Cirrus Cloud Boundaries from the Moisture ProfileCirrus Cloud Boundaries from the Moisture ProfileHyperspectral (i.e., Ultraspectral) IR SoundersHyperspectral (i.e., Ultraspectral) IR SoundersW. L. SmithW. L. Smith1,21,2, Jun-Li, Jun-Li22, and E, Weisz, and E, Weisz22

11Hampton University and Hampton University and 22University of WisconsinUniversity of WisconsinJCSDA-HFIP Workshop on Satellite Data Assimilation for Hurricane Forecasting

Atlantic Oceanographic and Meteorological Laboratory (AOML) December 2-3, 2010

Isabel Pays Unwelcome Visit To Seaford VAIsabel Pays Unwelcome Visit To Seaford VAThe 24-36 hour track forecast was goodThe 24-36 hour track forecast was good but the surge was missed by >1 meterbut the surge was missed by >1 meter

Can Ultraspectral Soundings Improve This! Can Ultraspectral Soundings Improve This!

My House

Seaford VA

Objective of Presentation• Review ultraspectral sounding capability - today and tomorrow

• Demonstrate accuracy and coverage achieved with current satellite ultraspectral sounders (AIRS and IASI) for a Hurricane situation (Isabel)

• Demonstrate that use of current polar sounding data will improve Hurricane track forecasts

• Discuss the need for geostationary satellite ultraspectral sounder

• Describe commercial data buy venture to implement the geostationary satellite ultraspectral sounding capability

Ultraspectral Atmospheric Sounders

• Broad Spectral Coverage • High Spectral Resolution • Thousands of Spectral Channels • High Information Content

AIRS (2002)CrIS (2011)IASI (2006)

GMW-GIFTS (≥2014) / IRS (2017)LWIR MWIR

Profile Information ContentITPRN

umbe

r of P

iece

s of

Info

rmat

ion

Radiosondes AIRS/IASI/CrIS HIRS/TOVS

Dual Regression TechniqueDual Regression Technique

Clear Training Data Set Isothermal Clear Training Data Set Cloudy Training Data Set

Clear trained EOF regression results

Radiances (calculated with clear FM)

For 8 cloud height classes (100-900 hPa)

Cloud trained EOF regression results

Cloud Top Altitude

Final Profile(clear-trained above,

cloud-trained below cloud level)

Radiances (calculated with cloudy FM)

For 8 cloud height classes (100-900 hPa)

MO

DIS

1km

imag

es (1

705,

171

0)Hurricane Isabel case study (Sept-13, 2003)

High Dense Cirrus Cirrus Outflow

Eye

Isabel (September 13, 2003, 18 UTC)Dual Regression AIRS Retrieval Results

.

.

850 hPa Temperature and Humidity

700 hPa Temperature and Humidity

.

.

500 hPa Temperature and Humidity

.

.

200 hPa Temperature and Humidity

.

.

Isabel Eye Sounding

http:///

AIRS SFOV soundings are used in WRF assimilations to improve hurricane/typhoon

forecastsBT (11m) and retrieved Temperature [K] at 500 hPa, 7 Sept 2008

http://cimss.ssec.wisc.edu/goes/realtime/If AIRS SFOV soundings are included in

assimilations improved track forecast can be obtained

AIRS

Tracks of ensemble mean analysis on Hurricane IKE (Analysis from 6-8 Sept 2008)

Li, J., H. Liu, 2009: Improved hurricane track and intensity forecast using single field-of-view advanced IR

sounding measurements, Geophysical Research Letters, 36, L11813.

17

Track errors of on Hurricane IKE

Analysis from 06 UTC 6 to 00UTC 8 September 2008

Li and Liu 2009 (GRL)

18

SLP Intensity on Hurricane IKE

Analysis from 06 UTC 6 to 00UTC 8 September 2008

Li and Liu 2009 (GRL)

19

LEO data have limitation on monitoring

weather due to orbital gap and low temporal resolution.

High temporal resolution is

unique aspect of GEO

measurements

GEO can provide data anytime for weather event,

unlike LEO !

Need for Geostationary Ultraspectral Sounder

4-d assimilation of high frequency thermodynamic soundings should improve intensity and track forecasts.

Summary• Ultraspectral resolution radiance data improve forecasts. It has been shown that they are the single most important data input for NWP, even though < 1% of the current data is being used.

• In order to assimilate “all” the information content of the radiance data, reliable sounding retrievals, which benefit from the use of all the radiance information, regardless of cloud condition or underlying surface condition.

• Although IR soundings cannot be obtained below a dense overcast, they can be obtained reliably down to cloud level and below a semi-transparent or broken cloud cover. The use of soundings obtained above and in the environment of tropical storms should help improve tropical storm intensity and track forecasts.

• The greatest benefit of ultraspectral resolution satellite radiance data will come with their availability from geostationary satellites. The geostationary ultraspectral sounder implementation is proceeding in China (2015 launch) and Europe (2017 launch). In the US, there is now a commercial (GeoMetWatch) initiative to produce as many as six imaging/sounding ultraspectral resolution sensors for geostationary Comsats positioned around the globe. The first system (GMW-1), which is based on GIFTS technology, is planned to be launched by 2015. Data would be obtained by NOAA under a data buy contract.