WD2013

Data collection on these Incoherent Scatter Coordinated Observation Days is to start no later than 1300 UT on the indicated day and stop not before 2000 UT the ending day. That means that an experiment scheduled for 1 day, actually runs for minimum 31 hours. Depending on local setups, it is recommended to extend the runs around the core hours to be sure to have the systems up at full power during the selected periods.

In the following table, columns 1 and 2 give the UT start dates of the experiments, column 3 lists the lengths of the experiments, column 4 shows the dates of new moon, and column 5 lists the experiment titles. See special notes associated with each World Day period.

2014 Incoherent Scatter Coordinated Observation Days
Month	Starting Date	Length (days)	New Moon	Experiment
January	14-31 Alert	10	01, 30	Effects of Sudden Stratospheric Warming (see Note 1)
February	1-14 Alert	10	--	Effects of Sudden Stratospheric Warming (see Note 1)
March	24-31 Alert	4	01, 30	Hemispheric and latitudinal stormtime behavior (see Note 2)
April	01-06 Alert	4	29	Hemispheric and latitudinal stormtime behavior (see Note 2)
May			28
June			27
July			26
August			25
September	14-30 Alert	4	24	Hemispheric and latitudinal stormtime behavior (see Note 2)
October	01 Alert	4	23	Hemispheric and latitudinal stormtime behavior (see Note 2)
November			22
December	15	7	22	Northern Deep Winter Observations (see Note 3)
Total		21
Note 1: The decision to start will be based on predictions of Sudden Stratospheric Warming. In the case of no SSW event, the World Day will revert to a 5-day run at the end of the alert period, 9-14 February. There should be one week's notice for the alert.
Note 2: There are two windows for this one alert run. The decision to start will be based on predictions of magnetic disturbances. If there is no run in the March-April window, the next possibility is during the period from 14 September to 01 October. In the case of no magnetic storm, the run will fulfill the alternating-year quiet time measurements and will start on 27 September. The alert should be announced 5 days before the start of the run.
Note 3: Designed to exploit the high-latitude dark skies near winter solstice. All proposals will be considered and operating modes for each facility will be designed to maximize the scientific goals of the interested parties. In particular, we expect to focus on SED, SAPS, and patch evolution, among other topics as requested.

Real-Time Data Links (when available)
Jicamarca	Arecibo	Millstone Hill
Sondrestrom	PFISR	RISR-N
EISCAT	Kharkov	Irkutsk
MU	SuperDARN

Send comments, questions and proposals for the World Day schedule to Mary McCready or Ian McCrea

World Day Facts

Establishing “World Day” schedules for coordinating the operations of the incoherent scatter radars around the world is one of the activities of the Incoherent Scatter Working Group (ISWG) of Commission G of URSI. These schedules are published yearly as part of the International Geophysical Calendar. Here are some of the facts about world days:

World Days (WD) provide for coordinated operations of the incoherent scatter radars (ISRs) for some common scientific objective. (Experiments that require only 1 UAF should be set up separately and directly with those in charge of that UAF.)
World Days should be scattered throughout the calendar year.
World Day data is to be promptly submitted to the CEDAR database and/or made available through other online databases as appropriate.

The World Day Schedule for 2013 can be found at WD2013.htm

Procedures for requesting World Day experiments

Notes on World Day observations proposed for 2014

Sudden Stratospheric Warming (StratWarm): Dynamics, electrodynamics, temperature and electron density in the lower and upper thermosphere and ionosphere during a sudden stratospheric warming event

Key objectives:

Background condition: The observations need to be made before and during the sudden stratospheric warming. A 10-day campaign is requested.

Primary parameters to measure: LTCS mode - electron and ion temperatures from lowest possible altitudes throughout
the F-region, zonal and meridional components of the neutral wind in the lower thermosphere (95-140km), ExB drift,
F-region meridional wind. Temporal resolution can be sacrificed and data integration period increased in order to obtain data at lower altitudes.

Need for simultaneous data: The idea is to measure how variations in temperatures, electric field and winds associated with sudden stratospheric warming change with latitude and altitude and relate to variations in electron density.

Principle investigator: Larisa P. Goncharenko, lpg@haystack.mit.edu, MIT Haystack Observatory, Westford, MA 01886, USA. Larisa is responsible for issuing the alert. She anticipates one week's notice.

Co-investigators: Jorge Chau (Leibniz-Institute for Atmospheric Physics, Rostock University, Germany), Hanli Liu (NCAR, USA), Peter Hoffmann (Institute for Atmospheric Physics, Germany).

Hemispheric and Latitudinal Stormtime Behavior

The science focus is the latitudinal variations and their east-west hemispheric differences during solar storms and/or under quiet magnetic conditions.

Need for simultaneous data: This coordinated observation involves ISR world day participants as well as the Chinese Meridian Project facilities. This major Chinese project for science and technology infrastructure provides comprehensive ground-based space weather observing in the Eastern Hemisphere, in particular along the 120E longitude where 15 observatories distributed from northern China to the South Pole are established. They are equipped with, among other instruments, ionospheric radio sensors (digisonds, GPS receivers, MF radars, coherent radars, etc) and optical sensors (Lidars, FPIs, all-sky imagers). For this campaign, intensive observational modes will be adopted for most of the instruments.

Principle investigator: Shunrong Zhang (MIT Haystack Observatory), email: shunrong@haystack.mit.edu

Co-investigators: Guotao Yang and Zhaohui Huang (National Space Science Center, China), and John Foster (MIT Haystack Observatory).

Time: Four days in the alert period from March 24 - April 6 or September 14 - October 01.

Modes: Synoptic for all radars, except for Millstone Hill where low elevation azimuth scans are preferred.

Northern Deep Winter Observations

Because of the proximity of the December 2014 New Moon to the solstice, this is a unique opportunity to capitalize on northern high-latitude measurements by optical instruments. This could be a prime time to study the formation, evolution, and decay of SAPS (Sub-Auroral Polarization Streams) and SED (Storm-Enhanced Densities) by measuring the penetration electric fields at low latitudes, the formation of SAPS electric fields and SED at mid-latitudes, and the motion of enhanced electron densities across the polar cap at high latitudes. This period will also be in high demand at the high-latitude ISRs, so proposals will be accepted up through the 2014 CEDAR Workshop for other science goals as well.

Principle investigator: Kjellmar Oksavik (University of Bergen, Norway), email: kjellmar.oksavik@uib.no

Need for simultaneous data: Geomagnetic storms are known to impact the ionosphere on a global scale. Penetration electric fields occur at low latitudes, enhanced SAPS flows occur at mid-latitudes, the plasma flow is enhanced in the polar cap, and dense F-region plasma is transported all the way from lower latitudes, into and across the polar cap. Therefore, all radars should be operating at the same time.

Contacts: Mary McCready, Ian McCrea, Ingemar Häggström

WD2014

World Day Schedule 2014

2014 Incoherent Scatter Coordinated Observation Days

URSI-ISWG [http://www.ursi.org]