# Presentation: 692002

## MMB Briefing on Clouds etc.10 February 2005 Brad Ferrier

** ****12-km EtaX  cloud-radiation changes + results**
** ****WRF NMM cloud-radiation changes**
** “****Eta” radiation now “sees” ice**
** ****S/W over central HRW, L/W over Alaska HRW**
** ****Mary Hart's FVS cloud verification**
** ****Sample AFWA and CLAVRx images**
** ****Sample Eta vs. EtaX total cloudiness**
** ****AFWA, CLAVRx verification of Eta, Eta**
** ****Overview of AFWA, CLAVRx (time permitting)**

##  Shortwave NAM vs. NAMX

** ****Shortwave NAM vs. NAMX**

##  NAMX snow cover, 2-m T diffs

** ****NAMX snow cover, 2-m T diffs**

## Same case, but with WRF NMM runs6-h fcst of SWdn valid 18Z 2 Feb 2005

**NMMx – NMM due to correcting for ice in WRF code**

**NMMx – NMM due to  higher cloud liquid water**
**               ****absorption as in NAMX**

## Cooler daytime 2-m Ts in NMMx

## Impacts on LW most evident over Alaska

## 2-m T over Alaska ... early results look good

## Jesse Meng's SURFRAD verification(ETAY is 32-km version of ETAX)

## NAM vs. NAMX total cloudiness

## New Cloud Fraction Parameterization

**σ**** = 1%  for EtaX**

- A Spring
- Fling

## AFWA, CLAVRX total cloudiness (%)(12Z 13 December 2004)

*Many thanks to Mary Hart!!*

**AFWA**

**CLAVRx**

***Missing data***

## Eta, EtaX scores from AFWA, CLAVRx

**00Z, 12Z analyses from 20041212 – 20050110****verified from 32-km Grid 221 over CONUS**

## Eta, EtaX scores from AFWA, CLAVRx

**00Z, 12Z analyses from 20041212 – 20050110****verified from 32-km Grid 221 over CONUS**

## Eta, EtaX scores from AFWA, CLAVRx

**00Z, 12Z 12-h fcsts from 20041212 – 20050110****verified from 32-km Grid 221 over CONUS**

## Eta, EtaX scores from AFWA, CLAVRx

**00Z, 12Z 48-h fcsts from 20041212 – 20050110****verified from 32-km Grid 221 over CONUS**

## Eta, EtaX scores from AFWA, CLAVRx

**00Z, 12Z 84-h fcsts from 20041212 – 20050110****verified from 32-km Grid 221 over CONUS**

## Clouds from AVHRR (CLAVR) Primer

**Thx to Ken Campana, A. Heidinger and A. Jelenak (NESDIS)**
**0.5****o lat/lon for ascend (night) & descend (day) orbits (NOAA 15, 15, 17);  00, 06, 12, 18 UTC w/ data in ±1.5 h windows**
**Multi-spectral (5 ch) cloud detection w/ sequence of threshold tests based on land, sea, day, & night**
**Ken archives 13 parameters from a total of 130 available**
**IWP, LWP during day (solar reflectance); total, liquid, ice, and L/M/H cloud amounts; obs time; T****cld top****; emissivity, optical depth, effective radius, LWP, IWP**
**Most of the parameters are collected during the daytime, weighted by upper portions of the cloud**
**LWPs very good from low stratus; larger errors with thick clouds where vertical profiles of condensate could vary**

## World Wide Merged Cloud Analysis (WWMCA => “AFWA”)

**Thanks to Ken Campana & Ken Mitchell**
**Hourly, 23.8 km N.H., 47.6 km S.H. at 60****o lat**
**DMSP + NOAA polar orbiters (RTNEPH, predecessor), but now dominated by “geosats” GOES, METEOSAT, & GMS; can also see “pinpricks” of surface observs**
**Total, BL, L/M/H cloud amts; cloud tops & bases (heights); cloud types; obs times**
**Mary’s analysis uses ±1.5 h windows, gets some polar orbiters**
**Uses visible & IR channels - possible diurnal effects**

## Advanced TIROS Operational Vertical Sampler (ATOVS)

**Thanks to K. Campana and M. Chalfant (NESDIS)**
**Daily composites of cloud fraction from polar HIRS instrument (High Resolution Infrared Radiometer Sounder), produced from NOAA-15, 16 only**
**Description of **_**[CO](http://www.ssec.wisc.edu/~baum/CloudPressure/CloudPressure.html)**__**[2](http://www.ssec.wisc.edu/~baum/CloudPressure/CloudPressure.html)**__**[ slicing method](http://www.ssec.wisc.edu/~baum/CloudPressure/CloudPressure.html)**_** (B. Baum, P. Menzel MODIS site)**
**Heights to 50-hPa for clouds above 3 km **
**Accuracy increases as the cloud optical thickness increases**
**Can operate during day & night**
**Problems w/ thin cirrus, multi-layered clouds (thin cirrus over low stratus), inversions (needs vertical T gradients, problems in polar regions), and low-level clouds**
**With GOES, must first compare T****ctop**** and P****ctop**** before comparing cloud amounts.  Larger diffs in determining P****ctop**** between WWMCA & ATOVS for higher cloud height**
**Higher correlation between ATOVS & CLAVRx (Chalfant)?**