# Presentation: 718777

## GPM and Tropical CyclonesFrank D. MarksNOAA/AOML, Hurricane Research Division, Miami, FL 33149

- Background
- 5-year TC Rainfall Climatology from TRMM
- Radial mean rain structure (global vs. basin)
- Rain probability distribution
- Asymmetries (global vs. basin)
- Vertical structure
- Opportunities for improved QPE & QPF in TCs
- MI R-CLIPER
- Where do we go from here? GPM opportunities!

- Support from NOAA JHT and NASA TRMM and CAMEX

## Characteristics of TC precipitation

- Perfect laboratory for testing QPF techniques.
- If can't improve TC QPF, then hopeless.

## Global TC Rain Climatology:

- TMI R estimates for 482 storms (December 1997-2002), globally, yielding 3979 events, from TD to CAT5 (Lonfat et al 2004).
_***	***__***	***_*1998-2002 TMI events by Intensity*
_***	***__***	***__***Storm Intensity***__***	***__***Events***__***	***__***%***_
- 		TD/TS	2577	65
- 		Category 1-2	966	24
- _	__	__Category 3-5__	__436__	__11_
**	****	****Total****	****3979**

## Global TC Rain Climatology (continued):

**Global TC Rain Climatology **(continued)**:**
- TMI over a 758.5 km swath ~5 km resolution. Surface rain (R, mm h-1) estimates from TB.

## Global TC Rain Climatology:

*Lonfat et al 2004*

## Global TC Rain Climatology:

- Radial distribution of PDF from TMI uniform at radii >150 km. R>20 mm h-1 occurs only at radii<75 km.

*TMI-500 km radius *
*(2121 events) *

*Lonfat et al 2004*

## Global TC Rain Climatology:

- More symmetry with increasing intensity.

*Lonfat et al 2004*

- % or mean

- % or mean

- % or mean

- % or mean

## Global TC Rain Climatology:

- Basin asymmetry differences.

*Lonfat et al 2004*

- ATL

- EPAC

- NPAC

- SPAC

- SIND

- Note left-right of track asymmetry between N/S hemispheres

- % or mean

- % or mean

## Global TC Rain Climatology:

- 		SE-NW cross-sections

- Vertical structure.

-  Hurricane Bret 19990921

## Opportunities:

- Project R-climatology on latitude-longitude grid along track, integrating R at each point.

- Vs

- Two versions:
- operational model uses ATCF track
- developmental model uses Best Track
- Grid resolution:
- operational - 1/4°
- developmental - 1/12°
- 10 min time steps for integration

## Opportunities:

- Stage IV Isabel Storm Total rain

- RCLIPER comparison in Isabel 20030918-20

## Where do we go from here?

- Need NOAA as a full partner. (Goal Teams)
- Improve TC rain climatology using TRMM, AMSR-E, CMIS, GPM, etc. (CLIMATE)
- PR & MI rain representativeness from different satellites
- Develop climatology of PR vertical rain structure - LH.
- Use R-CLIPER to estimate global TC rain contribution.
- Use PR & MI data to initialize and evaluate operational models. (WEATHER & WATER)
- R-CLIPER as benchmark to evaluate QPF techniques.
- Develop new approach to assimilate PR & MI data (JCSDA).

## Representativeness of R from different scales:

- Scale dependence:
- 10-s PMS sample area ~1 m-2
- 1-h gage sample area ~1-16,000 m2 (advection dependent)
- 1-h radar sample area 16 km2
- TMI sample are 25 km2
- ≥103 gages to cover radar/TMI sample area
- PDF narrower and skewed to smaller R as area increases
- Hence “representativeness error” between point observations and observations of different areal means

## THE EFFECT OF TROPICAL CYCLONES ON GLOBAL TROPICAL RAINFALL

**THE EFFECT OF TROPICAL CYCLONES ON GLOBAL TROPICAL RAINFALL**
**1 ****Monica Simo, ****1 ****Frank D. Marks, Jr., ****2 ****Manuel Lonfat**

## TCs contribute 6.2% of global rainfall in 1998, 4.7% in 1999, 6.1% in 2000, 6.3% in 2001, and 6.0% in 2002.

**THE EFFECT OF TROPICAL CYCLONES ON GLOBAL TROPICAL RAINFALL**
**1 ****Monica Simo, ****1 ****Frank D. Marks, Jr., ****2 ****Manuel Lonfat**

- TCs contribute 10-25% of rain in latitudes between 10°-25° poleward from the Equator, a region with the minimum of global rain.

## Plot of 24-h rain (in) from 1200 UTC 18 September for Isabel (2003) for NPVU and R-CLIPER

**Plot of 24-h rain (in) from 1200 UTC 18 September for Isabel (2003) for NPVU and R-CLIPER**

**NPVU**

**R-CLIPER**

**PDF and CDF comparisons of **
**rain flux binned by rain amount**

**  ****GFDL **

## Rainfall statistics for observations and forecasts of 24-h rain from 1200 UTC 18 September for Isabel (2003)

|  | Total areal coverage of rain (x 106 km2) | Total rain flux (x 106  in-km2) | Mean R (in) |
| --- | --- | --- | --- |
| NPVU | 1.201 | 1.536 | 1.28 |
| R-CLIPER | 1.936 | 2.191 | 1.13 |
| GFDL | 1.933 | 2.453 | 1.27 |
| GFS | 1.877 | 1.485 | 0.79 |
| Eta | 1.404 | 2.528 | 1.28 |

## Probability-matched 24-h rain estimates from NPVU vs. R-CLIPER, GFDL, GFS, and Eta for Hurricane Isabel.  

**Probability-matched 24-h rain estimates from NPVU vs. R-CLIPER, GFDL, GFS, and Eta for Hurricane Isabel.  **

## Plot of 24-h rain (in) from 1200 UTC 18 September for Isabel (2003) for NPVU and GFS

**NPVU**

**GFS**

**PDF and CDF comparisons of rain flux binned by rain amount**

**Plot of 24-h rain (in) from 1200 UTC 18 September for Isabel (2003) for NPVU and GFS**

## Plot of 24-h rain (in) from 1200 UTC 18 September for Isabel (2003) for NPVU and Eta

**NPVU**

**Eta**

**PDF and CDF comparisons of rain flux binned by rain amount**

**Plot of 24-h rain (in) from 1200 UTC 18 September for Isabel (2003) for NPVU and Eta**