{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:JNQF7KMKGKOS7VN5GPDJ4MTZCY","short_pith_number":"pith:JNQF7KMK","canonical_record":{"source":{"id":"1801.08474","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.data-an","submitted_at":"2018-01-25T16:33:01Z","cross_cats_sorted":["nlin.CD","stat.AP"],"title_canon_sha256":"354f940a8cb1f6e1962c92f1d0476f4e8e73854d9eb1c5d256e71cd7a41cf4ab","abstract_canon_sha256":"3b9320d8913a2fac730b781844e8ba30a366bdce236e0afd28f7e6f77c77a493"},"schema_version":"1.0"},"canonical_sha256":"4b605fa98a329d2fd5bd33c69e32791636eb89dbe5b041ac3d0452d970561213","source":{"kind":"arxiv","id":"1801.08474","version":4},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1801.08474","created_at":"2026-05-17T23:50:28Z"},{"alias_kind":"arxiv_version","alias_value":"1801.08474v4","created_at":"2026-05-17T23:50:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1801.08474","created_at":"2026-05-17T23:50:28Z"},{"alias_kind":"pith_short_12","alias_value":"JNQF7KMKGKOS","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_16","alias_value":"JNQF7KMKGKOS7VN5","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_8","alias_value":"JNQF7KMK","created_at":"2026-05-18T12:32:31Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:JNQF7KMKGKOS7VN5GPDJ4MTZCY","target":"record","payload":{"canonical_record":{"source":{"id":"1801.08474","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.data-an","submitted_at":"2018-01-25T16:33:01Z","cross_cats_sorted":["nlin.CD","stat.AP"],"title_canon_sha256":"354f940a8cb1f6e1962c92f1d0476f4e8e73854d9eb1c5d256e71cd7a41cf4ab","abstract_canon_sha256":"3b9320d8913a2fac730b781844e8ba30a366bdce236e0afd28f7e6f77c77a493"},"schema_version":"1.0"},"canonical_sha256":"4b605fa98a329d2fd5bd33c69e32791636eb89dbe5b041ac3d0452d970561213","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:50:28.570717Z","signature_b64":"UBjnJBKZkL2ZQfw63sxj6d9FQE4tT2Vnyg7/rYmq3Ei0kTH1/Le838mdY5qopn8Z9YpxjNzvtb8lLDlNB/48Cg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"4b605fa98a329d2fd5bd33c69e32791636eb89dbe5b041ac3d0452d970561213","last_reissued_at":"2026-05-17T23:50:28.570144Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:50:28.570144Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1801.08474","source_version":4,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:50:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"0nVOZEMWnERvYce3tHFC+vhMJfYNtA1WCShYeKE8i3fthPTPAVuGFaMyn0Ic9dNMU4WMPzirmH4brgrS46nVCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T23:43:51.838209Z"},"content_sha256":"59a008580677349e62234740363ace9e42aeeb8cb778551610704cf6eb3b90de","schema_version":"1.0","event_id":"sha256:59a008580677349e62234740363ace9e42aeeb8cb778551610704cf6eb3b90de"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:JNQF7KMKGKOS7VN5GPDJ4MTZCY","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Adaptive covariance inflation in the ensemble Kalman filter by Gaussian scale mixtures","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["nlin.CD","stat.AP"],"primary_cat":"physics.data-an","authors_text":"Alberto Carrassi, Marc Bocquet, Patrick N. Raanes","submitted_at":"2018-01-25T16:33:01Z","abstract_excerpt":"This paper studies multiplicative inflation: the complementary scaling of the state covariance in the ensemble Kalman filter (EnKF). Firstly, error sources in the EnKF are catalogued and discussed in relation to inflation; nonlinearity is given particular attention as a source of sampling error. In response, the \"finite-size\" refinement known as the EnKF-N is re-derived via a Gaussian scale mixture, again demonstrating how it yields adaptive inflation. Existing methods for adaptive inflation estimation are reviewed, and several insights are gained from a comparative analysis. One such adaptive"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.08474","kind":"arxiv","version":4},"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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:50:28Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"FZH2FroxZepsNPE9rrqLs+ghvQykHmYcJMyPdEQoOEDy/jFBVzKeVLZQ4fk1Y/B2HYKY+4LTN8wTLNH99VamAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T23:43:51.838872Z"},"content_sha256":"91b8bfe41a9820bfc08fa9681e6dc80d2d4e36825437953355bd5c7fbd30c652","schema_version":"1.0","event_id":"sha256:91b8bfe41a9820bfc08fa9681e6dc80d2d4e36825437953355bd5c7fbd30c652"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/JNQF7KMKGKOS7VN5GPDJ4MTZCY/bundle.json","state_url":"https://pith.science/pith/JNQF7KMKGKOS7VN5GPDJ4MTZCY/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/JNQF7KMKGKOS7VN5GPDJ4MTZCY/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-05-26T23:43:51Z","links":{"resolver":"https://pith.science/pith/JNQF7KMKGKOS7VN5GPDJ4MTZCY","bundle":"https://pith.science/pith/JNQF7KMKGKOS7VN5GPDJ4MTZCY/bundle.json","state":"https://pith.science/pith/JNQF7KMKGKOS7VN5GPDJ4MTZCY/state.json","well_known_bundle":"https://pith.science/.well-known/pith/JNQF7KMKGKOS7VN5GPDJ4MTZCY/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:JNQF7KMKGKOS7VN5GPDJ4MTZCY","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"3b9320d8913a2fac730b781844e8ba30a366bdce236e0afd28f7e6f77c77a493","cross_cats_sorted":["nlin.CD","stat.AP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.data-an","submitted_at":"2018-01-25T16:33:01Z","title_canon_sha256":"354f940a8cb1f6e1962c92f1d0476f4e8e73854d9eb1c5d256e71cd7a41cf4ab"},"schema_version":"1.0","source":{"id":"1801.08474","kind":"arxiv","version":4}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1801.08474","created_at":"2026-05-17T23:50:28Z"},{"alias_kind":"arxiv_version","alias_value":"1801.08474v4","created_at":"2026-05-17T23:50:28Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1801.08474","created_at":"2026-05-17T23:50:28Z"},{"alias_kind":"pith_short_12","alias_value":"JNQF7KMKGKOS","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_16","alias_value":"JNQF7KMKGKOS7VN5","created_at":"2026-05-18T12:32:31Z"},{"alias_kind":"pith_short_8","alias_value":"JNQF7KMK","created_at":"2026-05-18T12:32:31Z"}],"graph_snapshots":[{"event_id":"sha256:91b8bfe41a9820bfc08fa9681e6dc80d2d4e36825437953355bd5c7fbd30c652","target":"graph","created_at":"2026-05-17T23:50:28Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"paper":{"abstract_excerpt":"This paper studies multiplicative inflation: the complementary scaling of the state covariance in the ensemble Kalman filter (EnKF). Firstly, error sources in the EnKF are catalogued and discussed in relation to inflation; nonlinearity is given particular attention as a source of sampling error. In response, the \"finite-size\" refinement known as the EnKF-N is re-derived via a Gaussian scale mixture, again demonstrating how it yields adaptive inflation. Existing methods for adaptive inflation estimation are reviewed, and several insights are gained from a comparative analysis. One such adaptive","authors_text":"Alberto Carrassi, Marc Bocquet, Patrick N. Raanes","cross_cats":["nlin.CD","stat.AP"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.data-an","submitted_at":"2018-01-25T16:33:01Z","title":"Adaptive covariance inflation in the ensemble Kalman filter by Gaussian scale mixtures"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.08474","kind":"arxiv","version":4},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:59a008580677349e62234740363ace9e42aeeb8cb778551610704cf6eb3b90de","target":"record","created_at":"2026-05-17T23:50:28Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"3b9320d8913a2fac730b781844e8ba30a366bdce236e0afd28f7e6f77c77a493","cross_cats_sorted":["nlin.CD","stat.AP"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"physics.data-an","submitted_at":"2018-01-25T16:33:01Z","title_canon_sha256":"354f940a8cb1f6e1962c92f1d0476f4e8e73854d9eb1c5d256e71cd7a41cf4ab"},"schema_version":"1.0","source":{"id":"1801.08474","kind":"arxiv","version":4}},"canonical_sha256":"4b605fa98a329d2fd5bd33c69e32791636eb89dbe5b041ac3d0452d970561213","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"4b605fa98a329d2fd5bd33c69e32791636eb89dbe5b041ac3d0452d970561213","first_computed_at":"2026-05-17T23:50:28.570144Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:50:28.570144Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"UBjnJBKZkL2ZQfw63sxj6d9FQE4tT2Vnyg7/rYmq3Ei0kTH1/Le838mdY5qopn8Z9YpxjNzvtb8lLDlNB/48Cg==","signature_status":"signed_v1","signed_at":"2026-05-17T23:50:28.570717Z","signed_message":"canonical_sha256_bytes"},"source_id":"1801.08474","source_kind":"arxiv","source_version":4}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:59a008580677349e62234740363ace9e42aeeb8cb778551610704cf6eb3b90de","sha256:91b8bfe41a9820bfc08fa9681e6dc80d2d4e36825437953355bd5c7fbd30c652"],"state_sha256":"4714d10bb61a9ba8491219309a80cf2543e97b2f0b94cc6dadbc461c62937e53"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"8ns6/WBipo3Y52v84rs/ACM09Sj7bVk3Sr1LdXnzW+4510eUJLLKmm7bWZeN0qFQBiSfvEN5Q4rLvqfdAXRxAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-26T23:43:51.842539Z","bundle_sha256":"ff1ec1ad56495cb68aceff761d8867ccea0946309aee1ac00e8a2a39e8e665dc"}}