Cloud fraction and IWC

1. Cloud fraction and IWC Malcolm Brooks, 19/10/04, Delft

2. Contents The presentation covers the following sections • Cloud Fraction and Regimes • Ascent/Descent • Boundary Layer Stability • Summary of IWC Sampling Bias • Other Sampling Strategies • Leads into open discussion

3. Regimes Ascent/Descent defined by splitting distritution of w into 1/3.

4. Regimes Ascent/Descent defined by splitting distritution of w into 1/3.

5. Regimes

6. Regimes Ascent at 750hPA STABLE > > > > > > > > > > > > > > > NEUTRAL

7. Regimes Descent at 750hPA STABLE > > > > > > > > > > > > > > > NEUTRAL

8. IWC sampling biases CLOUD FRACTION IWC Sampling Biases of IWC much more significant than for Cloud fraction

9. Effect of different Exclusion policies BLUE – do not exclude IWC based on surface rainrate RED – Exclude Surface rain rates > 0.5 mmhr-1 (from Chilbolton ’99-’00 period)

10. Effect of different Exclusion policies Mid Level IWC (3-7km) BLUE – do not exclude IWC based on surface rainrate RED – Exclude Surface rain rates > 0.5 mmhr-1 (from Chilbolton ’99-’00 period)

11. Effect of different Exclusion policies High Level IWC (7+ km) BLUE – do not exclude IWC based on surface rainrate RED – Exclude Surface rain rates > 0.5 mmhr-1 (from Chilbolton ’99-’00 period)

12. Open Discussion OPEN DISCUSSION