Layered Structures Detected in GroundWinds New Hampshire Data

1
Layered Structures Detected in GroundWinds (New
Hampshire) Data

• RAMA VARMA RAJA MK, CIRA ORA
• Rama.Mundakkara_at_noaa.gov
• Jim Yoe, NOAA/NESDIS/ORA
• james.g.yoe_at_noaa.gov

2
Data Used

• From the September, 2000 GW Demonstration
  Campaign
• GroundWinds Aerosol-Molecular Ratio (AM)
• AM ( Number of aerosol photons)/(Total number
  of photons)
• Local Radiosonde
• Vertical Temperature profiles (T)
• Vertical Profiles of Relative Humidity (RH or q)
• ETA Model Analysis
• Vertical Profiles of Relative Humidity
• Vertical profiles of vertical velocity

3
Time_Height Section of AM 09/25/00,
144304-154404 (Z)LT 1043-1144

• Note maxima _at_
• In the BL
• 5 6 km
• 9 11 km

4
Time-Height Section, 09/25/00, 1617-1820
(Z)1217-1420 (Local noon)

• Diurnal Variation Layers replaced by low A/M
  thru entire troposph.

5
09/25/00, 1919-2017 (Z)1519-1617 (Local
evening)

• Layers return _at_ evenings onset

6
09/25/00, 2256-2438 (Z)1856-2038 (Local Time
Night)

• Strong layering
• At 9 10 km cirrus cloud with fine scale
  structures

7
09/26/00, 1422-1702 (Z)1022-1303 (Local
morning time to noon)

• Cirrus layer breaking, descending

8
09/26,1937-2051 (Z)1537-1651 (Local evening)

• Cirrus layer _at_ 5 km

9
09/27, 1427-1525 (Z)1027-1125 (Local Time)

• Layers not apparent
• Convection?

10
Vertical Profiles

• Comparison with ETA model analyses
• Fine scale enhanced structures in GWM AM Ratio
  and Relative Humidity profiles

11

• Tendency for Vertical Gradient of RH to be
  positive near the layers of increasing vertical
  velocity convergence

12

13
Sep 25

14
Sep 25

15
SUMMARY

• Can detect layers using GW A/M as tracer
• Layers show diurnal variation
• RS Relative Humidity ETA Model Analysis
  Relative Humidity show corresponding layered
  structures
• Comparison with ETA model analysis of vertical
  velocity suggests that the enhanced aerosol/RH
  layers in the upper troposphere are tending to
  occur in the layers of vertical velocity
  convergence
• It would be interesting to compare these layered
  structures with the directly observed vertical
  velocity profiles

16

17
09/27/00, 1729-1845 (Z)1329-1445 (Local
Evening)

• Layered Structure starts restoration
• Relative minimum in the free troposphere between
  2 and 8 km levels

18
09/27/00, 1957-2029 (Z)1557-1630 (Local Time
Evening)

• Layered Structure reappears

19
09/27, 2035-2136 (Z)1635-1731 (Local evening
to night)

• Layered structure

20
09/28, 2046 gt8hrs (Z)1646gt8hrs (Local
Evening to night time)

• Distorted Layered Structure
• Descending Cirrus Cloud

21

22

23

24
SUMMARY

• Spatial Contour patterns of Vertical Velocity
  from temporally nearest ETA model analysis also
  suggests the existence of alternate upward and
  downward motions horizontally and do show a
  pattern of 500 km to 1000 km wavelength
• Possibly these are inter-mediate scale
  inertio-gravity waves and layered structure might
  be related to these waves. However, more
  investigations are necessary to bring out this
  possibility in a clear way.