Domain: Natural Science — Marine Science
Target concept: Using a fan and dyed cold **bo** in a clear water flume to simulate coastal wind-driven upwelling

Video generation prompt: Cold water dyed blue is located at the bottom of a transparent rectangular tank, while a small fan continuously blows across the surface from one long side to the other.

Evaluation guide:
(i) Target concept: Wind-driven upwelling in a two-layer benchtop tank, where surface wind stress drags the top water layer downwind and away from the fan-side wall, and the resulting local water deficit there is refilled by upward flow of the underlying blue-dyed water: a tabletop analog of coastal upwelling, not a Coriolis/Ekman-transport effect (the tank is far too small and non-rotating for that mechanism to apply).
Minimum mechanism: Fan blows air horizontally across the water surface, from the fan-side wall toward the far wall → surface water is dragged downwind, away from the fan-side wall → this creates a local surface-water deficit next to the fan-side wall → the deficit is refilled by upward flow of the blue-dyed bottom water there, producing a rising plume at the fan-side wall → meanwhile the surface water piling up at the far wall is pushed downward instead, so the blue layer near the far wall stays flat or is pushed no higher than its starting height.
(ii) Storyline: [Frame 0–2] Static scene: clear water fills the tank, blue-dyed water fully settled and undisturbed at the bottom, fan idle beside one long side. [Frame 3–5] Fan activates → surface ripples appear and propagate from the fan-side wall toward the far wall → the blue layer has not yet changed. [Frame 6–8] Blue water begins rising along the fan-side wall, forming a plume with a visibly tilted blue-clear boundary: shallower near the fan, deeper toward the far wall; the blue layer near the far wall stays essentially flat. [Frame 9–10] The plume at the fan-side wall persists or broadens slightly, the tilted boundary remains visible across the tank, and the water away from the fan-side wall stays largely clear. Perspective: fixed frontal view showing full tank height, both long walls, and a clear sightline to the bottom and both walls; no oblique angle, no cropping of critical regions.

Manual:
Experimental Procedure
1. Fill a transparent rectangular tank with clear water.
2. Add blue dye to a bottom layer of water so it settles as a distinct band at the tank's bottom.
3. Position a small fan beside one long side of the tank, aimed to blow air horizontally across the water surface toward the opposite long side.
Observation of Experimental Phenomena
The blue-dyed water stays settled at the bottom while the fan is off. Once the fan runs, the surface water is dragged downwind, away from the fan-side wall; a plume of blue-dyed water then rises along the fan-side wall to replace the departing surface water, while the blue-clear boundary tilts — shallower near the fan, deeper toward the far wall, where the blue layer stays essentially undisturbed.
Summary of Experimental Principles
Wind stress at the surface drags the top water layer downwind, creating a surface-water deficit next to the fan-side wall; this deficit is refilled by upward flow of the cooler, denser blue-dyed water there, producing upwelling at the fan-side wall, while the water piling up at the far wall is pushed down instead. This direct, wind-stress-driven overturning is the tabletop analog of coastal wind-driven upwelling; it does not involve Earth-rotation-dependent Ekman transport, which requires spatial scales far larger than a benchtop flume.

Prompt Grounding rubric:
level_1: None of the required setup elements is visible: no transparent rectangular tank, no blue-dyed water at the bottom, and no fan beside a long side; the scene does not depict the described flume experiment at all.
level_2: Only one or two of the tank, blue-dyed water, and fan appear, and the basic layout is wrong: the blue dye is suspended or streaked through the water rather than settled at the bottom, the fan sits on a short end or inside the tank instead of beside a long side, or the tank is opaque or not rectangular.
level_3: A transparent rectangular tank holds clear water above a visibly distinct blue-dyed layer at the bottom, and a small fan sits next to one long side of the tank; the three required elements are present and roughly in the right places, though the fan's blowing direction may be unclear or the blue/clear boundary may look uneven or smeared.
level_4: The tank's walls are crisp and clearly transparent, the blue-dyed layer forms a clean, level band confined to the bottom with a well-defined boundary, and the fan is modeled with recognizable housing and blades sitting flush against one long side, blades oriented to blow horizontally across the water surface toward the opposite long side; no required element is missing, duplicated, or placed on the wrong side of the tank.
level_5: The tank's proportions read as a real benchtop flume (clearly longer/wider than tall) with the fan sized sensibly relative to it, the initial blue-dyed and clear layers are cleanly separated with a thickness that matches a bottom-heavy blue layer as described, and the fan's horizontal blowing orientation toward the far long wall is obvious from the first frame with no ambiguity; the initial setup is fully recognizable as this experiment regardless of what the water goes on to do once the fan starts running.

Scientific and Causal Correctness rubric:
level_1: The blue-dyed layer is missing from the bottom, or the fan produces no visible effect on the water whatsoever: there is no discernible causal link between the fan running and any change in the water, or the blue water is already mixed or rising before the fan ever turns on.
level_2: The blue layer sits at the bottom and the fan visibly ripples the surface, but the water's response contradicts wind-driven upwelling: blue water rises along the far wall (the one the fan blows toward) instead of near the fan itself, blue water rises equally at both walls, or the blue plume appears the instant the fan starts with no time for surface transport to develop.
level_3: The blue layer stays fully settled at the bottom while the fan is off; once the fan runs, surface ripples visibly spread from the fan wall toward the far wall, but no rise of blue water appears anywhere in the tank. The expected upwelling near the fan wall simply never occurs.
level_4: Building on the ripple response above, a plume of blue-dyed water clearly rises along the long wall next to the fan (the wall the airflow blows from) while the blue layer near the far wall (the wall the fan blows toward) stays flat at or below its starting height; the blue-clear boundary visibly tilts, sitting shallower near the fan and deeper toward the far wall.
level_5: The upwelling plume at the fan wall grows or holds together coherently rather than breaking apart at random, the tilted blue-clear boundary (shallow at the fan, deep at the far wall) stays visible and consistent for the rest of the sequence, and at no point does blue water incorrectly appear rising at the far wall or spreading as an even sheet across the whole surface.

Spatiotemporal Consistency rubric:
level_1: A severe continuity break occurs: the tank, the fan, or the blue-dyed water abruptly disappears from view or appears out of nowhere partway through the video, the fan jumps to a different wall of the tank, the tank's lighting cuts abruptly between bright and dark with no visible cause, or the camera view changes to a completely different framing without any visible camera movement.
level_2: A clear but less severe inconsistency occurs: the fan's size or position shifts without any motion shown, the blue water's upper boundary jumps to a new height between frames instead of rising gradually, the tank's proportions visibly change partway through, the tank's overall brightness shifts noticeably between frames with no change in light source, or the surface ripple pattern suddenly reverses direction with no visible cause.
level_3: The tank, fan, and blue-dyed layer stay in the same place and keep the same proportions throughout the video, and the surface ripples keep spreading from the fan wall toward the far wall without reversing; a brief, minor occlusion, such as a ripple crest momentarily covering part of the blue-clear boundary, is acceptable, but no wall, the fan, or the liquid ever disappears or snaps to a new position.
level_4: In addition to the steady framing above, the fan wall, the far wall, and the rising blue plume all remain clearly visible and unobstructed for the whole video, the tank walls stay sharp without warping, and the overall brightness on the tank looks the same from the first frame to the last, with no sudden flash or darkening.
level_5: The camera viewpoint stays completely still for the entire video (no drift, pan, tilt, or zoom), the rising blue plume's height and shape change smoothly from frame to frame with no sudden jumps, and the tilt of the blue-clear boundary across the tank shifts gradually rather than snapping between distinct states.