Speaker ： Li-Chiang Jiang

1. X. Jiang • D. E. Waliser • J.-L. Li • C. Woods, Vertical cloud structures of the boreal summer intraseasonal variability based on CloudSat observations and ERA-interim reanalysis,2010 Vertical cloud structures of the boreal summer intraseasonal variability based on CloudSat observations and ERA-interim reanalysis Xianan Jiang • Duane E. Waliser • Jui-Lin Li •Christopher Woods Speaker：Li-Chiang Jiang

2. Outline • Introduction • Datasets • An index for the boreal summer intraseasonal variability (BSISV) • Vertical cloud structures of the northward propagating BSISV • Summary

3. Introduction • Sikka and Gadgil(1980);Cadet(1986); Lawrence and Webster(2002). The meridional propagation of the BSISV is found to be intimately associated with active and break phases of the Asian summer monsoon • Jiang et al. (2004) Identified prominent meridional asymmetric structures associated with the northward propagating BSISV.

4. Introduction • Hsu et al.(2004);Fu et al.(2006) The northward shift of low-level moisture perturbation relative to the BSISV convection, which may suggest a pre-conditioning process for its northward propagation. • An “easterly vertical wind shear” mechanism to explain the northward propagation of the BSISV.

5. Datasets • European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-interim reanalysis Liquid water content (LWC) and ice and water content (IWC) (2006 ~ 2008) • CloudSat dataset Liquid water content (LWC) and ice and water content (IWC) (2006 ~ 2008) • Tropical Rainfall Measuring Mission (TRMM) Daily mean rainfall with a horizontal resolution of 1° × 1° (2006~2008)

6. An index for the BSISV

7. An index for the BSISV

8. Vertical cloud structures of the northward propagating BSISV CloudSat LWC CloudSat IWC

9. Vertical cloud structures of the northward propagating BSISV ERA-interim LWC ERA-interim IWC

10. Vertical cloud structures of the northward propagating BSISV LWC IWC 紅圈：不同的地方 CloudSat ERA- interim

11. Vertical cloud structures of the northward propagating BSISV 高層雲 Total CloudSat 高積雲 對流雲 ERA- interim 積\層積雲 卷雲

12. Summary and discussion • Increased LWC in the lower troposphere is located north of the BSISVrainfall maximum, and therefore leads the convection,so northward displacement. • Enhanced LWC anomalies to the north of the BSISV convection center are largely associated with low-level cumulus/stratocumulus clouds.

13. Summary and discussion • The maximum LWC anomalies are detected in the lower troposphere based on CloudSat, and in the middle troposphere in the ERA-interim. • Enhanced cloud IWC is evident in the upper troposphere corresponding to enhanced BSISV convection.

14. Summary and discussion • Aforementioned differences in LWC and IWC structures associated with the BSISV could be ascribed to model biases and differences between CloudSat and ERA-interim datasets could be due to data sampling.

15. Thanks for your attention !