Dynamical predictability of monthly means
The concept of predictability which is conditioned by synoptic-scale disturbance instabilities is extended to that of time averages, which are determined by low-frequency planetary wave predictability, in an attempt to determine the theoretical upper limit of dynamical predictability of monthly mean...
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ftnasantrs:oai:casi.ntrs.nasa.gov:19820041396 2023-05-15T18:18:15+02:00 Dynamical predictability of monthly means Shukla, J. Unclassified, Unlimited, Publicly available Dec 1, 1981 http://ntrs.nasa.gov/search.jsp?R=19820041396 unknown http://ntrs.nasa.gov/search.jsp?R=19820041396 Accession ID: 82A24931 Copyright Other Sources 47 Journal of the Atmospheric Sciences; 38; Dec. 198 1981 ftnasantrs 2012-02-15T15:02:44Z The concept of predictability which is conditioned by synoptic-scale disturbance instabilities is extended to that of time averages, which are determined by low-frequency planetary wave predictability, in an attempt to determine the theoretical upper limit of dynamical predictability of monthly means for prescribed, nonfluctuating external forcings. Sixty-day integrations of a global general circulation model with nine different initial conditions but identical boundary conditions of sea surface temperatures, snow, sea ice and soil moisture are carried out, where the rms vector wind error between the observed initial conditions is greater than 15 m/sec. It is found that while the variances among the first 30-day means, predicted from mostly different initial conditions, are significantly different from the variances due to random perturbations in the initial conditions, variances for days 31-60 are not so distinguishable. These results suggest that the evolution of long waves remains predictable for between one month and 45 days. Other/Unknown Material Sea ice NASA Technical Reports Server (NTRS) |
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Open Polar |
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NASA Technical Reports Server (NTRS) |
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ftnasantrs |
language |
unknown |
topic |
47 |
spellingShingle |
47 Shukla, J. Dynamical predictability of monthly means |
topic_facet |
47 |
description |
The concept of predictability which is conditioned by synoptic-scale disturbance instabilities is extended to that of time averages, which are determined by low-frequency planetary wave predictability, in an attempt to determine the theoretical upper limit of dynamical predictability of monthly means for prescribed, nonfluctuating external forcings. Sixty-day integrations of a global general circulation model with nine different initial conditions but identical boundary conditions of sea surface temperatures, snow, sea ice and soil moisture are carried out, where the rms vector wind error between the observed initial conditions is greater than 15 m/sec. It is found that while the variances among the first 30-day means, predicted from mostly different initial conditions, are significantly different from the variances due to random perturbations in the initial conditions, variances for days 31-60 are not so distinguishable. These results suggest that the evolution of long waves remains predictable for between one month and 45 days. |
format |
Other/Unknown Material |
author |
Shukla, J. |
author_facet |
Shukla, J. |
author_sort |
Shukla, J. |
title |
Dynamical predictability of monthly means |
title_short |
Dynamical predictability of monthly means |
title_full |
Dynamical predictability of monthly means |
title_fullStr |
Dynamical predictability of monthly means |
title_full_unstemmed |
Dynamical predictability of monthly means |
title_sort |
dynamical predictability of monthly means |
publishDate |
1981 |
url |
http://ntrs.nasa.gov/search.jsp?R=19820041396 |
op_coverage |
Unclassified, Unlimited, Publicly available |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Other Sources |
op_relation |
http://ntrs.nasa.gov/search.jsp?R=19820041396 Accession ID: 82A24931 |
op_rights |
Copyright |
_version_ |
1766194768924114944 |