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Index

Absolute humidity, 184 Bureau of Meteorology voluntary observer Access and security, 163 network, 387 Accuracy, 47, 63 Bureau of Meteorology website, 374, 392 Accuracy versus precision Climate data, 374 Humidity, 190 Meteorological and Oceanographic Society, 424 Precipitation measurements, 162 Satellite estimation of solar radiation, 241 Sunshine and solar radiation sensors, 266 World record wind speed, 207 Wind sensors, 208 Automatic weather stations. See AWS Air conditioning - and pressure sensors, 171 Averages and extremes, 351 Air frost, 222, 344 Long-period climate data, 374 Definition, 300 AWEKAS (Automatisches WEtterKArten Air temperature System), 382 See Temperature AWS Alter wind shield, 154 Accuracy and precision, 46 Altitude. See Metadata Advanced systems, 72 American Meteorological Society, 423 Advantages and disadvantages, 34 Analogue input, 286 Archiving records, 336 Analogue output, 409 Backup, 345 Analysis and presentation of AWS Backup systems, 39 data, 337 Battery backup, 41 Anemometer, 196 Best-selling systems, 60 Cup, 196 Budget categories, 32 Distance constant, 414 Budgeting, 52 Effective height, 214 Cairn Gorm, Scotland, 205 Handheld, 203 Categories, 55 Propeller or windmill type, 199 Choice of, 32 Response length λ, 415 Climatological continuity, 51 Sonic, 200 Collecting and storing data, 335 Starting speed, 201 Computing facilities and expertise, 51 System description, 410 Connections – cabled or wireless?, 42 Aneroid barometer, 169 Data analysis and presentation, 337 APRSWXNET, 381. See Citizen Weather Data file sizes, 337 Observer Program Data volumes, 336 Archive interval, 284, 335, See Logging interval Definition, 7 Archiving data to e-mail, 346 Degree of automation sought, 46 Armagh Observatory, Northern Ireland, 22 Development in 20th century, 14 ASCII format files, 336 Ease of setting up, 51 ASOS – Automated Surface Observing Elements to be measured, 39 System, 97 Expansion options, 41 Aspirated screens, 93, 106 Export data function, 336 Advantages, 107 Exposure considerations, 38 Davis Instruments FARS shield, 111 Hardware survey, 75 Atmospheric pressure. See Pressure Hooke’s weather-clock of 1679, 9 Australia, 128 Legality of altering records, 338 Bureau of Meteorology, 374 Logging interval, 48

435

436 Index

AWS (cont.) Calibration, 304 Longevity, 64 Absolute and comparative methods, 307 Portable, 69, 70, 71 Anemometer, 320 Power, 52 Drift, 304, 318, 415 Purchasing, 55 Humidity sensors, 188–189 Radiation shield, 93, 105 Pressure sensors, 319 Reliability measures, 40, 48 Earth temperature sensors, 229 Sampling interval, 48 Humidity sensors, 189, 318 School weather studies, 29 Inclusion in archived files, 338 Schools, colleges and universities, 5 Interval, 309 Selection and decision criteria, 37 One-minute summary, 320 Sensor accuracy, 67 Other sensors, 320 Sensor choice, 42 Portable calibration reference units, 69 Sensor exposure, 39 Pressure sensors, 176, 180, 319 Single-element systems, 61 Raingauge, 304 Software, 283 Raingauge measuring cylinder, 306 Cumulus, 290 Solar radiation and sunshine sensors, 258 Most popular (2011 survey), 289 Temperature, 310 Virtual Weather Software, 289 Temperature sensors, 307 Weather Display, 291 Multiple points, 309 Weather Link, 292 Tipping-bucket raingauge Weather Underground, 292 Variation with rainfall intensity, 305 Software suppliers, 434 Wind sensors, 208 Software survey, 75, 282, 289, 336 Calibration check, 64, 69 Software comparison, 290 Calibration table, 309 Support options, 56 Calibration table, thermometer, 310, 314, 315 Transition from traditional instruments, 26 Calibration thermometer, 309 User profiles, 56 Calm, 202 Uses of, 33 Campbell Scientific, 33, 57–58, 70–73, 105, 429 Website, 378 Campbell-Stokes sunshine recorder, 245, 246, Working lifetime, 48 249, 258 AWS datasets Disadvantages, 247 Hourly, daily and monthly examples, 338 Canada, 128 Climate data, 374 Backup, 337, 344, 345, 346, 353 Canadian Meteorological and Oceanographic Backup software, 345 Society, 423 Bare soil minimum temperature, 226 CD-ROM. See Backup Barograph, 11, 169, 171 Celsius (unit of temperature), 89 Barometric pressure. See Pressure Celsius, Anders, 17 Battery backup, 41, 283, 288 Central England Temperature (CET) series, 15 Beaufort wind scale, 203, 204, 358 Central European Time (CET), 271 Wind speed equivalents, 203 Central Park, New York, 25, 375 Belfort Instrument Company, 151 Chilterns Observatory Trust, 336, 346, 428 Binary coded input to datalogger, 286 Chinese Meteorological Society, 424 Blank cells. See Missing data convention Choosing a weather station Blogs and newsgroups, 383 One-minute summary, 53 Blue Hill Observatory, Massachusetts, 25, 257 Citizen Weather Observer Program (CWOP), 381 British Rainfall, 376, 392 Civil day, 273, 278 Bubbling (of spirit minimum thermometers), 226 Class sizes. See Microsoft Excel Budget, 52 Climatological continuity, 51 Budget systems, 64 Climatological Day, 274, 294 Buying a weather station, 55 Climatological Observers Link One-minute summary, 74 Forum, 384 Climatological Observers Link (COL), 81, 280, 336, Cabled connections 344, 376, 384, 392, 428 Cable specifications, 45 Web Forum, 384 Screened cable, 45 Shelter assessment, 83 Cadiz Royal Observatory, Spain, 258 Site grading scheme, 81, 82 Cairn Gorm AWS, 205 Cloud amount and type/s, 296

Index 437

Cloud storage, 346 Davis Instruments FARS shield, 111 CoCoRaHS, 385 Day maximum / night minimum, 275 Collecting and storing data, 335 Daylight Savings Time, 271 One-minute summary, 346 Advantages of consistent regional time, 272 Comma Separated Variable (CSV) files, 336 Days with, 298, 343 Communication options (datalogger), 288, 289 Definitions, 299 Components of a measurement system, 409 Dependent variables, 357 Computer connection. See PC connection Dew point Concrete minimum temperature, 226 Electrical sensors, 188 Conditional formatting. See Microsoft Excel Dew point and human comfort, 187 Cooperative Observer Program (COOP), 388 Dew point temperature, 183, 184 Coordinated Universal Time (UTC), 271 Dewfall in raingauge, 300 Cotton Region Shelter, 94 Diamond dust. See Ice crystals Cumulus AWS software, 289, 290 Diffuse solar radiation, 235 Cup anemometer, 196. See Anemometer Digital or pulse inputs to datalogger, 286 CWOP, 291, 381. See Citizen Weather Observer Direct solar radiation, 235 Program Distance constant. See Anemometer Distilling observations, 339 Daily dataset layout and format, 342 Dropbox, 346 Daily observational routine, 295 Dry bulb temperature, 116, 183 Data archiving. See Collecting and storing data Dynamic performance, 412 Data display, 289, 409 Data loss risks from datalogger failure, 288 Earliest weather observations, 7 Data management and analysis, 348 Earth temperatures Data storage, 409 Logging interval, 230 Data transmission, 409 One-minute summary, 230 Data volumes. See AWS: Data volumes Standard depths and measurement Datalogger, 282 methods, 228 Alternatives to, 287 Effective height (anemometer), 214 Battery backup, 283 Electronic sunshine sensor, 245, 249 Communication options, 288 Operating principles, 249 Dedicated, or PC, 45 E-mail as data archive, 346 Download interval vs memory capacity, 285 Entry-level systems, 61 Download schedule, 289 Environment Canada, 374 Event-based, 284 Error checking, 338 Input types, 286 European Meteorological Society, 425 Memory, 73, 284 Event-based datalogger, 284 Physical capacity, 73 Event-based rainfall logging, 157 Power supply, 283 Exporting AWS data, 336 Programming, 287 Exposure, 76, 415 Risks, 288 Air temperature and rainfall, 77 System design, 410 Assessing and grading, 81 Time-based, 284 Assessing shade impact on solar radiation Tinytag, 285 sensors, 261 Datalogger basics, 282 Definition, 76 Dataloggers and AWS software Differing requirements by sensor, 76 One-minute summary, 292 Earth temperature sensors, 229 Date Shelter ratio, 81 Formatting options, 340 Site survey, 78 Date conventions, Europe and US styles, 290 Solar radiation and sunshine sensors, 260 Davis Instruments, 33, 60, 66, 429 Summary requirements by element, 79 Anemometer and Hurricane Andrew, 1992, 207 Sunshine, 77 Estimation of sunshine duration, 256 Urban profile, 81, 84 Fan-assisted radiation shield (FARS), 111 Website information, 380 Passive radiation screen, 105 Wind instruments, 77, 195, 208 Solar radiation sensor, 238 Vantage Connect, 292 Fahrenheit (unit of temperature), 89 Vantage Pro2, 57–58, 60, 66, 75, 220 Fine Offset, 57–58, 60, 430 Raingauge calibration, 306 Fischer & Porter weighing raingauge, 151 Vantage Vue, 57–58, 65, 75 Five-inch raingauge, 391 WeatherLink software, 292, 337, 345 Float raingauge, 148

438 Index

Fog Humidity, 183 Definition, 296, 301 Accuracy versus precision, 190 Thick (definition of), 301 Calculation by datalogger, 191 Foster-Foskett sunshine switch, 245, 250, 257 Comfort levels, 186 Cessation of records, 251 Definition, 183 Threshold, 250 Electrical sensors, 187 France Hygroscopic effects on sensors, 189 Raingauge network, 130 Hysteresis, 414 Société Météorologique, 426 Logging requirements, 189 Franklin, Benjamin, 388 Measurement, 185 Mixing ratio, 184 Gale One-minute summary, 190 Definition, 299 Online calculator, 185, 191 Gemini Instruments, 69, 430 Sensor filter, 188, 189 Geonor weighing-bucket raingauge, 151 Sensors Germany Calibration drift, 188–189 Deutsche Meteorologische Gesellschaft, 426 Site and exposure requirements, 188 Raingauge network, 130 Terms, 183 Gifts - weather stations as gifts, 59 Tracking airmasses, 186 Global solar radiation, 235 Variation with temperature, 184 GMT, 271 Ventilation effects, 191 Google Earth, 323 Hygrograph, 186 Grass minimum, 222 Hysteresis, 414 Daytime exposure, 226 Depression, 224 Ice crystals, 300 Exposure, 223 Ice days, 344 Logging interval, 227 Ice needles. See Ice crystals One-minute summary, 230 Ice pellets, 299 Sensor requirements, 223 Ice prisms. See Ice crystals Terminal hours, 273, 278 Ice/water calibration, temperature sensors, 308 Greenwich Mean Time (GMT), 271 Ice-bulb, 186 Ground frost, 222, 344 Ice-point calibration, 225 Definition, 222, 300 iDrive, 346 Gust ratio, 198 Illuminance, 236 Gust speeds, 194 India Gusts Raingauge network, 130 Archiving gust speeds, 343 Indian Meteorological Society, 424 Corrections for height, 213 Information exchange, 384 Definition, 198 Infrared radiation, 234 Measurement, 198 Installation Sampling interval, 48, 198 Safety, 78 Instromet sunshine recorder, 251 Hail Instromet Weather Systems, 431 Definition, 300 Ireland Hailgauge, 300, 301 Met Éireann co-operating observer network, 391 Hair hygrograph. See Hygrograph Irish Meteorological Society, 427 Handheld anemometer, 203 Raingauge network, 130 Heat index formulae, 187 Irradiance, 236 Height corrections Wind sensors, 213 Japanese Meteorological Society, 424 Hohenpeißenberg, Germany, 20 Jefferson, Thomas, 388 Holm, John Campanius – weather records 1644–5, 7 Jordan photographic sunshine recorder, 245, 257 Hong Kong Meteorological Society, 424 Kestrel 4000 portable AWS, 71 Observatory, 109–110 Kestrel portable AWS, 203 Hooke, Robert, 8, 9 Kipp & Zonen, 240, 431 Weather clock of 1679, vi, 151 CMP3 pyranometer, 240 Hot days, 344 CSD sunshine recorder, 249, 253 Hourly data spreadsheet, 339 Knot, 194 Hourly dataset layout and format, 340 Koninklijk Nederlands Meteorologisch Instituut Howard, Luke, 9 (KNMI), 374

Index 439

La Crosse, 33, 56–58 Maximum thermometer, 116 Lag. See Sensor lag Resetting, 117 Latitude and longitude. See Metadata Medici network, 14 Legal isues when altering AWS data, 338 Memory Lightning risks, 80, 212, 288 Datalogger, 284 Linear system, 411 Memory stick. See Backup Linux software, 283 Memory, non-volatile, 282 Liquid-in-glass thermometers, 115 Mercury Local Apparent Time (LAT), 266 Safety restrictions, 169 Local time, 271 Mercury barometer, 169 Logging interval, 48, 284 Merle, William – weather diary 1337–44, 7 Earth or soil temperature, 227, 230 Met Éireann, 391 Grass minimum, 227 Met Office Multiple, 335 Archives and National Meteorological Logging requirements Library, 376 Solar radiation and sunshine sensors, 265 Data Policy, 375–376 Wind sensors, 217 Weather Observations Website (WOW), London Grid for Learning (LGfL), 382 291, 382 Long-period weather records, 14 Metadata, 322, 323 Armagh Observatory, Northern Ireland, 22 Definition, 322 Blue Hill Observatory, Massachusetts, 25 Elements to include, 322 Central England Temperature (CET) series, 15 Example documentation, 322 Central Park, New York, 25 Examples, 326, 327 Chapel Hill, North Carolina, 24 Format, 323 Des Moines, Iowa, 24 Importance, 322 Hohenpeißenberg, Germany, 20 Observing hours, 323 Milan, Italy, 19 One-minute summary, 326 Minneapolis, Minnesota, 24 Site location details, 323 Padua, Italy, 17 Website information, 379 Philadelphia, Pennsylvania, 24 WMO guidelines, 322 Prague, Czech Republic, 19 METAR, 381 Radcliffe Meteorological Station, Oxford, Metrology, 409 England, 23 Metspec, 96, 431 San Francisco, California, 24 Microsoft Excel, 337, 348, 349 Stockholm, Sweden, 17 Autosave, 353 Subiaco Abbey, Arkansas, 26 Class sizes, 360 Uppsala, Sweden, 16 Climatological functions, 351 Lookup table. See Microsoft Excel Conditional formatting, 358, 359 Louvred screen Dataset sizes, 356 Stevenson screen and Cotton Region Examples of climatological analyses, 361 Shelter, 94 Filtering, 356 Functions, 355 Manley, Gordon, 15, 26 Graphing, 351 Mannheim hours, 21 Lookup table, 357, 358 Manual observations, 294 Pivot tables, 361 Inclusion in datasets, 342 Sorting, 353 Storing, 336 Tips, 351, 353, 360 Maplin Electronics AWS, 33, 57–58 Mid-range AWS systems, 66 Maring-Marvin thermoelectric sunshine sensor, Milan, Italy, 19 250, 257 Minimum temperature Marvin sunshine sensor. See Maring-Marvin Air or screen minimum, 114, 342 Maximum air temperature, 342 Bare soil minimum, 226 Maximum and minimum air temperatures, 118 Concrete minimum, 226 Terminal hours, 273 Grass minimum, 222 Maximum and minimum thermometers Night minimum, 276 Calibration, 313, 314 Tarmac minimum, 226 Maximum Minimum Temperature System Minimum thermometer, 116 (MMTS). See MMTS Resetting, 117 Maximum temperature Missing data convention, 338 Day maximum, 276 Mission-critical systems, 50 Period of, 274 MMS – Meteorological Monitoring System, 99

440 Index

MMTS – Maximum-Minimum Temperatures Definition, 125 System, 97 Ireland, 128 Monthly data spreadsheet, 344 Long-period rainfall records, 128 Monthly Weather Report, 376 Measurement, 124 Morning observation, 294 Measurement and observing standards, 163 Mount Washington Observatory, New Observation times, 127, 163 Hampshire, 207 Shelter effects, 125 Mt Everest AWS, 3 Site and exposure requirements, 130 Snowfall equivalents, 160 National Climatic Data Center (NCDC), 375, 388 Splash height, 126 National Weather Service (NWS), 388 Terminal hours, 279 Netherlands ‘Throwing back’, 163 Climate data, 374 Traces, 136 Raingauge network, 130 United Kingdom, 128 New Zealand United States, 128 Climate data, 375 Units, 125 New Zealand Meteorological Society, 425 Litres per square metre, 125 Nielsen-Kellerman, 33, 60, 432 Variability, 124 Nipher wind shield, 153 Worldwide raingauge networks, 127 Non-instrumental weather observing, 294 Precipitation gauges. See Raingauges One-minute summary, 302 Precipitation measurement Non-volatile memory, 282 One-minute summary, 164 North – finding True North, 216 Reference method, 304 North wall exposure, 63 Precision versus accuracy, 47, 180, 304 Present weather Observations at set times, 294 WMO code, 297 Observing hours and time standards, 271–272 Present weather sensors. See Optical raingauge Air temperatures, 120 Preserving your observations, 344 Metadata, 324 Pressure, 167 One-minute summary, 280 Altitude corrections for aviation, 180 Occurrence frequencies, 298 Aneroid barometer, 169 Okta, 296 Aviation Q codes, 173 One-minute summary Barometer correction table, 175, 177, 179 All chapters combined, 393 Calibration, 180 Optical raingauges, 152 Calibration drift, 171, 319 Oregon Scientific, 33, 57–58, 60, 432 Correction for altitude, 173 Overlapping traditional and AWS records, 51 Definition, 167 Oxford, Radcliffe Meteorological Station, 23, 258 Electronic pressure sensor, 170 Hours of observation, 180 Padova (Padua), Italy, 17 Logging requirements, 172 PC connection, 62 London records, 1692 onwards, 169 Percentage of maximum possible sunshine, 234, 245 Mean Sea Level (MSL), 167 Period of record, 324. See Metadata Measurement, 168 Photographic weather records, 298 Mercury barometer, 169 Photographs. See Metadata One-minute summary, 181 Site and instruments, 323 Paris records, 1670 onwards, 169 Photometric measures, 236 Precision versus accuracy, 180 Pivot tables. See Microsoft Excel Semi-diurnal cycle, 180 Planning permission (wind instruments), 211 Sensor exposure and restrictions, 170 Platinum resistance thermometer (PRT), 117, Sensors, 171 118, 411 Static port, 171 Calibration, 309 Station level pressure (SLP), 173 Portable calibration reference units, 69 Terminal hours, 273 Portable weather stations, 69 Units, 169 Power supply for dataloggers, 283 Wind effects, 172 Prague, Czech Republic, 19 Privacy, in metadata descriptions, 323 Precipitation Programming dataloggers, 287 Accuracy of measurements, 125 Providing observations to official bodies, 385 Accuracy versus precision, 162 Psychrometer (dry- and wet-bulb), 185 Australia, 128 Pulse inputs to datalogger, 286 Canada, 128 PWSweather, 382

Index 441

Pyranometer, 237, 258 Small Double Fence Intercomparison Estimates of sunshine duration, 255, 417 Reference, 155 Exposure, 261 Tretyakov, 155 Key specifications, 239 Turf wall, 156 Performance in darkness, 241 WMO Double Fence Intercomparison Pyrheliometer, 236, 244, 258 Reference, 155 Raingauge suppliers. See Appendix 4 Q codes, 173 Raspberry Pi PC, 283 QFE, 173 Relative Humidity (RH), 183, 184 QFF, 174 Resistance Temperature Devices (RTDs), 117 QNH, 174 Response length λ, 415 Response time, 412, 413. See also Time constant Radcliffe Meteorological Station, Oxford, Thermometer screens, 412 England, 23 Wet bulb thermometer, 186 Radiation shield. See Thermometer screen Responsiveness Radio frequency interference (RFI), 288 In air temperature measurements, 114 RFI choke, 288 Riming, 205 Radiometric measures, 236 Robinson, Thomas Romney, 22 Rain day Roughness length z0, 213 Definition, 300 Royal Meteorological Society, 385, 428 Rain days, 344 Raingauge Safety, 78, 264, 265 Accessories required, 156 Installing and maintaining weather instruments, Aerodynamic, 156 209 Agreement between raingauges, 143 Sample Excel data templates, 340 Calculating funnel capacity, 306 Sampling and logging intervals, 335 Calibration, 156, 304 Sampling interval, 48, 284 Capacity, 140 Budget systems, 65 Combinationtipping-bucket–weighingmodels,151 Mid-range systems, 68 Country densities, 130 Wind gusts, 48, 199, 217 Design, construction and materials, 127 Sandaysoft, 383 Eight-inch, 305 Satellite estimation of solar radiation, 241 Event-based rainfall logging, 157 Scalar wind speed. See Wind speed Five-inch, 138, 305 Screen. See Thermometer screen Float gauges - Dines tilting-siphon gauge, 149 Screened cable, 45 Ground-level or pit gauge, 126, 130, 153 Sensor (definition), 409 Height above ground, 126 Sensor characteristics, 411 Height of the raingauge rim, 133 Sensor comparisons, 415 Importance of level rim, 127 Sensor lag, 412, 415 Logging requirements, 157 Sensors Manual, 136 Specifications, 57–59 Measuring cylinder, 139 Serial port. See PC Connection Optical, 152 Setting a barometer. See Pressure: Correction for Recording, 141 altitude Shallow-funnel type, 139 Sharing observations, 378 Shelter height-distance ratio, 133 One-minute summary, 391 Tipping-bucket, 42, 141, 411 Shelter Effects Common problems, 144 On air temperature measurements, 92 Loss in high-intensity rainfall events, 146 On precipitation measurements, 125 Snowfall, 144 On sunshine and solar radiation measurements, Stray pulses, 148 260–261 Types, 128, 135 Shelter ratio, 81 U.S. plastic model, 137 Signal processing, 409 U.S. standard, 136 Site, 76 UK and Ireland standard, 138 Access restrictions, 80 Vibrating-wire, 151 Definition, 76 Weighing, 150 Description, 324 Wind effects, 153 Geographical context, 324 Wind shield, 153 Map, 323. See also Metadata Alter, 154 Security, 264 Nipher, 153 Site and exposure, 63

442 Index

Site and exposure (cont.) Stefan’s law, 234 One-minute summary, 85 Stevenson screen, 9, 10, 93, 94, 412 Requirements and tolerance, 130–135 Plastic (Metspec), 96 Six, James Stevenson, Thomas, 10, 94 Maximum-minimum thermometer, 9 Stockholm, Sweden, 17 Skin temperature. See Grass minimum temperature Storage media lifetimes, 345 Smartphones, 378 Strathfield Turgis Smithsonian Institution, 24 Raingauge comparisons, 134 Snow core measurements, 161 Thermometer screen comparisons, 11 Snow depth measurements, 160 Subiaco Abbey, Arkansas, 26 Snow grains, 299 Summer Time, 271. See also Daylight savings time Snow lying Sunshine Definition, 300 Definition, 242 Snow or sleet Estimates from pyranometer, 255 Definitions, 299 Percentage of maximum possible, 234, 245 Snow pellets, 299 Terminal hours, 273 Snowdon raingauge, 138 Sunshine and solar radiation, See Solar radiation Snowfall and sunshine sensors Measurements with recording Sunshine recorder, 245 raingauges, 162 Blake-Larsen, 254 Precipitation measurements, 160 Campbell-Stokes, 246 Procedure for grass-tip thermometers, 225 Comparison between types of, 255 Snowfall equivalents of precipitation, 160 Exposure, 260 Snowfall measurement, 159 Foster-Foskett, 250 Societas Meteorologica Palatina observation Haenni, 254 network, 20 Instromet, 251 Soil temperature. See Earth temperature Jordan, 245 Solar and terrestrial radiation wavelengths, 234 Kipp & Zonen, 253 Solar constant, 235 Principles, 236 Solar elevation diagram, 261 Threshold, 245 Solar power, 52 Sunshine records Solar radiation Compatibility over time, 257 Atmospheric absorption, 235 Sunshine records using a pyranometer, 417 Daily totals (derivation of), 265 Suppliers of meteorological instruments. See Definitions, 233 Appendix 4 Direct Support (from supplier or manufacturer), 56 Measurement, 236 Switzerland Estimation from satellites, 241 Raingauge network, 130 Global System setup and configuration, 289 Measurement, 237 Sensors, 238 Tarmac minimum temperature, 226 Terminal hours, 273 Technical support, 56 Units, 234 Technoline, 33, 56–58, 62 Solar radiation and sunshine sensors, 232 Temperature, 89 Calibration, 258 Air Exposure Site and exposure requirements, 91 Levelling, azimuth and latitude Standard observing periods, 274 adjustments, 264 Air temperature measurements – One-minute Logging requirements, 265 summary, 120 Measurement methods, 235 Aspirated, 93 One-minute summary, 267 Definition, 89 Site and exposure requirements, 260 Earth temperatures, 228 Time standards, 266 Effects of shelter, 92 Solar UV Index (UVI). See Ultraviolet Factors influencing air temperature, 90 Solarimeter. See Pyranometer Grass and Earth, 222 Sonic anemometer, 200, 201 Height above ground, 91 Spares, 69 Hours of observation, 91 Specific humidity, 184 Logging requirements, 119 Starting speed (anemometer), 201 Measuring air temperature, 89 Static performance, 411 Radiation shield, 66, 67 Static port, 171. See Pressure Representative measurements, 93

Index 443

Sampling and logging intervals, 114 Tornado and Storm Research Organisation Sensor response time, 412 (TORRO), 385, 428 Sensor shielding, 63 Towneley, Richard, 9 Sensors, 115 Trace (of precipitation), 136 Units, 89 Transducer (definition), 409 Terminal hours, 272, 313 Tretyakov wind shield, 155 Civil day, 273 True solar time, 266. See Local Apparent Time Climatological day, 274 Tufte, Edward, 371, 377 Differences in extreme temperatures, 277 Turf wall raingauge shield, 156 Effects on mean temperature, 278 Grass minimum, 278 U.S. Climate Reference Network, 99 Incompatibility in temperature U.S. Historical Climate Network (HCN), 389 observations, 276 U.S. Regional Climate Reference Network, 102 Precipitation, 279 U.S. Weather Bureau, 24, 388 Survey of, 280 UK Weatherworld, 384 Synoptic observations, 275 uk.sci.weather, 384 Variation by element, 273 Ultraviolet (UV) radiation, 234 Wind observations, 219 Measurement and units, 242 Thermistor, 117, 119 Unit conversions, 420 Thermograph, 11, 119 United Kingdom Thermometer Climate data, 375 Calibration checks, 117 Raingauge network, 130 History, 8 United States Mechanical sensors, 119 Climate data, 375 Resistance Temperature Devices (RTDs), 117 Observing network population, 103 Sheathed, 116 Raingauge network, 130 Thermometer screen, 93 Units, 7, 89, 325, 339, 410 Blackened interior, 105 Precipitation, 125 Campbell Scientific Met21 screen, 70, 105 Pressure, 169 Choosing, 113 Solar radiation, 234 Comparisons, 94, 112 Sunshine, 234 Cotton Region Shelter, 94–96 Wind speed and direction, 194 Davis Instruments passive screen, 105 Uppsala, Sweden, 16 Differences between types, 109 USA In hot, dry climates, 110 Raingauge network, 130 Installation and maintenance, 103 USB. See PC connection Response time, 412 USB ‘dropouts’, 288 Self-assembly, 103, 104 USB port connection to datalogger, 288 Stevenson screen, 94–97 USCRN, 99, 415 Thatched, 109 USRCRN, 99, 102 Thermopile. See Pyranometer UTC, 271 Thick fog, 301 UV-A, UV-B and UV-C, 242. See Ultraviolet Throwing back Maximum temperature, 274, 342 Vaisala Oyj, 433 Precipitation, 163, 279 Vapour pressure, 183 Thunder heard Saturation vapour pressure, 183 Definition, 299 Vector Instruments, 434 Tilting-siphon rain recorder, 149 Cup anemometer A100, 197 Time constant, 114, 412 Vector mean wind, 217, 341, 416, 418 Time periods for daily observations. See Terminal Vereniging voor Weerkunde en Klimatologie, hours VWK, 427 Time standards and terminal hours, 271 Virtual Weather software, 289, 291 Time-based datalogger, 284 Visibility, 296 Tinytag logger, 69, 285, 310 Visibility objects, 296, 297 Earth temperature sensor, 230 Vlaamse Vereniging voor Weerkunde (VVW), 425 Use in calibration, 310 Voluntary observer programmes Tipping-bucket raingauge, 141, 411 Co-operating observers network, Ireland, 391 Calibration, 304 U.S. cooperating observers network, 388 Invention, 9 UK co-operating observers network, 390 Upgrading, 42 Voluntary observer rainfall network, UK, 391 Voluntary observers, 385

444 Index

Washington, George, 388 Wind sensors Weather Channel blog, 384 Accuracy versus precision, 208 Weather diary, 302 Calibration, 208 Weather Display software, 289, 291 Choosing, 205 Weather newsgroups, 383 Corrections for height, 213 Weather Observations Website WOW, 81, 291, 382 Exposure, 208, 211 Weather Underground, 289, 291–292, 381, 383 Height corrections, 214 Weather websites, 378 Installation and maintenance, 212 WeatherLink, 289, 292 Logging requirements, 217 WeatherLinkIP, 292 Masts and fittings, 216 Webcams, 298 Safety aspects, 209 Websites Severe weather performance, 205 AWS website, 378 Wind vane alignment, 215 Data aggregation, 380 Wind shields. See Raingauge: Wind shield Week numbers, 365 Wind speed, 194 Weerspiegel. See Vereniging voor Weerkunde Gust, 194 Weighing raingauge, 150 Gusts Wet bulb temperature, 116, 183, 185 Sampling interval, 195 Wet day Mean, 194 Definition, 300 Terminal hours, 273 Wien’s law, 234 Variation with height, 213 Wind World record, 207 Beaufort wind scale, 203 Wind speed and direction, 192 Data tabulations, 218 Measurements and sensors, 196–205 Definition, 193 One-minute summary, 219 Gusts Wind vane, 204 Sampling interval, 199 Alignment, 215 Measurement methods, 195 Wind velocity, 194 Terminal hours, 219 Wireless Units, 194 Statutory regulations, 43 Vector quantity, 194 Transmission and reception ranges, 43 Wind direction, 195 Wireless connections See AWS – Connections Degree equivalents, 195 Wireless range, 43, 64, 66, 68 Measurements, 204 World Meteorological Organization Modal, 217 (WMO), 6 Vector mean, 217 WOW. See Weather Observations Website Wind power, 52 Wren, Christopher, 8, 9 Wind roses, 373 Wind run, 217 Zoning permission, 211