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Produced by the NASA Center for Aerospace Information (CASI)
OF

SEMI-ANNUAL STATUS REPORT

Atmospheric Planetary-Wave Response to External Forcing

NASA Grant NAG 5-136

i

Principal Investigator: Duane E. Stevens i

Co-Investigator: Elmar R. Reiter

i

Department of Atmospheric Science

Colorado State University

August 1983

(NASA-CR-175165) AIMLSPHEBIC PLANLTAHX-WAVE N84-177L6

HE5PGW5 E TO EXTERNAL FGBCItG Semiannual

Status Report (colorauo State Uuiv.) b p

HC A01/8F A01 CSCL 04A Uncias

63/46 15116

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1

During the first part of 1983 we have continued our progress on

NASA Grant NAG 5-136, entitled "Atmospheric Planetary-Wave Response to

External Forcing". The following is a brief summary of some of our

activities during this period.

1. The study conducted by Adel Hanna for his Ph.D. dissertation (CSU

Atmospheric Science Paper No. 360) has been refined and extended. Early

in the year it was submitted for publication to the Journal of the

Atmospheric Sciences. We have just learned of its acceptance for publicaLion. A copy is attached as Appendix 1.

2. Some of the results from that study were reported at the Southern

Hemisphere Meteorology Conference in Brazil during the week of July 31 -

August 6, 1983. Dr. Hanna and Professor Stevens attended that conference under sponsorship of the National Science Foundation. A copy of

the preprint is attached as Appendix 2.

3. Duane Stevens has been invited by the University of Warsaw and the

Meteorological Service in Poland to present a series of seminars during

the week of Aug. 15-19, 1983. His presentations include a report of the

modeling approach and the results obtained to date.

4. A CSU Atmospheric Science Paper is in the final stages of preparation. It will give details of the numerical model, making the model

more accessible to other users.
t

r

2

5. A paper will be presented at the Paris conference on stationary

waves, to be held August 29 - September 2, 1983. We will compare the

model climatology with and without mountains.

6. The CSU Institute for Computational Studies has aided our group in

adapting the model to the Cyber 205. We hope this will enable us to use

the Cyber 205 at GLAS.

7. Under the supervision of E.R. Reiter, Mr. Jim Bossart (M.S. candidate) is adapting the Hanna model to summertime circulation conditions

for the specific purpose of studying planetary wave response to continental heat flux anomalies. Especially drought and heat wave conditions over the United States will be explored.

8. Ms. Sharon Gould-Stewart (M.S. candidate) is in the process of

comparing climatological results obtained from Hanna's model with those

available from the Community Climate Model at NCAR.

9. A paper by John Anderson and Duane Stevens was presented in Boston

during the week of March 22-25 at the AMS Conference on Waves and

Stability. We discussed the nonlinear evolution of inertial instabilities in the tropics. This work has potential theoretical implications

for the symmetric GCM simulations recently reported by Goswami and

Shukla.

10. This nonlinear inertial instability was submitted by Anderson and

Stevens to the Journal of Geophysical Research for publication. We have

not yet received any reviews. A copy is attached as Appendix 3.
3

References

Anderson, J., and D.E. Stevens, 1983: Non-linear evolution of equatorial

symmetric instabilities. (submitted to J. Geophys. Res., May 1983)

Ciesielski, P. and D.E. Stevens, 1983: Development of a linear primitive

equation model for tropical circulation studies. Colorado State

University Atmospheric Science Paper. (in preparation)

Hanna, A.F., E.R. Reiter, and D.E. Stevens, 1983: Short-term climatic

fluctuations forced by thermal anomalies. Paper prepared for the

First International Conference on Southern Hemisphere Meteorology;

July 31 - August 6, 1983; Sao Jose Dos Campos, Brazil.

Hanna, A.F., D.E. Stevens and E.R. Reiter, 1983: Short-term climatic

fluctuations forced by thermal anomalies. Accepted for publication

in J. Atmos. Sci., August 1983.

Stevens, D.E. and J. Anderson, 1983: Symmetric instability of sheared

zonal flows near the equator. Presented at the AMS 4th Conference on

Atmospheric and Oceanic Waves and Stability, Boston, MA, March 21-25,

1983.