slide1
Download
Skip this Video
Download Presentation
Meeting the challenge of obtaining and interpreting observations

Loading in 2 Seconds...

play fullscreen
1 / 18

Meeting the challenge of obtaining and interpreting observations - PowerPoint PPT Presentation


  • 83 Views
  • Uploaded on

Meeting the challenge of obtaining and interpreting observations of deep convection in tropical disturbances and hurricanes by

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Meeting the challenge of obtaining and interpreting observations' - sorley


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Meeting the challenge of obtaining and interpreting observations

of deep convection in tropical disturbances and hurricanes

by

Ed Zipser, Jon Zawislak, and Gabriel Susca-Lopata, University of Utah, Salt Lake City, with assistance of numerous colleagues on the GRIP and HS3 science teams, including

but not limited to Chris Velden, Gerry Heymsfield, Dan Cecil, Rob Rogers, APR-2 team …

OBJECTIVES:

Help in interpreting and improving the overflight criteria for the Global Hawk to maintain a safe operation, while obtaining much-needed data over and in the near-vicinity of deep convection during the remainder of HS-3.

Analyze and understand the vertical distribution of convective updrafts and downdrafts with respect to horizontal dimension, updraft magnitude, cloud dynamics and microphysics, radar reflectivity, anvil top temperature and height, overshooting tops, and associated turbulence.

MAJOR CHALLENGE: CAN REMOTE SENSING DATA SUBSTITUTE FOR IN-SITU DATA?

more motivation
More Motivation
  • Strong convection, convective bursts “don’t hurt” but do not usually precede genesis or RI (Jiang, 2011; Ramirez et al. 2012), and they are often completely absent 1-2 days before genesis (Zawislak 2013).
  • Numerical simulations of tropical disturbances often fail to get correct partitioning of convective/stratiform precipitation (incorrect latent heating profile). Suspected reason: Excessive convective vertical velocity vs. data (Varble et al. 2011; Fridlind et al. 2012; Zhu et al. 2012; Varble 2013).
slide3

Starting point: the period of rapid intensification of Hurricane Earl during GRIP, 28-30 August 2010

  • Next in line: The rapid intensification of Hurricane Karl, 16-17 September 2010 with 20 overpasses of the eye by the Global Hawk
  • Essential data: NOAA WP-3D dual-Doppler, DC-8 APR-2, HIWRAP, …
slide4

Example of Univ. of Wisconsin

ACHA product for a 40-minute

period during Earl’s RI. Interval

between images 6-9 minutes.

Circles identify overshooting

tops, meaning local IR Tb colder

than surrounding clouds.

slide10

Note that overshooting tops

are transient (expected)

Next: Examine evidence from

ER-2 (EDOP) overflights of

deep convection and

overshooting tops.

=>Strong evidence of buoyant

“bubbles” rising through

deep cloud systems

slide11

Chantal 2001

Courtesy Gerry Heymsfield; EDOP data

evidence from emily example
Evidence from Emily example:
  • Large area of cold (< -75 C) cloud, without overshooting tops and without lightning, seemed to give no problems to ER-2
  • Smaller (< 10 km) new vigorous convection, bubble-like, with strong electrification and frequent lightning, was a MAJOR problem…(and this was not apparent 10 minutes earlier)
evidence from emily example1
Evidence from Emily example:
  • Large area of cold (< -75 C) cloud, without overshooting tops and without lightning, seemed to give no problems to ER-2
  • Smaller (< 10 km) new vigorous convection, bubble-like, with strong electrification and frequent lightning, was a MAJOR problem…(and this was not apparent 10 minutes earlier)
  • NEXT: Remote sensing vs. (sigh) in situ data
major updraft in t d ophelia 2005
Major updraft in T.D.Ophelia (2005)

From Houze, Lee, Bell, MWR 2009

example of unusually strong oceanic updrafts at t 10 c top 0 1
Example of unusually strong oceanic updrafts at T ~ -10°C – top 0.1%?

We don’t get such data any more!

• See also Houze, Lee, and Bell, MWR 2009 showing updraft of comparable size and strength

in a convective burst in a tropical depression that later became Hurricane Ophelia (2005)

• Even these exceptionally strong (for oceans) updrafts are only about 2 km across in mid-troposphere. (We have no information on their size and intensity closer to cloud top.)

• Question: Do we expect a 1-km resolution simulation to handle 2-km updrafts accurately?

• Question: Do we expect dual-Doppler retrievals from aircraft to resolve 1-2 km updrafts?

How about HIWRAP?

slide18

More questions than answers right now.

  • But, we have lots of excellent data from GRIP and HS-3 that needs to be examined carefully to give good answers to these important questions. We have work to do!

Comments, questions, arguments?

ad