Cloud type identification by meteorological satellites

Cloud types identified by meteorological satellite and cloud forms observed from ground Cloud type identified Symbols used Level Cloud forms observed from ground Symbol High level cloud Ci High CirrusCi Middle level cloud CmCirrocumulusCc StratocumulusScCirrostratusCs Stratus/fogSt Middle AltocumulusAc CumulusCuAltostratusAs Cumulus congestus CgNimbostratusNs CumulonimbusCb Low StratocumulusSc StratusSt CumulusCu CumulonimbusCb

Infrared imageVisible image Both images taken at 0900 JST, July 9, 1984 (An arrow points at the vicinity of Tottori City, Tottori Prefecture). Cloud area of Ci only (Ci and Cs) CL=0 CM=3 CH=5 Photograph of clouds taken from the ground (Tottori City,Tottori Prefecture) at 0801 JST, July 9, 1984.

Both images taken at 1200 JST, September 22, (A circle Indicates the vicinity of Tottori City, Tottori Prefecture.) Infrared imageVisible image Cloud area of Ci and Cm superposed Translucent altocumulus (Ac) CL=0 CM=3 CH=0 Photograph of clouds taken from the ground (Tottori City,Tottori Prefecture) at 1111 JST, September 22, 1978.

Infrared image taken at 1800 JST, August 19, (Circle indicating the vicinity of Kiyose City, Tokyo.) Cloud area of coexisting Cu and Sc ( (Cu and Ac) CL=2 CM=4 CH=0 Photograph of clouds taken from the ground (Kiyose City, Tokyo) at 1740 JST, August 19, 1983.

Infrared image taken at 1800 JST, September 6, (An arrow points at Sendai City, Miyagi Prefecture.) Cloud area of Ci only Photograph of clouds taken from the ground (Sendai City, Miyagi Prefecture.) at 1710 JST, September 6,1981. (Ac) CL=0 CM=5 CH=0

Infrared imageVisible image Both images taken at 1200 JST,November 12,1984 (A circle indicates the vicinity of Tokyo ). Cloud area of Sc only (Sc) CL=5 CM=/ CH=/ Photograph of clouds taken from the ground (Chiyoda-ku,Tokyo) in November 12,1984.

Cloud area of coexisting Cb,Cg and Cu Capillary cumulonimbus cloud Photograph of clouds taken from the ground (Kiyose City, Tokyo) at 1810 JST, August 10,1985. Infrared image taken at 1800 JST,August 10, (A ×mark indicates the vicinity of Kiyose City Tokyo)

Visible image Both images taken in December 19,1994 (arrow pointing at Ohshima Motomachi, Tokyo) Cloud area of coexisting Cu and Cg Infrared image Cumulus (Cu) CL=2 CM=X CH=X Photograph of clouds taken from the ground

Features of cloud type identification by satellites – vs. Surface Observation Views cloud tops from the universe ( 36,000km above Equator) Coarse Resolution (GMS-5 ; 1.25km in VIS, 5km in IR ) Detailed classification impossible. Basically different from Surface observation – From Satellite : “cloud types”, – From Surface : “cloud forms”.

Classification of Cloud types Cloud typeClassification High level cloudCi Stratiform clouds High level clouds Middle level cloudCm Middle level clouds Stratus/fogSt Low level clouds StratocumulusSc  CumulusCu Convective clouds Cumulus congestusCg  CumulonimbusCb

Identification of cloud types Cloud type identification by computer – Uses VIS, IR, Water Vapor and the IR Split Window channel imageries. – Objective identification is possible. – Difficult to consider meteorological conditions and cloud patterns. Cloud type identification by human eyes – VIS and IR have been used – Being able to use other comprehensive meteorological knowledge

図２－３－１ 雲型判別ダイアグ ラム Identification by visible and infrared imageries

Identification of cloud types Identification by shapes Identification by texture Identification by movement Identification by changes with time

Figure b Visible image for cloud type identification taken a 03 UTC in March 20, Figure a Infrared image for cloud type identification taken at 03 UTC in March 20, Case study of cloud type identification

Infrared imageVisible image Ci ( High cloud )

Infrared image Visible image Cm ( Middle cloud )

Infrared imageVisible image St ( Stratus/Fog )

Infrared imageVisible image Sc ( Stratocumulus )

Infrared imageVisible image Cu ( Cumulus )

Infrared imageVisible image Cb ( Cumulonimbus) / Cg ( Cumulus congestus) Cb ( Cumulonimbus) / Cg ( Cumulus congestus) (F pointed by a wedge is Cb. G pointed by wedges is Cg.)

Infrared imageVisible image Dense Ci

Infrared imageVisible image Case study of the granular Ci