1、DC 001.6(08):003.62:550.3:551.5 DEUTSCHE NORM September 1989 Letter symbols for physical quantities Symbols for use in meteorology and geophysics DIN - 1304 Part 2 Formelzeichen; Formelzeichen fr Meteorologie und Geophysik Supersedes DIN 1358, July 1971 edition. In keeping with current practice in s
2、tandards published by the International Organization for Standardization (ISO), a comma has been used throughout as the decimal marker. Contents 1 Scope and field of application . 1 2 Tables 1 2.1 Meteorology in general . 2 2.2 Thermodynamics, humidity and cloud physics . 4 2.3 Radiation . 7 2.4 Atm
3、ospheric electricity . 9 2.5 Mechanics and seismics 10 2.6 Figure and gravity field of the Earth 10 2.7 Earths magnetism 13 Standards and other documents referred to . 15 Other relevant standard . 15 Previous edition . 15 Amendments . 15 Page 1 Scope and field of application In conjunction with DIN
4、1304 Part 1, this standard specifies letter symbols for quantities specific to meteorology and geophysics. Letter symbols specified in DIN 1304 Part 1 have been included here only as far as their meaning differs or has been restricted. Instead of the units given in the SI unit column of tables 1 to
5、7, other units specified in the present standard and in DIN 1301 Part 1 may be used. The SI units stated here are only intended for the identification of quantities. 2 Tables See clause 3 of DIN 1301 Part 1, March 1994 edition, for rules of using letter symbols. Continued on pages 2 to 15. Beuth Ver
6、/ag GmbH, Berlin, has the exclusive right of sale for German Standards (DIN-Normen). DIN 1304 Part 2 Engl. Price group 14 05.95 Sales No. O1 14 Page 2 DIN 1304 Part 2 2.1 Meteorology in general Table 1 No. Symbol Quantity SI unit Remarks 1.1 1.2 1.3 - - 1.4 AT temperature advection Kls The advection
7、 of a scalar quantity C can generally be ex pressed by A,= - v. VG, with Y as in No. 1.23; ci No. 1.41. vorticity advection S-2 Jlkg available portion of specific potential energy soil density of heat flow rate WIm2 Rate of heat flow in the soil (positive in the direction to wards Earths surface). D
8、ensity of heat flow flux due to heat conduction and con vection in the atmosphere. 1.5 4s sensible density of heat flow rate W/m* 1.6 41 latent density of heat flow W/m2 Rate of heat flow due to transfer of latent heat. 1.7 1.8 - - 1.9 Bo Bowen ratio 1 Ratio of the rate of sensible heat flow to late
9、nt heat flow rad/s f = 2 w sin 9, where 9 is the latitude and with w as i No. 6.42. Coriolis parameter Rossby parameter af 6 = - (gradient of Coriolis parameter), where y is the geographical coordinate directed North. Phase velocity of the Rossby waves: cRo = - A)*, where A is the wavelength 1) of t
10、he Rossby waves and with as in No. 1.24. ay rad/(m . s) 1.10 cRo Rossby velocity mls 1.11 critical wavelength wavelength of streamlines m m 1.12 Averaged over latitude q. 1.13 wavelength of trajectories m 1.14 1.15 - - 1.16 1.17 - stationary wavelength m B half width m Horizontal distance between th
11、e point of maximum veloc ity of fluid flow and the point where the velocity is half it! maximum value. P atmospheric pressure density of air radius of the streamline at point under consideration Pa kglm3 m 1 mbar = 1 hPa. Q 1.18 1.19 radius of the trajectory at point under consideration m 1.20 1.21
12、- - 1.22 orthogonal radius m (t, n) form a right-handed system; cf. DIN 1312. t 1 unit vector tangential to, and in the direction of, the streamline unit vector normal to the streamline n 1 1.23 21 wind speed mis l) In meteorology, the wavelength is often denoted by L. (continued) DIN 1304 Part 2 Pa
13、ge 3 Table 1 (continued) - No. Quantity SI unit Remarks Symbol 1.24 - U mean western component of the wind velocity along a par- allel of latitudez) mls Directed East. 1.25 VG speed of the gradient wind mls In the direction of u,: cf. No. 1.26. 6 Anticyclonic: 2 cyclonic: with r, as in No. 1.19 and
14、as in No. 1.17. 1.26 - 1.27 1.28 - - 1.29 speed of the geostrophic wind mls For a gradient wind when the isobar is a straight line, Hpx k 3) at constant height H, with e as in 1 No. 1.17. Gradient wind for zero Coriolis acceleration. vg =-v ef speed of cyclostrophic wind speed of thermal wind mls ml
15、s Vector difference between the velocities of the geo strophic winds on the geopotential surfaces W, and W,: qh = - k 3, x V, (W, - W, ) at constant pressure p. 1 f Vth vis speed of isallobaric wind rnls The speed of isallobaric wind, .e. wind due to changes i pressure, is expressed by: e as in No.
16、1.1 7). 1.30 speed of ageostrophic wind mls g v =Y-v ag 1.31 VF speed of a front mls The speed of a warm front or a cold front. 1.32 - 1.33 drag coefficient 1 L CD = 7 , where T is the shear stress; v, is the horizontal wind and with e as in No. 1.17. u* = E, with c as in No. 1.17. .vh U* drag veloc
17、ity mls 1.34 1.35 - - 1.36 z m height above ground mixing height roughness height z* m Cf. No. 1.50. zo =zexp - vhu,“, with Ka as in No. 1.50. For u, see No. 1.32. m 1.37 M Monin-Obukhov length m Length of stability. 1.38 aJ velocity potential m2/s v = V (cf. DIN 5492). 1.39 1.40 1.41 1.42 - - WM Jl
18、kg Montgomery stream function circulation speed vorticity absolute vorticity VC m Is s- t 1 S- v=C+f 2, In meteorology often referred to as zonal wind speed 3, k is the vertically directed unit vector: cf. DIN 1303. (continued) Page 4 DIN 1304 Part 2 Table 1 (concluded) - No. 1.43 - - 1.44 Quantity
19、SI unit Remarks Symbol ao g, = -, with 0 as in No. 2.3. ao potential vorticity geopotential tendency S- J/(kg . S) 4, aw at 1 x=- W. ith Was in No. 6.35. Et =2c 12 The barotropic model is calculated for this height. X 1.45 1.46 - - 1.47 - 1.48 S-2 enstrophy height of the level of non-di- vergence he
20、ight of homogeneous atmos- phere stability parameter h* m Height of a hypothetical atmosphere in the standard state, in which the density is constant (cf. DIN 1343). U J/S 1.49 individual rate of change in pressure Pa/s dP wp =- dt 1.50 Ka Krmns constant 1 z* z Ku = -, with z as in No. 1.34 and z* a
21、s in No. 1.35. 1.51 Ri Richardson number 1 Ri is the ratio of static stability to vertical wind shear of the mean wind speed in the flow direction. It is expresed by: g ao Ri = oafr, with O as in No. 2.3. fL) a ct 1 .52 Re Reynolds number 1 1.v Re = - (cf. DIN 5491), where I is the characteristic le
22、ngth; v is the kinematic viscosity; v is the characteristic speed. V 1.53 Fr Froude number 1 V* IR Fr = - (cf. DIN 5492). For I and v, see No. 1.52. 1.54 1.55 - turbulent diffusivity m2/s Cf. DIN 5491 A kg/(m . s) A = 0 D, with e as in No. 1.17 and D as in No. 1.54. austausch coefficient 2.2 Thermod
23、ynamics, humidity and cloud physics Table 2 No. Quantity Symbol SI unit Remarks 2.1 T“ 4) virtual temperature K T, is the virtual temperature to which absolutely dry air would have to be brought in order for it to have the same density as moist air of specific humidity, s, at the same pressure: T, =
24、 T (1 + 0,608 s), with s as in No. 2.16. 2.2 Te 4, equivalent temperature K Te is the temperature that a moist air parcel would have if all water vapour were condensed out at constant pres- sure, the latent heat released being used to heat the air, this being expressed by: L Te = T + m-, where CP L
25、is the latent heat of vaporization of water (cf. No. 2.21); cp is the specific heat capacity of dry air at constant pressure; rn as in No. 2.17. 4, The temperature indicated is the thermodynamic temperature, the associated Celsius temperature being designated (continued) by t or i?. DIN 1304 Part 2
26、Page 5 Table 2 (continued) - No. 2.3 - Symbol Quantity Remarks SI unit potential temperature The potential temperature of an air parcel is the tempera- ture assumed by it when brought by a dry-adiabatic pro- cess to a pressure, po, of l O5 Pa (= l O3 mbar): O = T( $) air and with p as in No. 1.1 6 a
27、nd cp as in No. 2.2. Rkp , where R, is the specific gas constant oi K 2.4 - 2.5 equivalent potential tempera- ture K The equivalent potential temperature is the temperature that a moist air parcel would have if, first, all water vapoui were condensed out at constant pressure, the latent heal release
28、d being used to heat the air, and then the air parcel were brought by a dry-adiabatic process to a pressure, po, of 1 O5 Pa (= 1 O3 m bar). wet-bulb potential temperature K The wet-bulb potential temperature of an air parcel is the temperature that this air parcel assumes after, starting from the we
29、t-bulb temperature, it was brought by a satu- ration-adiabatic process to a pressure, po, of lo5 Pa (= 1 O3 mbar). The pseudo-potential temperature of an air parcel is the temperature that this air parcel would assume after under- going the following process: - dry-adiabatic raising to the condensat
30、ion level; - further raising from the lifting condensation level by a saturation-adiabatic process until all water vapour is condensed and precipitated out; - dry-adiabatic compression to a pressure, po, of lo5 Pa (= 1 O3 mbar). 2.6 - 2.7 2.8 - - 2.9 2.10 - pseudo-potential temperature K Td 4, K dew
31、-point temperature dry-bulb temperature K Air temperature read on a dry-bulb thermometer (cf. DIN 19685). Cf. DIN 58660. wet-bulb temperature K soil temperature K Temperature in the soil, usually read at depths of 2, 5,10, 20,50 and 100 cm. 2.1 1 e partial pressure of water vapour Pa 2.1 2 - 2.13 -
32、2.14 saturation vapour pressure in the pure phase with respect to water Pa Pa saturation vapour pressure in the pure phase with respect to ice absolute humidity Ei, ei PW kg/m3 Partial mass density of water vapour. 2.15 2.16 - relative humidity 1 S specific humidity s is the ratio of the mass of wat
33、er vapour to that of moist air in the same volume. It is given by: , with eW as in No. 2.14 and d as in No. 2.19. s=- m is the ratio of the mass of water vapour to that of dry air in the same volume. It is given by: ew Pw +d m=eW Pd 2.17 rn mixing ratio (of moist air) For 4). see page 4. (continued)
34、 Page 6 DIN 1304 Part 2 2.18 2.19 2.20 2.21 2.22 2.23 2.24 2.25 Table 2 (concluded) s, Qd cp, L, L, ho E Ta4) No. I Symbol 2.26 2.27 2.28 2.29 SI unit TA4) t, h, h, Remarks 2.30 Quantity specific humidity at saturation h, 2.31 i, density of dry air kg/m3 K- e-e, P u - Tf ) CR = psychrometric constan
35、t specific latent enthalpy of evaporation (of water) J/kg specific latent enthalpy of melting ice altitude of the O OC isothermal surface entrainment coefficient J/kg m m-1 Also referred to as zero-degree line. E is the relative change of the mass flow, M, in the flow direction z. It is given by: ac
36、tivation temperature K K release temperature precipitation duration lifting condensation level cumulus condensation level S m m amount of precipitation, rainfall amount m Cf. DIN 4049 Part 1. precipitation intensity m/s Cf. DIN 4049 Part 1. Unit commonly used: mm/min. 2.32 V, +- 2.33 Vp rate of evap
37、oration mls potential rate of evaporation m/s Evaporation with water supply unrestricted (cf. DIN 4049 Part 1). Evaporation when evaporation demand of the atmosphert cannot be met because of water shortage of the evapo. rating medium (supply-restricted evaporation) (cf. alsc DIN 4049 Part 1). 2.34 V
38、a F 2.35 Ep5) actual rate of evaporation rn/s potential evapotranspiration m/s Total evaporation by the plants and the soil when wate1 supply is not restricted. actual (or effective) evapo- transpiration m/s Supply-restricted total evaporation by the plants and thc soil. runoff rate m/s depth of sno
39、w density of snow m kg/m3 Cf. DIN 4049 Part 1. For 4), see page 4. In agricultural meteorology, often designated as ETP. 6) In agricultural meteorology, often designated as ETA. DIN 1304 Part 2 Page 7 No. Symbol Quantity SI unit Remarks 3.1.1 3.1.2 3.1.3 3.1.4 E, D I E, r E, I, , I,-, 3.1.5 E, G I i
40、rradiance due to the direct solar radiation incident on a plane which is normal to the direction of incidence irradiance due to the extraterrestrial solar radiation incident on a plane which is nor- mal to the direction of incidence, the Earth being at its actual distance from the Sun, R irradiance
41、due to the extraterrestrial solar radiation incident on a plane which is nor- mal to the direction of incidence, the Earth b-eing at its mean distance from the Sun, R (solar constant) irradiance due to the diffuse solar radiation (sky radiation) incident on a horizontal plane irradiance due to the g
42、lobal solar radiation (global radiation) incident on a horizontal plane 3.2 Radiant exitance 3.2.1 M, R exitance due to the solar radiation reflected from the Earths surface (reflected solar ra- II diation) perature radiation) of the atmosphere (at- perature radiation) of the Earths surface (exitanc
43、e of the Earths surface) 3.3 Radiation balance W/m2 W/m2 W/m* W/m2 W/m2 - E, = Eo(R/R)2 E, =E, sin y+ E, with y as in No. 3.4.4. W/m2 I W/m2 3.3.1 Eabs, Qs short-wave (solar) radiation balance W/m* 3.3.2 Mnet, - Qt net terrestrial radiation 3.3.3 Eges, Q total radiation balance 3.4 Angular quantitie
44、s of the Sun Radiant energy fluence of the solar radia tion absorbed by the Earths surface. It i: given by: Mnet = ME -MA The negative value, - M, = Qt, is referrec to as longwave (terrestrial) radiation bal, ance. 3.4.1 w hour angle rad As in WMO Techn. Note No. 172. In DIN 13312, December 1983 edi
45、tion No. 10.1.3.4, f is specified to denote tht local hour angle. 3.4.2 I I declination I rad I As in DIN 13312, No. 10.1.3.3. 7) The main symbols in clauses 3.1, 3.2 and 3.3 are primarily used in lighting engineering to emphasize the difference il the dimension of the irradiance, E, and the radiant
46、 exposure, H. In applied meteorology, the reserve symbols arc preferred in order to identify the origin of the various simultaneous radiant energy fluxes. (continued) Page 8 Symbol a DIN 1304 Part 2 Quantity azimuth Table 3 (continued) No. 3.4.3 - SI unit Remarks _ _ Cf. No. 6.22 and DIN 13312, No.
47、10.1.3.2 A3 * rad 3.4.4 Y I vertical angle (altitude) rad As in WMO Techn. Note No. 172. In DIN 13312, No. 10.1.3.1, h is specified to denote the true height. As in WMO Techn. Note No. 172, Cf. DIN 18709 Part 1, August 1982 edition, No. 5.4.1 (z), and DIN 13312, No. 10.1.3.10, where z is specified t
48、o de- note the zenith distance (or coaltitude). (= (12) - y (Cf. NO. 6.24). 3.4.5 f zenith distance rad 3.5 Sunshine duration 3.5.1 S I actual sunshine duration S 3.5.2 so I astronomical sunshine duration S 3.5.3 S I topographically possible sunshine duration S Astronomical sunshine duration taking
49、re- strictions of horizon into account. 3.5.4 Srel I relative sunshine duration referred to So I 1 s, = SIS, 3.5.5 - relative sunshine duration referred to S 1 SleI = SIS; 3.6 Measures of turbidity 3.6.1 3.6.2 - scattering coefficient absorption coefficient m-1 m -1 u, a 3.6.3 extinction coefficient rn -1 u, = u, + ua 3.6.4 attenuation (of a layer along path length s) 1 S (s)= uS(S)dS s=O (usually referred to as optical thickness or optical depth). 3.6.5 atmospheric attenuation d
