Standard Broadband Format Manual

Chapter 5: Element Field and Element Code Descriptions

Appendix C

Cloud Layer Observations

The following information explains how to construct the cloud layer element code and position the cloud layer subfield codes within the data-element fields. The element subfield values for total cloud cover (element code 90CD), opaque cloud cover (9lCD), cloud type (92CD), and sky condition (93CD) are reported for one or more cloud layers. The number of layers is indicated by the last two positions (i.e., C and D) of the header's Element-Code field.

Position "C" of the Element-Code field specifies the total number of layers observed and reported in the data-element fields.

C = O. only total (no layers) recorded in the block

C = 1-9, the number of layers recorded in the file.

Position D of the Element-Code field specifies which layers are reported in this particular block (D cannot exceed C). The element subfields can report either one or two cloud layers at a time.

D = O. only total (no layers) reported in this block

D = 1, layer 1 reported in this block

D = 2, layer 1 and layer 2 reported in this block

D = 3, layer 3 reported in this block

D = 4, layer 3 and layer 4 reported in this block

D = 5, layer 5 reported in this block

D = 6, layer 5 and layer 6 reported in this block

D = 7, layer 7 reported in this block

D = 8, layer 7 and layer 8 reported in this block

D = 9, layer 9 reported in this block.

To summarize, a Data-Element field contains one element subfield if D is O or odd and two element subfields if D is even and not 0.

The Data-Element fields within the block use subfield codes to describe cloud layer observations. The position of the subfield codes within the field relate to element-code level D as follows:

Element Code D Data-Element Field
O aa.OOO
1 aa.OOO
2 aa.bbO
3 cc.OOO
4 cc.ddO
5 ee.OOO
6 ee.ffO
7 gg.OOO
8 gg.hhO
9 iiOOO

The layers of the subfield's contents are represented by the following letters. See Table C-1.

Element Code D	Data-Element Field
O	aa.OOO
1	aa.OOO
2	aa.bbO
3	cc.OOO
4	cc.ddO
5	ee.OOO
6	ee.ffO
7	gg.OOO
8	gg.hhO
9	iiOOO

aa = contents of the subfield for layer 1 or total of all layers

bb = contents of the subfield for layer 2

cc = contents of the subfield for layer 3

dd = contents of the subfield for layer 4

ee = contents of the subfield for layer 5

ff = contents of the subfield for layer 6

gg = contents of the subfield for layer 7

hh = contents of the subfield for layer 8

ii = contents of the subfield for layer 9.

**Table C-1. Element-Code Examples for Multiple Layers**
Element Code	Possible Element Subfield Data	Description
9000	08.000	There was 8/10 total cloud cover, all sky (no layers).
9122	04.060	Two layers were observed. Layer 1 has 4/10 opaque cloud cover, and layer 2 has 6/10 opaque cloud cover.
9242	00.110	Four layers were observed. Layer 1 is clear, and layer 2 has cumulus fractus clouds.
Followed by 9244	07.080	Four layers were observed. Layer 3 has altocumulus clouds, and layer 4 has cirrus clouds.
9332	01.020	Three layers were observed. Layer 1 has thin scattered l clouds, and layer 2 has opaque scattered clouds.
Followed by 9333	05.000	Three layers were observed. Layer 3 has thin overcast i clouds.

Appendix D: Sample Programs

Table of Contents

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