Wednesday, March 28, 2012

2958.txt

date: 15 Dec 1997 14:14:53 -0700
from: Tom Wigley <Tom_WigleyatXYZxyzte.ucar.edu>
subject: MAGICC CH4 results
to: Mike Hulme <m.hulmeatXYZxyz.ac.uk>, Sarah Raper <s.raperatXYZxyz.ac.uk>


Dear Mike and Sarah,

I have revised some of the code in MAGICC to improve the CH4 results.
There were two glitches. The first was in the initialization of ECH4 to
give a balanced 1990 budget. By a fluke, this didn't affect any results
because of the specific choice of parameters I had. The second was in the
calculated CH4 concentrations. I had tuned the model to match an early
set of IPCC results, and these are all somewhat lower than the published
values. This required tedious trial and error retuning of the methane
model parameters, which I have now done. The new parameters are better,
because a single set works for all IS92 scenarios---previously different
parameters were required for A,B,E,F versus C,D.

With regard to the distributed code, we have to make a choice whether to
stick to the old code (which agrees with Ch. 6, but not Ch. 2) or the new
code (which agrees with Ch.2). I'm inclined to go with Ch. 2 consistency
and the new code. What do you think?

I have more things to clean up in MAGICC, so I won't send the new code
(for MAG.FOR) until I've done these. In the meantime, here are the header
notes from the new code to fill in some details.

Cheers,

Tom
C MAG.FOR

C

C Revision history:

C

C 971214 * METHANE PARAMS CHANGED TO GIVE BETTER SIMULATIONS OF IPCC

C SAR RESULTS AS PER TABLE 2.5a IN SAR. 1990 TAU SET TO 9.1:

C PREVIOUSLY 9.08. IF DELTAU IS SET AT +/- 0.8 (CF. IPCC

C RANGE IS +/- 1.8), WHICH MAKES HIGH TAU = 9.9, AND

C ITAUMETH IS SET AT 3 (WHICH GIVES UPPER BOUND CONCS FOR

C THE ORIGINAL OSBORN & WIGLEY MODEL) THEN OUTPUT AGREES

C EXTREMELY WELL PRATHER'S IPCC RESULTS. THIS IMPLIES THAT

C PRATHER'S MODEL MUST HAVE A HIGH TAU AND/OR A TAU

C SENSITIVITY THAT DIFFERS SUBSTANTIALLY FROM THE CENTRAL

C OSBORN & WIGLEY VALUE.

C

C COMPARISON OF PRATHER IPCC (CH.2) AND CURRENT MODEL (IPCC

C VALUES HAVE 17ppbv ADDED BECAUSE THE IPCC VALUE IN 1990

C IS 17ppbv BELOW THE VALUE USED HERE - THIS MAKES THE

C COMPARISON HERE MORE TRUE TO A FORCING COMPARISON).

C

C RESULTS BELOW ARE IN ORDER : OLD VERSION (I.E., NUMBER

C USED IN CH.6 OF SAR); NEW VERSION; IPCC (CH.2). NOTE THAT

C THE MAIN REASON WHY THE CH.6 VALUES ARE SO DIFFERENT FROM

C THE IPCC CH.2 VALUES IS THAT THE PRESENT MODEL WAS TUNED

C TO AN EARLY VERSION OF PRATHER'S RESULTS.

C

C SCENARIO 2050 CONCS 2100 CONCS

C IS92A,B 2764 2833 2810 3467 3611 3633

C IS92C 2148 2252 2241 1997 2088 2086

C IS92D 2157 2259 2247 2056 2161 2163

C IS92E 2972 3056 3031 4109 4301 4308

C IS92F 2996 3081 3055 4492 4711 4686

C CH.6 NEW CH.2 CH.6 NEW CH.2

C

C

C THE TABLE BELOW COMPARES NEW WITH OLD (IPCC CH.6) T & MSL

C CHANGES OVER 1990-2100.

C

C SCENARIO SIMULATION OLD DT NEW DT OLD DMSL NEW DMSL

C IS92C LOW 0.8622 0.8747 12.63 12.86

C IS92A MID 2.0308 3.0504 48.94 49.28

C IS92E HIGH 3.5260 3.5601 94.75 95.21

C

C 971213 * ERROR IN CORRECTING INPUT METHANE EMISSIONS FOR 1990

C IMBALANCE CORRECTED (SUBSTANTIAL REVISION). THIS WAS FIRST

C CORRECTED IN OPT.FOR ON 961024. IT MAKES NO DIFFERENCE

C TO THE OUTPUT: OUTPUT IS ONLY AFFECTED FOR NON-ZERO DELTAU.

C IN PREVIOUS VERSION OF THE CODE, DELTAU WAS SET TO ZERO.

C 971123 * TWO ERRORS FOUND

C (1) S90IND=0.0 INPUT CAUSES CRASH. CORRECTED TEMPORARILY

C BY RESETTING S90IND=-0.0001

C (2) EQUIVCO2 MISCALCULATED (USED IF NOUT=4 ONLY).

C CODE CORRECTED.

TABLE 1: FOSSIL CO2 EMISSIONS DATA USED IN CARBON CYCLE CALCULATIONS.

MODIFIED IS92a KYOTO EXTENDED KYOTO

YEAR ANNEX I NON-I BUNKER GLOBAL ANNEX I GLOBAL ANNEX I GLOBAL

1990 3.907 2.088 0.114 6.109 3.907 6.109 3.907 6.109

1991 3.791 2.270 0.117 6.178 3.791 6.178 3.791 6.178

1992 3.708 2.240 0.136 6.084 3.708 6.084 3.708 6.084

1993 3.631 2.293 0.129 6.053 3.631 6.053 3.631 6.053

1994 3.676 2.484 0.132 6.292 3.676 6.292 3.676 6.292

1995 3.801 2.567 0.138 6.506 3.801 6.506 3.801 6.506

1996 3.869 2.662 0.138 6.669 3.869 6.669 3.869 6.669

1997 3.920 2.758 0.138 6.816 3.920 6.816 3.920 6.816

1998 3.971 2.854 0.138 6.963 3.971 6.963 3.971 6.963

1999 4.022 2.950 0.138 7.110 4.022 7.110 4.022 7.110

2000 4.073 3.046 0.138 7.257 4.073 7.257 4.073 7.257

2001 4.110 3.177 0.138 7.425 4.029 7.344 4.029 7.344

2002 4.147 3.308 0.138 7.593 3.985 7.431 3.985 7.431

2003 4.183 3.440 0.138 7.761 3.941 7.519 3.941 7.519

2004 4.220 3.571 0.138 7.929 3.897 7.606 3.897 7.606

2005 4.257 3.702 0.138 8.097 3.853 7.693 3.853 7.693

2006 4.294 3.814 0.138 8.246 3.810 7.762 3.810 7.762

2007 4.331 3.924 0.138 8.393 3.766 7.828 3.766 7.828

2008 4.367 4.036 0.138 8.541 3.722 7.896 3.722 7.896

2009 4.404 4.146 0.138 8.688 3.678 7.962 3.678 7.962

2010 4.441 4.258 0.138 8.837 3.634 8.030 3.634 8.030

2011 4.478 4.370 0.138 8.986 3.634 8.142 3.598 8.106

2012 4.515 4.480 0.138 9.133 3.634 8.252 3.562 8.180

2013 4.551 4.592 0.138 9.281 3.634 8.364 3.526 8.256

2014 4.588 4.702 0.138 9.428 3.634 8.474 3.491 8.331

2015 4.625 4.814 0.138 9.577 3.634 8.586 3.456 8.408

2016 4.662 4.945 0.138 9.745 3.634 8.717 3.421 8.504

2017 4.699 5.077 0.138 9.914 3.634 8.849 3.387 8.602

2018 4.735 5.207 0.138 10.080 3.634 8.979 3.353 8.698

2019 4.772 5.339 0.138 10.249 3.634 9.111 3.320 8.797

2020 4.809 5.470 0.138 10.417 3.634 9.242 3.287 8.895

2021 4.846 5.601 0.138 10.585 3.634 9.373 3.254 8.993

2022 4.883 5.733 0.138 10.754 3.634 9.505 3.221 9.092

2023 4.919 5.863 0.138 10.920 3.634 9.635 3.189 9.190

2024 4.956 5.995 0.138 11.089 3.634 9.767 3.157 9.290

2025 4.993 6.126 0.138 11.257 3.634 9.898 3.125 9.389

2026 4.993 6.230 0.138 11.361 3.634 10.002 3.094 9.462

2027 4.993 6.334 0.138 11.465 3.634 10.106 3.063 9.535

2028 4.993 6.438 0.138 11.569 3.634 10.210 3.033 9.609

2029 4.993 6.542 0.138 11.673 3.634 10.314 3.002 9.682

2030 4.993 6.646 0.138 11.777 3.634 10.418 2.972 9.756

2031 4.993 6.750 0.138 11.881 3.634 10.522 2.943 9.831

2032 4.993 6.854 0.138 11.985 3.634 10.626 2.913 9.905

2033 4.993 6.958 0.138 12.089 3.634 10.730 2.884 9.980

2034 4.993 7.062 0.138 12.193 3.634 10.834 2.855 10.055

2035 4.993 7.166 0.138 12.297 3.634 10.938 2.827 10.131

2036 4.993 7.270 0.138 12.401 3.634 11.042 2.798 10.206

2037 4.993 7.374 0.138 12.505 3.634 11.146 2.770 10.282

2038 4.993 7.478 0.138 12.609 3.634 11.250 2.743 10.359

2039 4.993 7.582 0.138 12.713 3.634 11.354 2.715 10.435

2040 4.993 7.686 0.138 12.817 3.634 11.458 2.688 10.512

2041 4.993 7.790 0.138 12.921 3.634 11.562 2.661 10.589

2042 4.993 7.894 0.138 13.025 3.634 11.666 2.635 10.667

2043 4.993 7.998 0.138 13.129 3.634 11.770 2.608 10.744

2044 4.993 8.102 0.138 13.233 3.634 11.874 2.582 10.822

2045 4.993 8.206 0.138 13.337 3.634 11.978 2.556 10.900

2046 4.993 8.310 0.138 13.441 3.634 12.082 2.531 10.979

2047 4.993 8.414 0.138 13.545 3.634 12.186 2.505 11.057

2048 4.993 8.518 0.138 13.649 3.634 12.290 2.480 11.136

2049 4.993 8.622 0.138 13.753 3.634 12.394 2.456 11.216

2050 4.993 8.726 0.138 13.857 3.634 12.498 2.431 11.295

2051 5.011 8.806 0.138 13.955 3.634 12.578 2.407 11.351

2052 5.028 8.886 0.138 14.052 3.634 12.658 2.383 11.407

2053 5.046 8.968 0.138 14.152 3.634 12.740 2.359 11.465

2054 5.063 9.048 0.138 14.249 3.634 12.820 2.335 11.521

2055 5.081 9.128 0.138 14.347 3.634 12.900 2.312 11.578

2056 5.099 9.208 0.138 14.445 3.634 12.980 2.289 11.635

2057 5.116 9.289 0.138 14.543 3.634 13.061 2.266 11.693

2058 5.134 9.369 0.138 14.641 3.634 13.141 2.243 11.750

2059 5.151 9.450 0.138 14.739 3.634 13.222 2.221 11.809

2060 5.169 9.530 0.138 14.837 3.634 13.302 2.199 11.867

2061 5.187 9.610 0.138 14.935 3.634 13.382 2.177 11.925

2062 5.204 9.691 0.138 15.033 3.634 13.463 2.155 11.984

2063 5.222 9.771 0.138 15.131 3.634 13.543 2.133 12.042

2064 5.239 9.852 0.138 15.229 3.634 13.624 2.112 12.102

2065 5.257 9.932 0.138 15.327 3.634 13.704 2.091 12.161

2066 5.275 10.012 0.138 15.425 3.634 13.784 2.070 12.220

2067 5.292 10.093 0.138 15.523 3.634 13.865 2.049 12.280

2068 5.310 10.173 0.138 15.621 3.634 13.945 2.029 12.340

2069 5.327 10.254 0.138 15.719 3.634 14.026 2.008 12.400

2070 5.345 10.334 0.138 15.817 3.634 14.106 1.988 12.460

2071 5.363 10.415 0.138 15.916 3.634 14.187 1.968 12.521

2072 5.380 10.495 0.138 16.013 3.634 14.267 1.949 12.582

2073 5.398 10.575 0.138 16.111 3.634 14.347 1.929 12.642

2074 5.415 10.655 0.138 16.208 3.634 14.427 1.910 12.703

2075 5.433 10.736 0.138 16.307 3.634 14.508 1.891 12.765

2076 5.451 10.888 0.138 16.477 3.634 14.660 1.872 12.898

2077 5.468 11.040 0.138 16.646 3.634 14.812 1.853 13.031

2078 5.486 11.194 0.138 16.818 3.634 14.966 1.835 13.167

2079 5.503 11.346 0.138 16.987 3.634 15.118 1.816 13.300

2080 5.521 11.498 0.138 17.157 3.634 15.270 1.798 13.434

2081 5.539 11.650 0.138 17.327 3.634 15.422 1.780 13.568

2082 5.556 11.803 0.138 17.497 3.634 15.575 1.762 13.703

2083 5.574 11.955 0.138 17.667 3.634 15.727 1.745 13.838

2084 5.591 12.108 0.138 17.837 3.634 15.880 1.727 13.973

2085 5.609 12.260 0.138 18.007 3.634 16.032 1.710 14.108

2086 5.627 12.412 0.138 18.177 3.634 16.184 1.693 14.243

2087 5.644 12.565 0.138 18.347 3.634 16.337 1.676 14.379

2088 5.662 12.717 0.138 18.517 3.634 16.489 1.659 14.514

2089 5.679 12.870 0.138 18.687 3.634 16.642 1.643 14.651

2090 5.697 13.022 0.138 18.857 3.634 16.794 1.626 14.786

2091 5.715 13.174 0.138 19.027 3.634 16.946 1.610 14.922

2092 5.732 13.327 0.138 19.197 3.634 17.099 1.594 15.059

2093 5.750 13.479 0.138 19.367 3.634 17.251 1.578 15.195

2094 5.767 13.632 0.138 19.537 3.634 17.404 1.562 15.332

2095 5.785 13.784 0.138 19.707 3.634 17.556 1.547 15.469

2096 5.803 13.937 0.138 19.878 3.634 17.709 1.531 15.606

2097 5.820 14.089 0.138 20.047 3.634 17.861 1.516 15.743

2098 5.838 14.241 0.138 20.217 3.634 18.013 1.501 15.880

2099 5.855 14.393 0.138 20.386 3.634 18.165 1.486 16.017

2100 5.873 14.546 0.138 20.557 3.634 18.318 1.471 16.155

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