The monthly values of the modulation parameter (in MV) reconstructed from the ground based cosmic ray data, using the the procedure described in Refs.(1 and 2). Data for the period Jun-1936 - Apr-1951 were taken from the pseudo-Climax NM count rate (ref. 3), and since Apr-1951 onwards - from the world NM network (Ref.1 and 2). Local Interstellar spectrum (LIS) corresponds to Ref. (4) References: [1] Usoskin, I.G., K. Alanko-Huotari, G.A. Kovaltsov, and K. Mursula, Heliospheric modulation of cosmic rays: Monthly reconstruction for 1951-2004, J. Geophys. Res., 110, A12108, 2005 (doi:10.1029/2005JA011250). [2] Usoskin, I. G., G. A. Bazilevskaya, and G. A. Kovaltsov, Solar modulation parameter for cosmic rays since 1936 reconstructed from ground-based neutron monitors and ionization chambers, J. Geophys. Res., 116, 2011 (doi:10.1029/2010JA016105). [3] McCracken, K.G., and J. Beer, Long-term changes in the cosmic ray intensity at Earth, 1428-2005, J. Geophys. Res., 112, A10101, 2007 (doi:10.1029/2006JA012117). [4] Burger, R. A., M. S. Potgieter, and B. Heber (2000), Rigidity dependence of cosmic ray proton latitudinal gradients measured by the Ulysses spacecraft: Implication for the diffusion tensor, J. Geophys. Res., 105, 27,447. +++++++++++++++++++++++++++++++++++++++++++ Year Phi (MV) 1936.500 252 1936.583 242 1936.667 260 1936.750 271 1936.833 290 1936.917 363 1937.000 401 1937.083 451 1937.167 516 1937.250 550 1937.333 546 1937.417 662 1937.500 557 1937.583 588 1937.667 546 1937.750 553 1937.833 492 1937.917 496 1938.000 716 1938.083 696 1938.167 560 1938.250 650 1938.333 502 1938.417 401 1938.500 348 1938.583 371 1938.667 389 1938.750 401 1938.833 401 1938.917 416 1939.000 416 1939.083 509 1939.167 506 1939.250 599 1939.333 632 1939.417 509 1939.500 422 1939.583 345 1939.667 389 1939.750 389 1939.833 295 1939.917 303 1940.000 287 1940.083 300 1940.167 292 1940.250 290 1940.333 255 1940.417 273 1940.500 268 1940.583 281 1940.667 287 1940.750 295 1940.833 320 1940.917 345 1941.000 389 1941.083 342 1941.167 371 1941.250 354 1941.333 323 1941.417 287 1941.500 303 1941.583 271 1941.667 309 1941.750 268 1941.833 273 1941.917 311 1942.000 273 1942.083 273 1942.167 447 1942.250 340 1942.333 287 1942.417 268 1942.500 279 1942.583 239 1942.667 237 1942.750 245 1942.833 242 1942.917 237 1943.000 250 1943.083 255 1943.167 258 1943.250 271 1943.333 268 1943.417 271 1943.500 306 1943.583 309 1943.667 314 1943.750 292 1943.833 279 1943.917 273 1944.000 279 1944.083 263 1944.167 258 1944.250 239 1944.333 211 1944.417 187 1944.500 184 1944.583 192 1944.667 177 1944.750 184 1944.833 170 1944.917 211 1945.000 250 1945.083 250 1945.167 334 1945.250 340 1945.333 258 1945.417 258 1945.500 255 1945.583 245 1945.667 234 1945.750 229 1945.833 242 1945.917 245 1946.000 303 1946.083 768 1946.167 610 1946.250 581 1946.333 647 1946.417 595 1946.500 602 1946.583 550 1946.667 578 1946.750 486 1946.833 457 1946.917 407 1947.000 432 1947.083 413 1947.167 560 1947.250 685 1947.333 658 1947.417 1166 1947.500 925 1947.583 1031 1947.667 1128 1947.750 1001 1947.833 911 1947.917 827 1948.000 716 1948.083 677 1948.167 708 1948.250 602 1948.333 748 1948.417 581 1948.500 581 1948.583 595 1948.667 712 1948.750 669 1948.833 602 1948.917 588 1949.000 696 1949.083 677 1949.167 613 1949.250 632 1949.333 585 1949.417 539 1949.500 486 1949.583 522 1949.667 479 1949.750 599 1949.833 526 1949.917 486 1950.000 606 1950.083 628 1950.167 512 1950.250 512 1950.333 526 1950.417 473 1950.500 496 1950.583 463 1950.667 512 1950.750 512 1950.833 435 1950.917 416 1951.000 492 1951.083 647 1951.167 631 1951.250 618 1951.333 555 1951.417 510 1951.500 553 1951.583 587 1951.667 523 1951.750 514 1951.833 535 1951.917 513 1952.000 551 1952.083 567 1952.167 587 1952.250 546 1952.333 489 1952.417 464 1952.500 447 1952.583 448 1952.667 436 1952.750 490 1952.833 465 1952.917 483 1953.000 515 1953.083 497 1953.167 506 1953.250 500 1953.333 500 1953.417 482 1953.500 495 1953.583 488 1953.667 483 1953.750 469 1953.833 472 1953.917 453 1954.000 445 1954.083 427 1954.167 401 1954.250 411 1954.333 404 1954.417 407 1954.500 399 1954.583 376 1954.667 384 1954.750 386 1954.833 399 1954.917 411 1955.000 462 1955.083 413 1955.167 409 1955.250 409 1955.333 399 1955.417 406 1955.500 405 1955.583 417 1955.667 400 1955.750 429 1955.833 425 1955.917 476 1956.000 511 1956.083 551 1956.167 623 1956.250 567 1956.333 604 1956.417 592 1956.500 555 1956.583 562 1956.667 598 1956.750 521 1956.833 647 1956.917 822 1957.000 955 1957.083 967 1957.167 929 1957.250 1053 1957.333 984 1957.417 1033 1957.500 1087 1957.583 1021 1957.667 1226 1957.750 1149 1957.833 1180 1957.917 1284 1958.000 1266 1958.083 1226 1958.167 1330 1958.250 1308 1958.333 1167 1958.417 1090 1958.500 1216 1958.583 1120 1958.667 1093 1958.750 1089 1958.833 1063 1958.917 1125 1959.000 1080 1959.083 1139 1959.167 1029 1959.250 965 1959.333 1072 1959.417 996 1959.500 1327 1959.583 1269 1959.667 1187 1959.750 1044 1959.833 1022 1959.917 1056 1960.000 1136 1960.083 1080 1960.167 1007 1960.250 1112 1960.333 1109 1960.417 1042 1960.500 1042 1960.583 953 1960.667 956 1960.750 953 1960.833 1024 1960.917 945 1961.000 848 1961.083 815 1961.167 813 1961.250 822 1961.333 776 1961.417 783 1961.500 956 1961.583 836 1961.667 787 1961.750 749 1961.833 676 1961.917 698 1962.000 700 1962.083 723 1962.167 708 1962.250 737 1962.333 689 1962.417 678 1962.500 667 1962.583 667 1962.667 699 1962.750 705 1962.833 668 1962.917 678 1963.000 612 1963.083 587 1963.167 592 1963.250 567 1963.333 603 1963.417 566 1963.500 562 1963.583 575 1963.667 613 1963.750 578 1963.833 561 1963.917 538 1964.000 515 1964.085 519 1964.167 495 1964.249 479 1964.331 468 1964.415 469 1964.497 459 1964.582 456 1964.667 430 1964.749 433 1964.833 436 1964.915 406 1965.000 389 1965.085 394 1965.162 371 1965.247 348 1965.329 338 1965.414 386 1965.496 406 1965.581 413 1965.666 406 1965.748 394 1965.833 371 1965.915 376 1966.000 412 1966.085 420 1966.162 441 1966.247 452 1966.329 431 1966.414 479 1966.496 507 1966.581 515 1966.666 665 1966.748 575 1966.833 541 1966.915 584 1967.000 632 1967.085 656 1967.162 597 1967.247 579 1967.329 630 1967.414 655 1967.496 625 1967.581 671 1967.666 658 1967.748 645 1967.833 690 1967.915 689 1968.000 674 1968.085 707 1968.164 713 1968.249 669 1968.331 694 1968.415 765 1968.497 761 1968.582 742 1968.667 789 1968.749 850 1968.833 985 1968.915 934 1969.000 811 1969.085 799 1969.162 820 1969.247 823 1969.329 962 1969.414 1014 1969.496 948 1969.581 861 1969.666 819 1969.748 798 1969.833 796 1969.915 791 1970.000 810 1970.085 769 1970.162 784 1970.247 834 1970.329 835 1970.414 937 1970.496 934 1970.581 855 1970.666 780 1970.748 758 1970.833 834 1970.915 706 1971.000 717 1971.085 641 1971.162 646 1971.247 624 1971.329 591 1971.414 515 1971.496 514 1971.581 493 1971.666 497 1971.748 465 1971.833 475 1971.915 488 1972.000 507 1972.085 520 1972.164 453 1972.249 427 1972.331 457 1972.415 528 1972.497 461 1972.582 636 1972.667 475 1972.749 461 1972.833 505 1972.915 476 1973.000 463 1973.085 473 1973.162 498 1973.247 565 1973.329 616 1973.414 524 1973.496 491 1973.581 466 1973.666 427 1973.748 428 1973.833 416 1973.915 418 1974.000 420 1974.085 402 1974.162 438 1974.247 461 1974.329 527 1974.414 567 1974.496 630 1974.581 563 1974.666 605 1974.748 590 1974.833 565 1974.915 499 1975.000 494 1975.085 459 1975.162 450 1975.247 429 1975.329 420 1975.414 407 1975.496 417 1975.581 442 1975.666 436 1975.748 437 1975.833 471 1975.915 448 1976.000 446 1976.085 440 1976.164 436 1976.249 461 1976.331 434 1976.415 426 1976.497 412 1976.582 408 1976.667 407 1976.749 408 1976.833 404 1976.915 411 1977.000 421 1977.085 417 1977.162 419 1977.247 416 1977.329 417 1977.414 442 1977.496 487 1977.581 476 1977.666 475 1977.748 438 1977.833 408 1977.915 418 1978.000 478 1978.085 496 1978.162 510 1978.247 588 1978.329 669 1978.414 602 1978.496 591 1978.581 495 1978.666 495 1978.748 566 1978.833 528 1978.915 530 1979.000 584 1979.085 609 1979.162 653 1979.247 738 1979.329 706 1979.414 812 1979.496 799 1979.581 906 1979.666 860 1979.748 778 1979.833 774 1979.915 688 1980.000 716 1980.085 743 1980.164 686 1980.249 762 1980.331 757 1980.415 886 1980.497 885 1980.582 855 1980.667 866 1980.749 960 1980.833 1052 1980.915 1038 1981.000 878 1981.085 968 1981.162 995 1981.247 1055 1981.329 1124 1981.414 967 1981.496 930 1981.581 923 1981.666 871 1981.748 1046 1981.833 1010 1981.915 886 1982.000 813 1982.085 982 1982.162 828 1982.247 798 1982.329 758 1982.414 1009 1982.496 1258 1982.581 1240 1982.666 1422 1982.748 1222 1982.833 1150 1982.915 1256 1983.000 1086 1983.085 969 1983.162 877 1983.247 874 1983.329 1029 1983.414 928 1983.496 826 1983.581 836 1983.666 803 1983.748 787 1983.833 762 1983.915 761 1984.000 709 1984.085 736 1984.164 800 1984.249 846 1984.331 967 1984.415 880 1984.497 842 1984.582 778 1984.667 753 1984.749 751 1984.833 772 1984.915 746 1985.000 724 1985.085 656 1985.162 636 1985.247 609 1985.329 596 1985.414 542 1985.496 549 1985.581 543 1985.666 501 1985.748 495 1985.833 464 1985.915 485 1986.000 486 1986.085 575 1986.162 507 1986.247 434 1986.329 416 1986.414 405 1986.496 403 1986.581 402 1986.666 401 1986.748 378 1986.833 433 1986.915 382 1987.000 339 1987.085 311 1987.162 312 1987.247 328 1987.329 349 1987.414 406 1987.496 435 1987.581 468 1987.666 501 1987.748 492 1987.833 534 1987.915 534 1988.000 626 1988.085 593 1988.164 581 1988.249 602 1988.331 590 1988.415 610 1988.497 681 1988.582 697 1988.667 682 1988.749 714 1988.833 728 1988.915 819 1989.000 893 1989.085 898 1989.162 1183 1989.247 1132 1989.329 1234 1989.414 1187 1989.496 1022 1989.581 1114 1989.666 1195 1989.748 1356 1989.833 1470 1989.915 1362 1990.000 1232 1990.085 1196 1990.162 1275 1990.247 1424 1990.329 1452 1990.414 1435 1990.496 1247 1990.581 1294 1990.666 1187 1990.748 1073 1990.833 996 1990.915 985 1991.000 872 1991.085 862 1991.162 1257 1991.247 1197 1991.329 1158 1991.414 2016 1991.496 1938 1991.581 1471 1991.666 1190 1991.748 1126 1991.833 1115 1991.915 1028 1992.000 1019 1992.085 1066 1992.164 948 1992.249 815 1992.331 860 1992.415 748 1992.497 682 1992.582 695 1992.667 724 1992.749 658 1992.833 679 1992.915 616 1993.000 632 1993.085 634 1993.162 685 1993.247 621 1993.329 599 1993.414 580 1993.496 573 1993.581 571 1993.666 548 1993.748 545 1993.833 534 1993.915 541 1994.000 536 1994.085 598 1994.162 603 1994.247 605 1994.329 576 1994.414 573 1994.496 544 1994.581 518 1994.666 497 1994.748 507 1994.833 499 1994.915 505 1995.000 484 1995.085 470 1995.162 494 1995.247 476 1995.329 468 1995.414 472 1995.496 473 1995.581 464 1995.666 459 1995.748 457 1995.833 451 1995.915 437 1996.000 436 1996.085 414 1996.164 412 1996.249 411 1996.331 419 1996.415 424 1996.497 425 1996.582 429 1996.667 431 1996.749 449 1996.833 451 1996.915 437 1997.000 418 1997.085 400 1997.162 404 1997.247 413 1997.329 404 1997.414 405 1997.496 409 1997.581 394 1997.666 404 1997.748 424 1997.833 439 1997.915 424 1998.000 427 1998.085 423 1998.162 413 1998.247 513 1998.329 572 1998.414 555 1998.496 514 1998.581 568 1998.666 515 1998.748 478 1998.833 502 1998.915 540 1999.000 602 1999.085 602 1999.162 589 1999.247 573 1999.329 589 1999.414 539 1999.496 513 1999.581 609 1999.666 691 1999.748 733 1999.833 751 1999.915 787 2000.000 752 2000.085 794 2000.164 865 2000.249 848 2000.331 967 2000.415 1073 2000.497 1167 2000.582 1057 2000.667 992 2000.749 882 2000.833 1023 2000.915 960 2001.000 881 2001.085 774 2001.162 725 2001.247 995 2001.329 874 2001.414 832 2001.496 808 2001.581 904 2001.666 897 2001.748 959 2001.833 865 2001.915 833 2002.000 977 2002.085 826 2002.162 888 2002.247 895 2002.329 900 2002.414 863 2002.496 948 2002.581 1058 2002.666 963 2002.748 926 2002.833 1023 2002.915 986 2003.000 895 2003.083 892 2003.167 876 2003.250 909 2003.333 945 2003.417 1067 2003.500 959 2003.583 908 2003.667 869 2003.750 963 2003.833 1281 2003.917 930 2004.000 936 2004.083 784 2004.167 705 2004.250 676 2004.333 630 2004.417 636 2004.500 693 2004.583 662 2004.667 632 2004.750 545 2004.833 645 2004.917 615 2005.000 788 2005.083 642 2005.167 620 2005.250 589 2005.333 681 2005.417 610 2005.500 643 2005.583 676 2005.667 798 2005.750 596 2005.833 542 2005.917 540 2006.000 516 2006.083 462 2006.167 435 2006.250 430 2006.333 423 2006.417 423 2006.500 443 2006.583 436 2006.667 440 2006.750 407 2006.833 408 2006.917 467 2007.000 391 2007.083 396 2007.167 376 2007.250 355 2007.333 351 2007.417 354 2007.500 357 2007.583 361 2007.667 352 2007.750 348 2007.833 353 2007.917 340 2008.000 360 2008.083 367 2008.167 362 2008.250 361 2008.333 370 2008.417 367 2008.500 356 2008.583 342 2008.667 336 2008.750 322 2008.833 302 2008.917 309 2009.000 302 2009.083 285 2009.167 276 2009.250 267 2009.333 267 2009.417 270 2009.500 269 2009.583 274 2009.667 270 2009.750 260 2009.833 258 2009.917 255 2010.000 271 2010.085 316 2010.162 347 2010.247 376 2010.329 361 2010.414 371 2010.496 377 2010.581 388 2010.666 388 2010.748 374 2010.833 389 2010.917 412 2011.000 398 2011.083 414 2011.167 426 2011.250 496 2011.333 453 2011.417 551 2011.500 518 2011.583 509 2011.667 513 2011.750 534 2011.833 488 2011.917 438 2012.000 490 2012.083 533 2012.167 634 2012.250 506 2012.333 494 2012.417 546 2012.500 664 2012.583 643 2012.667 583 2012.750 587 2012.833 571 2012.917 544 2013.000 533 2013.083 530 2013.167 564 2013.250 559 2013.333 674 2013.417 679 2013.500 665 2013.583 640 2013.667 614 2013.750 571 2013.833 590 2013.917 625 2014.000 606 2014.083 681 2014.167 652 2014.250 633 2014.333 600 2014.417 656 2014.500 628 2014.583 590 2014.667 634 2014.750 632 2014.833 645 2014.917 731 2015.000 695 2015.083 686 2015.167 743 2015.250 705 2015.333 655 2015.417 666 2015.500 617 2015.583 612 2015.667 611 2015.750 601 2015.833 585 2015.917 561 2016.000 500 2016.085 568 2016.164 475 2016.249 468 2016.331 464 2016.415 447 2016.497 464 2016.582 438 2016.667 436 2016.749 407 2016.833 385 2016.915 386 2017.000 366 2017.083 357 2017.167 348 2017.250 367 2017.333 359 2017.417 350 2017.500 383 2017.583 420 2017.667 444 2017.750 405 2017.833 367 2017.917 360 2018.000 358 2018.085 348 2018.162 344 2018.247 336 2018.329 341 2018.414 321 2018.496 323 2018.581 323 2018.666 318 2018.748 313 2018.833 319 2018.915 325 2019.000 324 2019.083 330 2019.167 308 2019.250 309 2019.333 337 2019.417 315 2019.500 315 2019.583 318 2019.667 305 2019.750 299 2019.833 305 2019.917 303 2020.000 294 2020.083 279 2020.167 283 2020.250 269 2020.333 280 2020.417 291 2020.500 295 2020.583 297 2020.667 298 2020.750 302 2020.833 301 2020.917 321 2021.000 326 2021.083 365 2021.167 320 2021.250 306 2021.333 309 2021.417 316 2021.500 330 2021.583 316 2021.667 322 2021.750 322 2021.833 349 2021.917 337 2022.000 345 2022.083 375 2022.167 378 2022.250 388 2022.333 433 2022.417 485 2022.500 526 2022.583 566 2022.667 531 2022.750 503 2022.833 507 2022.917 590 2023.000 607 2023.083 690 2023.167 701 2023.250 652 2023.333 672 2023.417 680 2023.500 731 2023.583 792 2023.667 708 2023.750 744 2023.833 810 2023.917 836 2024.000 817 2024.083 828 2024.167 820 2024.250 808 2024.333 899 2024.417 820 2024.500 757 2024.583 859 2024.667 967 2024.750 1072 2024.833 1051 2024.917 1026 2025.000 972 2025.083 934 2025.167 947 2025.250 979 2025.333 937 2025.417 1095 2025.500 975 2025.583 924 2025.667 979 2025.750 960 2025.833 1162 2025.917 1077