SOTSP: HOP 101 helioseismology
2011-02-25T04:39:00 to 2011-02-25T06:14:35
Science Goal: Helioseismology Observations of the Sun?fs polar regions with SOT
Program: Fast map, 220"x123", Q65, 1-side CCD
Target: S Pole
xcen=-16 ycen=-927
Instrument: SOTSP
HOP/JOP: 101
Description:
Request to SOT HOP Number 0101 -~1-min cadence. Constant cadence is highly required for our helioseismology analyses. -Continuous observation for 16 hours at least. -The limb should be included in the field of view for co-alignment. -The field of view should be fixed. No tracking. -NFI: Fe I 557.6nm Dopplergram (if telemetry allows) -BFI: Ca II H (this is the primary data set) -If NFI takes 1024x512 Dopplergrams (Q65) with 4x4 summing and BFI takes 2048x1024 images (Q50) with 2x2 summing program ID: 0x1f5, (see below, however), estimated data volume is 1.2 Gbits for 16-hr run. (Note: this is the reduced telemetry version, original used 3.13 Gbits.) -If we use only NFI, taking 2048x1024 Dopplergrams with 2x2 summing, estimated data volume is less than 450Mbits per hour if the compression factor is set at Q75. Scientific Objectives: The solar polar regions play a critical role in the solar dynamo and activity cycle. Magnetic field of active regions is transported by meridional flows from low latitudes to the polar regions. This flux transport causes reversals of the global magnetic field of the Sun around the time of activity maxima. The amount of magnetic flux accumulated in the polar regions determines the strength of the future sunspot cycle. For understanding the mechanism of the cyclic magnetic activity it is very important to measure the properties of the meridional flows and supergranular dynamics in the high-latitude regions, and their variations during the solar cycle. The current observations from SOHO/MDI and future observations from SDO/HMI cannot resolve the near polar regions due to foreshortening and the relatively low resolution. Hinode/SOT provides a unique opportunity to investigate the dynamics of the near-polar regions and measure the speed of high-latitude meridional flows and their variations during various periods of the solar cycle. These observations are best done during the periods of the high inclinations of the Sun?fs axis, 2-10 March and 3-11 September, every year. We propose helioseismology observations of the polar regions during 2-10 March and 3-11 September, every year. The observing runs must be at least 16 hour long, but longer continuous observations are highly desirable for investigation of the supergranular dynamics and short term variations of the polar rotation rate and meridional flow speed. Coordination with MDI and SDO will be being arranged.
