{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2012:EGMUPOTN2WQD764B4OPB5JZ7FU","short_pith_number":"pith:EGMUPOTN","schema_version":"1.0","canonical_sha256":"219947ba6dd5a03ffb81e39e1ea73f2d26b1dfcfed95d54960b751c770a1396d","source":{"kind":"arxiv","id":"1205.4411","version":2},"attestation_state":"computed","paper":{"title":"Field evidence for the upwind velocity shift at the crest of low dunes","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.geo-ph"],"primary_cat":"cond-mat.soft","authors_text":"B. Andreotti, G.F.S. Wiggs, P. Claudin","submitted_at":"2012-05-20T12:46:16Z","abstract_excerpt":"Wind topographically forced by hills and sand dunes accelerates on the upwind (stoss) slopes and reduces on the downwind (lee) slopes. This secondary wind regime, however, possesses a subtle effect, reported here for the first time from field measurements of near-surface wind velocity over a low dune: the wind velocity close to the surface reaches its maximum upwind of the crest. Our field-measured data show that this upwind phase shift of velocity with respect to topography is found to be in quantitative agreement with the prediction of hydrodynamical linear analysis for turbulent flows with "},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1205.4411","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cond-mat.soft","submitted_at":"2012-05-20T12:46:16Z","cross_cats_sorted":["physics.geo-ph"],"title_canon_sha256":"b0e6051bdaf370957d9e48e1111079b3de653657bef82bd056c8288462744006","abstract_canon_sha256":"dab438272d4d74bdaa2214e6a724e47a723d1e76a86965c6b7eb9b4f7007b9c1"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:57:25.332459Z","signature_b64":"HKEX/Yut9dl/Wly2XlBLn/NaIx3LtP6rJWqXO+i3BoMboDwdiU/Dq2bp1oQ1A4sPiN8LYJbwzpjGebevQFRSBw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"219947ba6dd5a03ffb81e39e1ea73f2d26b1dfcfed95d54960b751c770a1396d","last_reissued_at":"2026-05-18T01:57:25.331931Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:57:25.331931Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Field evidence for the upwind velocity shift at the crest of low dunes","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["physics.geo-ph"],"primary_cat":"cond-mat.soft","authors_text":"B. Andreotti, G.F.S. Wiggs, P. Claudin","submitted_at":"2012-05-20T12:46:16Z","abstract_excerpt":"Wind topographically forced by hills and sand dunes accelerates on the upwind (stoss) slopes and reduces on the downwind (lee) slopes. This secondary wind regime, however, possesses a subtle effect, reported here for the first time from field measurements of near-surface wind velocity over a low dune: the wind velocity close to the surface reaches its maximum upwind of the crest. Our field-measured data show that this upwind phase shift of velocity with respect to topography is found to be in quantitative agreement with the prediction of hydrodynamical linear analysis for turbulent flows with "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1205.4411","kind":"arxiv","version":2},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"1205.4411","created_at":"2026-05-18T01:57:25.331996+00:00"},{"alias_kind":"arxiv_version","alias_value":"1205.4411v2","created_at":"2026-05-18T01:57:25.331996+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1205.4411","created_at":"2026-05-18T01:57:25.331996+00:00"},{"alias_kind":"pith_short_12","alias_value":"EGMUPOTN2WQD","created_at":"2026-05-18T12:27:04.183437+00:00"},{"alias_kind":"pith_short_16","alias_value":"EGMUPOTN2WQD764B","created_at":"2026-05-18T12:27:04.183437+00:00"},{"alias_kind":"pith_short_8","alias_value":"EGMUPOTN","created_at":"2026-05-18T12:27:04.183437+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU","json":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU.json","graph_json":"https://pith.science/api/pith-number/EGMUPOTN2WQD764B4OPB5JZ7FU/graph.json","events_json":"https://pith.science/api/pith-number/EGMUPOTN2WQD764B4OPB5JZ7FU/events.json","paper":"https://pith.science/paper/EGMUPOTN"},"agent_actions":{"view_html":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU","download_json":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU.json","view_paper":"https://pith.science/paper/EGMUPOTN","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1205.4411&json=true","fetch_graph":"https://pith.science/api/pith-number/EGMUPOTN2WQD764B4OPB5JZ7FU/graph.json","fetch_events":"https://pith.science/api/pith-number/EGMUPOTN2WQD764B4OPB5JZ7FU/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU/action/timestamp_anchor","attest_storage":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU/action/storage_attestation","attest_author":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU/action/author_attestation","sign_citation":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU/action/citation_signature","submit_replication":"https://pith.science/pith/EGMUPOTN2WQD764B4OPB5JZ7FU/action/replication_record"}},"created_at":"2026-05-18T01:57:25.331996+00:00","updated_at":"2026-05-18T01:57:25.331996+00:00"}