| 1 | Geophysics | 1,540 | 75.6K | 43 | 36 |
| 2 | Atmospheric Physics | 1,001 | 53.9K | 8 | 14 |
| 3 | Atmospheric Chemistry | 806 | 47.2K | 6 | 10 |
| 4 | atmospheric models | 362 | 16.2K | 4 | 10 |
| 5 | Pollution | 138 | 15.1K | 721 | 369 |
| 6 | Meteorology | 377 | 13.9K | 108 | 149 |
| 7 | Science | 91 | 13.4K | 2786 | 1676 |
| 8 | Planets | 266 | 13.2K | 117 | 106 |
| 9 | Environment | 78 | 12.8K | 1001 | 490 |
| 10 | Physics | 78 | 12.8K | 2970 | 1807 |
| 11 | Biology | 60 | 12.0K | 3322 | 1750 |
| 12 | Biodiversity conservation | 44 | 10.9K | 410 | 114 |
| 13 | Climate change | 44 | 10.8K | 184 | 78 |
| 14 | Eutrophication | 43 | 10.8K | 184 | 78 |
| 15 | Natural history | 26 | 9.6K | 1703 | 1225 |
| 16 | Climatology | 155 | 9.0K | 152 | 144 |
| 17 | Earth Sciences | 113 | 6.8K | 387 | 259 |
| 18 | Astronomy | 140 | 6.3K | 680 | 712 |
| 19 | Aerosols | 134 | 6.1K | 12 | 8 |
| 20 | Environmental Health | 109 | 4.7K | 803 | 826 |
| 21 | aerosol | 97 | 4.1K | 10 | 5 |
| 22 | Environmental Engineering | 65 | 3.8K | 669 | 528 |
| 23 | Ecology | 71 | 3.7K | 1603 | 1520 |
| 24 | Astrophysics | 157 | 3.6K | 715 | 1064 |
| 25 | Biodiversity | 84 | 3.3K | 211 | 289 |
| 26 | Biogeochemistry | 85 | 3.2K | 95 | 196 |
| 27 | Chemistry | 39 | 2.9K | 4227 | 2961 |
| 28 | Environmental Policy | 38 | 2.7K | 835 | 621 |
| 29 | space environment | 55 | 2.6K | 19 | 5 |
| 30 | Oceanography | 80 | 2.5K | 343 | 391 |
| 31 | atmosphere | 73 | 2.4K | 40 | 44 |
| 32 | environmental pollution | 42 | 2.3K | 1362 | 1098 |
| 33 | cryosphere | 72 | 2.2K | 22 | 69 |
| 34 | Solar System | 62 | 2.1K | 178 | 188 |
| 35 | bioclimatology | 25 | 1.9K | 142 | 46 |
| 36 | Radiation | 32 | 1.8K | 609 | 262 |
| 37 | Environmental monitoring | 39 | 1.8K | 1072 | 1013 |
| 38 | sanitation | 42 | 1.8K | 373 | 572 |
| 39 | environmental protection | 19 | 1.5K | 1533 | 860 |
| 40 | Environmental Law | 18 | 1.4K | 372 | 323 |
| 41 | Data Mining | 16 | 1.4K | 550 | 333 |
| 41 | data collection | 16 | 1.4K | 286 | 236 |
| 43 | Photochemistry | 21 | 1.3K | 583 | 284 |
| 44 | Spectrum analysis | 29 | 1.1K | 1953 | 1697 |
| 45 | Geology | 32 | 1.1K | 1197 | 1014 |
| 46 | weather | 21 | 1.0K | 78 | 54 |
| 47 | global environmental change | 20 | 1.0K | 231 | 265 |
| 48 | Climate | 17 | 1.0K | 145 | 104 |
| 49 | Photobiology | 14 | 978 | 564 | 208 |
| 50 | Sun | 10 | 898 | 272 | 153 |
| 51 | Mathematics | 11 | 812 | 4301 | 1717 |
| 52 | radiative transfer | 18 | 798 | 215 | 131 |
| 53 | Engineering | 9 | 777 | 3356 | 1108 |
| 54 | Hydrology | 32 | 762 | 795 | 928 |
| 55 | Research | 34 | 652 | 4009 | 5101 |
| 56 | ecosystem | 12 | 618 | 737 | 712 |
| 57 | natural disasters | 23 | 587 | 282 | 413 |
| 58 | Biogeochemical cycles | 13 | 530 | 211 | 364 |
| 59 | Forest Ecology | 13 | 517 | 536 | 517 |
| 60 | soil microbiology | 13 | 516 | 758 | 986 |
| 61 | Marine Biology | 11 | 502 | 1702 | 1380 |
| 62 | emergency management | 21 | 496 | 149 | 185 |
| 63 | Geochemical Modeling | 9 | 490 | 161 | 159 |
| 63 | geological modeling | 9 | 490 | 240 | 181 |
| 65 | environmental issues | 8 | 459 | 208 | 120 |
| 66 | Geobiology | 8 | 441 | 283 | 179 |
| 67 | Geomagnetism | 23 | 439 | 242 | 293 |
| 68 | Plant physiology | 10 | 436 | 1374 | 1403 |
| 69 | Forest Management | 10 | 433 | 591 | 530 |
| 70 | polar regions | 13 | 431 | 294 | 237 |
| 70 | weather forecasting | 11 | 431 | 86 | 79 |
| 72 | Remote Sensing | 24 | 430 | 385 | 366 |
| 73 | Atmospheric Science | 15 | 423 | 47 | 57 |
| 74 | Medicine | 16 | 418 | 7308 | 7893 |
| 74 | Energy Policy | 6 | 418 | 2164 | 1774 |
| 76 | Environmental Toxicology | 8 | 414 | 1798 | 1585 |
| 77 | Biogeography | 7 | 411 | 740 | 800 |
| 78 | energy resources | 4 | 395 | 1339 | 1084 |
| 79 | Glaciology | 14 | 363 | 68 | 91 |
| 79 | glaciers | 14 | 363 | 64 | 89 |
| 81 | Geography | 9 | 355 | 1604 | 1204 |
| 82 | Ocean Engineering | 14 | 335 | 809 | 907 |
| 83 | extraterrestrial environment | 17 | 332 | 193 | 184 |
| 83 | astronomical phenomena | 17 | 332 | 178 | 167 |
| 85 | Plant diseases | 7 | 330 | 1557 | 1051 |
| 86 | plant communities | 6 | 324 | 900 | 857 |
| 87 | Light | 7 | 318 | 774 | 974 |
| 88 | Pharmacology | 3 | 298 | 6677 | 4142 |
| 89 | Plant cells | 5 | 287 | 1058 | 1339 |
| 90 | Sustainable Development | 3 | 286 | 2566 | 1367 |
| 91 | Economic Development | 2 | 280 | 2534 | 1236 |
| 91 | sustainability | 2 | 280 | 1221 | 671 |
| 93 | air quality | 8 | 279 | 62 | 51 |
| 94 | Toxicology | 3 | 278 | 5899 | 3826 |
| 95 | Geochemistry | 16 | 277 | 1108 | 1529 |
| 96 | Hydraulic Engineering | 1 | 268 | 1844 | 515 |
| 96 | Natural resources | 1 | 268 | 1551 | 510 |
| 96 | Hydrodynamics | 1 | 268 | 1067 | 367 |
| 99 | Botany | 12 | 265 | 2615 | 3043 |
| 100 | Developing countries | 11 | 258 | 1365 | 1458 |
| 101 | Solar Energy | 5 | 248 | 1570 | 1316 |
| 102 | Radio wave propagation | 11 | 231 | 374 | 297 |
| 103 | Biochemistry | 8 | 229 | 7447 | 7451 |
| 104 | Nutrition | 1 | 221 | 7901 | 3836 |
| 104 | Diet | 1 | 221 | 4280 | 2147 |
| 106 | Environmental pollutants | 9 | 208 | 1573 | 1949 |
| 107 | Artificial Intelligence | 2 | 203 | 5146 | 2586 |
| 108 | Electrical Engineering | 3 | 194 | 4115 | 1630 |
| 109 | Optics | 14 | 192 | 3052 | 2975 |
| 110 | Renewable Energy Sources | 4 | 190 | 2696 | 2914 |
| 111 | Geodesy | 9 | 187 | 373 | 441 |
| 112 | Soil Science | 6 | 186 | 1565 | 1599 |
| 113 | Plant Ecology | 6 | 182 | 1515 | 1740 |
| 114 | Physical Chemistry | 3 | 179 | 2728 | 1960 |
| 115 | air quality management | 10 | 176 | 192 | 405 |
| 116 | Environmental Management | 10 | 175 | 1879 | 3008 |
| 117 | coal | 3 | 172 | 1817 | 1581 |
| 118 | Ocean-atmosphere interaction | 13 | 171 | 29 | 25 |
| 119 | Marine Meteorology | 8 | 170 | 257 | 331 |
| 120 | Geographic information systems | 13 | 166 | 417 | 585 |
| 121 | Electronics | 2 | 165 | 4892 | 2429 |
| 122 | Marine Pollution | 7 | 158 | 890 | 1242 |
| 123 | Stochastic Processes | 1 | 156 | 1798 | 501 |
| 124 | pollutants | 8 | 151 | 1373 | 2009 |
| 125 | Water pollution | 7 | 137 | 2191 | 2973 |
| 126 | Soil biology | 5 | 136 | 828 | 1168 |
| 126 | Recycling | 1 | 136 | 1228 | 937 |
| 128 | Fluid Mechanics | 5 | 132 | 1599 | 1385 |
| 129 | China | 7 | 124 | 2294 | 2564 |
| 130 | actuators | 2 | 121 | 2980 | 2416 |
| 130 | transducers | 2 | 121 | 2980 | 2416 |
| 132 | Water | 6 | 120 | 2130 | 3097 |
| 133 | Microbiology | 3 | 119 | 7969 | 7703 |
| 134 | Ecosystem management | 4 | 117 | 684 | 735 |
| 135 | Continental shelf | 5 | 106 | 337 | 501 |
| 136 | Cosmochemistry | 4 | 103 | 959 | 1094 |
| 137 | Chemical Engineering | 2 | 102 | 5874 | 4864 |
| 137 | Molecular Biology | 2 | 102 | 10492 | 9435 |
| 137 | Metallurgy | 2 | 102 | 3501 | 2333 |
| 137 | Electrochemistry | 2 | 102 | 4831 | 3597 |
| 141 | Epidemiology | 4 | 99 | 4448 | 4696 |
| 142 | Wind power | 8 | 98 | 138 | 265 |
| 143 | Animal ecology | 2 | 94 | 1689 | 1316 |
| 143 | hazard mitigation | 2 | 94 | 1352 | 1040 |
| 145 | Agriculture | 8 | 93 | 1711 | 2548 |
| 146 | Technology | 5 | 92 | 4311 | 4438 |
| 146 | water supply | 5 | 92 | 842 | 1221 |
| 148 | Statistics | 2 | 89 | 3813 | 2455 |
| 149 | Radiochemistry | 6 | 87 | 886 | 809 |
| 150 | Occupational Health | 5 | 84 | 1079 | 1138 |
| 150 | occupational diseases | 5 | 84 | 858 | 1328 |
| 150 | environmental exposure | 5 | 84 | 1834 | 2610 |
| 153 | Analytical Chemistry | 4 | 83 | 4813 | 5155 |
| 154 | forestry | 5 | 79 | 200 | 285 |
| 155 | Clinical Immunology | 2 | 76 | 2048 | 1856 |
| 155 | Molecular Spectroscopy | 1 | 76 | 3169 | 2082 |
| 155 | Allergy | 2 | 76 | 1917 | 2185 |
| 158 | Nuclear Chemistry | 4 | 75 | 1201 | 985 |
| 159 | Microbial Ecology | 2 | 74 | 3325 | 3820 |
| 159 | Entomology | 1 | 74 | 4158 | 2341 |
| 161 | energy conservation | 4 | 71 | 2011 | 2928 |
| 162 | Paleontology | 1 | 66 | 2240 | 1442 |
| 162 | Climate Change Mitigation | 2 | 66 | 61 | 192 |
| 162 | Global warming | 2 | 66 | 185 | 216 |
| 162 | sea level | 2 | 66 | 61 | 192 |
| 166 | Biotechnology | 1 | 64 | 10153 | 8333 |
| 166 | Bioengineering | 1 | 64 | 7590 | 6364 |
| 166 | Cartography | 3 | 64 | 642 | 388 |
| 166 | air | 4 | 64 | 169 | 353 |
| 170 | Soil ecology | 2 | 63 | 1098 | 1254 |
| 171 | Environmental Chemistry | 4 | 60 | 2315 | 3343 |
| 172 | Combustion | 2 | 59 | 1718 | 1630 |
| 172 | environmental indicators | 3 | 59 | 1345 | 1944 |
| 174 | Mortgages | 1 | 57 | 439 | 286 |
| 174 | drug toxicity | 1 | 57 | 1108 | 818 |
| 176 | Nondestructive testing | 1 | 54 | 1370 | 852 |
| 176 | Structural health monitoring | 1 | 54 | 447 | 354 |
| 176 | structural stability | 1 | 54 | 912 | 642 |
| 179 | Transport | 1 | 53 | 1267 | 1091 |
| 179 | Sea | 1 | 53 | 1142 | 917 |
| 179 | Fishery resources | 1 | 53 | 1279 | 1010 |
| 179 | Fisheries | 1 | 53 | 3089 | 2202 |
| 183 | Palynology | 1 | 52 | 568 | 324 |
| 183 | place marketing | 1 | 52 | 237 | 263 |
| 185 | Environmental Microbiology | 1 | 50 | 2819 | 2820 |
| 185 | Medical Microbiology | 1 | 50 | 4532 | 4309 |
| 185 | Host-parasite interactions | 1 | 50 | 2508 | 2730 |
| 185 | Microorganisms | 1 | 50 | 2340 | 2422 |
| 185 | Virulence | 1 | 50 | 2272 | 2595 |
| 185 | biological monitoring | 3 | 50 | 584 | 937 |
| 185 | Immunity | 1 | 50 | 3565 | 3732 |
| 192 | Hypertension | 1 | 48 | 3111 | 3087 |
| 192 | Hemodynamics | 1 | 48 | 1251 | 1336 |
| 194 | Landscape Ecology | 3 | 47 | 557 | 926 |
| 194 | wind erosion | 1 | 47 | 264 | 244 |
| 196 | exobiology | 1 | 46 | 707 | 694 |
| 197 | Great Lakes | 1 | 44 | 494 | 399 |
| 198 | Paleoclimatology | 2 | 42 | 1453 | 1733 |
| 199 | Biophysics | 2 | 41 | 7949 | 8248 |
| 199 | Nanoelectronics | 1 | 41 | 1647 | 1092 |
| 199 | Microelectronics | 1 | 41 | 3117 | 2821 |
| 199 | Photogrammetry | 5 | 41 | 754 | 613 |
| 199 | Semiconductor industry | 1 | 41 | 1278 | 872 |
| 204 | Molecular Genetics | 1 | 38 | 3785 | 3790 |
| 204 | Population Genetics | 1 | 38 | 2320 | 2424 |
| 204 | Molecular ecology | 1 | 38 | 2085 | 2435 |
| 204 | Antarctica | 2 | 38 | 836 | 775 |
| 208 | Organic Chemistry | 1 | 37 | 5024 | 4497 |
| 208 | Bioorganic chemistry | 1 | 37 | 4629 | 4383 |
| 208 | Aquatic ecology | 2 | 37 | 1413 | 1567 |
| 211 | Shipping | 1 | 36 | 213 | 84 |
| 212 | Periglacial processes | 3 | 35 | 143 | 305 |
| 212 | Permafrost | 3 | 35 | 143 | 305 |
| 212 | Frozen ground | 3 | 35 | 146 | 305 |
| 215 | Public Policy | 1 | 34 | 3661 | 3336 |
| 215 | Systems Analysis | 1 | 34 | 2233 | 1756 |
| 215 | System analysis | 1 | 34 | 4572 | 3674 |
| 218 | primary prevention | 1 | 33 | 989 | 974 |
| 219 | Zoology | 3 | 32 | 3186 | 3693 |
| 219 | Waste management | 2 | 32 | 2057 | 2340 |
| 221 | indoor air pollution | 2 | 31 | 604 | 917 |
| 221 | Ventilation | 2 | 31 | 816 | 1069 |
| 221 | Sick building syndrome | 2 | 31 | 604 | 917 |
| 224 | Computational Fluid Dynamics | 1 | 30 | 1329 | 1161 |
| 225 | Dietetics | 4 | 29 | 905 | 1377 |
| 225 | Food | 4 | 29 | 3414 | 5593 |
| 227 | Chemical Oceanography | 1 | 28 | 585 | 757 |
| 228 | Public Health | 2 | 27 | 8911 | 10205 |
| 228 | Land use | 2 | 27 | 1629 | 2278 |
| 230 | Information Systems | 1 | 26 | 3096 | 2844 |
| 231 | Systems Biology | 1 | 25 | 3266 | 3529 |
| 231 | Hydrometeorology | 1 | 25 | 455 | 645 |
| 231 | Parasitology | 1 | 25 | 4234 | 4170 |
| 231 | Parasitic Diseases | 1 | 25 | 3929 | 4148 |
| 231 | disease vectors | 1 | 25 | 1965 | 2203 |
| 231 | Parasites | 1 | 25 | 3013 | 3039 |
| 237 | Civil Engineering | 2 | 24 | 2573 | 2320 |
| 237 | Aerospace Engineering | 2 | 24 | 508 | 476 |
| 239 | Pharmacognosy | 1 | 23 | 3365 | 3828 |
| 239 | Carbon | 2 | 23 | 1875 | 2864 |
| 241 | Environmental risk assessment | 1 | 21 | 996 | 1003 |
| 242 | Photography | 8 | 20 | 1392 | 1518 |
| 242 | Industrial Safety | 1 | 20 | 2552 | 2406 |
| 242 | Geodynamics | 1 | 20 | 1451 | 1610 |
| 245 | Biomass Energy | 1 | 17 | 4271 | 4893 |
| 245 | Municipal Engineering | 1 | 17 | 889 | 1043 |
| 245 | Mass Spectrometry | 3 | 17 | 1531 | 2636 |
| 245 | Biomass | 1 | 17 | 1355 | 1995 |
| 249 | Nuclear Physics | 2 | 16 | 5033 | 5596 |
| 249 | Underwater Archaeology | 1 | 16 | 287 | 195 |
| 249 | Ornithology | 1 | 16 | 1798 | 1742 |
| 249 | Birds | 1 | 16 | 2154 | 2010 |
| 253 | Water Purification | 1 | 15 | 2184 | 2508 |
| 253 | Water quality management | 1 | 15 | 3474 | 3833 |
| 255 | Information Theory | 1 | 14 | 2202 | 2204 |
| 255 | Quantum Optics | 1 | 14 | 1622 | 1705 |
| 255 | Building | 1 | 14 | 1292 | 1254 |
| 255 | Japan | 1 | 14 | 4079 | 3995 |
| 255 | Atomic spectroscopy | 1 | 14 | 2079 | 2241 |
| 255 | Laser Spectroscopy | 1 | 14 | 1540 | 1614 |
| 255 | Quantum theory | 1 | 14 | 1697 | 1753 |
| 262 | Paleoecology | 1 | 13 | 1754 | 2151 |
| 262 | Environmental Geology | 2 | 13 | 2207 | 3410 |
| 262 | Energy Consumption | 1 | 13 | 523 | 750 |
| 262 | Ecohydrology | 1 | 13 | 831 | 1016 |
| 262 | Paleogeography | 1 | 13 | 1567 | 1959 |
| 262 | Chromatography | 1 | 13 | 3141 | 3743 |
| 262 | Chromatographic analysis | 1 | 13 | 3573 | 4078 |
| 262 | freshwater biology | 1 | 13 | 1835 | 2182 |
| 270 | Psychiatry | 1 | 12 | 7911 | 8766 |
| 270 | Product life cycle | 1 | 12 | 702 | 1045 |
| 270 | green products | 1 | 12 | 615 | 972 |
| 270 | Mental illness | 1 | 12 | 4008 | 4927 |
| 270 | Evolution | 1 | 12 | 3611 | 4451 |
| 275 | Environmental Economics | 1 | 11 | 992 | 1219 |
| 276 | Sleep Disorders | 1 | 10 | 3312 | 3674 |
| 276 | Molecules | 1 | 10 | 2644 | 2855 |
| 276 | Sleep | 1 | 10 | 3323 | 3671 |
| 279 | Plant Pathology | 1 | 9 | 350 | 466 |
| 279 | Malaria | 1 | 9 | 1541 | 2185 |
| 281 | Engineering Geology | 1 | 8 | 2437 | 3044 |
| 281 | Sustainable urban development | 1 | 8 | 166 | 265 |
| 281 | greenhouse effect | 1 | 8 | 191 | 372 |
| 281 | Risk assessment | 1 | 8 | 1431 | 1961 |
| 281 | Carbon dioxide | 1 | 8 | 191 | 372 |
| 281 | city planning | 1 | 8 | 3065 | 3651 |
| 287 | Engineering Mathematics | 1 | 7 | 4448 | 4852 |
| 287 | Obesity | 1 | 7 | 3932 | 5462 |
| 289 | Global Health | 1 | 6 | 2576 | 3525 |
| 289 | Operations Research | 1 | 6 | 3744 | 4448 |
| 289 | Electromagnetic waves | 1 | 6 | 517 | 742 |
| 289 | Porous materials | 1 | 6 | 1493 | 2001 |
| 289 | management | 1 | 6 | 5999 | 7212 |
| 289 | winds | 2 | 6 | 181 | 414 |
| 295 | Computer Science | 1 | 5 | 4291 | 5143 |
| 295 | Geomorphology | 1 | 5 | 2317 | 3225 |
| 295 | animals | 1 | 5 | 2555 | 3373 |
| 298 | Marine Engineering | 1 | 4 | 653 | 770 |
| 298 | Naval Architecture | 1 | 4 | 690 | 958 |
| 298 | Measurement | 1 | 4 | 2501 | 3610 |
| 301 | Internet of Things | 1 | 3 | 1240 | 1913 |
| 301 | Numerical Analysis | 1 | 3 | 3905 | 4890 |
| 301 | Transportation | 1 | 3 | 2964 | 4118 |
| 301 | Multimedia Systems | 2 | 3 | 2422 | 4033 |
| 301 | Telecommunication | 1 | 3 | 4175 | 5114 |
| 301 | internet | 1 | 3 | 2476 | 3513 |
| 307 | Physiology | 1 | 2 | 7204 | 9459 |
| 307 | Emergency Nursing | 1 | 2 | 419 | 812 |
| 307 | Comparative Physiology | 1 | 2 | 1583 | 2243 |
| 307 | Diabetes mellitus | 1 | 2 | 4124 | 6001 |
| 307 | Schizophrenia | 1 | 2 | 2003 | 2831 |
| 307 | Primary health care | 1 | 2 | 3823 | 5763 |
| 307 | Radioisotopes | 1 | 2 | 2501 | 3462 |
| 307 | Spain | 1 | 2 | 1620 | 1846 |
| 307 | Europe | 2 | 2 | 5067 | 8377 |
| 307 | Radiation effects | 1 | 2 | 1321 | 2135 |
| 307 | Diabetes | 1 | 2 | 4209 | 6067 |
| 318 | Computational Biology | 1 | 1 | 5719 | 8014 |
| 318 | food contamination | 1 | 1 | 2199 | 3423 |
| 318 | Social Media | 1 | 1 | 448 | 721 |
| 318 | blogs | 1 | 1 | 16 | 60 |
| 318 | Detectors | 1 | 1 | 2008 | 3256 |
| 318 | Information Science | 1 | 1 | 4777 | 6895 |
| 324 | Systems Engineering | 1 | 0 | 3990 | 5763 |
| 324 | Planetary Science | 1 | 0 | 1052 | 1740 |
| 324 | Child | 2 | 0 | 3934 | 7249 |
| 324 | Moon | 1 | 0 | 423 | 713 |
| 324 | Adolescent | 2 | 0 | 3449 | 6583 |
