View
262
Download
1
Tags:
Embed Size (px)
Citation preview
Two ASCII-WWMPP sounding sites
72 MGAUSsoundings
(ASCII)
GPS-based soundings (GRAW)(1 sounding per RSE case)
ASCII Window C only
ASCII winds(220-270°)
Dixon Airportradiosonde launch site+ weather station (10 m wind, 2m q, T, net radiationcontinuously op.)
runway
views from this spot
Bridger Peak (38 km)Battle Mtn (13 km)Battle Town site (41 km)
Sandstone ridge
Red Mtn (38 km)
Elkhead Range
looking NE (downwind) looking south
How to use the 72 sondes?
• 72 units/15 IOPs = 4.8 sondes per IOP• proposal: we do NOT use a sonde for case calling • suggested distribution:
type of IOP # IOPs* # sondes first sonde frequency
double-flight up to 5 6 0.5 hr after IOP start
1.5 hrs
single-flight up to 10 4 1.0 hr after IOP start
2 hrs
blowing snow
2 2 0.5 hr after IOP start
2 hrs
* in the best-case scenario, we ‘ll need 74 sondes, that is 5*6 + 10*4 + 2*2 …
Temperature Sensor
Humidity Sensors
GPS Antenna
Battery Case
Antenna
GC25 Interface
Vaisala Ground Check set (GC25) for radiosonde
key sounding parameters
• wind speed and direction at 700 mb• temperature at 700 mb
• ST wind speed and direction• LCL level (m) and LCL temperature • ST Brunt-Väisälä frequency• ST Richardson number• temperature at the level of the generators
ST=surface to mountain top level average
} case calling parameters
Sounding Parameters
Parameters Altitude, m Altitude for ASCIIGround 1638 1987.3LCL 5123.14 N/AMountain 5354 3354.02
AgI Generators Altitude, m T, oCGen1 2435.4 1.98Gen2 2557.3 1.55Gen3 2431.4 1.98
From Boulder Sounding, Key parameters summaryDate: 20111018 Time: 175416Z
Paremeters 700 mb Average (ST) LCL (5123.14 m)Wind Speed, m/s 4.4 14.09 26.24Wind Direction 316.15 269.25 344.53Temparature, oC -3.46 -6.02 -15.2ST N (s-1) 0.01097 ST Fr 0.346 ST Ri 2.581
ST: Average value is calculated from surface to mountain top
• LCL is calculated assuming lowest 50mb are well mixed
• Mean θ and mr are calculated in the lowest 50 mb
• Surface T and Td is computed from mean theta and mr
LCL - 542.580 mb
Stable as Ri>0.25
Flow blocked as Fr<1
challenges, limitations• Cold and windy!• If instrument does not work after balloon launch• Need to launch another one immediately• no data transmission when GPS signal is lost• Some variables are available (pressure, Temperature, RH), but others are
not (Wind, altitude..)
• Sounding plot is available after the balloon reach tropopause• It takes about 90 minutes to reach tropopause• Calculated parameter is not available immediately• Temperature, wind speed, and wind direction at 700 mb can be available
from the display plot when balloon is ascending, but difficult to get the actual wind values
• Data will be processed using some software to get the actual wind data
Plans
• Mock IOP at Dixon airport with Tim Lim during the week of 19 Dec
• 2 persons on site most of the time:– Binod Pokharel– Other one from U Illinois
• Time to prepare sonde ~ 1 hour• Travel time from Savery to Dixon Airport ~10 min• Have to be ready ~2 hours before first sonde