F AD AlO? 904 AIRCRAFT RESEARCH AND DEVELOPMENT UNIT EDINBURGH (AUS--ETC Pie 4/2

MEAN A TMOSPHERIC CONDITIONS - AUSTRALIAN TROPICAL OPERATING CON--ETC(U)

OC T al G GARTRELL

UNCLASSIFIED ARDUTN-AERO 72

ARDU-TN-AERO-72 AR-002-477

DEPARTMENT OF DEFENCE

ROYAL AUSTRALIAN AIR FORCE

AIRCRAFT RESEARCH AND DEVELOPMENT UNIT

EDINBURGH, SOUTH AUSTRALIA

TECHNICAL NOTE AERONAUTICAL NO 72

MEAN ATMOSPHERIC CONDITIONS - AUSTRALIAN TROPICAL OPERATING CONDITIONS

COPY No 22 __ OCTOBER 1981

Ct... -- Commonwealth of Australia 1981 8 II 30 12

ocurity classification of this page UNCLASSIFIED

DOCUMENT CONTROL DATA SHEET

I F DOCUMENT NUMBERS 2 SECURITY rLASSIFICATION

AR a. CompleteNumber: AR-002-477 Document: Unclassified

Report b. Title inNumber: ARDU-TN-AERO-72 Isolation: Unclassified

Other c. Summary inNumbers Isolation: Unclassified

lTITLE]

Mean Atmospeheric Conditions - Australian Tropical Operating Conditions

4 P PERSONAL AUTHOR(S): 5 [RECLASSIFICATION AND CONTROL REVIEW AUTHORITY

Dr 1. Gartrell

6 DOCUMENT DATE:

October 1981

[ORPORATE AUTHOR(S): 8 r REFERENCE NUMBERS:

Aircraft Research and a. Task: TN AERO 72

Development Unit b. SponsoringAgency: CO ARDU

9 COMPUTER PROGRAM(S):(Titles) and lanquage~se )

lo. I RELEASE LIMITATIONS:

Approved for Public Release

Security classification of this page UNCLASSIFIED

-assification of this page UNCLASSIFIED

11. ANNOUNCEMENT LIMITATIONS (of the information on these pas):

Unlimited

~I

ii' DESCRIPTORS: 13. COSATI CODES:

Ternrature ProfileTropical AtmosphereStandard Atmosphere 0401Extreme Conditions 1201Mean Conditions

3UMK;.1MY OH ABSTRACT:

kif this is security classified, the announcement of this report will be similarly classified)

The ARDU mean tropical atmosphere differs significantly from)e ICA0 standard atmosphere and is based upon data gathered prior to

More recent data have been considered in a reassessment ofthe validity of the ARDU atmosphere. The new data support theretention of both the ARDU tropical atmosphere and the ICAO atmosphereto describe mean conditions in their respective regions of applic-ai ion. It is recommended, however, that where extreme operatingconditions for the Australian region are required, reference should be-ide to DEF(AUST) 5168 Part II Air Operations.

Security classification of this page F - - Cc LASS i tI E D

AIRCRAFT RESEARCH AND DEVELOPMENT UNIT

VfAN ATMOSPH.HIC CONDITIONS - AUSTRALIAN TROPICAL OPERATING CONDITIONS

"-e-t Offi--er Approved By

-,GARJ'RELL' 'P.N TIPPETTWing Commander

OIC Resear-h and Develce'7ent

Squadron

'RoG. GREEN,

Group CaptainCommanding Offizer

.',,7e Reference 2535/4/72 Tech

I

DEPARTMENT OF DEFENCE

ROYAL AUSTRALIAN AIR FORCE

AIRCRAFT RESEARCH AND DEVELOPMENT UNIT

TECHNICAL NOTE AERONAUTICAL NO 72

MEAN ATMOSPHERIC CONDITIONS - AUSTRALIAN TROPICAL OPERATING CONDITIONS

SUMMARY

The ARDU mean tropical atmosphere differs significantly from the ICAOstandard atmosphere and is based upon data gathered prior to 1965,

More recent data have been considered in a reassessment of the validity

of the ARDU atmosphere. The new data support the retention of both the ARDUtropical atmosphere and the ICAO atmosphere to describe mean conditions in theirrespective regions of application. It is recommended, however, that whereextreme operating conditions for the Australian region are required, referenceshould be made to DEF'AUST) 5168 Part II - Air Operations.

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LIST OF CONTENTS

Page No

1. lntroduction 3

2. Data Sources 3

2.1 The ARDU Mean Tropical Atmosphere 3

2.2 The ICAO Standard Atmosphere 4

2.3 Currert Australian Meteorological Data 4

3. Data Comparisons 4

4. Conclusions and Recommendations 5

References 6

LIST OF TABLES

2.1 ARDt Mean Tropical Atmosphere

ANNEXES

A. Mean and Extreme Temperatures for Australian Operating Conditions, afterARDU TS 1481

B. High and Low Temperatures for the Australian Region (DEF(AUST) 5168 Pt II -

Air Operationz)

3IMEAN ATMOSPHERIC CONDITIONS - AUSTRALIAN TROPICAL OPERATING CONDITIONS

i. INTRODUCTION

i.i Under Reference A, Aircraft Resea:.ch and Development Unit 'ARDU Lndertookto

a collate all information available on the original data base and

analysis method used to define the current ARDU mean ,opi:alatmosphere;

b. liaise with appropriate agencies 'eg DRCS, Bureau of Meteorologyto assess the validity of the ARDU atmosphere for Australiantropical operating conditions; and

c o define a more accurate mean atmosphere for Australian tropicaloperations if necessary

2. DATA SOURCES

2 " Te ARDU Mean Tropicai Atmosphei-e

2 a The ARDU mean tropical atmosphere, originally published as Figure I of

Referen--e B, is shown at Annex A This atmosphere was compiled from datapc'e-dating Dezembec" .963- A thorough searcuh failed to establish any trace of thedata sou-L ce, whi-h is not surprising since the work was carried out o,.eseventeen years ago Reference B states that the ARDU mean tropical atmosphere.as found satisfa -t.ory for Sabre operations at Darwin, Butterworth andSingapore.

I 2 Since the ARDU atmosphere has been widely used in the past and may:ontinue to be used in the future, it is important that it be clearly defined.Table 2 1 defines five Key points on the temperature profile between sea le,,el

and /0,000 ft Temperatures at intermediate altitudes are determined by linearinterpolation.

TABLE 2. - ARDU MEAN TROPICAL ATMOSPHERE

Tepe at-re1::e , !o000"-"

0 27.5

25 -20

45 -68

54 -80

/0 -60

4-

2., The ICAO Standard Atmosphere,.

2 2.1 Also included at Annex A are the ICAO standard temperature p;,otileIReference C, and ICAO + 1 0C curves, as well as maximum and minimum boundari-esfor temperatures liKely to be encountered in the Austr-alian region

. .3 Current Australian _',teorological Data.

23.1 The Bureau of Meteorology is the prime Australian agen-j -on:e-ned withthe collection and archival of meteorological data in the Australian .-egion

2 32 The Bureau, from time to time, publishes meteorologica] summaries, ofwhihh Reference D is an example. Reference D tabulates statisti.s of upper windand radiosonde data fo,' 21 stations throughout Australia and for- stations atCocos Island, Honiara, Casey, Davis, Macquarie Island and Mawson. Utherstatistics for these and other stations are available from the Bureau onrequest.

2,3,3 Such data are now routinely stored on computer tapes enabling effi. ientsorting techniques and modern statistical procedures to be readily applied tolarge quantities of data.

2.2.4 Timely preparation of a new Defence Standard Referen.-e E . oased oncurrent Bu'eau of Meteorology records, for the whole of the Australian region.has obviated the need for a direct referral to those records fo. this re-hni:alNote. Refe_'en-.ce E specifies the mean and extreme climatic factor's affe-.:ting thedesign of military materiel The data are aggregated for the whole of Australiawith a separate sec::tion covering the Antarc tic region; but, wnere particIarregions ha',e a strong influence on some of the data, note has been made ef this

2 3 5 Mean high and mean low temperature profiles, and 1% 1'isK high and .%risk low temperature profiles from Reference E ai'e shown at Annex B

3. DATA COMPARISONS

3o! As shown at Annex A, the ICAO standard atmosphere temperature profilevaries linearly with height from +15°C at sea level to -b,°C at 36,000 ft and,thereafter, remains constant to /0,000 ft The ARDU mean tropical atmosphere is

00

C at b4,1)t) ft, then increases in temperature to -60 C at 10,000 it

,Z The significant differences between the two profiles ai'e attributable tolatitude. The ARDU pr.ofile is based upon tropical data, while the .CAO profilerepresents latitude 450 N.

3.3 Since large scale meteorological phenomena tend to be similar on bothsides of the equator, the ICAO standard atmosphere can be expected to exhibitthe major trends encountered over southern Tasmania at latitude 450 S nspe:tionof Annex B demonstrates this to be the case.

I.I

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4. CONCLUSIONS AND RECOMMENDATIONS

4.1 Although the original data source for the ARDU mean tropical atmospherehas not been determined, the atmosphere is consistent with current Bureau ofMeteorology records which form the basis of Reference E.

4.2 The ICAO standard atmosphere used for comparison in Annex A is based uponlatitude 450 N and is inappropriate for use in tropical regions.

4.3 Both atmospheres are consistent with the more detailed bounds tabulated inReference E and shown at Annex B.

4.4 It is still appropriate to use the ARDU atmosphere and the ICAO atmosphereto represent mean operating conditions at the appropriate latitudes. However,for the representation of extreme operating conditions Referenze E should befollowed.

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REFERENCES

A- ARDU/2535/4/ /Te-eh I 29 August i9/9

B . ARDU Repoi't TS 1481, October" 196a

L . US Standard Atmosphere, U-S Govt I-rinting Offize, Washington, LW. 96-

D, J V Maher and D M Lee. Upper Air Statistis Aust'alia Su ifa e tc muto i9Y5 Aust:,alian Govt Publishing Sevvioe Canberra 9,',

E, DEF /AUST 568 Pa 't 11 Air Ope--ations - Prelimina.-y Diaft, July 98 _

I L

fxiNX A To

1N AEHO

Md.xN AND EX HEMV 1hLt. iL

A'i IS TiA, AIN 0 PF A~ r NG CUND I T, 0 ' A DLU T,-- 'A8.

DkV SBASEFD ubi DATA AVAILAD5L

/ IV- N Dir,(MBEEW 963

A -Ai% t Oi f,.. A "MJSFtAEI3- J 9

6(1, 1'10 5 STANDAPD AIVIO,3i--HE'3h ')Or,5

C.A0 SYANDAS D ;MSH

7CAO STANDASDl AINOJSPHERE-,

XTSKVIL TEMF.NPFDAI5.L

2 fI ( N

0-40 S - -

\MfN 0'a

ANNEX B TO

TN AERO 72

HIGH AND LOW TEMPERATURES FOR THE AUSTRALIAN REGION(DEF(AUST) 5168 PT II -AIR OPERATIONS)

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AM N iM AT P aI(

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