# Presentation: 479675

## Automated Quality Control and Analysis of NOAA WP-3D Airborne Doppler Data and its Use during the 2005 Hurricane Season

- John Gamache
- NOAA/AOML/Hurricane Research Division

## WP-3D Aircraft and their Radars

## Vertically scanning X-band Doppler radar 

**Vertically scanning X-band Doppler radar **
**aboard the NOAA P-3 Aircraft**
**NOAA Antenna**

## Slide 4

## Radar Characteristics

- 3.22 cm wavelength--X band
- Beam width normal to scanning is 1.35 deg--1 km resolution at 40 km--long range horizontal resolution
- Beam width along scan is 1.9 degrees--translates to 1 km at 30 km range or 2 km at 60 km range--long-range vertical resolution
- Radial (along beam) resolution is 150 m.  This is the resolution directly above and below the aircraft.

## JHT Project:  Real-Time Dissemination of Hurricane Wind Fields Determined from Airborne Doppler Radar DataProject officially ended June 30 2005

**Goals:**
**To demonstrate capability to automatically quality control airborne Doppler data well enough that they may be assimilated  in “real-time”, and also used to produce analyses of the hurricane core winds--*****demonstrated in 2004***
**To demonstrate capability to produce three-dimensional wind analyses in real time on the aircraft--*****demonstrated in 2004***
**To demonstrate capability to transmit the analyses to the NHC/TPC--*****demonstrated in 2005***
**To demonstrate transmission of the quality-controlled Doppler radial-velocity data to EMC for assimilation into HWRF--*****real time quality control has been done but transmission presently severely limited by bandwidth*****  **

## HRD Software Prior to JHT

**Three-dimensional variational analysis of winds from airborne Doppler radar data**
**Higher resolution radius height cross-section of wind along the inbound and outbound legs **

## Development Required for JHT Project

**Automated Quality Control of Raw Doppler Data (completed)**
**Software to generate batch job files (completed, although present implementation may still require too much operator input--improved in last 2 months)**
**Software to generate output files that can be transmitted off the aircraft by SATCOM to TPC (completed) and EMC (completed but not yet transmitted)**
**Path to TPC (completed, but will be revised to make more operational) and EMC (not yet completed)**

## Variational Analysis--Minimize the following simultaneously:

**The difference between the projection of wind analysis on the Doppler radials and the original Doppler radial velocities.**
**The three-dimensional mass divergence (analestic approximation).**
**Second derivative in all three directions, as well as cross derivatives.  This is a smoother and should be given a light weight.**
**Difference between vertical wind at vertical boundaries, and wind-analysis vertical wind.**

## Doppler projection equations

**Doppler projection equations**

**Anelastic mass-continuity equation**

## Filtering:

## where ijk = 0 if ijk does not represent a top boundary, 

******ijk**** = 1 if ijk does represent a top boundary.**

**Top boundary condition:**

**Bottom boundary condition:**

## For every point ijk there are three equations:

**For every point ijk there are three equations:**

**If there are N****p ****points then the system to be solved**
** ****will have 3N****p**** equations.  After solution points not**
**constrained by data are flagged.**

**The total cost function F is then given by:**

## Bousquet and Chong (1998)

## Doppler de-aliasing/unfolding

- Doppler velocity comes from phase shift (maximum unambiguous phase shift is -  to + ).
-  usually  represents 20 m/s or Nyquist velocity (VN).  21 m/s away from the Doppler radar will be interpreted as 19 m/s (-19 m/s) toward the radar.
- Thus VRobs = VDop + 2n * (VN).  De-aliasing or unfolding means determining n at each radar bin.
- Bargen-Brown de-aliasing consists of using the average of several radar bins inward from the present bin to determine the most likely value of n at the present bin.  First bin determined from wind measured at radar.
- This will even operate with a gap in data, although the process then becomes more unreliable.

## Automatic quality control

**Remove data with high velocity spectral width**
**Remove reflection of main- and side-lobe by sea surface**
**Remove isolated speckles which can fool the automatic Doppler unfolding process**
**Use single ray “Bargen-Brown” automatic unfolding**
**Use a full sweep de-aliasing method developed at HRD**
**Produce a wavenumber 0 and 1 analysis of wind velocity**
**Use low-wavenumber analysis to improve “Bargen-Brown” and sweep dealiasing and further quality control**
**Interpolate quality-controlled sweeps into three-dimensional cartesian analysis and higher-resolution radial-vertical cross-sections**

## Doppler Radial Velocity

**Doppler Radial Velocity**

**Hurricane Humberto**
**232855 UTC 23 Sep 2001**

## First Pass--Wave No. 0 and 1 total wind speed

**First Pass--Wave No. 0 and 1 total wind speed**
**Hurricane Katrina 28 August 2005 **

**North-south distance from center**

**East-west distance from center**

## Second Pass--Fully 3D cartesian analysis

**Second Pass--Fully 3D cartesian analysis**
**Hurricane Katrina 28 August 2005**

**East-west distance from center**

**North-south distance from center**

## Radius-height cross-section of total wind speed

**Radius-height cross-section of total wind speed**
**Hurricane Katrina 1725-1818 UTC  28 August 2005**

- 90 m/s

- 60

- 30

- 0 m/s

- 175 kts

- 58

- 117

**18 km**

## Radius-height cross-section of radial wind speed

**Radius-height cross-section of radial wind speed**
**Hurricane Katrina 1725-1818 UTC  28 August 2005**

- -40

- -20

- 0

- 20

- 40 m/s

**18 km**

## Dramatic 12-h change in Katrina Wind Profile: CAT5-CAT3

**Dramatic 12-h change in Katrina Wind Profile: CAT5-CAT3**

**Doppler Wind Profile - 29 Aug 1000-1040 UTC**

**W**

**NE**

**Doppler Wind Profile - 28 Aug 1725-1820 UTC**

**1 km**

**SW**

**NE**

**Flight Level**

**1 km**

**Flight Level**

**12 km**

**12 km**

**Notes:**
Comparison of the Doppler radar derived wind speed profiles between the 28th- 10 hrs before landfall- and the 29th, near landfall, show that a drastic change in vertical storm structure has occurred. On the 28th, eyewall convection is active and the isotachs are primarily vertical indicating vertical homogeneity with predominantly radial wind gradients at all levels, including the typical outward tilt of the wind maximum with height. On the 29th, the isotachs are predominantly horizontal and intense eyewall convection has diminished in intensity. The left-right asymmetry has become much more pronounced and a 3 km level wind max has appeared on the right side suggesting strong southwest to northeast flow from the environment has entered the storm. The dotted line is aircraft flight level and the solid line the level of the lowest Doppler horizontal analysis.

## Products produced on aircraft

**Three-dimensional wind field centered on storm center**
**	****domain:  (44 x 44 x 37), resolution:  (3-5 km x 3-5 km x .5 km)**
**	****variables:  horizontal and vertical wind velocity, radar reflectivity**
**Radial-vertical cross-sections of wind along the average azimuth flown outward from the storm center**
**	****domain:  (59 x 121), resolution (1.5 km radial, 150 m vertical)**
**	****variables:  tangential, radial, vertical, and total wind speed**
**Trimmed set of quality-controlled Doppler radial-velocity measurements**

## Products transmitted from aircraft via SATCOM in 2005

**u- and v-components of wind at 0.5- and 1.0-km levels (1640 and 3280 ft) sent in knots as 4 gzipped ASCII text files (4-5 km horizontal resolution**
**Inbound and outbound vertical-radial profiles of total wind speed (1.5 km radial resolution, .15 km vertical resolution, out to 88 km)**

## Wind speed in m/s at 1-km altitude

- Hurricane Ivan 12 September 1115-1145 UTC
- (digital camera picture of N43RF airborne workstation)

**Notes:**
Due to a bug only this low-wavenumber fourier analysis wind field worked properly in real time

## 40 Real-time analyses transmitted in 2005

**Hurricane Katrina--14 analyses**
**	****	****25 August (Florida Landfall)--5, 27 August--4, 28 August--5**
**Hurricane Ophelia--13 analyses**
**8 September--2, 9 September--3**
**11 September--6, 12 September--2 **
**(Extratropical Transition)16 September--1, 17 September--1**
**Hurricane Rita--6 analyses**
**20 September--1, 21 September--4, 22 September--1**
**Hurricane Wilma--7 analyses**
**22 October--5, 23 October--2**
**Higher resolution post-season analysis of all 2005 cases except Gert can be found in the data section at:  http://www.aoml.noaa.gov/hrd**

## Real-time 1600-ft analysis of Hurricane Katrina Wind

**Real-time 1600-ft analysis of Hurricane Katrina Wind**
**1725 - 1818 UTC, 28 August 2005**
**wind in knots**

## Real-time 

**Real-time **
**Radius-height**
**Profile of total **
**wind speed**

**Azimuth 045**
**from center**

**Azimuth 225**
**from center**

**Hurricane**
**Katrina**
**1725-1818 UTC**
**28 Aug 2005**

**50 nm**

**0 nm**

**10,000 ft**

**169 kt**

**168 kt**

**height**

**Radial distance (nm)**

## Sonde - Doppler total-wind-speed intercomparison

- Hurricane Katrina 28 August 2005

- Sonde
- Doppler
- Wind
- Radar
- reflecitivity

## Comparison for all drops on 28 August 2005 by NOAA 43

- Radial wind mean difference (sonde – Doppler):	  -6.7 m/s  -13.0 kts
- Tangential wind mean difference (sonde – Doppler):  -1.5 m/s  -2.9 kts
- Wind speed mean difference (sonde – Doppler):	  -0.4 m/s  -0.8 kts
- Radial wind RMS difference:			   13.6 m/s  26.4 kts
- Tangential wind RMS difference:			     7.5 m/s  14.6 kts
- Wind speed RMS difference:			     6.4 m/s  12.4 kts

- with real time airborne Doppler analysis (0.5 - 1.0 km layer)
**note--nearly all drops are eyewall (wind max) drops*
*where wind variability is high*

## Comparison of all NOAA drops in 2004

- Tangential wind mean difference (sonde – Doppler):	  0.2 m/s	   0.4 kts
- Wind speed mean difference (sonde – Doppler):	  0.8 m/s	   1.6 kts
- Radial wind RMS difference:			  7.3 m/s	 14.2 kts
- Tangential wind RMS difference:			  6.0 m/s	11.7 kts
- Wind speed RMS difference:			  6.2 m/s	12.1 kts

- with automatic quick-look airborne Doppler analyses
- (from 0.5 km to flight level)
**note--nearly all drops are eyewall (wind max) drops*
*where wind variability is high*

## Future work

**Automatically determine navigational coordinates for analysis **
**(with some help from operator)**
**Extend analysis beyond ~100 km from storm center--make it work more effectively with no well defined center (disturbances and depressions)--mainly involves allowing larger radial gaps in data in weaker systems with much weaker velocity gradients**
**With faster link in future--run analysis and quality software on the ground**
**Assimilation testing in HWRF**
**Determine errors in radial velocity better.**

## Slide 33

## Aircraft &  Aerosonde Plots/Ophelia 16 Aug, 2005

## Aerosonde/Doppler radar Ophelia 20050916

- Doppler radar analysis at time of closest approach of Aerosonde to wind center and just after WP-3D SFMR penetration across the eye.

## Aerosonde/Doppler 20050916

- Real-time Doppler winds and vertical profiles

- NE

- SW

- Aerosonde/Doppler 20050916

- Nominal Aerosonde ht:  2500 ft (~.75 km)

## Hurricane Wilma  1900-1945 UTC  23 October 2005

- Total Wind Speed
- 0.5 km altitude                        1.0 km altitude

**96**

**96**

**-96**

## Hurricane Wilma  2025-2110 UTC  23 October 2005

- Total Wind Speed
- 0.5 km altitude                        1.0 km altitude

## Hurricane Wilma  23 October 2005

- Total Wind Speed at 3.0 km altitude

- 1900-1945 UTC

- 2025-2110 UTC

## Hurricane Wilma  1920-1945 UTC

- Radius-height cross-section along  Azimuth 045
-   23 October 2005       Total Wind Speed

## Hurricane Wilma  2047-2110 UTC 

- Hurricane Wilma  2047-2110 UTC
- Radial-vertical cross-section along azimuth 135
-   23 October 2005       Total Wind Speed