 0.3009 54344.0 2007.6653 -0.4841695212263E-03 -0.4891 0.3308 54374.0 2007.7474 -0.4841695435271E-03 -0.7121 0.3294 54405.0 2007.8323 -0.4841695412494E-03 -0.6894 0.3553 54435.0 2007.9144 -0.4841694738024E-03 -0.0149 0.3828 54466.0 2008.0000 -0.4841694938270E-03 -0.2151 0.3790 54497.0 2008.0849 -0.4841694608583E-03 0.1145 0.3142 54526.0 2008.1643 -0.4841694106179E-03 0.6169 0.3264 54557.0 2008.2491 -0.4841693834258E-03 0.8889 0.3540 54587.0 2008.3313 -0.4841694110220E-03 0.6129 0.3251 54618.0 2008.4162 -0.4841694397258E-03 0.3259 0.3454 54648.0 2008.4983 -0.4841695395424E-03 -0.6723 0.3206 54679.0 2008.5832 -0.4841695905623E-03 -1.1825 0.2878 54710.0 2008.6680 -0.4841695268458E-03 -0.5453 0.3414 54740.0 2008.7502 -0.4841695172229E-03 -0.4491 0.3096 54771.0 2008.8350 -0.4841695208581E-03 -0.4855 0.3593 54801.0 2008.9172 -0.4841695110001E-03 -0.3869 0.3612 54832.0 2009.0000 -0.4841694765820E-03 -0.0427 0.3342 54863.0 2009.0849 -0.4841694530538E-03 0.1926 0.3461 54891.0 2009.1615 -0.4841694590423E-03 0.1327 0.3220 54922.0 2009.2464 -0.4841694436092E-03 0.2870 0.3393 54952.0 2009.3285 -0.4841694498867E-03 0.2243 0.3431 54983.0 2009.4134 -0.4841694429268E-03 0.2939 0.4397 55013.0 2009.4956 -0.4841695234585E-03 -0.5115 0.3353 55044.0 2009.5804 -0.4841695485941E-03 -0.7628 0.3226 55075.0 2009.6653 -0.4841695580824E-03 -0.8577 0.3305 55105.0 2009.7474 -0.4841695063548E-03 -0.3404 0.3540 55136.0 2009.8323 -0.4841695129274E-03 -0.4061 0.3949 55166.0 2009.9144 -0.4841694454111E-03 0.2690 0.4222 55197.0 2010.0000 -0.4841694497740E-03 0.2254 0.3434 55228.0 2010.0849 -0.4841694596470E-03 0.1267 0.3658 55256.0 2010.1615 -0.4841694201329E-03 0.5218 0.3406 55287.0 2010.2464 -0.4841694435959E-03 0.2872 0.4059 55317.0 2010.3285 -0.4841694056170E-03 0.6670 0.3921 55348.0 2010.4134 -0.4841694362064E-03 0.3611 0.3901 55378.0 2010.4956 -0.4841695743494E-03 -1.0204 0.3758 55409.0 2010.5804 -0.4841695974890E-03 -1.2518 0.3316 55440.0 2010.6653 -0.4841695902560E-03 -1.1794 0.3398 55470.0 2010.7474 -0.4841696000372E-03 -1.2772 0.3569 55501.0 2010.8323 -0.4841695398262E-03 -0.6751 0.3620 55531.0 2010.9144 -0.4841694549992E-03 0.1731 0.4251 55562.0 2011.0000 -0.4841694950281E-03 -0.2272 0.3594 55593.0 2011.0849 -0.4841694463018E-03 0.2601 0.4166 55621.0 2011.1615 -0.4841694738537E-03 -0.0154 0.3192 55652.0 2011.2464 -0.4841694738879E-03 -0.0158 0.3885 55682.0 2011.3285 -0.4841694661974E-03 0.0612 0.3110 55713.0 2011.4134 -0.4841694647176E-03 0.0760 0.3293 55743.0 2011.4956 -0.4841695822849E-03 -1.0997 0.3352 55774.0 2011.5804 -0.4841695739314E-03 -1.0162 0.3075 55805.0 2011.6653 -0.4841695677361E-03 -0.9542 0.3055 55835.0 2011.7474 -0.4841695953753E-03 -1.2306 0.3290 55851.0 2011.7912 -0.4841695729627E-03 -1.0065 0.3620 * (See Note 1) 55866.0 2011.8323 -0.4841695553899E-03 -0.8308 0.3672 55896.0 2011.9144 -0.4841695368896E-03 -0.6458 0.4279 55907.0 2011.9446 -0.4841695742499E-03 -1.0194 0.3730 * (See Note 2) 55927.0 2012.0000 -0.4841695866996E-03 -1.1439 0.3267 55958.0 2012.0849 -0.4841695518052E-03 -0.7949 0.3477 55987.0 2012.1643 -0.4841695275709E-03 -0.5526 0.3098 56006.0 2012.2190 -0.4841695148200E-03 -0.4251 0.2990 * (See Note 3) 56018.0 2012.2491 -0.4841695058827E-03 -0.3357 0.3588 56048.0 2012.3313 -0.4841694731213E-03 -0.0081 0.2987 56079.0 2012.4162 -0.4841695397941E-03 -0.6748 0.3540 56109.0 2012.4983 -0.4841696634275E-03 -1.9111 0.2972 56140.0 2012.5832 -0.4841696441770E-03 -1.7186 0.2993 56171.0 2012.6680 -0.4841696122462E-03 -1.3993 0.3494 56201.0 2012.7502 -0.4841695858912E-03 -1.1358 0.3250 56232.0 2012.8350 -0.4841695517315E-03 -0.7942 0.4129 56262.0 2012.9172 -0.4841695679780E-03 -0.9567 0.4669 56293.0 2013.0000 -0.4841695575330E-03 -0.8522 0.3786 56324.0 2013.0849 -0.4841695512656E-03 -0.7895 0.3795 56352.0 2013.1615 -0.4841695167508E-03 -0.4444 0.3736 56383.0 2013.2464 -0.4841694797757E-03 -0.0746 0.3464 56413.0 2013.3285 -0.4841694822276E-03 -0.0991 0.3549 56444.0 2013.4134 -0.4841695115362E-03 -0.3922 0.3563 56474.0 2013.4956 -0.4841696439758E-03 -1.7166 0.3780 56505.0 2013.5804 -0.4841696634632E-03 -1.9115 0.3723 56536.0 2013.6653 -0.4841696298757E-03 -1.5756 0.3512 56566.0 2013.7474 -0.4841696241018E-03 -1.5179 0.3602 56597.0 2013.8323 -0.4841696089628E-03 -1.3665 0.4013 56627.0 2013.9144 -0.4841695226064E-03 -0.5029 0.3799 56658.0 2014.0000 -0.4841695486524E-03 -0.7634 0.3529 56689.0 2014.0849 -0.4841695241689E-03 -0.5186 0.3789 56717.0 2014.1615 -0.4841695245941E-03 -0.5228 0.3360 56748.0 2014.2464 -0.4841695040352E-03 -0.3172 0.3565 56778.0 2014.3285 -0.4841695005230E-03 -0.2821 0.3551 56809.0 2014.4134 -0.4841695490766E-03 -0.7676 0.3201 56839.0 2014.4956 -0.4841696082708E-03 -1.3596 0.3196 56870.0 2014.5804 -0.4841696397317E-03 -1.6742 0.3265 56901.0 2014.6653 -0.4841696620322E-03 -1.8972 0.3815 56931.0 2014.7474 -0.4841696359107E-03 -1.6360 0.3603 56962.0 2014.8323 -0.4841695597222E-03 -0.8741 0.3687 56992.0 2014.9144 -0.4841696090520E-03 -1.3674 0.3821 57023.0 2015.0000 -0.4841696116465E-03 -1.3933 0.4172 57054.0 2015.0849 -0.4841695428376E-03 -0.7052 0.5009 57082.0 2015.1615 -0.4841695302427E-03 -0.5793 0.3544 57113.0 2015.2464 -0.4841695557087E-03 -0.8340 0.3683 57124.0 2015.2793 -0.4841695372290E-03 -0.6491 0.3237 * (See Note 5) 57143.0 2015.3285 -0.4841695086451E-03 -0.3633 0.3126 57174.0 2015.4134 -0.4841695406170E-03 -0.6830 0.3263 57204.0 2015.4956 -0.4841696395216E-03 -1.6721 0.3330 57235.0 2015.5804 -0.4841696604856E-03 -1.8817 0.3237 57266.0 2015.6653 -0.4841696292592E-03 -1.5695 0.3558 57296.0 2015.7474 -0.4841695816383E-03 -1.0933 0.3713 57327.0 2015.8323 -0.4841695565857E-03 -0.8427 0.4155 57367.0 2015.9309 -0.4841695453111E-03 -0.7300 0.4758 * (See Note 6) 57391.0 2016.0082 -0.4841695171993E-03 -0.4489 0.4692 57419.0 2016.0849 -0.4841694901853E-03 -0.1787 0.3273 57448.0 2016.1643 -0.4841695048973E-03 -0.3258 0.3986 57479.0 2016.2491 -0.4841694447353E-03 0.2758 0.4282 57509.0 2016.3313 -0.4841694684923E-03 0.0382 0.4058 57540.0 2016.4162 -0.4841695204527E-03 -0.4814 0.4337 57570.0 2016.4983 -0.4841696386919E-03 -1.6638 0.4564 57601.0 2016.5832 -0.4841696158870E-03 -1.4357 0.3789 57632.0 2016.6680 -0.4841696601181E-03 -1.8781 0.3713 57662.0 2016.7502 -0.4841696501004E-03 -1.7779 0.3733 57693.0 2016.8350 -0.4841695649319E-03 -0.9262 0.4586 57705.0 2016.8679 -0.4841695365816E-03 -0.6427 0.4332 * (See Note 6) 57723.0 2016.9172 -0.4841695131951E-03 -0.4088 0.5342 57733.0 2016.9446 -0.4841695222197E-03 -0.4991 0.4626 * (See Note 6) 57754.0 2017.0000 -0.4841695526755E-03 -0.8036 0.4804 57760.0 2017.0164 -0.4841695588747E-03 -0.8656 0.4246 * (See Note 6) 57785.0 2017.0849 -0.4841695249116E-03 -0.5260 0.4625 57813.0 2017.1615 -0.4841695376848E-03 -0.6537 0.4045 57829.0 2017.2081 -0.4841695452048E-03 -0.7289 0.4963 * (See Note 6) 'March' 0317-0414,2017 57844.0 2017.2464 -0.4841695213035E-03 -0.4899 0.3955 57853.0 2017.2738 -0.4841694981835E-03 -0.2587 0.4689 * (See Note 6) 'April' 0410-0508,2017 57874.0 2017.3285 -0.4841694947931E-03 -0.2248 0.3966 57896.0 2017.3915 -0.4841694998393E-03 -0.2753 0.4659 * (See Note 6) 'June' 0523-0629,2017 57905.0 2017.4134 -0.4841695071228E-03 -0.3481 0.4019 57935.0 2017.4956 -0.4841696040257E-03 -1.3171 0.4724 57966.0 2017.5804 -0.4841696682959E-03 -1.9598 0.4008 57997.0 2017.6653 -0.4841696540569E-03 -1.8174 0.4711 58027.0 2017.7474 -0.4841696099174E-03 -1.3760 0.4102 58058.0 2017.8323 -0.4841695898638E-03 -1.1755 0.4679