Cloud type identificationCloud type identificationby meteorological satellitesby meteorological satellites

Cloud types identified by Cloud types identified by meteorological satellite and cloud meteorological satellite and cloud

forms observed from groundforms observed from ground   

   

   

   

   

   

   

   

   

       

       

       

Cloud type identified

Symbols used

 Level

Cloud forms observed from ground

Symbol

High level cloud CiHigh

Cirrus Ci

Middle level cloud Cm Cirrocumulus Cc

Stratocumulus Sc Cirrostratus Cs

Stratus/fog StMiddle

Altocumulus Ac

Cumulus Cu Altostratus As

Cumulus congestus Cg Nimbostratus Ns

Cumulonimbus Cb

Low

Stratocumulus Sc

Stratus St

Cumulus Cu

Cumulonimbus Cb

Infrared image Visible imageBoth images taken at 0900 JST, July 9, 1984 (An arrow points at the vicinity of Tottori City, Tottori Prefecture).

<Cloud types from satellite>Cloud area of Ci only

<Cloud forms observed from ground> (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, 1978. (A circle Indicates the vicinity of Tottori City, Tottori Prefecture.)

Infrared image

Visible image <Cloud types observed from satellite> Cloud area of Ci and Cm superposed

<Cloud form observed from ground > 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, 1983. (Circle indicating the vicinity of Kiyose City, Tokyo.)

<Cloud types observed from satellite> Cloud area of coexisting Cu and Sc

<Cloud forms observed from ground > ((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, 1981. (An arrow points at Sendai City, Miyagi Prefecture.)

<Cloud types observed from satellite> Cloud area of Ci only

Photograph of clouds taken from the ground (Sendai City, Miyagi Prefecture.) at 1710 JST, September 6,1981.

<Cloud forms observed from ground> (Ac) CL=0 CM=5 CH=0

Infrared image Visible imageBoth images taken at 1200 JST,November 12,1984 (A circle indicates the vicinity of Tokyo).

<Cloud types observed from satellite> Cloud area of Sc only

< Cloud forms observed from ground> (Sc) CL=5 CM=/ CH=/

Photograph of clouds taken from the ground (Chiyoda-ku,Tokyo) in November 12,1984.

<Cloud types observed from satellite> Cloud area of coexisting Cb ,Cg and Cu

<Cloud forms observed from ground> 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, 1985. (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 types observed from satellite> Cloud area of coexisting Cu and Cg

Infrared image

<Cloud forms observed from ground> Cumulus (Cu) CL=2 CM=X CH=X

Photograph of clouds taken from the ground

Features of cloud type Features of cloud type identification by satellitesidentification by satellites

– vs. Surface ObservationViews 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 observa

tion– From Satellite : “cloud types”, – From Surface : “cloud forms”.

Classification of Cloud typesClassification of Cloud typesCloud type Classification

High level cloud Ci

Stratiform clouds

High level clouds

Middle level cloud CmMiddle level

clouds

Stratus/fog StLow level

cloudsStratocumulus Sc

Cumulus Cu

Convective cloudsCumulus congestus Cg

Cumulonimbus Cb

Identification of cloud typesIdentification of cloud typesCloud 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

Visible image BrightDark

Infr

ared

imag

eD

ark

Bri

ght

Identification of cloud typesIdentification of cloud types

Identification by shapesIdentification by textureIdentification by movementIdentification by changes with time

Figure 2-4-1 b Visible image for cloud type identification taken a 03 UTC in March 20, 1999.

Figure 2-4-1 a Infrared image for cloud type identification taken at 03 UTC in March 20, 1999.

Case study of cloud type identificationCase study of cloud type identification

Infrared image Visible image

Ci ( High cloud ) Ci ( High cloud )

Infrared image Visible image

Cm ( Middle cloud )Cm ( Middle cloud )

Infrared image Visible image

St ( Stratus/Fog )St ( Stratus/Fog )

Infrared image Visible image

Sc ( Stratocumulus )Sc ( Stratocumulus )

Infrared image Visible image

Cu ( Cumulus )Cu ( Cumulus )

Infrared image Visible image

Cb Cb ((Cumulonimbus)Cumulonimbus) // Cg Cg ((Cumulus congestus) Cumulus congestus)

(F pointed by a wedge is Cb. G pointed by wedges is Cg.)

Infrared image Visible image

Dense CiDense Ci

Infrared image Visible image

Case study of the granular Ci