### Abstract

An intercomparison of the reanalysis datasets of NCEP and ECMWF is performed with respect to the response of the axial angular momentum M to the torques. While both sets satisfy the budget equations of M reasonably well (except for the time mean). this is not the case with respect to the budget equations for the difference of both sets, where the analysis data explain only a small fraction of the difference of the angular momenta in terms of the difference of the torques. It is hypothesized that the larger fraction of the difference is a manifestation of analysis error. The autocorrelation functions of the differences of the mountain and friction torques between both sets exhibita a long memory, which reflects errors in the low-frequency components of the datasets. Probability distributions of M are considered as well. It is shown that the mean torque for a given M has to be positive (negative) for negative (positive) deviations of M. It is found that the NCEP torques, as analyzed, satisfy this basic requirement. The distribution of the difference of the angular momenta cannot be explained on the basis of the corresponding difference of the torques.

Original language | English (US) |
---|---|

Pages (from-to) | 2577-2585 |

Number of pages | 9 |

Journal | Monthly Weather Review |

Volume | 131 |

Issue number | 11 |

DOIs | |

State | Published - Nov 2003 |

Externally published | Yes |

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### ASJC Scopus subject areas

- Atmospheric Science

### Cite this

*Monthly Weather Review*,

*131*(11), 2577-2585. https://doi.org/10.1175/1520-0493(2003)131<2577:AMBBON>2.0.CO;2

**Angular momentum budgets based on NCEP and ECMWF reanlaysis data : An intercomparison.** / Egger, Joseph; Hoinka, Klaus Peter; Weickmann, Klaus; Huang, Huei-Ping.

Research output: Contribution to journal › Article

*Monthly Weather Review*, vol. 131, no. 11, pp. 2577-2585. https://doi.org/10.1175/1520-0493(2003)131<2577:AMBBON>2.0.CO;2

}

TY - JOUR

T1 - Angular momentum budgets based on NCEP and ECMWF reanlaysis data

T2 - An intercomparison

AU - Egger, Joseph

AU - Hoinka, Klaus Peter

AU - Weickmann, Klaus

AU - Huang, Huei-Ping

PY - 2003/11

Y1 - 2003/11

N2 - An intercomparison of the reanalysis datasets of NCEP and ECMWF is performed with respect to the response of the axial angular momentum M to the torques. While both sets satisfy the budget equations of M reasonably well (except for the time mean). this is not the case with respect to the budget equations for the difference of both sets, where the analysis data explain only a small fraction of the difference of the angular momenta in terms of the difference of the torques. It is hypothesized that the larger fraction of the difference is a manifestation of analysis error. The autocorrelation functions of the differences of the mountain and friction torques between both sets exhibita a long memory, which reflects errors in the low-frequency components of the datasets. Probability distributions of M are considered as well. It is shown that the mean torque for a given M has to be positive (negative) for negative (positive) deviations of M. It is found that the NCEP torques, as analyzed, satisfy this basic requirement. The distribution of the difference of the angular momenta cannot be explained on the basis of the corresponding difference of the torques.

AB - An intercomparison of the reanalysis datasets of NCEP and ECMWF is performed with respect to the response of the axial angular momentum M to the torques. While both sets satisfy the budget equations of M reasonably well (except for the time mean). this is not the case with respect to the budget equations for the difference of both sets, where the analysis data explain only a small fraction of the difference of the angular momenta in terms of the difference of the torques. It is hypothesized that the larger fraction of the difference is a manifestation of analysis error. The autocorrelation functions of the differences of the mountain and friction torques between both sets exhibita a long memory, which reflects errors in the low-frequency components of the datasets. Probability distributions of M are considered as well. It is shown that the mean torque for a given M has to be positive (negative) for negative (positive) deviations of M. It is found that the NCEP torques, as analyzed, satisfy this basic requirement. The distribution of the difference of the angular momenta cannot be explained on the basis of the corresponding difference of the torques.

UR - http://www.scopus.com/inward/record.url?scp=0346121743&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0346121743&partnerID=8YFLogxK

U2 - 10.1175/1520-0493(2003)131<2577:AMBBON>2.0.CO;2

DO - 10.1175/1520-0493(2003)131<2577:AMBBON>2.0.CO;2

M3 - Article

AN - SCOPUS:0346121743

VL - 131

SP - 2577

EP - 2585

JO - Monthly Weather Review

JF - Monthly Weather Review

SN - 0027-0644

IS - 11

ER -