Another cool, calm and clear day with just some widely scattered strato-cirrus, and some haze. A non-fog or ephemeral fog IOP started at local noon today and will run overnight until tomorrow noon with 8 soundings. We did the first two soundings (around 2:30pm and 4:15pm), the Utah group will do the remaining soundings.
Liz arrived last night and she assisted Isabel with lowering and raising the DC supersite tower, assisted me on the lidar and camera, and carried out a sounding.
At the ISS1 site at Liz's suggestion, upped the duty cycle of the winds mode on the Modular Profiler. Previously the winds mode had been running at a duty cycle of 3.8% but increased to 5.3% by decreasing the PRT from 70 microsec to 50 microsec at 1715 UTC. This decreased the range aliasing from 10.5km to 7.5km. Increased the coherent integration from 30 to 40 to keep the velocity aliasing around 20 m/s. Kept RASS mode unchanged with a duty cycle of 4.17%. In winds mode the 50V power supply went from 3.16A to 4.24A and the 31V supply went from 1.756A to 1.86A. In RASS mode the 50V was 3.30A and the 31V was 1.905A around 1730UT. The duty cycle change didn't change the SNR and winds much (should have only changed the SNR by about 1.4 dB), but curiously seems to have affected the vertical velocity, perhaps because of a change in RFI bands.
Switched profiler into CFACT_DBP_RIM_100m_Code4 mode (had accidentally started the profiler in a LOTOS mode with very similar parameters). There was no discernable change in the measurements after correcting the mode at 0412 UTC (Jan 17).
Cleared off the CL51 ceilometer, NR01, and camera at ISS1 around 1740 UT.
The sounding system is ingesting the surface met (as Holger found when he checked the mwx files), although it is not obvious while carrying out a sounding because it no longer shows the surface data on the main sounding screen for some unknown reason.
At the lidar site, checked the lidar, secured and adjusted the ELP camera to point better at the DC reservoir.
Isabel and Liz doing the 2:30pm sounding and Sebastian and his helpers doing the 4:15pm sounding
1 Comment
John Sobtzak
I'm surprised the SNR did not increase at all with the increase duty cycle and increased NCI. If you get a chance, can you elaborate on how it "seems to have affected the vertical velocity, perhaps because of a change in RFI bands"?