Mannoji95 Mannoji, N., 1995: OLR and cloud cover in JMA T42L21 Model. Abstracts of the First International AMIP Scientific Conference, Monterey, California, 21.


Systematic error of OLR and interannual variability of OLR of JMA T42L21 global model will be investigated in relation to the cloud distribution. Prior to the investigation of the AMIP 10-year run. The results of the operational model of JMA, that is T106L21 version, are examined. The cloud amount of the first 24-hour forecasts in July, 1990 and January, 1991 are compared with the ISCCP C1 data. It is found that 1) upper cloud in the tropics has smoother distribution than observation possibly due to the low threshold value of relative humidity used in the diagnosis of cloud, 2) distribution of the mid-level cloud agrees well with the observation, and 3) lower cloud amount is much less than observations in middle latitude, especially off the west coast of continents in summer. Other than these features, there are some contradiction between model's results and observation due to deficits in the model and also uncertainty of satellite observation. Further investigation is necessary.