160 likes | 306 Views
ASCII S oundings Binod Pokharel. Two ASCII-WWMPP sounding sites. GPS-based soundings (GRAW) (1 sounding per RSE case) ASCII Window C only. MGAUS soundings (ASCII). ASCII winds (220-270 °) . MGAUS sounding site Battle Pass . 43 km. Elkhead Range.
E N D
Two ASCII-WWMPP sounding sites GPS-based soundings (GRAW) (1 sounding per RSE case) ASCII Window C only MGAUS soundings (ASCII) ASCII winds (220-270°)
Elkhead Range Battle Town site (41 km) Battle Mtn (13 km) Bridger Peak (38 km) Red Mtn (38 km) Sandstone ridge looking NE (downwind) looking south views from this spot Dixon Airport radiosonde launch site + weather station (10 m wind, 2m q, T, net radiation continuously op.) runway
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: * in the best-case scenario, we ‘ll need 74 sondes, that is 5*6 + 10*4 + 2*2 …
Radiosonde Training • Training in Boulder with Tim Lim
GPS Antenna Temperature Sensor Humidity Sensors Vaisala Ground Check set (GC25) for radiosonde Battery Case GC25 Interface Antenna
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 } case calling parameters ST=surface to mountain top level average
Sounding Parameters • 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 Flow blocked as Fr<1 Stable as Ri>0.25
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